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D'Souza AW, Yoo JK, Bhai S, Sarma S, Anderson EH, Levine BD, Fu Q. Attenuated peripheral oxygen extraction and greater cardiac output in women with posttraumatic stress disorder during exercise. J Appl Physiol (1985) 2024; 136:141-150. [PMID: 38031720 PMCID: PMC11219012 DOI: 10.1152/japplphysiol.00161.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 11/20/2023] [Accepted: 11/20/2023] [Indexed: 12/01/2023] Open
Abstract
Posttraumatic stress disorder (PTSD) is associated with an increased risk of developing cardiovascular disease, especially in women. Evidence indicates that men with PTSD exhibit lower maximal oxygen uptake (V̇o2max) relative to controls; however, whether V̇o2max is blunted in women with PTSD remains unknown. Furthermore, it is unclear what determinants (i.e., central and/or peripheral) of V̇o2max are impacted by PTSD. Therefore, we evaluated the central (i.e., cardiac output; Q̇c) and peripheral (i.e., arteriovenous oxygen difference) determinants of V̇o2max in women with PTSD; hypothesizing that V̇o2max would be lower in women with PTSD compared with women without PTSD (controls), primarily due to smaller increases in stroke volume (SV), and therefore Q̇c. Oxygen uptake (V̇o2), heart rate (HR), Q̇c, SV, and arteriovenous oxygen difference were measured in women with PTSD (n = 14; mean [SD]: 43 [11] yr,) and controls (n = 17; 45 [11] yr) at rest, and during an incremental maximal treadmill exercise test, and the Q̇c/V̇o2 slope was calculated. V̇o2max was not different between women with and without PTSD (24.3 [5.6] vs. 26.4 [5.0] mL/kg/min; P = 0.265). However, women with PTSD had higher Q̇c [P = 0.002; primarily due to greater SV (P = 0.069), not HR (P = 0.285)], and lower arteriovenous oxygen difference (P = 0.002) throughout exercise compared with controls. Furthermore, the Q̇c/V̇o2 slope was steeper in women with PTSD relative to controls (6.6 [1.4] vs. 5.7 [1.0] AU; P = 0.033). Following maximal exercise, women with PTSD exhibited slower HR recovery than controls (P = 0.046). Thus, despite attenuated peripheral oxygen extraction, V̇o2max is not reduced in women with PTSD, likely due to larger increases in Q̇c.NEW & NOTEWORTHY The current study indicates that V̇o2max is not different between women with and without PTSD; however, women with PTSD exhibit blunted peripheral extraction of oxygen, thus requiring an increase in Q̇c to meet metabolic demand during exercise. Furthermore, following exercise, women with PTSD demonstrate impaired autonomic cardiovascular control relative to sedentary controls. We interpret these data to indicate that women with PTSD demonstrate aberrant cardiovascular responses during and immediately following fatiguing exercise.
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Affiliation(s)
- Andrew W D'Souza
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Jeung-Ki Yoo
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Salman Bhai
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Department of Neurology, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Satyam Sarma
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Elizabeth H Anderson
- Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Veterans Affairs North Texas Health Care System, Dallas, Texas, United States
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Qi Fu
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
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Webb KL, Gorman EK, Morkeberg OH, Klassen SA, Regimbal RJ, Wiggins CC, Joyner MJ, Hammer SM, Senefeld JW. The relationship between hemoglobin and [Formula: see text]: A systematic review and meta-analysis. PLoS One 2023; 18:e0292835. [PMID: 37824583 PMCID: PMC10569622 DOI: 10.1371/journal.pone.0292835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 09/29/2023] [Indexed: 10/14/2023] Open
Abstract
OBJECTIVE There is widespread agreement about the key role of hemoglobin for oxygen transport. Both observational and interventional studies have examined the relationship between hemoglobin levels and maximal oxygen uptake ([Formula: see text]) in humans. However, there exists considerable variability in the scientific literature regarding the potential relationship between hemoglobin and [Formula: see text]. Thus, we aimed to provide a comprehensive analysis of the diverse literature and examine the relationship between hemoglobin levels (hemoglobin concentration and mass) and [Formula: see text] (absolute and relative [Formula: see text]) among both observational and interventional studies. METHODS A systematic search was performed on December 6th, 2021. The study procedures and reporting of findings followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Article selection and data abstraction were performed in duplicate by two independent reviewers. Primary outcomes were hemoglobin levels and [Formula: see text] values (absolute and relative). For observational studies, meta-regression models were performed to examine the relationship between hemoglobin levels and [Formula: see text] values. For interventional studies, meta-analysis models were performed to determine the change in [Formula: see text] values (standard paired difference) associated with interventions designed to modify hemoglobin levels or [Formula: see text]. Meta-regression models were then performed to determine the relationship between a change in hemoglobin levels and the change in [Formula: see text] values. RESULTS Data from 384 studies (226 observational studies and 158 interventional studies) were examined. For observational data, there was a positive association between absolute [Formula: see text] and hemoglobin levels (hemoglobin concentration, hemoglobin mass, and hematocrit (P<0.001 for all)). Prespecified subgroup analyses demonstrated no apparent sex-related differences among these relationships. For interventional data, there was a positive association between the change of absolute [Formula: see text] (standard paired difference) and the change in hemoglobin levels (hemoglobin concentration (P<0.0001) and hemoglobin mass (P = 0.006)). CONCLUSION These findings suggest that [Formula: see text] values are closely associated with hemoglobin levels among both observational and interventional studies. Although our findings suggest a lack of sex differences in these relationships, there were limited studies incorporating females or stratifying results by biological sex.
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Affiliation(s)
- Kevin L. Webb
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Ellen K. Gorman
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Olaf H. Morkeberg
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Stephen A. Klassen
- Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Riley J. Regimbal
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Chad C. Wiggins
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Michael J. Joyner
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Shane M. Hammer
- Department of Kinesiology, Applied Health, and Recreation, Oklahoma State University, Stillwater, Oklahoma, United States of America
| | - Jonathon W. Senefeld
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois
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Wu H, Shui YB, Liu Y, Liu X, Siegfried CJ. Trabecular Meshwork Mitochondrial Function and Oxidative Stress. OPHTHALMOLOGY SCIENCE 2022; 2:100107. [PMID: 36246185 PMCID: PMC9562365 DOI: 10.1016/j.xops.2021.100107] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 12/11/2021] [Accepted: 12/16/2021] [Indexed: 11/17/2022]
Affiliation(s)
- Hongli Wu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - Ying-Bo Shui
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Ying Liu
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Xiaobin Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Carla J. Siegfried
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri
- Correspondence: Carla J. Siegfried, MD, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8096, St. Louis, MO 63110.
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Foster J, Smallcombe JW, Hodder SG, Jay O, Flouris AD, Morris NB, Nybo L, Havenith G. Aerobic fitness as a parameter of importance for labour loss in the heat. J Sci Med Sport 2021; 24:824-830. [DOI: 10.1016/j.jsams.2021.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/16/2021] [Accepted: 05/02/2021] [Indexed: 02/07/2023]
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Arad AD, Albu JB, DiMenna FJ. Feasibility of a progressive protocol of high-intensity interval training for overweight/obese, sedentary African American women: a retrospective analysis. BMC Sports Sci Med Rehabil 2020; 12:59. [PMID: 32974034 PMCID: PMC7507624 DOI: 10.1186/s13102-020-00207-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 09/03/2020] [Indexed: 01/15/2023]
Abstract
Background African American (AA) women have a higher prevalence of obesity and related metabolic dysfunction and lower level of physical activity compared to white counterparts. Determining feasible exercise alternatives for AA women is, therefore, paramount. Time-efficient high-intensity interval training (HIIT) might be particularly suited for AA women who cite time constraints as a frequent barrier to exercise adherence. The purpose of this study was to assess the feasibility of a 14-week progressive HIIT protocol for previously-sedentary overweight/obese AA women. Methods Twenty-eight healthy, premenopausal (age, 20-40 yr), sedentary, nondiabetic, overweight/obese AA women volunteered to participate in the randomized controlled clinical trial from which these data were retrospectively analysed. After assessment, participants were randomly allocated to a HIIT group (n = 14) or a no-exercise control group. The HIIT intervention consisted of 24-min sessions performed three times per week for 14 weeks during which work-interval intensity (75 to 90% of heart rate reserve; HRR) and duration (30 to 60 s) and work/recovery ratio (1:7 to 1:3) were progressed in four stages. Feasibility was assessed based on adherence (attrition rate), perceptual response (RPE) and success rate, which was calculated based on the degree to which target intensities for work intervals were achieved/maintained. Results Five of 14 participants (35%) in the HIIT group dropped out during the intervention. One-way repeated-measures ANOVA revealed a significant difference across stages for success rate (p = 0.018) with post-hoc analysis indicating a significant difference between stage 1 and the other stages and stage 4 and the other stages. There was no significant difference in RPE across stages (p = 0.057). Conclusion Albeit based on a limited number of participants, we found an attrition rate that was higher than what has been reported previously for HIIT (~ 17.6%) when previously-sedentary overweight/obese AA women performed a protocol with work-interval intensity progressed from 75 to 90% HRR during a 14-week intervention. With respect to intensity, the precipitous drop for achievement of the target HR during the fourth stage (weeks 8-14) for those who did complete the protocol implies that it might be advisable to restrict work-interval intensity to < 90% HRR. Trial registration ClinicalTrials.gov. (NCT04293367). Registered 03 March 2020 - Retrospectively registered.
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Affiliation(s)
- Avigdor D Arad
- Division of Endocrinology, Diabetes and Bone, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Jeanine B Albu
- Division of Endocrinology, Diabetes and Bone, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Fred J DiMenna
- Division of Endocrinology, Diabetes and Bone, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY USA
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Gower BA, Fowler LA. Obesity in African-Americans: The role of physiology. J Intern Med 2020; 288:295-304. [PMID: 32350924 DOI: 10.1111/joim.13090] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/18/2020] [Accepted: 03/02/2020] [Indexed: 12/18/2022]
Abstract
The disproportionate obesity in African American (AA) women has a physiologic basis and can be explained by the interactive effects of insulin secretion, insulin clearance, insulin sensitivity and the glycaemic load of the diet. This review will present data supporting a physiologic basis for obesity propensity in obesity-prone AA women that resides in their unique metabolic/endocrine phenotype: high beta-cell responsiveness, low hepatic insulin extraction and relatively high insulin sensitivity, which together result in a high exposure of tissues and organs to insulin. When combined with a high-glycaemic (HG) diet (that stimulates insulin secretion), this underlying propensity to obesity becomes manifest, as ingested calories are diverted from energy production to storage. Our data indicate that both weight loss and weight loss maintenance are optimized with low-glycaemic (LG) vs HG diet in AA. Whether greater obesity in AA is mechanistically related to their greater prevalence of type 2 diabetes is debatable. This review provides data indicating that obesity is not strongly related to insulin resistance in AA. Rather, insulin resistance in AA is associated with relatively low adipose tissue in the leg, consistent with a genetic predisposition to impaired lipid storage. Greater bioenergetic efficiency has been reported in AA and, via resultant oxidative damage, could plausibly contribute to insulin resistance. In summary, it is proposed here that a subset of AA women are predisposed to obesity due to a specific metabolic/endocrine phenotype. However, greater diabetes risk in AA has an independent aetiology based on impaired lipid storage and mitochondrial efficiency/oxidative stress.
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Affiliation(s)
- B A Gower
- From the, Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - L A Fowler
- From the, Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
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Bonomi AG, Ten Hoor GA, de Morree HM, Plasqui G, Sartor F. Cardiorespiratory fitness estimation from heart rate and body movement in daily life. J Appl Physiol (1985) 2020; 128:493-500. [PMID: 31999530 DOI: 10.1152/japplphysiol.00631.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Low cardiorespiratory fitness (CRF) increases risk of all-cause mortality and cardiovascular events. Periodic CRF assessment can have an important preventive function. The objective of this study was to develop a protocol-free method to estimate CRF in daily life based on heart rate (HR) and body acceleration measurements. Acceleration and HR data were collected from 37 subjects (men = 49%) while they performed a standardized laboratory activity protocol (sitting, walking, running, cycling) and during a 5-day free-living monitoring period. CRF was determined by oxygen uptake (V̇o2max) during maximal exercise testing. A doubly labeled water-validated equation was used to predict total energy expenditure (TEE) from acceleration data. A fitness index was defined as the ratio between TEE and HR (TEE-pulse). Activity recognition techniques were used to process acceleration features and classify sedentary, ambulatory, and other activity types. Regression equations based on TEE-pulse data from each activity type were developed to predict V̇o2max. TEE-pulse measured within each activity type of the laboratory protocol was highly correlated with V̇o2max (r from 0.74-0.91). Averaging the outcome of each activity-type specific equation based on TEE-pulse from the laboratory data led to accurate estimates of V̇o2max [root mean square error (RMSE): 300 mL O2/min, or 10%]. The difference between laboratory and free-living determined TEE-pulse was 3.7 ± 11% (r = 0.85). The prediction method preserved the prediction accuracy when applied to free-living data (RMSE: 367 mL O2/min, or 12%). Measurements of body acceleration and HR can be used to predict V̇o2max in daily life. Activity-specific prediction equations are needed to achieve highly accurate estimates of CRF.NEW & NOTEWORTHY This is among the very few studies validating, in free-living conditions, a method to estimate cardiorespiratory fitness using heart rate and body acceleration data. A novel parameter called TEE-pulse, which was defined as the ratio between accelerometer-determined energy expenditure and heart rate, was highly correlated with maximal oxygen uptake (V̇o2max). Activity classification and the use of activity-selective prediction equations outperformed previously published methods for estimating V̇o2max from heart rate and acceleration data.
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Affiliation(s)
- Alberto G Bonomi
- Patient Care and Measurements Department, Philips Research, Eindhoven, The Netherlands
| | - Gill A Ten Hoor
- Department of Work and Social Psychology, Maastricht University, Maastricht, The Netherlands
| | - Helma M de Morree
- Patient Care and Measurements Department, Philips Research, Eindhoven, The Netherlands
| | - Guy Plasqui
- Department of Nutrition and Movement Sciences, Maastricht University, Maastricht, The Netherlands
| | - Francesco Sartor
- Patient Care and Measurements Department, Philips Research, Eindhoven, The Netherlands.,College of Health and Behavioural Sciences, Bangor University, Bangor, United Kingdom
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Ghosh S, Hota M, Chai X, Kiranya J, Ghosh P, He Z, Ruiz-Ramie JJ, Sarzynski MA, Bouchard C. Exploring the underlying biology of intrinsic cardiorespiratory fitness through integrative analysis of genomic variants and muscle gene expression profiling. J Appl Physiol (1985) 2019; 126:1292-1314. [PMID: 30605401 PMCID: PMC6589809 DOI: 10.1152/japplphysiol.00035.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 11/02/2018] [Accepted: 12/09/2018] [Indexed: 12/22/2022] Open
Abstract
Intrinsic cardiorespiratory fitness (CRF) is defined as the level of CRF in the sedentary state. There are large individual differences in intrinsic CRF among sedentary adults. The physiology of variability in CRF has received much attention, but little is known about the genetic and molecular mechanisms that impact intrinsic CRF. These issues were explored in the present study by interrogating intrinsic CRF-associated DNA sequence variation and skeletal muscle gene expression data from the HERITAGE Family Study through an integrative bioinformatics guided approach. A combined analytic strategy involving genetic association, pathway enrichment, tissue-specific network structure, cis-regulatory genome effects, and expression quantitative trait loci was used to select and rank genes through a variation-adjusted weighted ranking scheme. Prioritized genes were further interrogated for corroborative evidence from knockout mouse phenotypes and relevant physiological traits from the HERITAGE cohort. The mean intrinsic V̇o2max was 33.1 ml O2·kg-1·min-1 (SD = 8.8) for the sample of 493 sedentary adults. Suggestive evidence was found for gene loci related to cardiovascular physiology (ATE1, CASQ2, NOTO, and SGCG), hematopoiesis (PICALM, SSB, CA9, and CASQ2), skeletal muscle phenotypes (SGCG, DMRT2, ADARB1, and CASQ2), and metabolism (ATE1, PICALM, RAB11FIP5, GBA2, SGCG, PRADC1, ARL6IP5, and CASQ2). Supportive evidence for a role of several of these loci was uncovered via association between DNA variants and muscle gene expression levels with exercise cardiovascular and muscle physiological traits. This initial effort to define the underlying molecular substrates of intrinsic CRF warrants further studies based on appropriate cohorts and study designs, complemented by functional investigations. NEW & NOTEWORTHY Intrinsic cardiorespiratory fitness (CRF) is measured in the sedentary state and is highly variable among sedentary adults. The physiology of variability in intrinsic cardiorespiratory fitness has received much attention, but little is known about the genetic and molecular mechanisms that impact intrinsic CRF. These issues were explored computationally in the present study, with further corroborative evidence obtained from analysis of phenotype data from knockout mouse models and human cardiovascular and skeletal muscle measurements.
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Affiliation(s)
- Sujoy Ghosh
- Human Genomics Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
- Cardiovascular and Metabolic Disorders Program and Centre for Computational Biology, Duke-National University of Singapore Medical School , Singapore
| | - Monalisa Hota
- Cardiovascular and Metabolic Disorders Program and Centre for Computational Biology, Duke-National University of Singapore Medical School , Singapore
| | - Xiaoran Chai
- Cardiovascular and Metabolic Disorders Program and Centre for Computational Biology, Duke-National University of Singapore Medical School , Singapore
| | - Jencee Kiranya
- Cardiovascular and Metabolic Disorders Program and Centre for Computational Biology, Duke-National University of Singapore Medical School , Singapore
| | - Palash Ghosh
- Center for Quantitative Medicine, Duke-National University of Singapore Medical School , Singapore
| | - Zihong He
- Human Genomics Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
- Department of Biology, China Institute of Sport Science , Beijing , China
| | - Jonathan J Ruiz-Ramie
- Department of Exercise Science, Arnold School of Public Health, University of South Carolina , Columbia, South Carolina
| | - Mark A Sarzynski
- Department of Exercise Science, Arnold School of Public Health, University of South Carolina , Columbia, South Carolina
| | - Claude Bouchard
- Human Genomics Laboratory, Pennington Biomedical Research Center , Baton Rouge, Louisiana
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Prediction of maximal oxygen consumption using the Young Men's Christian Association-step test in Korean adults. Eur J Appl Physiol 2019; 119:1245-1252. [PMID: 30850877 DOI: 10.1007/s00421-019-04115-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 02/27/2019] [Indexed: 01/29/2023]
Abstract
PURPOSE To develop accurate and practical prediction models of maximal oxygen consumption (VO2max) using the Young Men's Christian Association (YMCA)-step test in South Korean adults. METHODS In total, 568 adults (20-66 years) were included in this study. To develop and cross-validate prediction models of VO2max, the total sample was divided into 80% training and 20% testing using a simple random sampling method. VO2max was measured using the maximal-graded exercise treadmill test. Sex, age, 1-min recovery heart rate, body weight, and height were measured as potential predictors. Each test was conducted within a 2- to 3-day interval, ensuring sufficient rest. Preliminary prediction models were developed from training datasets, which were cross-validated using regression analyses and/or repeated-measures analysis of variance. The accuracy of prediction models was evaluated using R2, standard error of estimate (SEE), and mean difference (MD) against a criterion-measured VO2max. RESULTS The average age and VO2max were 43.5 ± 12.9 years and 39.1 ± 7.5 ml/kg/min, respectively. For model development, three practical models with acceptable accuracy were developed (R2 = 0.56-0.61; SEE = 4.74-5.01). For model cross-validation, significant relationships between the criterion-measured and predicted VO2max were observed in all three models (R2 = 0.56-0.61; SEE = 4.62-4.88). The difference between criterion-measured and predicted VO2max was not significant in the models (MD =- 0.03 to - 0.14). CONCLUSIONS The prediction models included 3-5 variables as significant predictors of VO2max and had acceptable accuracy in a large sample of South Korean adults. The selected models provide a simple and practical method to estimate VO2max using the YMCA-step test for South Korean adults.
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10
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Carter SJ, Hunter GR, Norian LA, Turan B, Rogers LQ. Ease of walking associates with greater free-living physical activity and reduced depressive symptomology in breast cancer survivors: pilot randomized trial. Support Care Cancer 2017; 26:1675-1683. [PMID: 29243165 DOI: 10.1007/s00520-017-4015-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 12/05/2017] [Indexed: 12/25/2022]
Abstract
PURPOSE We hypothesized exercise training-induced improvements in ease of walking would associate with favorable changes in objectively measured physical activity (PA) and self-reported depressive symptoms following a PA behavior-change intervention in non-metastatic breast cancer survivors (BCS). METHODS Twenty-seven BCS received random assignment to an intervention (INT) or control group (CON). INT included counseling/group discussions coupled with supervised exercise tapered to unsupervised exercise. PA, depressive symptoms, and ease of walking were evaluated pre-/post-intervention using 10-day accelerometry, HADS depression subscale, and indirect calorimetry during a standardized treadmill test, respectively. PA composite score was calculated by converting weekly minutes of moderate-to-vigorous PA and average steps/day to z-scores then dividing the sum by 2. Cardiac efficiency was determined by dividing steady-state oxygen uptake by heart rate to evaluate the volume of oxygen consumed per heartbeat. RESULTS ANCOVA revealed a significant time by group interaction showing the INT group exhibited greater positive changes in the PA composite compared to the CON (INT, + 0.14 ± 0.66 au vs. CON, - 0.48 ± 0.49 au; p = 0.019; η p2 = 0.21). Changes occurring from baseline to follow-up, among all participants, revealed improved ease of walking (less oxygen uptake) associated with increased PA composite (r = - 0.52; p = 0.010) and lower depressive symptomology (r = 0.50; p = 0.012) adjusted for age, race, and months since cancer diagnosis. Increased cardiac efficiency during the standardized treadmill test also associated with less daily sedentary time (r = - 0.52; p = 0.021). CONCLUSIONS These data support the assertion that reducing the physiological difficulty of walking may contribute to greater engagement in free-living PA, less sedentary time, and decreased psychosocial distress among BCS.
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Affiliation(s)
- Stephen J Carter
- Department of Nutrition Sciences, University of Alabama at Birmingham, 1675 University Blvd, Webb Building #248, Birmingham, AL, 35233-2432, USA.
| | - Gary R Hunter
- Department of Nutrition Sciences, University of Alabama at Birmingham, 1675 University Blvd, Webb Building #248, Birmingham, AL, 35233-2432, USA.,Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Lyse A Norian
- Department of Nutrition Sciences, University of Alabama at Birmingham, 1675 University Blvd, Webb Building #248, Birmingham, AL, 35233-2432, USA
| | - Bulent Turan
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Laura Q Rogers
- Department of Nutrition Sciences, University of Alabama at Birmingham, 1675 University Blvd, Webb Building #248, Birmingham, AL, 35233-2432, USA
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11
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Gammon C, Pfeiffer KA, Kazanis A, Ling J, Robbins LB. Cardiorespiratory fitness in urban adolescent girls: associations with race and pubertal status. J Sports Sci 2016; 35:29-34. [PMID: 26942487 DOI: 10.1080/02640414.2016.1154594] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Cardiorespiratory fitness affords health benefits to youth. Among females, weight-relative fitness declines during puberty and is lower among African American (AA) than Caucasian girls. Data indicate racial differences in pubertal timing and tempo, yet the interactive influence of puberty and race on fitness, and the role of physical activity (PA) in these associations have not been examined. Thus, independent and interactive associations of race and pubertal development with fitness in adolescent girls, controlling for PA were examined. Girls in grades 5-8 (n = 1011; Caucasian = 25.2%, AA = 52.3%, Other Race group = 22.5%) completed the Pubertal Development Scale (pubertal stage assessment) and Fitnessgram® Progressive Aerobic Cardiovascular Endurance Run (PACER) test (cardiorespiratory fitness assessment). PA was assessed by accelerometry. Bivariate and multivariate analyses were used to examine associations among race, pubertal stage and fitness, controlling for vigorous PA, AA, and pubertally advanced girls demonstrated lower fitness than Caucasian and less mature counterparts. Puberty and race remained significantly associated with fitness after controlling for vigorous PA. The interaction effect of race and puberty on fitness was non-significant. The pubertal influence on fitness is observed among AA adolescents. Associations between fitness and race/puberty appear to be independent of each other and vigorous PA. Pubertally advanced AA girls represent a priority group for fitness interventions.
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Affiliation(s)
- Catherine Gammon
- a Department of Kinesiology , Michigan State University , East Lansing , MI , USA
| | - Karin A Pfeiffer
- a Department of Kinesiology , Michigan State University , East Lansing , MI , USA
| | - Anamaria Kazanis
- b College of Nursing , Michigan State University , East Lansing , MI , USA.,c School of Health Sciences , Oakland University , Rochester , MI , USA
| | - Jiying Ling
- b College of Nursing , Michigan State University , East Lansing , MI , USA
| | - Lorraine B Robbins
- b College of Nursing , Michigan State University , East Lansing , MI , USA
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Arad AD, DiMenna FJ, Thomas N, Tamis-Holland J, Weil R, Geliebter A, Albu JB. High-intensity interval training without weight loss improves exercise but not basal or insulin-induced metabolism in overweight/obese African American women. J Appl Physiol (1985) 2015; 119:352-62. [PMID: 26112241 DOI: 10.1152/japplphysiol.00306.2015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/22/2015] [Indexed: 12/20/2022] Open
Abstract
The purpose of this randomized controlled clinical trial was to determine the effect of a 14-week high-intensity interval training (HIIT) intervention with weight stability on metabolic flexibility, insulin sensitivity, and cardiorespiratory fitness in sedentary, premenopausal, nondiabetic, overweight/obese African American women. Twenty-eight subjects were allocated to one of two groups: HIIT, which performed three sessions per week of four high-intensity cycling intervals, or a control group (CON), which maintained their normal level of physical activity. Diet was controlled for all subjects to ensure weight stability. Pre- and postintervention (pre/post), subjects completed an incremental cycling test to limit of tolerance and, following a 10-day high-fat controlled feeding period, a euglycemic-hyperinsulinemic clamp to determine insulin sensitivity and substrate oxidation. Nine members of HIIT (age, 29 ± 4 yr; body mass, 90.1 ± 13.8 kg) and eleven members of CON (age, 30 ± 7 yr; body mass, 85.5 ± 10.7 kg) completed the study. HIIT experienced an increased limit of tolerance (post, 1,124 ± 202 s; pre, 987 ± 146 s; P < 0.05), gas exchange threshold (post, 1.29 ± 0.34 liters/min; pre, 0.97 ± 0.23 liters/min; P < 0.05), and fat oxidation at the same absolute submaximal work rate compared with CON (P < 0.05 for group-by-time interaction in all cases). However, changes in peak oxygen consumption (V̇o2peak), insulin sensitivity, free fatty acid suppression during insulin stimulation, and metabolic flexibility were not different in HIIT compared with CON. High-intensity interval training with weight stability increased exercise fat oxidation and tolerance in subjects at risk for diabetic progression, but did not improve insulin sensitivity or fat oxidation in the postabsorptive or insulin-stimulated state.
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Affiliation(s)
- Avigdor D Arad
- The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and
| | - Fred J DiMenna
- Teachers College, Department of Biobehavioral Sciences, Columbia University, New York, New York
| | - Naketa Thomas
- The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and
| | - Jacqueline Tamis-Holland
- The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and
| | - Richard Weil
- The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and
| | - Allan Geliebter
- The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and
| | - Jeanine B Albu
- The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and
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Associations of objectively measured sedentary behavior, light activity, and markers of cardiometabolic health in young women. Eur J Appl Physiol 2014; 114:907-19. [PMID: 24463602 DOI: 10.1007/s00421-014-2822-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 01/09/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate the associations among objectively measured sedentary behavior, light physical activity, and markers of cardiometabolic health in young women. METHODS Cardiovascular disease risk factors, homeostasis model assessment for insulin resistance (HOMA-IR), lipid accumulation product, and inflammatory markers were measured in 50 young, adult women. Accelerometers were worn over 7 days to assess sedentary time (<150 counts min(-1)), light physical activity (150-2,689 counts min(-1)), and moderate-to-vigorous physical activity (MVPA; ≥2,690 counts min(-1)). Multivariate regression examined independent associations of sedentary behavior and light physical activity with cardiometabolic health. Covariates included MVPA, cardiorespiratory fitness (VO2peak) and body mass, and body composition. RESULTS Sedentary behavior was associated with triglycerides (p = 0.03) and lipid accumulation product (p = 0.02) independent of MVPA. These associations were attenuated by VO2peak and body mass or body composition (p ≥ 0.05). Light physical activity was independently associated with triglycerides and lipid accumulation product after adjustment for all covariates (p < 0.05). The association between light physical activity and HOMA-IR was independent of MVPA (p = 0.02) but was attenuated by VO2peak and body mass or body composition (p > 0.05). CONCLUSIONS Sedentary behavior and light physical activity were independently associated with markers of cardiometabolic health in young, adult women. Our data suggest that VO2peak and body composition may be important mediators of these associations. Decreasing sedentary behavior and increasing light physical activity may be important for maintaining cardiometabolic health in young, adult women.
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Willig AL, Hunter GR, Casazza K, Heimburger DC, Beasley TM, Fernandez JR. Body fat and racial genetic admixture are associated with aerobic fitness levels in a multiethnic pediatric population. Obesity (Silver Spring) 2011; 19:2222-7. [PMID: 21546928 PMCID: PMC3182292 DOI: 10.1038/oby.2011.109] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Aerobic fitness and adiposity are each independently associated with health outcomes among children, although the relationship between these two variables is unclear. Our objectives were to evaluate (i) the association of adiposity with aerobic fitness using objectively measured levels of percent body fat, compared to BMI as a percentile proxy for adiposity while controlling for genetic admixture, and (ii) the congruence of BMI categories with high and low body fat categories of objectively measured percent body fat. Participants were 232 African-American (AA), European-American (EA), and Hispanic-American (HA) children aged 7-12 years (Tanner stage <3). Aerobic fitness was measured via a submaximal indirect calorimetry treadmill test (VO(2-170)), and physical activity levels with accelerometry. Genetic admixture estimates were obtained using 140 genetic ancestry informative markers to estimate European, African, and Amerindian admixture. Fat mass was determined using dual-energy x-ray absorptiometry (DXA). Children were classified into a low body fat group (<25% in males, <30% in females) or a high body fat group based on their percent body fat; children were also categorized according to BMI percentile. Children in the low body fat group had significantly higher aerobic fitness (P < 0.05) regardless of BMI percentile classification. Higher African genetic admixture was associated with lower aerobic fitness (P < 0.05), while physical activity was positively associated with fitness (P < 0.01). In conclusion, aerobic fitness levels differ by percent body fat and genetic admixture irrespective of BMI classification, and such differences should be taken into account when evaluating outcomes of health interventions.
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Affiliation(s)
- Amanda L Willig
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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Siegfried CJ, Shui YB, Holekamp NM, Bai F, Beebe DC. Racial differences in ocular oxidative metabolism: implications for ocular disease. ACTA ACUST UNITED AC 2011; 129:849-54. [PMID: 21746975 DOI: 10.1001/archophthalmol.2011.169] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To compare the Po(2) distribution in different regions in the eyes of patients undergoing intraocular surgery. METHODS Before initiation of intraocular cataract and/or glaucoma surgery, an optical oxygen sensor was introduced into the anterior chamber via a peripheral corneal paracentesis. The tip of the flexible fiberoptic probe was positioned by the surgeon for 3 measurements in all patients: (1) near the central corneal endothelium, (2) in the mid-anterior chamber, and (3) in the anterior chamber angle. In patients scheduled to undergo cataract extraction, Po(2) was also measured (4) at the anterior lens surface and (5) in the posterior chamber just behind the iris. Oxygen measurements at the 5 locations were compared using a 2-tailed unpaired t test and multivariate regression. RESULTS The Po(2) value was significantly higher in African American patients at all 5 locations compared with Caucasian patients. Adjusting for age increased the significance of this association. Adjusting for race revealed that age was associated with increased Po(2) beneath the central cornea. CONCLUSIONS Racial differences in oxygen levels in the human eye reflect an important difference in oxidative metabolism in the cornea and lens and may reflect differences in systemic physiologic function. Increased oxygen or oxygen metabolites may increase oxidative stress, cell damage, intraocular pressure, and the risk of developing glaucoma. Oxygen use by the cornea decreases with age.
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Affiliation(s)
- Carla J Siegfried
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, MO 63110, USA.
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16
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Lai N, Tolentino-Silva F, Nasca MM, Silva MA, Gladden LB, Cabrera ME. Exercise intensity and oxygen uptake kinetics in African-American and Caucasian women. Eur J Appl Physiol 2011; 112:973-82. [PMID: 21717119 DOI: 10.1007/s00421-011-2054-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 06/18/2011] [Indexed: 11/24/2022]
Abstract
The effect of exercise intensity on the on- and off-transient kinetics of oxygen uptake (VO(2)) was investigated in African American (AA) and Caucasian (C) women. African American (n = 7) and Caucasian (n = 6) women of similar age, body mass index and weight, performed an incremental test and bouts of square-wave exercise at moderate, heavy and very heavy intensities on a cycle ergometer. Gas exchange threshold (LT(GE)) was lower in AA (13.6 ± 2.3 mL kg(-1) min(-1)) than C (18.6 ± 5.6 mL kg(-1) min(-1)). The dynamic exercise and recovery VO(2) responses were characterized by mathematical models. There were no significant differences in (1) peak oxygen uptake (VO(2peak)) between AA (28.5 ± 5 mL kg(-1) min(-1)) and C (31.1 ± 6.6 mL kg(-1) min(-1)) and (2) VO(2) kinetics at any exercise intensity. At moderate exercise, the on- and off- VO(2) kinetics was described by a monoexponential function with similar time constants τ (1,on) (39.4 ± 12.5; 38.8 ± 15 s) and τ (1,off) (52.7 ± 10.1; 40.7 ± 4.4 s) for AA and C, respectively. At heavy and very heavy exercise, the VO(2) kinetics was described by a double-exponential function. The parameter values for heavy and very heavy exercise in the AA group were, respectively: τ (1,on) (47.0 ± 10.8; 44.3 ± 10 s), τ (2,on) (289 ± 63; 219 ± 90 s), τ (1,off) (45.9 ± 6.2; 50.7 ± 10 s), τ (2,off) (259 ± 120; 243 ± 93 s) while in the C group were, respectively: τ (1,on) (41 ± 12; 43.2 ± 15 s); τ (2, on) (277 ± 81; 215 ± 36 s), τ (1,off) (40.2 ± 3.4; 42.3 ± 7.2 s), τ (2,off) (215 ± 133; 228 ± 64 s). The on- and off-transients were symmetrical with respect to model order and dependent on exercise intensity regardless of race. Despite similar VO(2) kinetics, LT(GE) and gain of the VO(2) on-kinetics at moderate intensity were lower in AA than C. However, generalization to the African American and Caucasian populations is constrained by the small subject numbers.
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Affiliation(s)
- Nicola Lai
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Wickenden Bldg. Rm 524, Cleveland, OH 44106-7207, USA.
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Casazza K, Willig AL, Gower BA, Nagy TR, Hunter GR, Wallace S, Amaya M, Franklin F, Beasley M, Fernandez JR. The role of European genetic admixture in the etiology of the insulin resistance syndrome in children: are the effects mediated by fat accumulation? J Pediatr 2010; 157:50-56.e1. [PMID: 20304426 PMCID: PMC3119818 DOI: 10.1016/j.jpeds.2010.01.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 11/24/2009] [Accepted: 01/26/2010] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To evaluate the contribution of European genetic admixture (EUADM) to insulin resistance syndrome (IRS) in a multiethnic sample of children age 7-12 years, and to explore whether body fat affects this relationship. STUDY DESIGN Anthropometric measurements and blood pressure were assessed in 243 children. After an overnight fast, an intravenous glucose tolerance test was conducted, and measures of fasting insulin/glucose, lipids, insulin sensitivity (SI), and acute insulin response to glucose (AIRg) were obtained. The proportion of EUADM was determined by maximum likelihood estimation using 140 ancestry informative markers. Subjects were stratified into tertiles according to the proportion of EUADM for analyses. Subjects were categorized as lean or obese using body fat percentage cutpoints (25% in boys, 30% in girls). RESULTS Among lean subjects (72%), the tertile representing the greatest proportion of EUADM was associated with higher SI (P<.001) and serum glucose (P<.05) and lower insulin (P<.05), AIRg (P<.001), high-density lipoprotein cholesterol (P=.05), and blood pressure (P<.05). However, among obese subjects, EUADM was associated only with SI (P<.05). CONCLUSIONS Our results suggest that population differences in IRS likely have a genetic component, but that the influence of genetic background may be masked by obesity.
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Affiliation(s)
- Krista Casazza
- Department of Nutrition Sciences and Clinical Nutrition Research Center, University of Alabama at Birmingham, Birmingham, AL
| | - Amanda L. Willig
- Department of Nutrition Sciences and Clinical Nutrition Research Center, University of Alabama at Birmingham, Birmingham, AL
| | - Barbara A. Gower
- Department of Nutrition Sciences and Clinical Nutrition Research Center, University of Alabama at Birmingham, Birmingham, AL
| | - Tim R. Nagy
- Department of Nutrition Sciences and Clinical Nutrition Research Center, University of Alabama at Birmingham, Birmingham, AL
| | - Gary R. Hunter
- Department of Education and Clinical Nutrition Research Center, University of Alabama at Birmingham, Birmingham, AL
| | - Stephenie Wallace
- Department of Pediatrics and Clinical Nutrition Research Center, University of Alabama at Birmingham, Birmingham, AL
| | - Mia Amaya
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC
| | - Frank Franklin
- Department of Health Behaviors, University of Alabama at Birmingham, Birmingham, AL
| | - Mark Beasley
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL
| | - Jose R. Fernandez
- Department of Nutrition Sciences and Clinical Nutrition Research Center, University of Alabama at Birmingham, Birmingham, AL,Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL
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A conserved role for syndecan family members in the regulation of whole-body energy metabolism. PLoS One 2010; 5:e11286. [PMID: 20585652 PMCID: PMC2890571 DOI: 10.1371/journal.pone.0011286] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Accepted: 06/02/2010] [Indexed: 01/02/2023] Open
Abstract
Syndecans are a family of type-I transmembrane proteins that are involved in cell-matrix adhesion, migration, neuronal development, and inflammation. Previous quantitative genetic studies pinpointed Drosophila Syndecan (dSdc) as a positional candidate gene affecting variation in fat storage between two Drosophila melanogaster strains. Here, we first used quantitative complementation tests with dSdc mutants to confirm that natural variation in this gene affects variability in Drosophila fat storage. Next, we examined the effects of a viable dSdc mutant on Drosophila whole-body energy metabolism and associated traits. We observed that young flies homozygous for the dSdc mutation had reduced fat storage and slept longer than homozygous wild-type flies. They also displayed significantly reduced metabolic rate, lower expression of spargel (the Drosophila homologue of PGC-1), and reduced mitochondrial respiration. Compared to control flies, dSdc mutants had lower expression of brain insulin-like peptides, were less fecund, more sensitive to starvation, and had reduced life span. Finally, we tested for association between single nucleotide polymorphisms (SNPs) in the human SDC4 gene and variation in body composition, metabolism, glucose homeostasis, and sleep traits in a cohort of healthy early pubertal children. We found that SNP rs4599 was significantly associated with resting energy expenditure (P = 0.001 after Bonferroni correction) and nominally associated with fasting glucose levels (P = 0.01) and sleep duration (P = 0.044). On average, children homozygous for the minor allele had lower levels of glucose, higher resting energy expenditure, and slept shorter than children homozygous for the common allele. We also observed that SNP rs1981429 was nominally associated with lean tissue mass (P = 0.035) and intra-abdominal fat (P = 0.049), and SNP rs2267871 with insulin sensitivity (P = 0.037). Collectively, our results in Drosophila and humans argue that syndecan family members play a key role in the regulation of body metabolism.
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Abstract
The objectives of this study were to identify the independent effect of physical activity and fitness on insulin dynamics in a cohort of European-, African-, and Hispanic-American children (n = 215) age 7-12 years and to determine if racial/ethnic in insulin dynamics could be statistically explained by racial/ethnic differences in physical activity or fitness. An intravenous glucose tolerance test and minimal modeling were used to derive the insulin sensitivity index (SI) and acute insulin response to glucose (AIRg). Fitness was assessed as VO2-170 and physical activity by accelerometer. Multiple regression models were tested for contributions of fitness and physical activity to SI and AIRg. Fitness was a stronger predictor of SI and AIRg than physical activity regardless of ethnicity; racial/ethnic differences in insulin dynamics were not accounted for by differences in fitness and/or physical activity.
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Hunter GR, Byrne NM, Sirikul B, Fernández JR, Zuckerman PA, Darnell BE, Gower BA. Resistance training conserves fat-free mass and resting energy expenditure following weight loss. Obesity (Silver Spring) 2008; 16:1045-51. [PMID: 18356845 DOI: 10.1038/oby.2008.38] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To determine what effect diet-induced approximately 12 kg weight loss in combination with exercise training has on body composition and resting energy expenditure (REE) in premenopausal African-American (AA) and European-American (EA) women. METHODS AND PROCEDURES This study was a longitudinal, randomized weight loss clinical intervention, with either aerobic (AT), resistance (RT), or no exercise training (NT). Forty-eight AA and forty-six EA premenopausal overweight (BMI between 27 and 30) women underwent weight loss to a BMI<25. Body composition (densitometry), REE (indirect calorimetry), maximal oxygen uptake (VO2max), and muscular strength (isometric elbow flexion) were evaluated when subjects were in energy balance. RESULTS AA women lost less fat-free mass (FFM, P<or=0.05) (47.0+/-4.6 to 46.9+/-5.0 kg) than EA women (46.4+/-4.9 to 45.2+/-4.6 kg). Regardless of race, RT maintained FFM (P<or=0.05) following weight loss (46.9+/-5.2 to 47.2+/-5.0 kg) whereas AT (45.4+/-4.2 to 44.4+/-4.1 kg) and NT (47.9+/-4.7 to 46.4+/-5.1 kg) decreased FFM (P<or=0.05). Both AT and NT decreased in REE with weight loss but RT did not. Significant time by group interactions (all P<or=0.05) for strength indicated that RT maintained strength and AT did not. DISCUSSION AA women lost less FFM than EA women during equivalent weight losses. However, following weight loss in both AA and EA, RT conserved FFM, REE, and strength fitness when compared to women who AT or did not train.
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Affiliation(s)
- Gary R Hunter
- Department of Human Studies, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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Blaudeau TE, Hunter GR, St-Onge MP, Gower BA, Roy JLP, Bryan DR, Zuckerman PA, Darnell BE. IAAT, catecholamines, and parity in African-American and European-American women. Obesity (Silver Spring) 2008; 16:797-803. [PMID: 18239569 DOI: 10.1038/oby.2007.137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE We have recently reported that parous European-American (EA) women have disproportionately more intra-abdominal adipose tissue (IAAT) than their nulliparous counterparts. Mediating mechanisms for IAAT accumulation remain unknown; however, some evidence suggests a possible catecholamine link. The objective of this study was to determine whether the IAAT-parity relationship found in EA women exists in African-American (AA) women and to determine whether catecholamines play a mediating role. METHODS AND PROCEDURES Subjects included 44 EA and 47 AA premenopausal women. Free-living physical activity by doubly labeled water (activity-related time equivalent (ARTE)), body composition (air plethysmography, computed tomography), and 24-h fractionated urinary catecholamines were measured. RESULTS Repeated measures ANOVA revealed parous EA and AA women had significantly higher IAAT than their nulliparous counterparts (100.1 +/- 28.5 and 76.2 +/- 34.8 cm(2) vs. 75.9 +/- 29.1 and 59.6 +/- 15.0 cm(2)). In AA women and nulliparous women, 24-h urinary dopamine was significantly higher (AA parous 260.8 +/- 88; EA parous 197.2 +/- 78.8; AA nulliparous 376.5 +/- 81; EA nulliparous 289.6 +/- 62). Multiple regression analysis for modeling IAAT indicated that race, parity, dopamine, ARTE, and VO(2max) were all significant and independent contributors to the model (Unstandardized betas: race -32.6 +/- 7.4; parity (number of births) 10.0 +/- 3.4; 24-h urinary dopamine 0.08 +/- 0.04; ARTE (min/day) -0.09 +/- 0.04; VO(2max) (ml/kg/min) -2.8 +/- 1.0). DISCUSSION Independent of the potential confounders: age, race, percent body fat, IAAT, 24-h fractionated urinary catecholamines, physical activity, and VO(2max), parous EA and AA women had more IAAT than their nulliparous counterparts. Of the catecholamines, dopamine was found to be significantly lower in parous women and higher in AA's. Dopamine, however, did not explain racial or parity differences in IAAT.
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Affiliation(s)
- Tamilane E Blaudeau
- Department of Human Studies, University of Alabama at Birmingham, Birmingham, Alabama, USA.
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