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Zou L, Herold F, Cheval B, Wheeler MJ, Pindus DM, Erickson KI, Raichlen DA, Alexander GE, Müller NG, Dunstan DW, Kramer AF, Hillman CH, Hallgren M, Ekelund U, Maltagliati S, Owen N. Sedentary behavior and lifespan brain health. Trends Cogn Sci 2024; 28:369-382. [PMID: 38431428 DOI: 10.1016/j.tics.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 03/05/2024]
Abstract
Higher levels of physical activity are known to benefit aspects of brain health across the lifespan. However, the role of sedentary behavior (SB) is less well understood. In this review we summarize and discuss evidence on the role of SB on brain health (including cognitive performance, structural or functional brain measures, and dementia risk) for different age groups, critically compare assessment approaches to capture SB, and offer insights into emerging opportunities to assess SB via digital technologies. Across the lifespan, specific characteristics of SB (particularly whether they are cognitively active or cognitively passive) potentially act as moderators influencing the associations between SB and specific brain health outcomes. We outline challenges and opportunities for future research aiming to provide more robust empirical evidence on these observations.
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Affiliation(s)
- Liye Zou
- Body-Brain-Mind Laboratory, School of Psychology, Shenzhen University, Shenzhen, China.
| | - Fabian Herold
- Body-Brain-Mind Laboratory, School of Psychology, Shenzhen University, Shenzhen, China; Research Group Degenerative and Chronic Diseases, Movement, Faculty of Health Sciences Brandenburg, University of Potsdam, 14476 Potsdam, Germany
| | - Boris Cheval
- Department of Sport Sciences and Physical Education, Ecole Normale Supérieure Rennes, Bruz, France; Laboratory VIPS2, University of Rennes, Rennes, France
| | - Michael J Wheeler
- Physical Activity Laboratory, Baker Heart & Diabetes Institute, Melbourne, Victoria, Australia; Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Dominika M Pindus
- Kinesiology and Community Health, University of Illinois at Chicago, Chicago, IL, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kirk I Erickson
- AdventHealth Research Institute, Department of Neuroscience, AdventHealth, Orlando, FL, USA; Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, USA
| | - David A Raichlen
- Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA; Department of Anthropology, University of Southern California, Los Angeles, CA 90089, USA
| | - Gene E Alexander
- BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA; Department of Psychology, University of Arizona, Tucson, AZ 85721, USA; Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, USA; Department of Psychiatry, University of Arizona, Tucson, AZ 85721, USA; Neuroscience Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ 85721, USA; Physiological Sciences Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ85721, USA
| | - Notger G Müller
- Research Group Degenerative and Chronic Diseases, Movement, Faculty of Health Sciences Brandenburg, University of Potsdam, 14476 Potsdam, Germany
| | - David W Dunstan
- Physical Activity Laboratory, Baker Heart & Diabetes Institute, Melbourne, Victoria, Australia; Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Arthur F Kramer
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Center for Cognitive and Brain Health, Northeastern University, Boston, MA, USA; Department of Psychology, Northeastern University, Boston, MA, 02115, USA
| | - Charles H Hillman
- Center for Cognitive and Brain Health, Northeastern University, Boston, MA, USA; Department of Psychology, Northeastern University, Boston, MA, 02115, USA; Department of Physical Therapy, Movement, & Rehabilitation Sciences, Northeastern University, Boston, MA, 02115, USA
| | - Mats Hallgren
- Epidemiology of Psychiatric Conditions, Substance Use and Social Environment (EPiCSS), Department of Public Health Sciences, Karolinska Institutet, Solna, Sweden
| | - Ulf Ekelund
- Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway; Department of Chronic Diseases and Ageing, The Norwegian Institute for Public Health, Oslo, Norway
| | - Silvio Maltagliati
- Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Neville Owen
- Physical Activity Laboratory, Baker Heart & Diabetes Institute, Melbourne, Victoria, Australia; Centre for Urban Transitions, Swinburne University of Technology, Melbourne, Victoria, Australia
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Cherry AL, Wheeler MJ, Mathisova K, Di Miceli M. In silico analyses of the involvement of GPR55, CB1R and TRPV1: response to THC, contribution to temporal lobe epilepsy, structural modeling and updated evolution. Front Neuroinform 2024; 18:1294939. [PMID: 38404644 PMCID: PMC10894036 DOI: 10.3389/fninf.2024.1294939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 01/19/2024] [Indexed: 02/27/2024] Open
Abstract
Introduction The endocannabinoid (eCB) system is named after the discovery that endogenous cannabinoids bind to the same receptors as the phytochemical compounds found in Cannabis. While endogenous cannabinoids include anandamide (AEA) and 2-arachidonoylglycerol (2-AG), exogenous phytocannabinoids include Δ-9 tetrahydrocannabinol (THC) and cannabidiol (CBD). These compounds finely tune neurotransmission following synapse activation, via retrograde signaling that activates cannabinoid receptor 1 (CB1R) and/or transient receptor potential cation channel subfamily V member 1 (TRPV1). Recently, the eCB system has been linked to several neurological diseases, such as neuro-ocular abnormalities, pain insensitivity, migraine, epilepsy, addiction and neurodevelopmental disorders. In the current study, we aim to: (i) highlight a potential link between the eCB system and neurological disorders, (ii) assess if THC exposure alters the expression of eCB-related genes, and (iii) identify evolutionary-conserved residues in CB1R or TRPV1 in light of their function. Methods To address this, we used several bioinformatic approaches, such as transcriptomic (Gene Expression Omnibus), protein-protein (STRING), phylogenic (BLASTP, MEGA) and structural (Phyre2, AutoDock, Vina, PyMol) analyzes. Results Using RNA sequencing datasets, we did not observe any dysregulation of eCB-related transcripts in major depressive disorders, bipolar disorder or schizophrenia in the anterior cingulate cortex, nucleus accumbens or dorsolateral striatum. Following in vivo THC exposure in adolescent mice, GPR55 was significantly upregulated in neurons from the ventral tegmental area, while other transcripts involved in the eCB system were not affected by THC exposure. Our results also suggest that THC likely induces neuroinflammation following in vitro application on mice microglia. Significant downregulation of TPRV1 occurred in the hippocampi of mice in which a model of temporal lobe epilepsy was induced, confirming previous observations. In addition, several transcriptomic dysregulations were observed in neurons of both epileptic mice and humans, which included transcripts involved in neuronal death. When scanning known interactions for transcripts involved in the eCB system (n = 12), we observed branching between the eCB system and neurophysiology, including proteins involved in the dopaminergic system. Our protein phylogenic analyzes revealed that CB1R forms a clade with CB2R, which is distinct from related paralogues such as sphingosine-1-phosphate, receptors, lysophosphatidic acid receptors and melanocortin receptors. As expected, several conserved residues were identified, which are crucial for CB1R receptor function. The anandamide-binding pocket seems to have appeared later in evolution. Similar results were observed for TRPV1, with conserved residues involved in receptor activation. Conclusion The current study found that GPR55 is upregulated in neurons following THC exposure, while TRPV1 is downregulated in temporal lobe epilepsy. Caution is advised when interpreting the present results, as we have employed secondary analyzes. Common ancestors for CB1R and TRPV1 diverged from jawless vertebrates during the late Ordovician, 450 million years ago. Conserved residues are identified, which mediate crucial receptor functions.
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Affiliation(s)
- Amy L. Cherry
- Worcester Biomedical Research Group, School of Science and the Environment, University of Worcester, Worcester, United Kingdom
| | - Michael J. Wheeler
- Sustainable Environments Research Group, School of Science and the Environment University of Worcester, Worcester, United Kingdom
| | - Karolina Mathisova
- School of Science and the Environment University of Worcester, Worcester, United Kingdom
| | - Mathieu Di Miceli
- Worcester Biomedical Research Group, School of Science and the Environment, University of Worcester, Worcester, United Kingdom
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Mesinovic J, Fyfe JJ, Talevski J, Wheeler MJ, Leung GK, George ES, Hunegnaw MT, Glavas C, Jansons P, Daly RM, Scott D. Type 2 Diabetes Mellitus and Sarcopenia as Comorbid Chronic Diseases in Older Adults: Established and Emerging Treatments and Therapies. Diabetes Metab J 2023; 47:719-742. [PMID: 37709502 PMCID: PMC10695715 DOI: 10.4093/dmj.2023.0112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/12/2023] [Indexed: 09/16/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) and sarcopenia (low skeletal muscle mass and function) share a bidirectional relationship. The prevalence of these diseases increases with age and they share common risk factors. Skeletal muscle fat infiltration, commonly referred to as myosteatosis, may be a major contributor to both T2DM and sarcopenia in older adults via independent effects on insulin resistance and muscle health. Many strategies to manage T2DM result in energy restriction and subsequent weight loss, and this can lead to significant declines in muscle mass in the absence of resistance exercise, which is also a first-line treatment for sarcopenia. In this review, we highlight recent evidence on established treatments and emerging therapies targeting weight loss and muscle mass and function improvements in older adults with, or at risk of, T2DM and/or sarcopenia. This includes dietary, physical activity and exercise interventions, new generation incretin-based agonists and myostatin-based antagonists, and endoscopic bariatric therapies. We also highlight how digital health technologies and health literacy interventions can increase uptake of, and adherence to, established and emerging treatments and therapies in older adults with T2DM and/or sarcopenia.
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Affiliation(s)
- Jakub Mesinovic
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, Australia
| | - Jackson J. Fyfe
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Jason Talevski
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St Albans, Australia
- School of Rural Health, Monash University, Warragul, Australia
| | - Michael J. Wheeler
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Gloria K.W. Leung
- Department of Nutrition, Dietetics and Food, Monash University, Notting Hill, Australia
| | - Elena S. George
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Melkamu T. Hunegnaw
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, Australia
| | - Costas Glavas
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, Australia
| | - Paul Jansons
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, Australia
| | - Robin M. Daly
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - David Scott
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, Australia
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Wren SN, McLinden CA, Griffin D, Li SM, Cober SG, Darlington A, Hayden K, Mihele C, Mittermeier RL, Wheeler MJ, Wolde M, Liggio J. Aircraft and satellite observations reveal historical gap between top-down and bottom-up CO 2 emissions from Canadian oil sands. PNAS Nexus 2023; 2:pgad140. [PMID: 37168672 PMCID: PMC10165801 DOI: 10.1093/pnasnexus/pgad140] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 05/13/2023]
Abstract
Measurement-based estimates of greenhouse gas (GHG) emissions from complex industrial operations are challenging to obtain, but serve as an important, independent check on inventory-reported emissions. Such top-down estimates, while important for oil and gas (O&G) emissions globally, are particularly relevant for Canadian oil sands (OS) operations, which represent the largest O&G contributor to national GHG emissions. We present a multifaceted top-down approach for estimating CO2 emissions that combines aircraft-measured CO2/NOx emission ratios (ERs) with inventory and satellite-derived NOx emissions from Ozone Monitoring Instrument (OMI) and TROPOspheric Ozone Monitoring Instrument (TROPOMI) and apply it to the Athabasca Oil Sands Region (AOSR) in Alberta, Canada. Historical CO2 emissions were reconstructed for the surface mining region, and average top-down estimates were found to be >65% higher than facility-reported, bottom-up estimates from 2005 to 2020. Higher top-down vs. bottom-up emissions estimates were also consistently obtained for individual surface mining and in situ extraction facilities, which represent a growing category of energy-intensive OS operations. Although the magnitudes of the measured discrepancies vary between facilities, they combine such that the observed reporting gap for total AOSR emissions is ≥(31 ± 8) Mt for each of the last 3 years (2018-2020). This potential underestimation is large and broadly highlights the importance of continued review and refinement of bottom-up estimation methodologies and inventories. The ER method herein offers a powerful approach for upscaling measured facility-level or regional fossil fuel CO2 emissions by taking advantage of satellite remote sensing observations.
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Affiliation(s)
- Sumi N Wren
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Chris A McLinden
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Debora Griffin
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Shao-Meng Li
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Stewart G Cober
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Andrea Darlington
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Katherine Hayden
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Cristian Mihele
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Richard L Mittermeier
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Michael J Wheeler
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
| | - Mengistu Wolde
- Flight Research Laboratory, National Research Council Canada Aerospace Research Centre, Ottawa, ON K1V 1J8, Canada
| | - John Liggio
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, Canada
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Parr EB, Kouw IWK, Wheeler MJ, Radford BE, Hall RC, Senden JM, Goessens JPB, van Loon LJC, Hawley JA. Eight-hour time-restricted eating does not lower daily myofibrillar protein synthesis rates: A randomized control trial. Obesity (Silver Spring) 2023; 31 Suppl 1:116-126. [PMID: 36546330 PMCID: PMC10107304 DOI: 10.1002/oby.23637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/18/2022] [Accepted: 10/22/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE This study aimed to assess the impact of time-restricted eating (TRE) on integrated skeletal muscle myofibrillar protein synthesis (MyoPS) rates in males with overweight/obesity. METHODS A total of 18 healthy males (age 46 ± 5 years; BMI: 30 ± 2 kg/m2 ) completed this exploratory, parallel, randomized dietary intervention after a 3-day lead-in diet. Participants then consumed an isoenergetic diet (protein: ~1.0 g/kg body mass per day) following either TRE (10:00 a.m. to 6:00 p.m.) or an extended eating control (CON; 8:00 a.m. to 8:00 p.m.) protocol for 10 days. Integrated MyoPS rates were measured using deuterated water administration with repeated saliva, blood, and muscle sampling. Secondary measures included continuous glucose monitoring and body composition (dual-energy x-ray absorptiometry). RESULTS There were no differences in daily integrated MyoPS rates (TRE: 1.28% ± 0.18% per day, CON: 1.26% ± 0.22% per day; p = 0.82) between groups. From continuous glucose monitoring, 24-hour total area under the curve was reduced following TRE (-578 ± 271 vs. CON: 12 ± 272 mmol/L × 24 hours; p = 0.001). Total body mass declined (TRE: -1.6 ± 0.9 and CON: -1.1 ± 0.7 kg; p < 0.001) with no differences between groups (p = 0.22). Lean mass loss was greater following TRE compared with CON (-1.0 ± 0.7 vs. -0.2 ± 0.5 kg, respectively; p = 0.01). CONCLUSION Consuming food within an 8-hour time-restricted period does not lower daily MyoPS rates when compared with an isoenergetic diet consumed over 12 hours. Future research should investigate whether these results translate to free-living TRE.
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Affiliation(s)
- Evelyn B Parr
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
| | - Imre W K Kouw
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
| | - Michael J Wheeler
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
| | - Bridget E Radford
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
| | - Rebecca C Hall
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
| | - Joan M Senden
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Joy P B Goessens
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Luc J C van Loon
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - John A Hawley
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
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Karlsson L, Baccarini A, Duplessis P, Baumgardner D, Brooks IM, Chang RY, Dada L, Dällenbach KR, Heikkinen L, Krejci R, Leaitch WR, Leck C, Partridge DG, Salter ME, Wernli H, Wheeler MJ, Schmale J, Zieger P. Physical and Chemical Properties of Cloud Droplet Residuals and Aerosol Particles During the Arctic Ocean 2018 Expedition. J Geophys Res Atmos 2022; 127:e2021JD036383. [PMID: 35859907 PMCID: PMC9285477 DOI: 10.1029/2021jd036383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/08/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Detailed knowledge of the physical and chemical properties and sources of particles that form clouds is especially important in pristine areas like the Arctic, where particle concentrations are often low and observations are sparse. Here, we present in situ cloud and aerosol measurements from the central Arctic Ocean in August-September 2018 combined with air parcel source analysis. We provide direct experimental evidence that Aitken mode particles (particles with diameters ≲70 nm) significantly contribute to cloud condensation nuclei (CCN) or cloud droplet residuals, especially after the freeze-up of the sea ice in the transition toward fall. These Aitken mode particles were associated with air that spent more time over the pack ice, while size distributions dominated by accumulation mode particles (particles with diameters ≳70 nm) showed a stronger contribution of oceanic air and slightly different source regions. This was accompanied by changes in the average chemical composition of the accumulation mode aerosol with an increased relative contribution of organic material toward fall. Addition of aerosol mass due to aqueous-phase chemistry during in-cloud processing was probably small over the pack ice given the fact that we observed very similar particle size distributions in both the whole-air and cloud droplet residual data. These aerosol-cloud interaction observations provide valuable insight into the origin and physical and chemical properties of CCN over the pristine central Arctic Ocean.
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Affiliation(s)
- Linn Karlsson
- Department of Environmental ScienceStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
| | - Andrea Baccarini
- Extreme Environments Research LaboratoryÉcole Polytechnique fédérale de LausanneSionSwitzerland
- Laboratory of Atmospheric ChemistryPaul Scherrer InstituteVilligenSwitzerland
| | - Patrick Duplessis
- Department of Physics and Atmospheric ScienceDalhousie UniversityHalifaxNSCanada
| | | | - Ian M. Brooks
- Institute for Climate and Atmospheric ScienceSchool of Earth and EnvironmentUniversity of LeedsLeedsUK
| | - Rachel Y.‐W. Chang
- Department of Physics and Atmospheric ScienceDalhousie UniversityHalifaxNSCanada
| | - Lubna Dada
- Extreme Environments Research LaboratoryÉcole Polytechnique fédérale de LausanneSionSwitzerland
- Laboratory of Atmospheric ChemistryPaul Scherrer InstituteVilligenSwitzerland
| | | | - Liine Heikkinen
- Department of Environmental ScienceStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
| | - Radovan Krejci
- Department of Environmental ScienceStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
| | - W. Richard Leaitch
- Climate Research DivisionEnvironment and Climate Change CanadaTorontoONCanada
| | - Caroline Leck
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
- Department of MeteorologyStockholm UniversityStockholmSweden
| | - Daniel G. Partridge
- College of Engineering, Mathematics and Physical SciencesUniversity of ExeterExeterUK
| | - Matthew E. Salter
- Department of Environmental ScienceStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
| | - Heini Wernli
- Department of Environmental Systems ScienceETH ZürichZurichSwitzerland
| | - Michael J. Wheeler
- Air Quality Research DivisionEnvironment and Climate Change CanadaTorontoONCanada
| | - Julia Schmale
- Extreme Environments Research LaboratoryÉcole Polytechnique fédérale de LausanneSionSwitzerland
| | - Paul Zieger
- Department of Environmental ScienceStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
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Li K, Wentzell JJB, Liu Q, Leithead A, Moussa SG, Wheeler MJ, Han C, Lee P, Li SM, Liggio J. Evolution of Atmospheric Total Organic Carbon from Petrochemical Mixtures. Environ Sci Technol 2021; 55:12841-12851. [PMID: 34525806 DOI: 10.1021/acs.est.1c02620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Reactive organic compounds play a central role in the formation of ozone and secondary organic aerosols. The ability to accurately predict their fate, in part, relies upon quantitative knowledge of the chemical and physical parameters associated with the total organic carbon (TOC), which includes both precursors and oxidation products that evolve in the atmosphere over short to long time scales. However, such knowledge, obtained via limited carbon closure experiments, has not been attained for complex anthropogenic emissions. Here we present the first comprehensive characterization of TOC in the atmospheric oxidation of organic vapors from light and heavy oil mixtures associated with oil sand operations. Despite the complexity of the investigated oil mixtures, we are able to achieve carbon closure (83-116%) within the uncertainties (±20%), with the degree of the closure being dependent upon the vapor composition and NOx levels. In contrast to biogenic precursors (e.g., α-pinene), the photochemical time scale required for a largely complete oxidation and evolution of chemical parameters is very long for the petrochemical vapors (i.e., ∼7-10 days vs ∼1 day), likely due to the lower initial precursor reactivity. This suggests that petrochemical emissions and their impacts are likely to extend further spatially than biogenic emissions, and retain more of their complex composition and reactivity for many days. The results of this work provide key parameters to regional models for further improving the representation of the chemical evolution of petrochemical emissions.
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Affiliation(s)
- Kun Li
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen 5232, Switzerland
| | - Jeremy J B Wentzell
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Qifan Liu
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Amy Leithead
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Samar G Moussa
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Michael J Wheeler
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Chong Han
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Patrick Lee
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
| | - Shao-Meng Li
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - John Liggio
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario M3H 5T4, Canada
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Homer AR, Taylor FC, Dempsey PC, Wheeler MJ, Sethi P, Grace MS, Green DJ, Cohen ND, Larsen RN, Kingwell BA, Owen N, Dunstan DW. Different frequencies of active interruptions to sitting have distinct effects on 22 h glycemic control in type 2 diabetes. Nutr Metab Cardiovasc Dis 2021; 31:2969-2978. [PMID: 34364775 DOI: 10.1016/j.numecd.2021.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/01/2021] [Accepted: 07/01/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND & AIMS Whether the frequency of interruptions to sitting time involving simple resistance activities (SRAs), compared to uninterrupted sitting, differentially affected 22 h glycemic control in adults with medication-controlled type 2 diabetes (T2D). METHODS & RESULTS Twenty-four participants (13 men; mean ± SD age 62 ± 8 years) completed three 8 h laboratory conditions: SIT: uninterrupted sitting; SRA3: sitting interrupted with 3 min of SRAs every 30 min; and, SRA6: sitting interrupted with 6 min of SRAs every 60 min. Flash glucose monitors assessed glycemic control over a 22 h period. No differences were observed between conditions for overall 22 h glycemic control as measured by AUCtotal, mean glucose and time in hyperglycemia. During the 3.5 h post-lunch period, mean glucose was significantly lower during SRA6 (10.1 mmol·L-1, 95%CI 9.2, 11.0) compared to SIT (11.1 mmol·L-1, 95%CI 10.2, 12.0; P = 0.006). Post-lunch iAUCnet was significantly lower during SRA6 (6.2 mmol·h·L-1, 95%CI 3.3, 9.1) compared to SIT (9.9 mmol·h·L-1, 95%CI 7.0, 12.9; P = 0.003). During the post-lunch period, compared to SIT (2.2 h, 95%CI 1.7, 2.6), time in hyperglycemia was significantly lower during SRA6 (1.5 h, 95%CI 1.0, 1.9, P = 0.001). Nocturnal mean glucose was significantly lower following the SRA3 condition (7.6 mmol·L-1, 95%CI 7.1, 8.1) compared to SIT (8.1 mmol·L-1, 95%CI 7.6, 8.7, P = 0.024). CONCLUSIONS With standardized total activity time, less-frequent active interruptions to sitting may acutely improve glycemic control; while more-frequent interruptions may be beneficial for nocturnal glucose in those with medication-controlled T2D.
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Affiliation(s)
- Ashleigh R Homer
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Australia.
| | - Frances C Taylor
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Australia
| | - Paddy C Dempsey
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Diabetes Research Centre, University of Leicester, Leicester General Hospital, Leicester, UK
| | - Michael J Wheeler
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Australia; School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia
| | - Parneet Sethi
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Megan S Grace
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; School of Clinical Medicine, University of Queensland, Brisbane, QLD, Australia
| | - Daniel J Green
- School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia
| | - Neale D Cohen
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Robyn N Larsen
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; School of Agriculture and Food, University of Melbourne, Melbourne, VIC, Australia
| | - Bronwyn A Kingwell
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; CSL Ltd, Bio21, Parkville, Australia; Department of Physiology, School of Biomedical Science, University of Melbourne, Melbourne, VIC, Australia; Department of Physiology, School of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
| | - Neville Owen
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; Centre for Urban Transitions, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - David W Dunstan
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia; Mary MacKillop Institute for Health Research, Australian Catholic University, Australia
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Homer AR, Taylor FC, Dempsey PC, Wheeler MJ, Sethi P, Townsend MK, Grace MS, Green DJ, Cohen ND, Larsen RN, Kingwell BA, Owen N, Dunstan DW. Frequency of Interruptions to Sitting Time: Benefits for Postprandial Metabolism in Type 2 Diabetes. Diabetes Care 2021; 44:1254-1263. [PMID: 33905343 PMCID: PMC8247505 DOI: 10.2337/dc20-1410] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To determine whether interrupting sitting with brief bouts of simple resistance activities (SRAs) at different frequencies improves postprandial glucose, insulin, and triglycerides in adults with medication-controlled type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS Participants (n = 23, 10 of whom were female, with mean ± SD age 62 ± 8 years and BMI 32.7 ± 3.5 kg · m-2) completed a three-armed randomized crossover trial (6- to 14-day washout): sitting uninterrupted for 7 h (SIT), sitting with 3-min SRAs (half squats, calf raises, gluteal contractions, and knee raises) every 30 min (SRA3), and sitting with 6-min SRAs every 60 min (SRA6). Net incremental areas under the curve (iAUCnet) for glucose, insulin, and triglycerides were compared between conditions. RESULTS Glucose and insulin 7-h iAUCnet were attenuated significantly during SRA6 (glucose 17.0 mmol · h · L-1, 95% CI 12.5, 21.4; insulin 1,229 pmol · h · L-1, 95% CI 982, 1,538) in comparison with SIT (glucose 21.4 mmol · h · L-1, 95% CI 16.9, 25.8; insulin 1,411 pmol · h · L-1, 95% CI 1,128, 1,767; P < 0.05) and in comparison with SRA3 (for glucose only) (22.1 mmol · h · L-1, 95% CI 17.7, 26.6; P = 0.01) No significant differences in glucose or insulin iAUCnet were observed in comparison of SRA3 and SIT. There was no statistically significant effect of condition on triglyceride iAUCnet. CONCLUSIONS In adults with medication-controlled T2D, interrupting prolonged sitting with 6-min SRAs every 60 min reduced postprandial glucose and insulin responses. Other frequencies of interruptions and potential longer-term benefits require examination to clarify clinical relevance.
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Affiliation(s)
- Ashleigh R Homer
- Baker Heart and Diabetes Institute, Melbourne, Australia .,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
| | - Frances C Taylor
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
| | - Paddy C Dempsey
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Institute of Metabolic Science, University of Cambridge, Cambridge, U.K
| | - Michael J Wheeler
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia.,School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia
| | - Parneet Sethi
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | | | - Megan S Grace
- Baker Heart and Diabetes Institute, Melbourne, Australia.,School of Clinical Medicine, University of Queensland, Brisbane, Australia
| | - Daniel J Green
- School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia
| | - Neale D Cohen
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Robyn N Larsen
- Baker Heart and Diabetes Institute, Melbourne, Australia.,School of Agriculture and Food, University of Melbourne, Melbourne, Australia
| | - Bronwyn A Kingwell
- Baker Heart and Diabetes Institute, Melbourne, Australia.,CSL Limited, Bio21 Molecular Science & Biotechnology Institute, Parkville, Australia
| | - Neville Owen
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Centre for Urban Transitions, Swinburne University of Technology, Melbourne, Australia
| | - David W Dunstan
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
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10
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Wheeler MJ, Green DJ, Cerin E, Ellis KA, Heinonen I, Lewis J, Naylor LH, Cohen N, Larsen R, Dempsey PC, Kingwell BA, Owen N, Dunstan DW. Combined effects of continuous exercise and intermittent active interruptions to prolonged sitting on postprandial glucose, insulin, and triglycerides in adults with obesity: a randomized crossover trial. Int J Behav Nutr Phys Act 2020; 17:152. [PMID: 33308235 PMCID: PMC7734727 DOI: 10.1186/s12966-020-01057-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 11/11/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Postprandial glucose, insulin, and triglyceride metabolism is impaired by prolonged sitting, but enhanced by exercise. The aim of this study was to assess the effects of a continuous exercise bout with and without intermittent active interruptions to prolonged sitting on postprandial glucose, insulin, and triglycerides. METHODS Sedentary adults who were overweight to obese (n = 67; mean age 67 yr SD ± 7; BMI 31.2 kg∙m- 2 SD ± 4.1), completed three conditions: SIT: uninterrupted sitting (8-h, control); EX+SIT: sitting (1-h), moderate-intensity walking (30-min), uninterrupted sitting (6.5-h); EX+BR: sitting (1-h), moderate-intensity walking (30- min), sitting interrupted every 30-min with 3-min of light-intensity walking (6.5 h). Participants consumed standardized breakfast and lunch meals and blood was sampled at 13 time-points. RESULTS When compared to SIT, EX+SIT increased total area under the curve (tAUC) for glucose by 2% [0.1-4.1%] and EX+BR by 3% [0.6-4.7%] (all p < 0.05). Compared to SIT, EX+SIT reduced insulin and insulin:glucose ratio tAUC by 18% [11-22%] and 21% [8-33%], respectively; and EX+BR reduced values by 25% [19-31%] and 28% [15-38%], respectively (all p < 0.001 vs SIT, all p < 0.05 EX+SIT-vs-EX+BR). Compared to SIT, EX+BR reduced triglyceride tAUC by 6% [1-10%] (p = 0.01 vs SIT), and compared to EX+SIT, EX+BR reduced this value by 5% [0.1-8.8%] (p = 0.047 vs EX+SIT). The magnitude of reduction in insulin tAUC from SIT-to-EX+BR was greater in those with increased basal insulin resistance. No reduction in triglyceride tAUC from SIT-to-EX+BR was apparent in those with high fasting triglycerides. CONCLUSIONS Additional reductions in postprandial insulin-glucose dynamics and triglycerides may be achieved by combining exercise with breaks in sitting. Relative to uninterrupted sitting, this strategy may reduce postprandial insulin more in those with high basal insulin resistance, but those with high fasting triglycerides may be resistant to such intervention-induced reductions in triglycerides. TRIAL REGISTRATION Australia New Zealand Clinical Trials Registry ( ACTRN12614000737639 ).
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Affiliation(s)
- Michael J Wheeler
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia.
- Baker Heart and Diabetes Institute, 99 Commercial Rd, Melbourne, Victoria, 3004, Australia.
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia.
| | - Daniel J Green
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
| | - Ester Cerin
- Baker Heart and Diabetes Institute, 99 Commercial Rd, Melbourne, Victoria, 3004, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
- School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Kathryn A Ellis
- Department of Psychiatry, University of Melbourne, Parkville, VIC, Australia
| | - Ilkka Heinonen
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
- Turku PET Centre, University of Turku, Turku, Finland
- Rydberg Laboratory of Applied Sciences, ETN, Halmstad University, Halmstad, Sweden
| | - Jaye Lewis
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
| | - Louise H Naylor
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
| | - Neale Cohen
- Baker Heart and Diabetes Institute, 99 Commercial Rd, Melbourne, Victoria, 3004, Australia
| | - Robyn Larsen
- Baker Heart and Diabetes Institute, 99 Commercial Rd, Melbourne, Victoria, 3004, Australia
| | - Paddy C Dempsey
- Baker Heart and Diabetes Institute, 99 Commercial Rd, Melbourne, Victoria, 3004, Australia
- MRC Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
- Diabetes Research Centre, University of Leicester, Leicester General Hospital, Leicester, UK
| | - Bronwyn A Kingwell
- Baker Heart and Diabetes Institute, 99 Commercial Rd, Melbourne, Victoria, 3004, Australia
| | - Neville Owen
- Baker Heart and Diabetes Institute, 99 Commercial Rd, Melbourne, Victoria, 3004, Australia
- Centre for Urban Transitions, Swinburne University of Technology, Hawthorn, Australia
| | - David W Dunstan
- Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Australia
- Baker Heart and Diabetes Institute, 99 Commercial Rd, Melbourne, Victoria, 3004, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
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11
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Taylor FC, Dunstan DW, Homer AR, Dempsey PC, Kingwell BA, Climie RE, Owen N, Cohen ND, Larsen RN, Grace M, Eikelis N, Wheeler MJ, Townsend MK, Maniar N, Green DJ. Acute effects of interrupting prolonged sitting on vascular function in type 2 diabetes. Am J Physiol Heart Circ Physiol 2020; 320:H393-H403. [PMID: 33164575 DOI: 10.1152/ajpheart.00422.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In healthy and overweight/obese adults, interrupting prolonged sitting with activity bouts mitigates impairment in vascular function. However, it is unknown whether these benefits extend to those with type 2 diabetes (T2D), nor whether an optimal frequency of activity interruptions exist. We examined the acute effects on vascular function in T2D of interrupting prolonged sitting with simple resistance activities (SRA) at different frequencies. In a randomized crossover trial, 24 adults with T2D (35-70 yr) completed three 7-h conditions: 1) uninterrupted sitting (SIT), 2) sitting with 3-min bouts of SRA every 30 min (SRA3), and 3) sitting with 6 min bouts of SRA every 60 min (SRA6). Femoral artery flow-mediated dilation (FMD), resting shear rate, blood flow, and endothelin-1 were measured at 0, 1, 3.5, 4.5, and 6.5-7 h. Mean femoral artery FMD over 7 h was significantly higher in SRA3 (4.1 ± 0.3%) compared with SIT (3.7 ± 0.3%, P = 0.04) but not in SRA6. Mean resting femoral shear rate over 7 h was increased significantly for SRA3 (45.3 ± 4.1/s, P < 0.001) and SRA6 (46.2 ± 4.1/s, P < 0.001) relative to SIT (33.1 ± 4.1/s). Endothelin-1 concentrations were not statistically different between conditions. Interrupting sitting with activity breaks every 30 min, but not 60 min, significantly increased mean femoral artery FMD over 7 h, relative to SIT. Our findings suggest that more frequent and shorter breaks may be more beneficial than longer, less frequent breaks for vascular health in those with T2D.NEW & NOTEWORTHY This is the first trial to examine both the effects of interrupting prolonged sitting on vascular function in type 2 diabetes and the effects of the frequency and duration of interruptions. Brief, simple resistance activity bouts every 30 min, but not every 60 min, increased mean femoral artery flow-mediated dilation over 7 h, relative to uninterrupted sitting. With further supporting evidence, these initial findings can have important implications for cardiovascular health in type 2 diabetes.
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Affiliation(s)
- Frances C Taylor
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
| | - David W Dunstan
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia.,School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia
| | - Ashleigh R Homer
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
| | - Paddy C Dempsey
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.,Diabetes Research Centre, University of Leicester, Leicester General Hospital, Leicester, United Kingdom
| | - Bronwyn A Kingwell
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,CSL Limited, Bio21, Parkville, Victoria, Australia
| | - Rachel E Climie
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Neville Owen
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Centre for Urban Transitions, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Neale D Cohen
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Robyn N Larsen
- School of Agriculture and Food, The University of Melbourne, Melbourne, Victoria, Australia
| | - Megan Grace
- School of Clinical Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Nina Eikelis
- Iverson Health Innovation Research Institute and School of Health Science, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Michael J Wheeler
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia
| | | | - Nirav Maniar
- School of Behavioural and Health Sciences, Australian Catholic University, Australia
| | - Daniel J Green
- School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia
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12
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Homer AR, Taylor FC, Dempsey PC, Wheeler MJ, Sethi P, Townsend M, Green DJ, Owen N, Larsen RN, Kingwell BA, Dunstan DW. Effect Of Frequency Of Breaks During Prolonged Sitting On Postprandial Metabolism In Type 2 Diabetes. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000670048.66395.a8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Taylor FC, Dunstan DW, Homer AR, Kingwell BA, Dempsey PC, Climie RE, Owen N, Larsen RN, Wheeler MJ, Townsend MK, Maniar N, Green DJ. Acute Effects Of Interrupting Prolonged Sitting On Vascular Function In Type 2 Diabetes. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000670104.57762.50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Wheeler MJ, Dunstan DW, Ellis KA, Cerin E, Phillips S, Lambert G, Naylor LH, Dempsey PC, Kingwell BA, Green DJ. Effect of Morning Exercise With or Without Breaks in Prolonged Sitting on Blood Pressure in Older Overweight/Obese Adults. Hypertension 2019; 73:859-867. [PMID: 30782027 DOI: 10.1161/hypertensionaha.118.12373] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Both exercise and breaks in prolonged sitting can reduce blood pressure (BP) in older overweight/obese adults. We investigated whether there is an additive hypotensive effect when exercise is combined with subsequent breaks in sitting. Sex differences and changes in plasma catecholamines as a potential candidate mechanism underlying BP responses were also examined. Sedentary older adults (n=67; 67±7 years; 31.2±4.1 kg/m2) completed 3 conditions in random order-sitting (SIT): uninterrupted sitting (8 hours, control); exercise+sitting (EX+SIT): sitting (1 hour), moderate-intensity walking (30 minutes), uninterrupted sitting (6.5 hours); exercise+breaks (EX+BR): sitting (1 hour), moderate-intensity walking (30 minutes), sitting interrupted every 30 minutes with 3 minutes of light-intensity walking (6.5 hours). Serial BP and plasma epinephrine/norepinephrine measurements occurred during 8 hours. The 8-hour average systolic and diastolic BP (mm Hg 95% CI) was lower in EX+SIT -3.4 (-4.5 to -2.3), -0.8 (-1.6 to -0.04), and EX+BR -5.1 (-6.2 to -4.0), -1.1 (-1.8 to -0.3), respectively, relative to SIT (all P <0.05). There was an additional reduction in average systolic BP of -1.7 (-2.8 to -0.6) in EX+BR relative to EX+SIT ( P=0.003). This additional reduction in systolic BP was driven by women -3.2 (-4.7 to -1.7; P<0.001 EX+BR versus EX+SIT). Average epinephrine decreased in EX+SIT and EX+BR in women (-13% to -12%) but increased in men (+12% to +23%), respectively, relative to SIT ( P<0.05). No differences in average norepinephrine were observed. Morning exercise reduces BP during a period of 8 hours in older overweight/obese adults compared with prolonged sitting. Combining exercise with regular breaks in sitting may be of more benefit for lowering BP in women than in men. Clinical Trial Registration- URL: https://www.anzctr.org.au . Unique identifier: ACTRN12614000737639.
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Affiliation(s)
- Michael J Wheeler
- From the School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth (M.J.W., D.W.D., L.H.N., D.J.G.).,Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.J.W., D.W.D., E.C., S.P., G.L., P.C.D., B.A.K.)
| | - David W Dunstan
- From the School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth (M.J.W., D.W.D., L.H.N., D.J.G.).,Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.J.W., D.W.D., E.C., S.P., G.L., P.C.D., B.A.K.).,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria (D.W.D., E.C.)
| | - Kathryn A Ellis
- Department of Psychiatry, University of Melbourne, Parkville, Victoria, Australia (K.A.E.)
| | - Ester Cerin
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.J.W., D.W.D., E.C., S.P., G.L., P.C.D., B.A.K.).,School of Public Health, University of Hong Kong (E.C.).,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria (D.W.D., E.C.)
| | - Sarah Phillips
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.J.W., D.W.D., E.C., S.P., G.L., P.C.D., B.A.K.).,Iverson Health Innovation Research Institute and School of Health Science, Swinburne University of Technology, Melbourne, Victoria, Australia (S.P., G.L.)
| | - Gavin Lambert
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.J.W., D.W.D., E.C., S.P., G.L., P.C.D., B.A.K.).,Iverson Health Innovation Research Institute and School of Health Science, Swinburne University of Technology, Melbourne, Victoria, Australia (S.P., G.L.)
| | - Louise H Naylor
- From the School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth (M.J.W., D.W.D., L.H.N., D.J.G.)
| | - Paddy C Dempsey
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.J.W., D.W.D., E.C., S.P., G.L., P.C.D., B.A.K.).,Institute of Metabolic Science, University of Cambridge, United Kingdom (P.C.D.)
| | - Bronwyn A Kingwell
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (M.J.W., D.W.D., E.C., S.P., G.L., P.C.D., B.A.K.)
| | - Daniel J Green
- From the School of Human Sciences (Exercise and Sport Science), University of Western Australia, Perth (M.J.W., D.W.D., L.H.N., D.J.G.)
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15
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Wheeler MJ, Green DJ, Ellis KA, Cerin E, Heinonen I, Naylor LH, Larsen R, Wennberg P, Boraxbekk CJ, Lewis J, Eikelis N, Lautenschlager NT, Kingwell BA, Lambert G, Owen N, Dunstan DW. Distinct effects of acute exercise and breaks in sitting on working memory and executive function in older adults: a three-arm, randomised cross-over trial to evaluate the effects of exercise with and without breaks in sitting on cognition. Br J Sports Med 2019; 54:776-781. [PMID: 31036563 DOI: 10.1136/bjsports-2018-100168] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2019] [Indexed: 12/23/2022]
Abstract
BACKGROUND Sedentary behaviour is associated with impaired cognition, whereas exercise can acutely improve cognition. OBJECTIVE We compared the effects of a morning bout of moderate-intensity exercise, with and without subsequent light-intensity walking breaks from sitting, on cognition in older adults. METHODS Sedentary overweight/obese older adults with normal cognitive function (n=67, 67±7 years, 31.2±4.1 kg/m2) completed three conditions (6-day washout): SIT (sitting): uninterrupted sitting (8 hours, control); EX+SIT (exercise + sitting): sitting (1 hour), moderate-intensity walking (30 min), uninterrupted sitting (6.5 hours); and EX+BR (exercise + breaks): sitting (1 hour), moderate-intensity walking (30 min), sitting interrupted every 30 min with 3 min of light-intensity walking (6.5 hours). Cognitive testing (Cogstate) was completed at four time points assessing psychomotor function, attention, executive function, visual learning and working memory. Serum brain-derived neurotrophic growth factor (BDNF) was assessed at six time points. The 8-hour net area under the curve (AUC) was calculated for each outcome. RESULTS Working memory net AUC z-score·hour (95% CI) was improved in EX+BR with a z-score of +28 (-26 to +81), relative to SIT, -25 (-79 to +29, p=0.04 vs EX+BR). Executive function net AUC was improved in EX+SIT, -8 (- 71 to +55), relative to SIT, -80 (-142 to -17, p=0.03 vs EX+SIT). Serum BDNF net AUC ng/mL·hour (95% CI) was increased in both EX+SIT, +171 (-449 to +791, p=0.03 vs SIT), and EX+BR, +139 (-481 to +759, p=0.045 vs SIT), relative to SIT, -227 (-851 to +396). CONCLUSION A morning bout of moderate-intensity exercise improves serum BDNF and working memory or executive function in older adults, depending on whether or not subsequent sitting is also interrupted with intermittent light-intensity walking. TRIAL REGISTRATION NUMBER ACTRN12614000737639.
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Affiliation(s)
- Michael J Wheeler
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Western Australia, Australia .,Physical Activity, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Daniel J Green
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Western Australia, Australia
| | - Kathryn A Ellis
- Academic Unit for Psychiatry of Old Age, Department of Psychiatry, University of Melbourne, Melbourne, Victoria, Australia
| | - Ester Cerin
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia.,School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong
| | - Ilkka Heinonen
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Western Australia, Australia.,Turku PET Centre, University of Turku, Turku, Finland
| | - Louise H Naylor
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Western Australia, Australia
| | - Robyn Larsen
- Physical Activity, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Patrik Wennberg
- Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Carl-Johan Boraxbekk
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark.,Centre for Demographic and Ageing Research (CEDAR), Umeå University, Umeå, Sweden
| | - Jaye Lewis
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Western Australia, Australia
| | - Nina Eikelis
- Physical Activity, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Iverson Health Innovation Research Institute and School of Health Science, Swinburne University of Technology, Melbourne, Victoria, Australia
| | | | - Bronwyn A Kingwell
- Metabolic and Vascular Physiology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Gavin Lambert
- Iverson Health Innovation Research Institute and School of Health Science, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Neville Owen
- Behavioural Epidemiology, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Centre for Urban Transitions, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - David W Dunstan
- Physical Activity, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, Victoria, Australia
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Wheeler MJ, Dunstan DW, Smith B, Smith KJ, Scheer A, Lewis J, Naylor LH, Heinonen I, Ellis KA, Cerin E, Ainslie PN, Green DJ. Morning exercise mitigates the impact of prolonged sitting on cerebral blood flow in older adults. J Appl Physiol (1985) 2019; 126:1049-1055. [PMID: 30730813 PMCID: PMC6485691 DOI: 10.1152/japplphysiol.00001.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 01/22/2019] [Accepted: 02/01/2019] [Indexed: 12/20/2022] Open
Abstract
Preventing declines in cerebral blood flow is important for maintaining optimal brain health with aging. We compared the effects of a morning bout of moderate-intensity exercise, with and without subsequent light-intensity walking breaks from sitting, on cerebral blood velocity over 8 h in older adults. In a randomized crossover trial, overweight/obese older adults ( n = 12, 70 ± 7 yr; 30.4 ± 4.3 kg/m2), completed three acute conditions (6-day washout); SIT: prolonged sitting (8 h, control); EX+SIT: sitting (1 h), moderate-intensity walking (30 min), followed by uninterrupted sitting (6.5 h); and EX + BR: sitting (1 h), moderate-intensity walking (30 min), followed by sitting (6.5 h) interrupted with 3 min of light-intensity walking every 30 min. Bilateral middle cerebral artery velocities (MCAv) were determined using transcranial Doppler at 13 time points across the day. The temporal pattern and average MCAv over 8 h was determined. The pattern of MCAv over 8 h was a negative linear trend in SIT ( P < 0.001), but a positive quadratic trend in EX + SIT ( P < 0.001) and EX + BR ( P < 0.01). Afternoon time points in SIT were lower than baseline within condition ( P ≤ 0.001 for all). A morning dip in MCAv was observed in EX + SIT and EX + BR ( P < 0.05 relative to baseline), but afternoon time points were not significantly lower than baseline. The average MCAv over 8 h was higher in EX + SIT than SIT ( P = 0.007) or EX + BR ( P = 0.024). Uninterrupted sitting should be avoided, and moderate-intensity exercise should be encouraged for the daily maintenance of cerebral blood flow in older adults. The clinical implications of maintaining adequate cerebral blood flow include the delivery of vital oxygen and nutrients to the brain. NEW & NOTEWORTHY This is the first study to measure the combined effects of an exercise bout with breaks in sitting on cerebral blood velocity in older adults. Using frequent recordings over an 8-h period, we have performed a novel analysis of the pattern of cerebral blood velocity, adjusting for concurrent measures of mean arterial pressure and other potential confounders in a linear mixed effects regression.
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Affiliation(s)
- Michael J Wheeler
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia , Perth, Western Australia , Australia
- Baker Heart and Diabetes Institute , Melbourne, Victoria , Australia
| | - David W Dunstan
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia , Perth, Western Australia , Australia
- Baker Heart and Diabetes Institute , Melbourne, Victoria , Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University , Melbourne, Victoria , Australia
| | - Brianne Smith
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia , Perth, Western Australia , Australia
| | - Kurt J Smith
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia , Perth, Western Australia , Australia
- School of Kinesiology, Lakehead University, Thunderbay, Ontario , Canada
| | - Anna Scheer
- School of Physiotherapy and Exercise Science, Faculty of Health Science, Curtin University , Perth, Western Australia , Australia
| | - Jaye Lewis
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia , Perth, Western Australia , Australia
| | - Louise H Naylor
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia , Perth, Western Australia , Australia
| | - Ilkka Heinonen
- Turku PET Centre, University of Turku , Finland
- Rydberg Laboratory of Applied Sciences, School of Engineering and Science (ETN), Halmstad University, Halmstad, Sweden
| | - Kathryn A Ellis
- Department of Psychiatry, University of Melbourne, Parkville, Melbourne, Victoria , Australia
| | - Ester Cerin
- Baker Heart and Diabetes Institute , Melbourne, Victoria , Australia
- School of Public Health, The University of Hong Kong , Hong Kong
- Mary MacKillop Institute for Health Research, Australian Catholic University , Melbourne, Victoria , Australia
| | - Philip N Ainslie
- School of Health and Exercise Sciences, The University of British Columbia , Vancouver, British Columbia , Canada
| | - Daniel J Green
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia , Perth, Western Australia , Australia
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Climie RE, Wheeler MJ, Grace M, Lambert EA, Cohen N, Owen N, Kingwell BA, Dunstan DW, Green DJ. Simple intermittent resistance activity mitigates the detrimental effect of prolonged unbroken sitting on arterial function in overweight and obese adults. J Appl Physiol (1985) 2018; 125:1787-1794. [DOI: 10.1152/japplphysiol.00544.2018] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prolonged sitting contributes to cardiovascular disease (CVD) risk. The underlying mechanisms are unknown but may include changes in arterial function and vasoactive mediators. We examined the effects of prolonged unbroken sitting, relative to regular active interruptions to sitting time, on arterial function in adults at increased CVD risk. In a randomized crossover trial, 19 sedentary overweight/obese adults (mean ± SD age 57 ± 12 yr) completed 2 laboratory-based conditions: 5 h uninterrupted sitting (SIT) and 5 h sitting interrupted every 30 min by 3 min of simple resistance activities (SRA). Femoral artery function [flow-mediated dilation (FMD)], blood flow, and shear rate were measured at 0 h, 30 min, 1 h, 2 h, and 5 h. Brachial FMD was assessed at 0 and 5 h. Plasma was collected hourly for measurement of endothelin-1 (ET-1), nitrates/nitrites, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). There was a significant decline in femoral artery FMD, averaged over 5 h in the SIT condition, relative to SRA ( P < 0.001). Plasma ET-1 total area under the curve over 5 h increased in the SIT condition compared with SRA ( P = 0.006). There was no significant difference between conditions in femoral or brachial shear rate, brachial FMD, nitrates/nitrites, VCAM-1, or ICAM-1 ( P > 0.05 for all). Five hours of prolonged sitting, relative to regular interruptions to sitting time, impaired femoral artery vasodilator function and increased circulating ET-1 in overweight/obese adults. There is the need to build on this evidence beyond acute observations to better understand the potential longer-term vascular-related consequences of prolonged sitting. NEW & NOTEWORTHY This is the first study to examine the effect of prolonged sitting on arterial function in adults at increased cardiovascular disease risk. We have shown that 5 h of prolonged sitting, relative to regular interruptions to sitting time, impaired femoral artery vasodilator function and increased circulating endothelin-1 in overweight/obese adults. There is now the need to build on this evidence beyond acute observations to better understand the potential longer-term vascular-related consequences of prolonged sitting.
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Affiliation(s)
- Rachel E. Climie
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Michael J. Wheeler
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Western Australia, Australia
| | - Megan Grace
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Elisabeth A. Lambert
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Neale Cohen
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Neville Owen
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Bronwyn A. Kingwell
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Central Clinical School and Department of Physiology, School of Medicine, Nursing and Health Services, Monash University, Melbourne, Victoria, Australia
| | - David W. Dunstan
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Western Australia, Australia
- School of Public Health, University of Queensland, Brisbane, Queensland, Australia
- Mary MacKillop Institute of Health Research, Australian Catholic University, Melbourne, Victoria, Australia
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Daniel J. Green
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, Western Australia, Australia
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Lynch BM, Nguyen NH, Reeves MM, Moore MM, Rosenberg DE, Wheeler MJ, Boyle T, Vallance JK, Friedenreich CM, English DR. Study design and methods for the ACTIVity And TEchnology (ACTIVATE) trial. Contemp Clin Trials 2017; 64:112-117. [PMID: 29097298 DOI: 10.1016/j.cct.2017.10.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/25/2017] [Accepted: 10/29/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Physical activity is positively associated with survival and quality of life among breast cancer survivors. Despite these benefits, the majority of breast cancer survivors are insufficiently active. The potential health benefits of reducing sedentary behaviour (sitting time) in this population have not been extensively investigated. The ACTIVATE Trial will evaluate the efficacy of an intervention that combines wearable technology (the Garmin Vivofit2®) with traditional behavioural change approaches to increase physical activity and reduce sedentary behaviour performed by breast cancer survivors. METHODS/DESIGN This randomised controlled trial includes inactive, postmenopausal women diagnosed with stage I-III breast cancer who have completed their primary treatment. Participants are randomly assigned to the primary intervention group (Garmin Vivofit2®; behavioural feedback and goal setting session; and, five telephone-delivered health coaching sessions) or to the wait-list control group. The primary intervention is delivered over a 12-week period. The second 12-week period comprises a maintenance phase for the primary intervention group, and an abridged intervention (Garmin Vivofit2® only) for the wait-list control group. Moderate- to vigorous-intensity physical activity (MVPA) and sedentary behaviour are assessed by accelerometry at baseline (T1), end of intervention (T2), and end of maintenance phase (T3). DISCUSSION The ACTIVATE Trial is one of the first studies to incorporate wearable technology into an intervention for cancer survivors. If the use of wearable technology (in combination with behaviour change strategies, or alone) proves efficacious, it may become an inexpensive and sustainable addition to the health promotion strategies available to health care providers in the cancer survivorship context. TRIAL REGISTRATION ACTRN12616000175471.
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Affiliation(s)
- Brigid M Lynch
- Cancer Epidemiology and Intelligence Division, Cancer Council Victoria, Melbourne, Australia; Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Australia; Physical Activity Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia.
| | - Nga H Nguyen
- Cancer Epidemiology and Intelligence Division, Cancer Council Victoria, Melbourne, Australia
| | - Marina M Reeves
- Cancer Prevention Research Centre, School of Public Health, The University of Queensland, Brisbane, Australia
| | - Melissa M Moore
- Medical Oncology, St Vincent's Hospital, Melbourne, Australia
| | - Dori E Rosenberg
- Group Health Research Institute, Seattle, USA; School of Public Health, The University of Washington, Seattle, USA
| | - Michael J Wheeler
- Physical Activity Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia; School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Terry Boyle
- School of Public Health, Curtin University, Perth, Australia
| | - Jeff K Vallance
- Faculty of Health Disciplines, Athabasca University, Athabasca, Canada
| | - Christine M Friedenreich
- Department of Cancer Epidemiology and Prevention Research, Health Services, Alberta, Calgary, Canada; Departments of Oncology and Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Dallas R English
- Cancer Epidemiology and Intelligence Division, Cancer Council Victoria, Melbourne, Australia; Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Australia
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Wheeler MJ, Mason RH, Steunenberg K, Wagstaff M, Chou C, Bertram AK. Immersion freezing of supermicron mineral dust particles: freezing results, testing different schemes for describing ice nucleation, and ice nucleation active site densities. J Phys Chem A 2014; 119:4358-72. [PMID: 25345526 DOI: 10.1021/jp507875q] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ice nucleation on mineral dust particles is known to be an important process in the atmosphere. To accurately implement ice nucleation on mineral dust particles in atmospheric simulations, a suitable theory or scheme is desirable to describe laboratory freezing data in atmospheric models. In the following, we investigated ice nucleation by supermicron mineral dust particles [kaolinite and Arizona Test Dust (ATD)] in the immersion mode. The median freezing temperature for ATD was measured to be approximately -30 °C compared with approximately -36 °C for kaolinite. The freezing results were then used to test four different schemes previously used to describe ice nucleation in atmospheric models. In terms of ability to fit the data (quantified by calculating the reduced chi-squared values), the following order was found for ATD (from best to worst): active site, pdf-α, deterministic, single-α. For kaolinite, the following order was found (from best to worst): active site, deterministic, pdf-α, single-α. The variation in the predicted median freezing temperature per decade change in the cooling rate for each of the schemes was also compared with experimental results from other studies. The deterministic model predicts the median freezing temperature to be independent of cooling rate, while experimental results show a weak dependence on cooling rate. The single-α, pdf-α, and active site schemes all agree with the experimental results within roughly a factor of 2. On the basis of our results and previous results where different schemes were tested, the active site scheme is recommended for describing the freezing of ATD and kaolinite particles. We also used our ice nucleation results to determine the ice nucleation active site (INAS) density for the supermicron dust particles tested. Using the data, we show that the INAS densities of supermicron kaolinite and ATD particles studied here are smaller than the INAS densities of submicron kaolinite and ATD particles previously reported in the literature.
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Affiliation(s)
- M J Wheeler
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
| | - R H Mason
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
| | - K Steunenberg
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
| | - M Wagstaff
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
| | - C Chou
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
| | - A K Bertram
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
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Healy ML, Gibney J, Pentecost C, Wheeler MJ, Sonksen PH. Endocrine profiles in 693 elite athletes in the postcompetition setting. Clin Endocrinol (Oxf) 2014; 81:294-305. [PMID: 24593684 DOI: 10.1111/cen.12445] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/23/2014] [Accepted: 02/27/2014] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To measure a profile of hormones in a group of elite athletes. Increasing awareness of the widespread use of hormones as performance-enhancing agents focusses attention on what may be considered as normal in this unusual group. DESIGN Blood samples were obtained from 813 volunteer elite athletes from a cross-section of 15 sporting categories. An endocrine profile was measured on a subset of 693. PARTICIPANTS Volunteer elite athletes. Samples were drawn within two hours of an event at a major national or international competition. MEASUREMENTS Demographics and hormone profiles were obtained on 454 male and 239 female elite athletes. RESULTS Hormone profiles showed significant differences in 19 of the 24 measured variables between sexes and between all of the 15 sporting disciplines in men and 11 out of 24 in women. 16.5% of men had low testosterone levels, whereas 13.7% of women had high levels with complete overlap between the sexes. Women had a lean body mass 85% that of men - sufficient to account for sex differences in performance. There were highly significant correlations between many of the measured hormones. CONCLUSIONS Hormone profiles from elite athletes differ from usual reference ranges. Individual results are dependent on a number of factors including age, gender and physique. Differences in profiles between sports suggest that an individual's profile may contribute to his/her proficiency in a particular sport. The IOC definition of a woman as one who has a 'normal' testosterone level is untenable.
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Affiliation(s)
- M L Healy
- Department of Endocrinology, St James's Hospital, Dublin, Ireland
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21
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Abstract
No other development has had such a major impact on the measurement of hormones as immunoassay. Reagents and assay kits can now be bought commercially but not for the more esoteric or new hormones. This chapter explains the basics of the immunoassay reaction and gives simple methods for immunoassays and immunometric assays and for the production of reagents for both antigenic and hapten hormones. Alternative methods are given for the preparation of labeled hormones as well as several possible separation procedures. The methods described here have been previously used in a wide range of assays and have stood the test of time. They will allow the production of usable immunoassays in a relatively short period of time.
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Abstract
In the clinical laboratory, the reproductive hormones are probably the second most commonly measured hormones after the thyroid hormones. More than 300 laboratories participate in the UK National External Quality Control Scheme. In addition, investigations into reproduction and fertility in humans and animals remain a major area of research. Illustrative methods are described for the three reproductive hormones (luteinizing hormone, follicle-stimulating hormone, prolactin). Radioimmunoassay, immunoradiometric, and enzyme assays are described to give a wide choice of assay formats. There are many commercial assays available and illustrative ones are described. Possible interferences are discussed and procedures for investigating their presence and removal are given.
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Abstract
Huge changes have occurred in the measurement of hormones over the last 50 years or so. Methods have become simplified, sensitivity has increased manyfold, and automation has allowed the analysis of large number of specimens in a single day. The most significant steps in the history of hormone measurement were the development of radioimmunoassay and later the production of monoclonal antibodies. There has also been increased commercialization, the technique has been applied to an ever-increasing range of substances, and radioactive measurement has been replaced with colorimetric, fluorescent, and chemiluminescent end-points. However, all these changes have not been without their problems. Collaboration between laboratories has seen standardization of reagents and methods, the development of reference methods, and the setting up of external quality assurance schemes. All these have led to improved sensitivity, precision, and reliability. More recently tandem mass spectrometry has brought further improvements in the measurement of certain hormones. Although many hormones are now measured by automated systems there is still a place for manual assays whether developed in-house or by using a commercial kit.
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Abstract
Anti-Müllerian hormone (AMH) has long been associated with sexual differentiation in the fetus where in the male it suppresses the development of the female reproductive tracts. More recently it has been shown to be secreted in low concentrations by the granulosa cells of the adult and related to follicular development in the ovary. A number of laboratories are now measuring this hormone as part of IVF treatment and in the investigation of polycystic ovarian disease in particular. Early immunoassays for this hormone were not stable and currently laboratories are using the assay sold by Beckman Coulter, Inc., the AMH Gen II ELISA. This assay has been developed from two commercial assays purchased by Beckman and is reported to be precise and convenient. It is the assay described here.
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Carter GD, Berry JL, Gunter E, Jones G, Jones JC, Makin HLJ, Sufi S, Wheeler MJ. Proficiency testing of 25-hydroxyvitamin D (25-OHD) assays. J Steroid Biochem Mol Biol 2010; 121:176-9. [PMID: 20302938 DOI: 10.1016/j.jsbmb.2010.03.033] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Accepted: 03/10/2010] [Indexed: 11/29/2022]
Abstract
The Vitamin D External Quality Assessment Scheme (DEQAS) has been monitoring 25-OHD assay performance since 1989. The scheme has expanded rapidly in recent years and has 670 participants in 35 countries (July 2009). Five samples of human serum are distributed quarterly and the results analyzed to give an All-Laboratory Trimmed Mean (ALTM) and SD. Each participant has internet access to a preliminary report after submission of results and, following the results deadline, a final report is e-mailed to designated staff in each laboratory. The last 15 years has seen an improvement in mean inter-laboratory imprecision (CV), from 32.0% (1994) to 15.3% (2009) and most major methods are now giving results within plus or minus 7.4% of the ALTM (2009). DEQAS has regularly conducted and reported on a number of investigations into the performance of 25-OHD methods. A gas chromatography-mass spectrometry (GC-MS) reference method for 25-OHD is under development and will be used to assess whether the ALTM remains the most appropriate target for DEQAS samples.
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Affiliation(s)
- G D Carter
- Clinical Biochemistry, Imperial College Healthcare NHS Trust, Charing Cross Hospital, Fulham Palace Road, London W6 8RF, UK.
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Díaz Arias MM, Batzer JC, Harrington TC, Wong AW, Bost SC, Cooley DR, Ellis MA, Hartman JR, Rosenberger DA, Sundin GW, Sutton TB, Travis JW, Wheeler MJ, Yoder KS, Gleason ML. Diversity and biogeography of sooty blotch and flyspeck fungi on apple in the eastern and midwestern United States. Phytopathology 2010; 100:345-355. [PMID: 20205538 DOI: 10.1094/phyto-100-4-0345] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Sooty blotch and flyspeck (SBFS) fungi on apple fruit were sampled from nine orchards in four midwestern U.S. states during 2000 and 30 orchards in 10 eastern U.S. states during 2005 in order to estimate taxonomic diversity and discern patterns of geographic distribution. Forty apple fruit per orchard were arbitrarily sampled and colonies of each mycelial phenotype were counted on each apple. Representative colonies were isolated, cultures were purified, and DNA was extracted. For representative isolates, the internal transcribed spacer (ITS) and large subunit (LSU) regions of ribosomal DNA were amplified and sequenced. In total, 60 SBFS putative species were identified based on ITS sequences and morphological characteristics; 30 of these were discovered in the 2005 survey. Modified Koch's postulates were fulfilled for all 60 species in an Iowa orchard; colonies resulting from inoculation of apple fruit were matched to the original isolates on the basis of mycelial type and ITS sequence. Parsimony analysis for LSU sequences from both surveys revealed that 58 putative SBFS species were members of the Dothideomycetes, 52 were members of the Capnodiales, and 36 were members of the Mycosphaerellaceae. The number of SBFS species per orchard varied from 2 to 15. Number of SBFS species and values of the Margalef and Shannon indexes were significantly (P < 0.05) lower in 21 orchards that had received conventional fungicide sprays during the fruit maturation period than in 14 unsprayed orchards. Several SBFS species, including Schizothyrium pomi, Peltaster fructicola, and Pseudocercosporella sp. RH1, were nearly ubiquitous, whereas other species, such as Stomiopeltis sp. RS5.2, Phialophora sessilis, and Geastrumia polystigmatis, were found only within restricted geographic regions. The results document that the SBFS complex is far more taxonomically diverse than previously recognized and provide strong evidence that SBFS species differ in geographic distribution. To achieve more efficient management of SBFS, it may be necessary to understand the environmental biology of key SBFS species in each geographic region.
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Wheeler MJ, Vatovec S, Franklin-Tong VE. The pollen S-determinant in Papaver: comparisons with known plant receptors and protein ligand partners. J Exp Bot 2010; 61:2015-25. [PMID: 20097844 DOI: 10.1093/jxb/erp383] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Cell-cell communication is vital to multicellular organisms and much of it is controlled by the interactions of secreted protein ligands (or other molecules) with cell surface receptors. In plants, receptor-ligand interactions are known to control phenomena as diverse as floral abscission, shoot apical meristem maintenance, wound response, and self-incompatibility (SI). SI, in which 'self' (incompatible) pollen is rejected, is a classic cell-cell recognition system. Genetic control of SI is maintained by an S-locus, in which male (pollen) and female (pistil) S-determinants are encoded. In Papaver rhoeas, PrsS proteins encoded by the pistil S-determinant interact with incompatible pollen to effect inhibition of pollen growth via a Ca(2+)-dependent signalling network, resulting in programmed cell death of 'self' pollen. Recent studies are described here that identified and characterized the pollen S-determinant of SI in P. rhoeas. Cloning of three alleles of a highly polymorphic pollen-expressed gene, PrpS, which is linked to pistil-expressed PrsS revealed that PrpS encodes a novel approximately 20 kDa transmembrane protein. Use of antisense oligodeoxynucleotides provided data showing that PrpS functions in SI and is the pollen S-determinant. Identification of PrpS represents a milestone in the SI field. The nature of PrpS suggests that it belongs to a novel class of 'receptor' proteins. This opens up new questions about plant 'receptor'-ligand pairs, and PrpS-PrsS have been examined in the light of what is known about other receptors and their protein-ligand pairs in plants.
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Affiliation(s)
- Michael J Wheeler
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Affiliation(s)
- M J Wheeler
- Department of Chemical Pathology, St Thomas'Hospital, London, SEI 7EH, UK, Department of Chemical Pathology and Immunology, St Mary's Hospital, London, W2 1NY, UK
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Abstract
UNLABELLED Problems in the measurement of androgens and in interpreting results have been reviewed and classified as follows: PREANALYTICAL FACTORS: The exact sampling conditions in relation to circadian and seasonal variations, diet, alcohol, physical activity and posture. PHYSIOLOGICAL AND MEDICAL FACTORS Androgen levels vary according to the patient's general health, stress, sexual activity and smoking habits. Analytical variables. Sample preservation and storage variables are often unknown. The different androgen assays used have widely differing accuracy and precision and are subject to large inter-laboratory variation, which especially in women and children can render the results of routinely available direct immunoassays meaningless. INTERPRETATION OF RESULTS Laboratory reference ranges vary widely, largely independent of methodology, and fail to take into account the log-normal distribution of androgen values, causing errors in clinical diagnosis and treatment. Other unknowns are antagonists such as SHBG, estrogens, catecholamines, cortisol, and anti-androgens. As well as age, androgen receptor polymorphisms play a major role in regulating androgen levels and resistance to their action. CONCLUSIONS Though laboratory assays can support a diagnosis of androgen deficiency in men, they should not be used to exclude it. It is suggested that there needs to be greater reliance on the history and clinical features, together with careful evaluation of the symptomatology, and where necessary a therapeutic trial of androgen treatment given.
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Abstract
This review provides a short history of the development of robotic systems in Clinical Chemistry and discusses the early expectations for these systems. The systems currently available are discussed and every attempt has been made to keep this section up-to-date, but this is a constantly changing field. Much of the review is taken up looking at the impact resulting from the introduction of robotic systems in the laboratory and whether they have met the expectations of the laboratory. It is difficult to get hard data since laboratories are most concerned with getting their instrumentation up and running and there is little time, or thought given, to pre- and post-introduction studies. Therefore, the literature is sparse but much of the data for the UK has come from a Medicines and Healthcare products Regulatory Agency (MHRA) review of pre-analytical systems. Finally thought has been given to future developments and their possible impact on the functioning of the laboratory.
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Affiliation(s)
- M J Wheeler
- The Old Dairy, Old Bystock Drive, Exmouth EX8 5EQ, UK.
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Howes OD, Wheeler MJ, Pilowsky LS, Landau S, Murray RM, Smith S. Sexual function and gonadal hormones in patients taking antipsychotic treatment for schizophrenia or schizoaffective disorder. J Clin Psychiatry 2007; 68:361-7. [PMID: 17388704 PMCID: PMC3666283 DOI: 10.4088/jcp.v68n0302] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To determine rates of sexual dysfunction and hypogonadism and establish the relationship between gonadal hormone levels and sexual function in patients taking antipsychotic treatment for schizophrenia or schizoaffective disorder. METHOD We studied 103 patients with schizophrenia or schizoaffective disorder (mean age = 46.2 (SD = 12.9) years; 51.5% male) from October 2003 through March 2005. Sexual function was assessed using the Sexual Functioning Questionnaire (SFQ) and compared with (1) normal controls (N = 62; mean age = 36.1 (SD = 9.6) years; 55% male) recruited from primary care attendees and (2) sexually dysfunctional controls recruited from a local sexual dysfunction clinic (N = 57; mean age = 39.1 (SD = 10.7) years; 79% male). Prolactin, sex hormone-binding globulin, testosterone, estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone levels; psychopathology; and side effects were measured. RESULTS Mean (SD) total SFQ scores were significantly greater in patients (women = 9.9 [5.3]; men = 7.8 [4.9]) compared with normal controls (women = 4.1 [2.9]; men = 4.09 [2.95]), and similar to the scores of sexual dysfunction clinic attendees (women = 7.2 [2.9]; men = 9.9 [4.5]). The odds ratios of patients having sexual dysfunction compared with normal controls were 15.2 for women and 3.7 for men. Hypogonadism was common (in premenopausal women, 79% showed hypoestrogenism and 92% showed low progesterone levels, and 28% of men showed hypotestosteronism). There was no association between total SFQ scores and prolactin or gonadal hormone levels. CONCLUSION Patients receiving treatment for schizophrenia or schizoaffective disorder show high rates of sexual dysfunction and hypogonadism. Sexual functioning was not related to prolactin or gonadal hormone levels.
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Affiliation(s)
| | - Vernonica E Franklin-Tong
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK (Correspondence: Vernonica Franklin-Tong: tel +44 121414 3702; fax +44 121414 5925; email . Michael Wheeler: email )
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de Graaf BHJ, Rudd JJ, Wheeler MJ, Perry RM, Bell EM, Osman K, Franklin FCH, Franklin-Tong VE. Self-incompatibility in Papaver targets soluble inorganic pyrophosphatases in pollen. Nature 2006; 444:490-3. [PMID: 17086195 DOI: 10.1038/nature05311] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Accepted: 10/04/2006] [Indexed: 11/09/2022]
Abstract
In higher plants, sexual reproduction involves interactions between pollen and pistil. A key mechanism to prevent inbreeding is self-incompatibility through rejection of incompatible ('self') pollen. In Papaver rhoeas, S proteins encoded by the stigma interact with incompatible pollen, triggering a Ca2+-dependent signalling network resulting in pollen tube inhibition and programmed cell death. The cytosolic phosphoprotein p26.1, which has been identified in incompatible pollen, shows rapid, self-incompatibility-induced Ca2+-dependent hyperphosphorylation in vivo. Here we show that p26.1 comprises two proteins, Pr-p26.1a and Pr-p26.1b, which are soluble inorganic pyrophosphatases (sPPases). These proteins have classic Mg2+-dependent sPPase activity, which is inhibited by Ca2+, and unexpectedly can be phosphorylated in vitro. We show that phosphorylation inhibits sPPase activity, establishing a previously unknown mechanism for regulating eukaryotic sPPases. Reduced sPPase activity is predicted to result in the inhibition of many biosynthetic pathways, suggesting that there may be additional mechanisms of self-incompatibility-mediated pollen tube inhibition. We provide evidence that sPPases are required for growth and that self-incompatibility results in an increase in inorganic pyrophosphate, implying a functional role for Pr-p26.1.
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Affiliation(s)
- Barend H J de Graaf
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Abstract
Testosterone is the major androgen measured in clinical and research investigations of both men and women. Nevertheless, many other androgens have an important role in the investigation of andrenal and gonadal physiology and pathology. Commercial assays are generally used in clinical laboratories but these have poor precision at low concentrations and poor sensitivity. Extraction assays, described in this chapter, can be much more sensitive and precise. There is interest in measuring free steriods and a steady-state gel filtration method used in the author's laboratory is described. Methods are also provided for the measurement of steroids in saliva and hair.
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Abstract
No other development has had such a major impact on the measurement of hormones as immunoassay. Reagents and assay kits can now be bought commercially but not for the more esoteric or new hormones. This chapter explains the basics of the immunoassay reaction and gives simple methods for immunoassays and immunometric assays and for the production of reagents for both antigenic and hapten hormones. Alternative methods are given for the preparation of labeled hormones as well as several possible separation procedures. The methods described here have been previously used in a wide range of assays and have stood the test of time. They will allow the production of usable immunoassays in a relatively short period of time.
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Abstract
In the clinical laboratory the reproductive hormones are probably the most commonly measured hormones after the thyroid hormones. More than 300 laboratories participate in the UK National External Quality Control Scheme. In addition, investigations into reproduction and fertility in humans and animals remains a major area of research. Illustrative methods are described for the three reproductive hormones (leutinizing hormone, follicle-stimulating hormone, prolactin). Radioimmunoassay, immunoradiometric assay, and enzyme assays are described to give a wide choice of assay formats. There are many commercial assays available and illustrative ones are described. Possible interferences are discussed and procedures for investigating their presence and removal are given.
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Howes OD, Wheeler MJ, Meaney AM, O'Keane V, Fogelman I, Blake G, Murray RM, Smith S. Bone mineral density and its relationship to prolactin levels in patients taking antipsychotic treatment. J Clin Psychopharmacol 2005; 25:259-61. [PMID: 15876906 PMCID: PMC3666284 DOI: 10.1097/01.jcp.0000162798.87249.4d] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Antipsychotic treatment is frequently associated with elevated prolactin levels. Raised prolactin levels have been linked with osteoporosis. The objective of this study is to determine whether patients taking antipsychotics show reduced bone mineral density (BMD), and whether this is associated with prolactin levels. BMD (standardized as z scores) was compared using dual x-ray absorptiometry of the lumbar spine and hip in patients taking antipsychotics (n = 102, mean age: 46.0, SD: 13.1, 47% male, median treatment duration: 3.0 years) to matched reference controls. Levels of prolactin, markers of bone metabolism, and risk factors for osteoporosis were measured. Mean BMD was not significantly reduced, other than the total spine score for black males (mean z score: -0.88, P = 0.00001). BMD was correlated with body mass index but there was no correlation with prolactin. BMD was not correlated with prolactin levels and showed no clinically significant reduction. The low BMD in black males warrants further investigation.
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Bassindale T, Cowan DA, Dale S, Hutt AJ, Leeds AR, Wheeler MJ, Kicman AT. Effects of oral administration of androstenedione on plasma androgens in young women using hormonal contraception. J Clin Endocrinol Metab 2004; 89:6030-8. [PMID: 15579755 DOI: 10.1210/jc.2004-0790] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Androstenedione as a dietary supplement has been targeted at the sporting community, but there are limited data regarding its effects on plasma androgens in young women. A double-blind, cross-over study was undertaken involving 10 women (20-32 yr) using hormonal contraception. Because contamination of supplements has been reported, an in-house oral formulation was prepared containing purified androstenedione, the control being lactose only. After oral administration of a single dose of androstenedione (100 mg), blood was collected frequently up to 8 h and at 24 h. Maximum plasma androgen concentrations observed between volunteers were well above the upper limit of reference ranges for women, being 121-346 nmol/liter for androstenedione, 14-54 nmol/liter for testosterone (T), 11-32 nmol/liter for 5alpha-dihydrotestosterone, and 23-90 nmol/liter for 3alpha-androstanediol glucuronide. The free androgen index and T concentration changed in a similar manner. The mean change in area under the plasma concentration-time curve (0-24 h), compared with control data were: androstenedione approximately 7-fold, T approximately 16-fold, 5alpha-dihydrotestosterone approximately 9-fold, and 3alpha-androstanediol glucuronide approximately 5-fold; the mean conversion ratio of androstenedione to T was 12.5% (range 7.8-21.6%). Increases in T area under the plasma concentration-time curve were correlated with SHBG concentration (r = 0.80; P = 0.005). Formulation characteristics and SHBG levels appear to be important factors when considering plasma androgen increases after acute androstenedione administration.
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Affiliation(s)
- Thomas Bassindale
- Department of Forensic Science and Drug Monitoring (Drug Control Centre), King's College London, London SE1 9NH, United Kingdom
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Wheeler MJ, Armstrong SA, Franklin-Tong VE, Franklin FCH. Genomic organization of the Papaver rhoeas self-incompatibility S(1) locus. J Exp Bot 2003; 54:131-139. [PMID: 12456763 DOI: 10.1093/jxb/erg006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The self-incompatibility (SI) response in Papaver rhoeas depends upon the cognate interaction between a pollen-expressed receptor and a stigmatically expressed ligand. The genes encoding these components are situated within the S-locus. In order for SI to be maintained, the genes encoded by the S-locus must be co-inherited with no recombination between them. Several hypotheses, including sequence heterogeneity and chromosomal position, have been put forward to explain the maintenance of the S-locus in the SI systems of the Brassicaceae and the Solanaceae. A region of the Papaver rhoeas genome encompassing part of the self-incompatibility S(1) locus has been cloned and sequenced. The clone contains the gene encoding the stigmatic component of the response, but does not contain a putative pollen S-gene. The sequence surrounding the S(1) gene contains several diverse repetitive DNA elements. As such, the P. rhoeas S-locus bears similarities to the S-loci of other SI systems. An attempt to localize the P. rhoeas S-locus using fluorescence in situ hybridization (FISH) has also been made. The potential relevance of the findings to mechanisms of recombination suppression is discussed.
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Affiliation(s)
- M J Wheeler
- Wolfson Laboratory for Plant Molecular Biology, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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Abstract
BACKGROUND The biologically active component of a hormone is the unbound or free fraction. Changes in cortisol-binding protein could give misleading results if only total cortisol is measured for the interpretation of dynamic function tests. METHODS This study aimed to measure serum free cortisol using a steady-state gel-filtration method and then to evaluate the correlation between the serum free cortisol and the free cortisol index (FCI), defined as serum total cortisol/cortisol-binding globulin (CBG). RESULTS Forty-eight serum samples from healthy volunteers undergoing a short Synacthen test were analysed for total cortisol, free cortisol and CBG. The FCI correlated well with a previously established, but more complex, calculation of serum free cortisol (R = 0.98, P <0.001) and with measured serum free cortisol (R = 0.90, P < 0.001). CONCLUSION Free cortisol index is a reliable and user-friendly measure of serum free cortisol.
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Affiliation(s)
- Carel W le Roux
- Department of Chemical Pathology, Charing Cross Hospital, London W6 8RF, UK.
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Abstract
Hyperprolactinaemia is commonly induced by antipsychotic medications that have dopamine-blockade as their main mechanism of action. The purpose of this study was to assess the effect of antipsychotic-induced hyperprolactinaemia on hypothalamic-pituitary-gonadal axis (HPG) function.HPG axis function was assessed in 67 consecutive outpatients who were diagnosed with schizophrenia and stabilized for a period of not less than 2 years on typical antipsychotic medication, by means of clinical history, relevant questionnaires and measurement of plasma prolactin, estradiol, progesterone, testosterone, LH, FSH, sex hormone binding globulin, and TSH levels. Normative laboratory data were used to assess whether hormone levels fell within the reference range for a normal population. There was a significant correlation between dose of medication and plasma prolactin levels for the total group (P<0.001). Prolactin levels were significantly negatively associated with sex hormone levels in females (P<0.05). Males taking antipsychotic medication had a mean prolactin level of 404.1m/IU and mean gonadotrophin and sex hormone levels that fell within normal limits. The results of this study indicate that neuroleptic-induced prolactin secretion is a dose-related side effect and, in females, the level of hyperprolactinaemia is correlated with the degree of suppression of the HPG axis. Women taking long-term prolactin-raising antipsychotic medications are likely to be hyperprolactinaemic and have an associated hypogonadal state. In males, prolactin levels remain within normal limits, but at the upper end, with no apparent disturbance of reproductive hormones.
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Affiliation(s)
- Shubulade Smith
- Institute of Psychiatry, Camberwell, London, United Kingdom.
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Abstract
Over the past decade or so, there has been significant progress towards elucidating the molecular events occurring during pollination in flowering plants. This process involves a series of complex cellular interactions that culminates in the fusion between male and female gametes. The process also regulates crucial events such as pollen adhesion, hydration, pollen tube growth and guidance to the ovules. Additionally, in many instances, incompatibility mechanisms that control the acceptance or rejection of pollen alighting on a recipient plant play a major role in the pollination process. In this article we aim to review our current understanding of the components that are implicated in enabling the pollen to deliver the male gametes to the ovary and the molecular mechanisms by which they are thought to act. Contents Summary 565 I. Introduction 565 II. Adhesion of pollen to the stigma 566 III. Pollen hydration 567 IV. Pollen germination and initial growth on the stigma surface 568 V. Pollen tube growth through the style and pollen tube guidance 569 VI. Control of pollen viability by incompatibility responses 572 1. Self incompatibility (SI) 573 Gametophytic SI 573 SI in the Solanaceae 573 SI in Papaver 575 Sporophytic SI 577 SI in Brassica 577 SI in Ipomoea 579 2. Interspecific incompatibility responses 579 VII. Conclusions and perspective 580 References 580.
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Affiliation(s)
- M J Wheeler
- Wolfson Laboratory for Plant Molecular Biology, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - V E Franklin-Tong
- Wolfson Laboratory for Plant Molecular Biology, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - F C H Franklin
- Wolfson Laboratory for Plant Molecular Biology, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Affiliation(s)
- M J Wheeler
- Department of Chemical Pathology, St Thomas' Hospital, London, UK.
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45
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Palmer HE, Stanford MR, Lowy C, Wheeler MJ, Wallace GR, Graham EM. The pituitary-adrenal axis in idiopathic retinal vasculitis. Br J Ophthalmol 1999; 83:1393-5. [PMID: 10574821 PMCID: PMC1722887 DOI: 10.1136/bjo.83.12.1393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To determine whether patients with idiopathic retinal vasculitis have altered production of cortisol and dehydroepiandrosterone sulphate (DHEA-S), and whether differences in these variables occur between those who are sensitive (SS) and resistant (SR) to steroids. METHODS 20 patients with retinal vasculitis (off treatment) and 10 control subjects were prospectively recruited. Morning cortisol and DHEA-S levels were measured, and cortisol secretion rates and short synacthen tests (SST) carried out in patients before treatment, when on prednisolone 20 mg/day, and in controls. RESULTS There were no differences in any variables between patients and controls. For retinal vasculitis patients pretreatment, the SST was lower in SR patients (p=0.02). More of the SR patients had ischaemic retinal vasculitis ( p<0.001). CONCLUSIONS Cortisol and DHEA-S are not involved in the pathogenesis of retinal vasculitis. SR in retinal vasculitis may be associated with a defective hypothalamic-pituitary-adrenal axis.
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Affiliation(s)
- H E Palmer
- Medical Eye Unit, St Thomas's Hospital, London
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Abstract
OBJECTIVE Evidence is accumulating that the nocturnal increase in melatonin may influence pituitary hormone secretion. The aim of this study was to determine the effect of exogenous melatonin, in concencetrations spanning the physiological range, on the release of pituitary hormones in man during daylight hours. DESIGN A double blind, randomized, crossover study. SUBJECTS Eight healthy male volunteers with a mean age of 21 +/- 0.5 years were studied on four occasions, observations being made after the adminstration of melatonin in doses of 0.05, 0.5 or 5.0 mg or placebo. They refrained from taking heavy exercise, alcohol and from smoking for 24 h prior to the study. MEASUREMENTS Serum cortisol, growth hormone, prolactin and plasma oxytocin, vasopressin, sodium, osmolality and packed cell volume were measured in samples taken at 30 minutes intervals for 150 minutes after the administration of melatonin. RESULTS Melatonin produced dose-dependent changes in circulating concentrations of oxytocin and vasopressin, the 0.5 mg dose being stimulatory, while 5.0 mg was inhibitory. These two doses stimulated growth hormone release, while there was no significant effect on prolactin or cortisol release. CONCLUSIONS These results confirm that the nocturnal increase in melatonin could contribute to the patterns of oxytocin, vasopressin and growth hormone release seen over 24 h.
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Affiliation(s)
- M L Forsling
- Departments of Gynaecology and Physiology King's College, St Thomas' Campus, London, UK.
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Flaxel CJ, Wheeler MJ, Mulholland B, Gregor ZJ. Detection of prednisolone in vitreous following systemic administration. Eye (Lond) 1999; 12 ( Pt 6):1013-4. [PMID: 10326006 DOI: 10.1038/eye.1998.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Abstract
Trace metals and drugs have been measured in hair for a number of years but there are no published papers on the measurement of steroids in human hair. We report here the measurement of testosterone in hair samples taken from men, women and prepubertal children. This was a preliminary investigation to see whether testosterone was detectable in hair and whether concentrations between men and women, and men and prepubertal children were different in line with concentrations of testosterone in the blood. Hair was digested in sodium hydroxide and the testosterone extracted before measurement by radioimmuno- assay. There was a clear difference between testosterone concentrations found in heir collected from men (12.9-77.7 pmol/g) and those found in hair from women (<0.9-10.8 pmol/g). There was no significant difference between the concentrations found in women and children. The authenticity of the testosterone measured was confirmed with GCMS.
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Affiliation(s)
- M J Wheeler
- Department of Chemical Pathology, Guy's and St Thomas' NHS Trust, St Thomas' Hospital, London, SE1 7EH
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Kostoglou-Athanassiou I, Athanassiou P, Treacher DF, Wheeler MJ, Forsling ML. Neurohypophysial hormone and melatonin secretion over the natural and suppressed menstrual cycle in premenopausal women. Clin Endocrinol (Oxf) 1998; 49:209-16. [PMID: 9828909 DOI: 10.1046/j.1365-2265.1998.00504.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE Vasopressin, oxytocin and melatonin have been reported to be influenced by ovarian steroids. The neurohypophysial hormones have also been shown to display a diurnal pattern of secretion in men. We therefore studied the diurnal pattern of neurohypophysial hormone and melatonin secretion in premenopausal women and in women on oral contraceptives. DESIGN Healthy normally cycling premenopausal women were studied over 24 hours during the midfollicular and midluteal phases of the menstrual cycle. Healthy premenopausal women on oral contraceptives were studied over 24 hours at similar times. SUBJECTS Eight healthy normally cycling women and 7 healthy premenopausal women on oral contraceptives. MEASUREMENTS Plasma vasopressin, oxytocin and melatonin were measured by radioimmunoassay. RESULTS Vasopressin concentrations and its nocturnal peak were highest in the follicular phase of the natural menstrual cycle and attenuated in the women on oral contraceptives. Oxytocin concentrations did not vary between the two phases of the menstrual cycle, but increased on oestrogen administration. Overall melatonin secretion was augmented in the women on oral contraceptives. CONCLUSIONS Vasopressin release and its nocturnal peak were greatest in the follicular phase of the menstrual cycle, while melatonin secretion was augmented in the women on oral contraception.
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Abstract
BACKGROUND Cortisol non-suppression following the dexamethasone suppression test (DST) has been found to a variable extent in schizophrenia. The aetiology is unclear but may be related to depression or negative symptoms. METHODS The DST was administered to 64 patients with DSM-IV schizophrenia. All patients were screened for DSM-IV major depression and rated on the Hamilton Rating Scale for Depression (HRSD), Scale for Assessment of Negative Symptoms (SANS) and the Brief Psychiatric Rating Scale (BPRS). RESULTS DSM-IV criteria for major depression was fulfilled by 36% of the patients and 42% of patients had a history of parasuicide. Four patients had undetectable levels of dexamethasone and were excluded from the endocrine analyses. Only one remaining patient had a cortisol level above the cut-off point (> 138 nmol/l), indicating escape from dexamethasone suppression. The post-dexamethasone cortisol level correlated significantly with HRSD and BPRS scores but not with the SANS. The SANS and HRSD scores were not correlated, but they were independently correlated with the BPRS score. CONCLUSIONS In contrast to some other work, rates of dexamethasone non-suppression were very low; together with the high rates of depression, this suggests that depression in schizophrenia may have a different neuroendocrine profile from major depressive disorders. Failure to measure dexamethasone levels can be misleading.
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Affiliation(s)
- K Ismail
- Maudsley Hospital, Department of Psychological Medicine, King's College School of Medicine and Dentistry, London
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