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van der Spoel E, Roelfsema F, van Heemst D. Relationships Between 24-hour LH and Testosterone Concentrations and With Other Pituitary Hormones in Healthy Older Men. J Endocr Soc 2021; 5:bvab075. [PMID: 34337275 PMCID: PMC8315483 DOI: 10.1210/jendso/bvab075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Indexed: 12/04/2022] Open
Abstract
Objective To investigate the relationship between LH and testosterone (T), which characteristics associate with the strength of this relationship, and their interrelationships with GH, TSH, cortisol, and ACTH. Design Hormones were measured in serum samples collected every 10 minutes during 24 hours from 20 healthy men, comprising 10 offspring of long-lived families and 10 control subjects, with a mean (SD) age of 65.6 (5.3) years. We performed cross-correlation analyses to assess the relative strength between 2 timeseries for all possible time shifts. Results Mean (95% CI) maximal correlation was 0.21 (0.10-0.31) at lag time of 60 minutes between LH and total T concentrations. Results were comparable for calculated free, bioavailable, or secretion rates of T. Men with strong LH-T cross-correlations had, compared with men with no cross-correlation, lower fat mass (18.5 [14.9-19.7] vs. 22.3 [18.4-29.4] kg), waist circumference (93.6 [5.7] vs. 103.1 [12.0] cm), high-sensitivity C-reactive protein (0.7 [0.4-1.3] vs. 1.8 [0.8-12.3] mg/L), IL-6 (0.8 [0.6-1.0] vs. 1.2 [0.9-3.0] pg/mL), and 24-hour mean LH (4.3 [2.0] vs. 6.1 [1.5] U/L), and stronger LH-T feedforward synchrony (1.5 [0.3] vs. 1.9 [0.2]). Furthermore, T was positively cross-correlated with TSH (0.32 [0.21-0.43]), cortisol (0.26 [0.19-0.33]), and ACTH (0.26 [0.19-0.32]). Conclusions LH is followed by T with a delay of 60 minutes in healthy older men. Men with a strong LH-T relationship had more favorable body composition, inflammatory markers, LH levels, and LH-T feedforward synchrony. We observed positive correlations between T and TSH, cortisol, and ACTH.
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Affiliation(s)
- Evie van der Spoel
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Ferdinand Roelfsema
- Section Endocrinology, Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Diana van Heemst
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
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O'Byrne NA, Yuen F, Butt WZ, Liu PY. Sleep and Circadian Regulation of Cortisol: A Short Review. CURRENT OPINION IN ENDOCRINE AND METABOLIC RESEARCH 2021; 18:178-186. [PMID: 35128146 DOI: 10.1016/j.coemr.2021.03.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The central circadian pacemaker (CCP) located in the suprachiasmatic nucleus (SCN) of the hypothalamus drives the 24-hour pattern in cortisol, which functions as the main central synchronizing signal that coordinates peripheral clocks in organs that control whole body metabolism. A superimposed pulsatile pattern of cortisol allows rapid responses that fine tune the body's reaction to changes in the environment. In addition to coordinating metabolic processes to predictable environmental events, cortisol is the main catabolic signal which acts with testosterone, the quintessential male anabolic hormone, to maintain catabolic-anabolic homeostasis in men. Sleep restriction, when sufficiently substantial, increases late afternoon/early evening cortisol, but does not alter 24-hour cortisol; whereas even maximal acute circadian misalignment only slightly delays the cortisol rhythm. Prolonged circadian misalignment decreases overall cortisol exposure. The implications of these regulatory changes on health and disease requires further evaluation.
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Affiliation(s)
- Nora A O'Byrne
- The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Fiona Yuen
- The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Waleed Z Butt
- The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Peter Y Liu
- The Lundquist Institute at Harbor-UCLA Medical Center, Torrance, CA.,Department of Medicine, Division of Endocrinology, David Geffen School of Medicine at UCLA
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van der Spoel E, Roelfsema F, Akintola AA, Jansen SW, Slagboom PE, Westendorp RGJ, Blauw GJ, Pijl H, van Heemst D. Interrelationships Between Pituitary Hormones as Assessed From 24-hour Serum Concentrations in Healthy Older Subjects. J Clin Endocrinol Metab 2020; 105:5680671. [PMID: 31853555 PMCID: PMC7065845 DOI: 10.1210/clinem/dgz253] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 12/17/2019] [Indexed: 12/17/2022]
Abstract
CONTEXT Hormones of the hypothalamic-pituitary-target gland axes are mostly investigated separately, whereas the interplay between hormones might be as important as each separate hormonal axis. OBJECTIVE Our aim is to determine the interrelationships between GH, TSH, ACTH, and cortisol in healthy older individuals. DESIGN We made use of 24-hour hormone serum concentrations assessed with intervals of 10 minutes from 38 healthy older individuals with a mean age (SD) of 65.1 (5.1) years from the Leiden Longevity Study. Cross-correlation analyses were performed to assess the relative strength between 2 24-hour hormone serum concentration series for all possible time shifts. Cross-approximate entropy was used to assess pattern synchronicity between 2 24-hour hormone serum concentration series. RESULTS Within an interlinked hormonal axis, ACTH and cortisol were positively correlated with a mean (95% confidence interval) correlation coefficient of 0.78 (0.74-0.81) with cortisol following ACTH concentrations with a delay of 10 minutes. Between different hormonal axes, we observed a negative correlation coefficient between cortisol and TSH of -0.30 (-0.36 to -0.25) with TSH following cortisol concentrations with a delay of 170 minutes. Furthermore, a positive mean (95% confidence interval) correlation coefficient of 0.29 (0.22-0.37) was found between TSH and GH concentrations without any delay. Moreover, cross-approximate entropy analyses showed that GH and cortisol exhibit synchronous serum concentration patterns. CONCLUSIONS This study demonstrates that interrelations between hormones from interlinked as well as different hypothalamic-pituitary-target gland axes are observed in healthy older individuals. More research is needed to determine the biological meaning and clinical consequences of these observations.
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Affiliation(s)
- Evie van der Spoel
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, RC Leiden, The Netherlands
- Correspondence and Reprint Requests: Evie van der Spoel, Section Gerontology and Geriatrics, Department of Internal, Medicine, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, The Netherlands. E-mail:
| | - Ferdinand Roelfsema
- Section Endocrinology, Department of Internal Medicine, Leiden University Medical Center, RC Leiden, The Netherlands
| | - Abimbola A Akintola
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, RC Leiden, The Netherlands
| | - Steffy W Jansen
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, RC Leiden, The Netherlands
| | - P Eline Slagboom
- Section Molecular Epidemiology, Department of Biomedical Data Sciences, Leiden University Medical Center, RC Leiden The Netherlands
| | - Rudi G J Westendorp
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, RC Leiden, The Netherlands
- Department of Public Health, Center of Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Gerard J Blauw
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, RC Leiden, The Netherlands
| | - Hanno Pijl
- Section Endocrinology, Department of Internal Medicine, Leiden University Medical Center, RC Leiden, The Netherlands
| | - Diana van Heemst
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, RC Leiden, The Netherlands
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Roelfsema F, Liu PY, Takahashi PY, Yang RJ, Veldhuis JD. Dynamic Interactions Between LH and Testosterone in Healthy Community-Dwelling Men: Impact of Age and Body Composition. J Clin Endocrinol Metab 2020; 105:5650390. [PMID: 31790144 PMCID: PMC7025815 DOI: 10.1210/clinem/dgz246] [Citation(s) in RCA: 7] [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] [Received: 06/09/2019] [Accepted: 11/30/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Aging is associated with diminished testosterone (Te) secretion, which may be attributed to Leydig cell dysfunction, decreased pituitary stimulation, and altered Te feedback. OBJECTIVE To study all regulatory nodes-gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and Leydig cell-in the same cohort of healthy men. STUDY DESIGN This was a placebo-controlled, blinded, prospectively randomized cross-over study in 40 men, age range 19 to 73 years, and body mass index (BMI) range 20 to 34.3 kg/m2. A submaximal dose of the GnRH antagonist ganirelix was used to assess outflow of GnRH, by calculating the difference between LH output during the control arm and ganirelix arm. Ketoconazole (a steroidogenic inhibitor) was used to estimate feedback, by the difference in LH output during the ketoconazole and control arm. High-dose ganirelix and repeated LH infusions were used to measure testicular responsivity. Blood sampling was performed at 10-minute intervals. RESULTS There were age-related, but not body composition-related decreases in estimated GnRH secretion, the feedback strength of Te on LH, and Leydig cell responsivity to LH, accompanied by changes in approximate entropy. Bioavailable Te levels were negatively related to both age and computed tomography (CT)-estimated abdominal visceral mass (AVF), without interaction between these variables. The LH response to a submaximal dose of GnRH was independent of age and AVF. CONCLUSION Advancing age is associated with (1) attenuated bioavailable Te secretion caused by diminished GnRH outflow and not by decreased GnRH responsivity of the gonadotrope, (2) diminished testicular responsivity to infused LH pulses, and (3) partial compensation by diminished Te feedback on central gonadotropic regulation.
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Affiliation(s)
- Ferdinand Roelfsema
- Department of Internal Medicine, Section Endocrinology and Metabolism, Leiden University Medical Center, Leiden, The Netherlands
| | - Peter Y Liu
- Department of Medicine, David Geffen School of Medicine at UCLA, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Los Angeles, California
| | - Paul Y Takahashi
- Department of Primary Care Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Rebecca J Yang
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota
| | - Johannes D Veldhuis
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota
- Correspondence: Johannes Veldhuis, MD, Endocrine Research Unit, Mayo Clinic, 200 First Street SW, Rochester, MN 55906, USA. Email
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Roelfsema F, Yang RJ, Bowers CY, Veldhuis JD. Modulating Effects of Progesterone on Spontaneous Nocturnal and Ghrelin-Induced GH Secretion in Postmenopausal Women. J Clin Endocrinol Metab 2019; 104:2385-2394. [PMID: 30721950 PMCID: PMC6505453 DOI: 10.1210/jc.2018-02639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 01/31/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Oral administration of estradiol (E2) generally increases GH secretion in postmenopausal women. Oral administration of E2 is associated with a decrease in IGF-1, whereas parenteral or transdermally administered E2 may have no effect on GH. The effect of progesterone (P4) on GH secretion has rarely been studied. We hypothesized that moderately increased serum E2 levels stimulate GH and that P4 modulates E2-stimulated GH secretion. STUDY DESIGN Four parallel groups of randomly assigned postmenopausal women (n = 40). Treatments were saline placebo and oral placebo, saline placebo and oral micronized P4 (3 × 200 mg/d IM), E2 (5 mg IM) and oral placebo, and E2 IM and oral micronized P4. Outcome measures were overnight GH secretion (10 hours), stimulated (ghrelin, 0.3 µg/kg IV bolus) GH secretion, and CT-estimated visceral fat. RESULTS Intramuscular E2 administration did not alter nocturnal and ghrelin-stimulated GH secretion. Nocturnal GH secretion was not changed by P4 administration. However, P4 diminished ghrelin-stimulated pulsatile GH release with or without E2 (average, 7.20 ± 2.14 and 9.58 ± 1.97 µg/L/2 h, respectively; P = 0.045). Respective outcomes for mean GH concentrations and GH peak amplitudes were 0.97 ± 0.31 and 1.52 μg/L ± 0.29 (P = 0.025) and 2.76 ± 1.04 and 3.95 μg/L ± 0.90 (P = 0.031). Ghrelin-stimulated GH secretion correlated negatively with P4 concentration with or without correction for visceral fat area in the regression equation (R = 0.49, P = 0.04, β = -0.040 ± 0.016). CONCLUSIONS Low-range physiological E2 concentrations do not affect spontaneous or ghrelin-stimulated pulsatile GH secretion. Conversely, P4 inhibits ghrelin-stimulated GH secretion in a concentration-dependent fashion. The mechanistic aspects and physiological significance of natural P4's regulation of ghrelin-evoked GH secretion require further study.
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Affiliation(s)
- Ferdinand Roelfsema
- Department of Internal Medicine, Section of Endocrinology and Metabolism, Leiden University Medical Center, Leiden, Netherlands
| | - Rebecca J Yang
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota
| | - Cyril Y Bowers
- Department of Internal Medicine, Endocrine Division, Tulane University Health Sciences Center, New Orleans, Louisiana
| | - Johannes D Veldhuis
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota
- Correspondence and Reprint Requests: Johannes D. Veldhuis, MD, Endocrine Research Unit, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905. E-mail:
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Jin Y, Chen C, Cao Z, Sun B, Lo IL, Liu TM, Zheng J, Sun S, Shi Y, Zhang XD. Entropy change of biological dynamics in COPD. Int J Chron Obstruct Pulmon Dis 2017; 12:2997-3005. [PMID: 29066881 PMCID: PMC5644543 DOI: 10.2147/copd.s140636] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In this century, the rapid development of large data storage technologies, mobile network technology, and portable medical devices makes it possible to measure, record, store, and track analysis of large amount of data in human physiological signals. Entropy is a key metric for quantifying the irregularity contained in physiological signals. In this review, we focus on how entropy changes in various physiological signals in COPD. Our review concludes that the entropy change relies on the types of physiological signals under investigation. For major physiological signals related to respiratory diseases, such as airflow, heart rate variability, and gait variability, the entropy of a patient with COPD is lower than that of a healthy person. However, in case of hormone secretion and respiratory sound, the entropy of a patient is higher than that of a healthy person. For mechanomyogram signal, the entropy increases with the increased severity of COPD. This result should give valuable guidance for the use of entropy for physiological signals measured by wearable medical device as well as for further research on entropy in COPD.
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Affiliation(s)
- Yu Jin
- Faculty of Health Sciences, University of Macau, Taipa, Macau
| | - Chang Chen
- Faculty of Health Sciences, University of Macau, Taipa, Macau
| | - Zhixin Cao
- Beijing Engineering Research Center of Diagnosis and Treatment of Respiratory and Critical Care Medicine, Beijing Chaoyang Hospital, Beijing
| | - Baoqing Sun
- State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou
| | - Iek Long Lo
- Department of Geriatrics, Centro Hospital Conde de Sao Januario, Macau
| | - Tzu-Ming Liu
- Faculty of Health Sciences, University of Macau, Taipa, Macau
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Taipa, Macau
| | - Shixue Sun
- Faculty of Health Sciences, University of Macau, Taipa, Macau
| | - Yan Shi
- School of Automation Science and Electrical Engineering, Beihang University, Beijing, China
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Roelfsema F, Yang RJ, Olson TP, Joyner MJ, Takahashi PY, Veldhuis JD. Enhanced Coupling Within Gonadotropic and Adrenocorticotropic Axes by Moderate Exercise in Healthy Men. J Clin Endocrinol Metab 2017; 102:2482-2490. [PMID: 28453740 PMCID: PMC5505190 DOI: 10.1210/jc.2017-00036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/17/2017] [Indexed: 11/19/2022]
Abstract
CONTEXT Exercise elicits incompletely defined adaptations of metabolic and endocrine milieu, including the gonadotropic and corticotropic axes. OBJECTIVE To quantify the impact of acute exercise on coordinate luteinizing hormone (LH) and testosterone (T) and adrenocorticotropic hormone (ACTH) and cortisol secretion in healthy men in relation to age. PARTICIPANTS AND DESIGN Prospectively randomized, within-subject crossover study in 23 men aged 19 to 77 years old. Subjects underwent rest and 30 minutes of mixed exercise at 65% of maximal aerobic capacity with 10-minute blood sampling between 7:00 am and 1:00 pm, 2 weeks apart. MAIN OUTCOME MEASURES Incremental changes in LH, T, ACTH, and cortisol concentrations, the feedforward and feedback strength between exercise and rest, quantified by approximate entropy (ApEn), and bihormonal synchrony, quantitated by cross-ApEn. RESULTS Mean hourly exercise-minus-rest LH and ACTH increments increased from -0.055 ± 0.187 to 0.755 ± 0.245 IU/L (P = 0.003) and from 2.9 ± 2.2 to 71.2 ± 16.1 ng/L (P < 0.0001), respectively, during exercise. T and cortisol increments increased concurrently from -9.6 ± 16.7 to 47.6 ± 17.1 ng/dL (P < 0.0001) and 0.45 ± 0.76 to 7.27 ± 0.64 µg/dL (P < 0.0001), respectively. During exercise, feedforward and feedback LH-T and ACTH-cortisol cross-ApEn decreased markedly quantifying enhanced hormonal coupling. CONCLUSIONS Acute moderate mixed exercise in healthy men rapidly enhances feedforward LH-T and ACTH-cortisol coordination and reciprocal feedback within the gonadotropic and corticotropic axes. In principle, enhancement of both LH-T and ACTH-cortisol secretory synchrony by exercise could reflect augmented coupling between brain-testicular and brain-adrenal neural outflow.
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Affiliation(s)
- Ferdinand Roelfsema
- Department of Endocrinology and Metabolism, Leiden University Medical Center, 2333ZA Leiden, The Netherlands
| | - Rebecca J. Yang
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905
| | - Thomas P. Olson
- Department of Cardiovascular Research, Mayo Clinic, Rochester, Minnesota 55905
| | - Michael J. Joyner
- Department of Anesthesia Research, Department of Physiology and Biomedical Engineering, and Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota 55905
| | - Paul Y. Takahashi
- Department of Primary Care Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905
| | - Johannes D. Veldhuis
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905
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Keenan DM, Veldhuis JD. Pulsatility of Hypothalamo-Pituitary Hormones: A Challenge in Quantification. Physiology (Bethesda) 2017; 31:34-50. [PMID: 26674550 DOI: 10.1152/physiol.00027.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuroendocrine systems control many of the most fundamental physiological processes, e.g., reproduction, growth, adaptations to stress, and metabolism. Each such system involves the hypothalamus, the pituitary, and a specific target gland or organ. In the quantification of the interactions among these components, biostatistical modeling has played an important role. In the present article, five key challenges to an understanding of the interactions of these systems are illustrated and discussed critically.
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Affiliation(s)
- Daniel M Keenan
- Department of Statistics, University of Virginia, Charlottesville, Virginia; and
| | - Johannes D Veldhuis
- Department of Medicine, Endocrine Research Unit, Mayo School of Graduate Medical Education, Clinical Translational Science Center, Mayo Clinic, Rochester, Minnesota
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van der Spoel E, Roelfsema F, Jansen SW, Akintola AA, Ballieux BE, Cobbaert CM, Blauw GJ, Slagboom PE, Westendorp RGJ, Pijl H, van Heemst D. Familial Longevity Is Not Associated with Major Differences in the Hypothalamic-Pituitary-Gonadal Axis in Healthy Middle-Aged Men. Front Endocrinol (Lausanne) 2016; 7:143. [PMID: 27881971 PMCID: PMC5101217 DOI: 10.3389/fendo.2016.00143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 10/25/2016] [Indexed: 12/02/2022] Open
Abstract
CONTEXT A trade-off between fertility and longevity possibly exists. The association of the male hypothalamic-pituitary-gonadal (HPG) axis with familial longevity has not yet been investigated. OBJECTIVE To study 24-h hormone concentration profiles of the HPG axis in men enriched for familial longevity and controls. DESIGN We frequently sampled blood over 24 h in 10 healthy middle-aged male offspring of nonagenarian participants from the Leiden Longevity Study together with 10 male age-matched controls. Individual 24-h luteinizing hormone (LH) and testosterone concentration profiles were analyzed by deconvolution analyses to estimate secretion parameters. Furthermore, the temporal relationship between LH and testosterone was assessed by cross-correlation analysis. We used (cross-)approximate entropy to quantify the strength of feedback and/or feedforward control of LH and testosterone secretion. RESULTS Mean [95% confidence interval (CI)] total LH secretion of the offspring was 212 (156-268) U/L/24 h, which did not differ significantly (p = 0.51) from the total LH secretion of controls [186 (130-242) U/L/24 h]. Likewise, mean (95% CI) total testosterone secretion of the offspring [806 (671-941) nmol/L/24 h] and controls [811 (676-947) nmol/L/24 h] were similar (p = 0.95). Other parameters of LH and testosterone secretion were also not significantly different between offspring and controls. The temporal relationship between LH and testosterone and the strength of feedforward/feedback regulation within the HPG axis were similar between offspring of long-lived families and controls. CONCLUSION This relatively small study suggests that in healthy male middle-aged participants, familial longevity is not associated with major differences in the HPG axis. Selection on both fertility and health may in part explain the results.
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Affiliation(s)
- Evie van der Spoel
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Ferdinand Roelfsema
- Section Endocrinology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Steffy W. Jansen
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Abimbola A. Akintola
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Bart E. Ballieux
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Christa M. Cobbaert
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Gerard J. Blauw
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - P. Eline Slagboom
- Section Molecular Epidemiology, Department of Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
| | - Rudi G. J. Westendorp
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
- Department of Public Health, Center of Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Hanno Pijl
- Section Endocrinology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Diana van Heemst
- Section Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
- *Correspondence: Diana van Heemst,
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Boonen E, Meersseman P, Vervenne H, Meyfroidt G, Guïza F, Wouters PJ, Veldhuis JD, Van den Berghe G. Reduced nocturnal ACTH-driven cortisol secretion during critical illness. Am J Physiol Endocrinol Metab 2014; 306:E883-92. [PMID: 24569590 PMCID: PMC3989736 DOI: 10.1152/ajpendo.00009.2014] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recently, during critical illness, cortisol metabolism was found to be reduced. We hypothesize that such reduced cortisol breakdown may suppress pulsatile ACTH and cortisol secretion via feedback inhibition. To test this hypothesis, nocturnal ACTH and cortisol secretory profiles were constructed by deconvolution analysis from plasma concentration time series in 40 matched critically ill patients and eight healthy controls, excluding diseases or drugs that affect the hypothalamic-pituitary-adrenal axis. Blood was sampled every 10 min between 2100 and 0600 to quantify plasma concentrations of ACTH and (free) cortisol. Approximate entropy, an estimation of process irregularity, cross-approximate entropy, a measure of ACTH-cortisol asynchrony, and ACTH-cortisol dose-response relationships were calculated. Total and free plasma cortisol concentrations were higher at all times in patients than in controls (all P < 0.04). Pulsatile cortisol secretion was 54% lower in patients than in controls (P = 0.005), explained by reduced cortisol burst mass (P = 0.03), whereas cortisol pulse frequency (P = 0.35) and nonpulsatile cortisol secretion (P = 0.80) were unaltered. Pulsatile ACTH secretion was 31% lower in patients than in controls (P = 0.03), again explained by a lower ACTH burst mass (P = 0.02), whereas ACTH pulse frequency (P = 0.50) and nonpulsatile ACTH secretion (P = 0.80) were unchanged. ACTH-cortisol dose response estimates were similar in patients and controls. ACTH and cortisol approximate entropy were higher in patients (P ≤ 0.03), as was ACTH-cortisol cross-approximate entropy (P ≤ 0.001). We conclude that hypercortisolism during critical illness coincided with suppressed pulsatile ACTH and cortisol secretion and a normal ACTH-cortisol dose response. Increased irregularity and asynchrony of the ACTH and cortisol time series supported non-ACTH-dependent mechanisms driving hypercortisolism during critical illness.
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Affiliation(s)
- Eva Boonen
- Clinical Division and Laboratory of Intensive Care Medicine, Department of Cellular and Molecular Medicine, and
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Abstract
As America’s baby boomer population matures, there is an increasing interest in supplements that can delay or oppose the aging process. This antiaging movement has exploded over the past decade. While most supplements are not supported by scientific literature or government controls, a number of products have been the subject of significant scientific inquiry. Hormone replacement therapy, including testosterone and growth hormone, has mixed results, and antioxidative strategies are supported by basic science but lack clinical evidence-based outcomes. While the process of aging has become better understood leading to more rational approaches to combat its effects on health, the clinician is reminded to carefully discern between the science and marketing that is available in this area.
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Abstract
Thyroid hormones are extremely important for metabolism, development, and growth during the lifetime. The hypothalamo-pituitary-thyroid axis is precisely regulated for these purposes. Much of our knowledge of this hormonal axis is derived from experiments in animals and mutations in man. This review examines the hypothalamo-pituitary-thyroid axis particularly in relation to the regulated 24-hour serum TSH concentration profiles in physiological and pathophysiological conditions, including obesity, primary hypothyroidism, pituitary diseases, psychiatric disorders, and selected neurological diseases. Diurnal TSH rhythms can be analyzed with novel and precise techniques, eg, operator-independent deconvolution and approximate entropy. These approaches provide indirect insight in the regulatory components in pathophysiological conditions.
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Affiliation(s)
- Ferdinand Roelfsema
- Leiden University Medical Center, Department of Endocrinology and Metabolic Diseases, PO Box 9600, 2300 RC Leiden, The Netherlands.
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Carroll BJ, Iranmanesh A, Keenan DM, Cassidy F, Wilson WH, Veldhuis JD. Pathophysiology of hypercortisolism in depression: pituitary and adrenal responses to low glucocorticoid feedback. Acta Psychiatr Scand 2012; 125:478-91. [PMID: 22211368 PMCID: PMC3893569 DOI: 10.1111/j.1600-0447.2011.01821.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To test three theories of hypercortisolemia in depression-hypothalamic overdrive, impaired glucocorticoid feedback, or autonomous cortisol production. METHOD We applied an overnight low-cortisol feedback strategy by administering metyrapone to hypercortisolemic depressed in-patients and control subjects. RESULTS Under metyrapone, the increases of plasma adrenocorticotropic hormone (ACTH) concentrations and of basal and pulsatile ACTH secretion were not exaggerated in hypercortisolemic depressed patients compared with control subjects. ACTH approximate entropy (ApEn) did not differ at baseline or under metyrapone. Thus, neither hypothalamic overdrive nor irregular ACTH secretion was seen. We did not detect impaired cortisol feedback: the ACTH response was not reduced, and ApEn measures that are sensitive to feedback changes were comparable in both groups. Metyrapone disrupted cortisol secretory regularity in depressed and control subjects. On the baseline day, basal cortisol secretion was significantly increased and was highly irregular (high ApEn), and ACTH-cortisol cross-ApEn was markedly elevated in high-cortisol patients. CONCLUSION Classical feed-forward overdrive and impaired feedback theories of hypercortisolemia in depression were not supported. Depressive hypercortisolemia may result from alternative pathophysiological mechanisms involving irregular basal hypersecretion of cortisol, associated with adrenal enlargement, possibly through splanchnic sympathetic activation of the adrenal cortex.
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Affiliation(s)
| | - Ali Iranmanesh
- Endocrine Service, Medical Section, Salem Veterans Affairs Medical Center, Salem, VA 24153
| | - Daniel M. Keenan
- Department of Statistics, University of Virginia, Charlottesville, VA 22904
| | - Frederick Cassidy
- Department of Psychiatry, Duke University Medical Center, Durham, NC 27710
| | - William H. Wilson
- Department of Psychiatry, Duke University Medical Center, Durham, NC 27710
| | - Johannes D. Veldhuis
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, 200 First Street SW, Rochester, MN 55905
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Wang X, Keenan DM, Pincus SM, Liu PY, Veldhuis JD. Oscillations in joint synchrony of reproductive hormones in healthy men. Am J Physiol Endocrinol Metab 2011; 301:E1163-73. [PMID: 21900124 PMCID: PMC3233781 DOI: 10.1152/ajpendo.00138.2011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Negative-feedback (inhibitory) and positive-feedforward (stimulatory) processes regulate physiological systems. Whether such processes are themselves rhythmic is not known. Here, we apply cross-approximate entropy (cross-ApEn), a noninvasive measurement of joint (pairwise) signal synchrony, to inferentially assess hypothesized circadian and ultradian variations in feedback coupling. The data comprised simultaneous measurements of three pituitary and one peripheral hormone (LH, FSH, prolactin, and testosterone) in 12 healthy men each sampled every 10 min for 4 days (5,760 min). Ergodicity, due to the time series stationarity of the measurements over the 4 days, allows for effective estimation of parameters based upon the 12 subjects. Cross-ApEn changes were quantified via moving-window estimates applied to 4-day time series pairs. The resultant ordered windowed cross-ApEn series (in time) were subjected to power spectrum analysis. Rhythmicity was assessed against the null hypothesis of randomness using 1,000 simulated periodograms derived by shuffling the interpulse-interval hormone-concentration segments and redoing cross-ApEn windows and spectral analysis. By forward cross-ApEn analysis, paired LH-testosterone, LH-prolactin, and LH-FSH synchrony maintained dominant rhythms with periodicities of 18-22.5, 18, and 22.5 h, respectively (each P < 0.001). By reverse (feedback) cross-ApEn analysis, testosterone-LH, testosterone-prolactin, and testosterone-FSH synchrony cycles were 30, 18, and 30-45 h, respectively (each P ≤ 0.001). Significant 8- or 24-h rhythms were also detected in most linkages, and maximal bihormonal synchrony occurred consistently at ∼0400-0500. Collectively, these analyses demonstrate significant ultradian (<24 h), circadian (∼24 h), and infradian (>24 h) oscillations in pituitary-testis synchrony, wherein maximal biglandular coordination is strongly constrained to the early morning hours.
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Affiliation(s)
- Xin Wang
- Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota 55905, USA
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Iranmanesh A, Rochester DF, Liu J, Veldhuis JD. Impaired adrenergic- and corticotropic-axis outflow during exercise in chronic obstructive pulmonary disease. Metabolism 2011; 60:1521-9. [PMID: 21632072 PMCID: PMC3181386 DOI: 10.1016/j.metabol.2011.03.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 03/21/2011] [Accepted: 03/26/2011] [Indexed: 10/18/2022]
Abstract
Exercise stimulates coordinated release of the sympathoadrenal hormones adrenocorticotropic hormone (ACTH), cortisol, norepinephrine (NE), and epinephrine (Epi). The study hypothesis was that chronic obstructive pulmonary disease (COPD) is marked by heightened sympathoadrenal outflow at comparable relative workloads. The location of the study was at a clinical research unit. Eight healthy men and 9 men with stable COPD (forced expiratory volume at 1 second <75% predicted) were studied. Volunteers rested (baseline) or exercised at individual submaximal (35% ± 5%) or maximal oxygen consumption. Blood was sampled every 2 minutes for 40 minutes concurrently. Two-way analysis of covariance was applied to examine group (healthy/COPD) and exercise (3 levels) effects on ACTH, cortisol, NE, and Epi release and regularity (estimable by approximate entropy). The timing of peak hormone concentrations was Epi, 14 minutes; NE, 16 minutes; ACTH, 22 minutes; and cortisol, 34 minutes in both cohorts. Type of exercise regimen influenced all 4 hormones (each P < .001), and subject group (control vs COPD) affected cortisol (P < .001) and Epi (P = .048) responses. Exercise regimen and group together controlled ACTH, cortisol, and Epi (each P < .001), but not NE, responses. In particular, endocrine responses were attenuated in COPD compared with control subjects. Approximate entropy analysis also identified loss of maximal exercise-induced ACTH-secretory regularity in COPD patients (P = .042). These outcomes demonstrate impaired rather than augmented exercise-associated sympathocorticotropic-axis outflow in patients with COPD even when outcomes are normalized to maximal oxygen consumption, suggesting that factors other than fitness are at work.
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Affiliation(s)
- Ali Iranmanesh
- Endocrine Service, Medical Section, Salem Veterans Affairs Medical Center, Salem, VA 24153
| | - Dudley F. Rochester
- Division of Pulmonary and Critical Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22901
| | - Jing Liu
- Division of Pulmonary and Critical Medicine, University of Virginia Health Sciences Center, Charlottesville, VA 22901
| | - Johannes D. Veldhuis
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, MN 55905
- Corresponding author: Tel: (507) 255-0906, Fax: (507) 255-0901,
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Menge BA, Grüber L, Jørgensen SM, Deacon CF, Schmidt WE, Veldhuis JD, Holst JJ, Meier JJ. Loss of inverse relationship between pulsatile insulin and glucagon secretion in patients with type 2 diabetes. Diabetes 2011; 60:2160-8. [PMID: 21677283 PMCID: PMC3142077 DOI: 10.2337/db11-0251] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE In patients with type 2 diabetes, glucagon levels are often increased. Furthermore, pulsatile secretion of insulin is disturbed in such patients. Whether pulsatile glucagon secretion is altered in type 2 diabetes is not known. RESEARCH DESIGN AND METHODS Twelve patients with type 2 diabetes and 13 nondiabetic individuals were examined in the fasting state and after mixed meal ingestion. Deconvolution analyses were performed on insulin and glucagon concentration time series sampled at 1-min intervals. RESULTS Both insulin and glucagon were secreted in distinct pulses, occurring at ∼5-min intervals. In patients with diabetes, postprandial insulin pulse mass was reduced by 74% (P < 0.001). Glucagon concentrations were increased in the patients during fasting and after meal ingestion (P < 0.05), specifically through an increased glucagon pulse mass (P < 0.01). In healthy subjects, the increase in postprandial insulin levels was inversely related to respective glucagon levels (P < 0.05). This relationship was absent in the fasting state and in patients with diabetes. CONCLUSIONS Glucagon and insulin are secreted in a coordinated, pulsatile manner. A plausible model is that the postprandial increase in insulin burst mass represses the corresponding glucagon pulses. Disruption of the insulin-glucagon interaction in patients with type 2 diabetes could potentially contribute to hyperglucagonemia.
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Affiliation(s)
- Björn A. Menge
- Department of Medicine I, St. Josef Hospital, Ruhr University Bochum, Bochum, Germany
| | - Lena Grüber
- Department of Medicine I, St. Josef Hospital, Ruhr University Bochum, Bochum, Germany
| | - Signe M. Jørgensen
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Carolyn F. Deacon
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Wolfgang E. Schmidt
- Department of Medicine I, St. Josef Hospital, Ruhr University Bochum, Bochum, Germany
| | - Johannes D. Veldhuis
- Department of Medicine, Endocrine Research Unit, Mayo School of Graduate Medical Education, Mayo Clinic, Rochester, Minnesota
| | - Jens J. Holst
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Juris J. Meier
- Department of Medicine I, St. Josef Hospital, Ruhr University Bochum, Bochum, Germany
- Corresponding author: Juris J. Meier,
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Veldhuis JD, Takahashi PY, Keenan DM, Liu PY, Mielke KL, Weist SM. Age disrupts androgen receptor-modulated negative feedback in the gonadal axis in healthy men. Am J Physiol Endocrinol Metab 2010; 299:E675-82. [PMID: 20682842 PMCID: PMC2957871 DOI: 10.1152/ajpendo.00300.2010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Testosterone (T) exerts negative feedback on the hypothalamo-pituitary (GnRH-LH) unit, but the relative roles of the CNS and pituitary are not established. We postulated that relatively greater LH responses to flutamide (brain-permeant antiandrogen) than bicalutamide (brain-impermeant antiandrogen) should reflect greater feedback via CNS than pituitary/peripheral androgen receptor-dependent pathways. To this end, 24 healthy men ages 20-73 yr, BMI 21-32 kg/m2, participated in a prospective, placebo-controlled, randomized, double-blind crossover study of the effects of antiandrogen control of pulsatile, basal, and entropic (pattern regularity) measurements of LH secretion. Analysis of covariance revealed that flutamide but not bicalutamide 1) increased pulsatile LH secretion (P = 0.003), 2) potentiated the age-related abbreviation of LH secretory bursts (P = 0.025), 3) suppressed incremental GnRH-induced LH release (P = 0.015), and 4) decreased the regularity of GnRH-stimulated LH release (P = 0.012). Furthermore, the effect of flutamide exceeded that of bicalutamide in 1) raising mean LH (P = 0.002) and T (P = 0.017) concentrations, 2) accelerating LH pulse frequency (P = 0.013), 3) amplifying total (basal plus pulsatile) LH (P = 0.002) and T (P < 0.001) secretion, 4) shortening LH secretory bursts (P = 0.032), and 5) reducing LH secretory regularity (P < 0.001). Both flutamide and bicalutamide elevated basal (nonpulsatile) LH secretion (P < 0.001). These data suggest the hypothesis that topographically selective androgen receptor pathways mediate brain-predominant and pituitary-dependent feedback mechanisms in healthy men.
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Affiliation(s)
- Johannes D Veldhuis
- Mayo School of Graduate Medical Education, Mayo Clinic, 200 First St. SW/Mayo Clinic, Rochester, MN 55905, USA.
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Xie HB, Zheng YP, Guo JY, Chen X. Cross-fuzzy entropy: A new method to test pattern synchrony of bivariate time series. Inf Sci (N Y) 2010. [DOI: 10.1016/j.ins.2010.01.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Henley DE, Russell GM, Douthwaite JA, Wood SA, Buchanan F, Gibson R, Woltersdorf WW, Catterall JR, Lightman SL. Hypothalamic-pituitary-adrenal axis activation in obstructive sleep apnea: the effect of continuous positive airway pressure therapy. J Clin Endocrinol Metab 2009; 94:4234-42. [PMID: 19820009 DOI: 10.1210/jc.2009-1174] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
CONTEXT Obstructive sleep apnea (OSA) is a common condition with significant cardiovascular and metabolic comorbidity. We hypothesized that these may result from OSA-induced perturbations of endogenous ultradian hypothalamic-pituitary-adrenal axis activity. OBJECTIVE The aim of the study was to investigate ACTH and cortisol ultradian patterns using an automated, repetitive blood sampling technique. DESIGN Samples for ACTH and cortisol were collected from 10 patients with moderate to severe OSA under basal conditions, at 10-min intervals over 24 h, at diagnosis and 3 months after compliant continuous positive airway pressure (CPAP) therapy. Multiple-parameter deconvolution estimated specific measures of ACTH and cortisol pulsatile secretion from blood hormone concentrations. RESULTS Mean total ACTH and cortisol production were elevated pre-CPAP compared to post-CPAP (ACTH, 1459.8 +/- 123.0 vs. 808.1 +/- 97.9 pg/ml, P < 0.001; cortisol, 5748.9 +/- 364.9 vs. 3817.7 +/- 351.7 nmol/liter, P < 0.001) as were mean total pulsatile production (ACTH, 764.1 +/- 86.3 vs. 383.5 +/- 50.0 pg/ml, P = 0.002; cortisol, 4715.9 +/- 253.3 vs. 3227.7 +/- 258.8 nmol/liter, P < 0.001). ACTH and cortisol secretory burst mean half-duration were higher at diagnosis (12.3 +/- 0.7 and 13.5 +/- 0.7 vs. 7.8 +/- 0.4 and 8.4 +/- 0.6 min, respectively, P < 0.001); thus, 95% of each ACTH secretion occurred in 21.0 +/- 1.2 vs. 12.9 +/- 0.8 min post-CPAP (P < 0.001) and for cortisol in 23.0 +/- 1.2 vs. 14.2 +/- 1.1 min post-CPAP (P < 0.001). Approximate entropy (ApEn) revealed greater disorderliness in both ACTH (P = 0.03) and cortisol (P = 0.001) time series pre-CPAP. Forward and reverse cross-ApEn suggested nodal disruption at central and adrenal levels pre-CPAP (P = 0.01). Significantly elevated cortisol responses to a single breath of 35% CO(2) occurred pre-CPAP (P = 0.006). CONCLUSIONS Untreated compared to treated OSA is associated with marked disturbances in ACTH and cortisol secretory dynamics, resulting in prolonged tissue exposure to disordered, elevated hormone levels.
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Affiliation(s)
- David E Henley
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol BS1 3NY, United Kingdom.
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Álvarez D, Hornero R, Abásolo D, del Campo F, Zamarrón C, López M. Nonlinear measure of synchrony between blood oxygen saturation and heart rate from nocturnal pulse oximetry in obstructive sleep apnoea syndrome. Physiol Meas 2009; 30:967-82. [DOI: 10.1088/0967-3334/30/9/008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Henley DE, Leendertz JA, Russell GM, Wood SA, Taheri S, Woltersdorf WW, Lightman SL. Development of an automated blood sampling system for use in humans. J Med Eng Technol 2009; 33:199-208. [PMID: 19340690 DOI: 10.1080/03091900802185970] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Many hormones are released in a pulsatile or burst-like pattern resulting in fluctuating blood levels that can undergo rapid modulation by physiological and pathological signals. To accurately measure these changes in hormone concentration requires frequent blood sampling, often over extended periods as the overall rhythmicity may vary over 24 hours. The aim of this study was to develop a computerized, automated blood sampling system which allows repeated stress-free blood sample collection from humans over an extended period under basal or test conditions. The system incorporates a peristaltic pump, fraction collector and standard infusion pump together with a custom built electronic control unit linked to a personal computer. Disposable tubing prevents cross-contamination between study participants. The computer programme is modifiable to adjust for the number of specimen tubes and volume of blood collected per sampling cycle. Patency of the collecting line is maintained with 0.9% saline, without the need for heparinization. To validate the system, 10-minute samples for cortisol were collected over 24 hours from five healthy volunteers, of whom two had additional concomitant ACTH sampling. Deconvolution analysis revealed an expected number of hormone secretory episodes and a non-pathological degree of orderliness within the data. There was high concordance between ACTH and cortisol secretory events. The ability of the system to allow multiple measurements and of the software program to link with other physiological monitoring equipment provides a powerful tool to study physiologic/pathophysiologic change in relation to blood hormone and other biomarker levels.
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Affiliation(s)
- D E Henley
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK.
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Roelfsema F, Kok P, Frolich M, Pereira AM, Pijl H. Disordered and increased adrenocorticotropin secretion with diminished adrenocorticotropin potency in obese in premenopausal women. J Clin Endocrinol Metab 2009; 94:2991-7. [PMID: 19454578 DOI: 10.1210/jc.2009-0350] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT The pituitary-adrenal ensemble of obese humans is marked by increased urinary excretion of cortisol and its metabolites in the face of normal circulating cortisol levels. For better understanding of the (patho) physiological meaning of these changes, the mechanistic underpinnings need to be clarified. INTERVENTION AND METHODS We investigated 17 obese women [body mass index (BMI) 30-39.4 kg/m(2)] and 14 normal women (BMI, 18.3-24.8 kg/m(2)) who underwent 24-h blood sampling at 10-min intervals, and plasma ACTH and cortisol concentrations were measured with sensitive assays. Data were analyzed with a new deconvolution program, approximate entropy (ApEn) analyses, and cosinor regression. OUTCOME ACTH and cortisol production rates were higher in obese women than in controls and correlated with BMI. Secretion of ACTH correlated with leptin (R = 0.63; P = 0.0001) and insulin (R = 0.67; P = 0.0001). ACTH ApEn and forward ACTH-cortisol cross-ApEn were diminished in obese women. The half-maximal effective concentration (ED(50)) of ACTH pulses vs. cortisol pulses was higher in obese women (38.3 +/- 4.9 vs. 25.1 +/- 3.7 ng/liter; P = 0.03), indicating decreased potency of ACTH. The diurnal properties of ACTH and cortisol secretion were unchanged in obese females. CONCLUSION Obese women exhibit enhanced ACTH and cortisol 24-h production compared with lean controls. The amplified ACTH drive is accompanied by decreased secretory regularity and diminished forward coupling between ACTH and cortisol. In addition, the potency of ACTH is decreased in obesity.
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Affiliation(s)
- Ferdinand Roelfsema
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Albinusdreef 2, Leiden, The Netherlands.
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Keenan DM, Roelfsema F, Carroll BJ, Iranmanesh A, Veldhuis JD. Sex defines the age dependence of endogenous ACTH-cortisol dose responsiveness. Am J Physiol Regul Integr Comp Physiol 2009; 297:R515-23. [PMID: 19535673 DOI: 10.1152/ajpregu.00200.2009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sex influences adrenal glucocorticoid responses to ACTH in experimental animals. Whether similar sex differences operate in humans is unknown. To test this notion, we estimated ACTH-cortisol dose-response properties analytically in 48 healthy adults (n = 22 women, n = 26 men), ages 18-77 yr, body mass index (BMI) 18-32 kg/m(2), previously studied at two medical centers. Plasma ACTH and cortisol concentrations were measured every 10 min for 24 h. The 145 sample pairs were used in each subject to estimate ACTH-cortisol drive via a logistic function. Statistical analyses revealed that 24-h cortisol secretion (>82% pulsatile) fell in men (r = -0.38, P = 0.028) and rose in women (r = +0.37, P = 0.045) with age (P = 0.01 sex effect). The mechanisms involved decreased ACTH efficacy with age in men (r = -0.35, P = 0.04), and increased ACTH efficacy with age in women (r = +0.42, P = 0.025) [P = 0.009 sex effect]. ACTH potency diminished with higher BMI in men (r = +0.38, P = 0.029) and in the cohort as a whole (r = 0.34, P = 0.0085). These outcomes demonstrate that sex, age, and BMI modulate selective properties of endogenous ACTH-cortisol drive in humans, thereby indicating the need to control these three major variables in experimental comparisons.
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Affiliation(s)
- Daniel M Keenan
- Department of Statistics, University of Virginia, Charlottesville, Virginia, USA
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Kok P, Roelfsema F, Frölich M, van Pelt J, Meinders AE, Pijl H. Bromocriptine reduces augmented thyrotropin secretion in obese premenopausal women. J Clin Endocrinol Metab 2009; 94:1176-81. [PMID: 19190107 DOI: 10.1210/jc.2008-2303] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Diurnal TSH secretion is enhanced in obese premenopausal women. Dopamine inhibits TSH secretion through activation of dopamine D(2) receptors (D(2)R). Dopamine D(2)R availability in the brain is reduced in obese humans in proportion to body adiposity. We hypothesized that deficient dopamine D(2)R signaling is involved in the enhanced TSH secretion associated with obesity. OBJECTIVE The effect of short-term bromocriptine treatment on spontaneous TSH secretion in obese women was studied while body weight and caloric intake remained constant. DESIGN AND SETTING We conducted a prospective, fixed-order, crossover study in a Clinical Research Center. PARTICIPANTS Seventeen obese women (body mass index, 33.2 +/- 0.6 kg/m(2)) were studied twice in the early follicular phase of their menstrual cycle. INTERVENTION Subjects were treated for 8 d with placebo and bromocriptine. MAIN OUTCOME MEASURE(S) Blood was collected for 24 h at 10-min intervals, and TSH and leptin were analyzed with deconvolution and correlation techniques, approximate entropy, and cosine regression. RESULTS Bromocriptine reduced 24-h TSH secretion (placebo, 29.8 +/- 4.6 mU/liter . 24 h, vs. bromocriptine, 22.4 +/- 3.7 mU/liter . 24 h; P = 0.001), whereas free T(4) and total T(3) concentrations did not change. Bromocriptine administration reduced the mesor and amplitude of the 24-h rhythm without resetting the phase. The regularity of the subordinate TSH pattern and synchrony between leptin and TSH were unaffected by bromocriptine. CONCLUSION Activation of dopamine D(2)R by bromocriptine reverses enhanced diurnal TSH secretion in obese women. Thus, reduced dopaminergic neuronal signaling might be involved in the perturbation of the thyrotrope hormonal axis in obese premenopausal women.
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Affiliation(s)
- Petra Kok
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden, The Netherlands
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Veldhuis JD, Keenan DM, Liu PY, Iranmanesh A, Takahashi PY, Nehra AX. The aging male hypothalamic-pituitary-gonadal axis: pulsatility and feedback. Mol Cell Endocrinol 2009; 299:14-22. [PMID: 18838102 PMCID: PMC2662347 DOI: 10.1016/j.mce.2008.09.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2007] [Revised: 09/02/2008] [Accepted: 09/04/2008] [Indexed: 11/29/2022]
Abstract
Aging results in insidious decremental changes in hypothalamic, pituitary and gonadal function. The foregoing three main anatomic loci of control are regulated by intermittent time-delayed signal exchange, principally via gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and testosterone/estradiol (Te/E(2)). A mathematical framework is required to embody these dynamics. The present review highlights integrative adaptations in the aging male hypothalamic-pituitary-gonadal axis, as assessed by recent objective ensemble models of the axis as a whole.
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Affiliation(s)
- Johannes D Veldhuis
- Endocrine Research Unit, Department of Internal Medicine, Mayo Clinic College of Medicine, Mayo Clinic, 200 First Steet SW, Rochester, MN 55905, United States.
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Roelfsema F, Kok S, Kok P, Pereira AM, Biermasz NR, Smit JW, Frolich M, Keenan DM, Veldhuis JD, Romijn JA. Pituitary-hormone secretion by thyrotropinomas. Pituitary 2009; 12:200-10. [PMID: 19051037 PMCID: PMC2712623 DOI: 10.1007/s11102-008-0159-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.
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Affiliation(s)
- Ferdinand Roelfsema
- Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Albinusdreef 2 NL2333ZA, Leiden, The Netherlands.
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Xie HB, Zheng YP, Jing-Yi G. Detection of synchrony in biosignals using cross fuzzy entropy. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2009:2971-2974. [PMID: 19963549 DOI: 10.1109/iembs.2009.5332503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A new method, namely Cross fuzzy entropy (C-FuzzyEn) analysis, that could enable the measurement of the synchrony or similarity of patterns between two distinct signals, was presented in this study. Tests on simulated data sets showed that C-FuzzyEn was superior to the conventional cross sample entropy (C-SampEn) in several aspects, including giving entropy definition in case of small parameters, better relative consistency, and less dependence on record length. The proposed C-FuzzyEn was then applied for the analysis of simultaneously recorded electromyography (EMG) and mechanomyography (MMG) signals during sustained isometric contraction for monitoring local muscle fatigue. The results showed that the C-FuzzyEn of EMG-MMG decreased significantly during the development of muscle fatigue. The time-decrease trend of C-FuzzyEn is similar to the mean frequency (MNF) of EMG, the commonly used muscle fatigue indicator.
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Affiliation(s)
- Hong-Bo Xie
- Jiangsu University, Jiangsu, 212013 PR of China.
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Veldhuis JD, Keenan DM, Pincus SM. Motivations and methods for analyzing pulsatile hormone secretion. Endocr Rev 2008; 29:823-64. [PMID: 18940916 PMCID: PMC2647703 DOI: 10.1210/er.2008-0005] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 09/16/2008] [Indexed: 01/05/2023]
Abstract
Endocrine glands communicate with remote target cells via a mixture of continuous and intermittent signal exchange. Continuous signaling allows slowly varying control, whereas intermittency permits large rapid adjustments. The control systems that mediate such homeostatic corrections operate in a species-, gender-, age-, and context-selective fashion. Significant progress has been made in understanding mechanisms of adaptive interglandular signaling in vivo. Principal goals are to understand the physiological origins, significance, and mechanisms of pulsatile hormone secretion. Key analytical issues are: 1) to quantify the number, size, shape, and uniformity of pulses, nonpulsatile (basal) secretion, and elimination kinetics; 2) to evaluate regulation of the axis as a whole; and 3) to reconstruct dose-response interactions without disrupting hormone connections. This review will focus on the motivations driving and the methodologies used for such analyses.
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Affiliation(s)
- Johannes D Veldhuis
- Endocrine Research Unit, Department of Internal Medicine, Mayo Medical School, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Liu PY, Iranmanesh A, Keenan DM, Pincus SM, Veldhuis JD. A noninvasive measure of negative-feedback strength, approximate entropy, unmasks strong diurnal variations in the regularity of LH secretion. Am J Physiol Endocrinol Metab 2007; 293:E1409-15. [PMID: 17848633 DOI: 10.1152/ajpendo.00365.2007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The secretion of anterior-pituitary hormones is subject to negative feedback. Whether negative feedback evolves dynamically over 24 h is not known. Conventional experimental paradigms to test this concept may induce artifacts due to nonphysiological feedback. These limitations might be overcome by a noninvasive methodology to quantify negative feedback continuously over 24 h without disrupting the axis. The present study exploits a recently validated model-free regularity statistic, approximate entropy (ApEn), which monitors feedback changes with high sensitivity and specificity (both >90%; Pincus SM, Hartman ML, Roelfsema F, Thorner MO, Veldhuis JD. Am J Physiol Endocrinol Metab 273: E948-E957, 1999). A time-incremented moving window of ApEn was applied to LH time series obtained by intensive (10-min) blood sampling for four consecutive days (577 successive measurements) in each of eight healthy men. Analyses unveiled marked 24-h variations in ApEn with daily maxima (lowest feedback) at 1100 +/- 1.7 h (mean +/- SE) and minima (highest feedback) at 0430 +/- 1.9 h. The mean difference between maximal and minimal 24-h LH ApEn was 0.348 +/- 0.018, which differed by P < 0.001 from all three of randomly shuffled versions of the same LH time series, simulated pulsatile data and assay noise. Analyses artificially limited to 24-h rather than 96-h data yielded reproducibility coefficients of 3.7-9.0% for ApEn maxima and minima. In conclusion, a feedback-sensitive regularity statistic unmasks strong and consistent 24-h rhythmicity of the orderliness of unperturbed pituitary-hormone secretion. These outcomes suggest that ApEn may have general utility in probing dynamic mechanisms mediating feedback in other endocrine systems.
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Affiliation(s)
- Peter Y Liu
- Endocrine Research Unit, Mayo School of Graduate Medical Education, General Clinical Research Center, Mayo Clinic, Rochester, MN 55905, USA
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30
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Carroll BJ, Cassidy F, Naftolowitz D, Tatham NE, Wilson WH, Iranmanesh A, Liu PY, Veldhuis JD. Pathophysiology of hypercortisolism in depression. Acta Psychiatr Scand Suppl 2007:90-103. [PMID: 17280575 DOI: 10.1111/j.1600-0447.2007.00967.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The mechanisms mediating hypercortisolemia in depression remain controversial. Adopting the biomarker strategy, we studied adrenocorticotropin (ACTH) and cortisol dynamics in hypercortisolemic and non-hypercortisolemic depressed in-patients, and in normal volunteers. METHOD Deconvolution analysis of 24-h pulsatile secretion, approximate entropy (ApEn) estimation of secretory regularity, cross-ApEn quantitation of forward and reverse ACTH-cortisol synchrony, and cosine regression of 24-h rhythmicity. RESULTS Hypercortisolemia was strongly associated with melancholic and psychotic depressive subtypes. Hypercortisolemic patients had elevated ACTH and cortisol secretion, mediated chiefly by increased burst masses. Basal ACTH secretion was increased, ACTH half-life was reduced, and mean 24-h ACTH concentration was normal. Cortisol secretion was increased in a highly irregular pattern (high ApEn), with high ACTH --> cortisol cross-ApEn (impaired feedforward coupling). Cortisol-mediated feedback on the secretory pattern of ACTH was normal. Hypercortisolemic depressed patients had normal programming of the central hypothalamo-pituitary-adrenal (HPA) axis pulse generator: ACTH pulse frequency, cortisol pulse frequency, circadian acrophases, and ApEn of ACTH secretion were normal. Responsiveness of the adrenal cortex to endogenous ACTH was normal. Non-hypercortisolemic patients resembled hypercortisolemic patients on ACTH regulatory parameters but had low total cortisol secretion. CONCLUSION Increased ACTH secretion occurs in depressed in-patients regardless of cortisolemic status, confirming central HPA axis overdrive in severe depression. Depressive hypercortisolemia results from an additional change in the adrenal cortex that causes ACTH-independent, disorderly basal cortisol release, a sign of physiological stress in melancholic/psychotic depression.
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Affiliation(s)
- B J Carroll
- Pacific Behavioral Research Foundation, Carmel, CA, USA.
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Liu PY, Takahashi PY, Roebuck PD, Veldhuis JD. Age or factors associated with aging attenuate testosterone's concentration-dependent enhancement of the regularity of luteinizing hormone secretion in healthy men. J Clin Endocrinol Metab 2006; 91:4077-84. [PMID: 16868060 DOI: 10.1210/jc.2005-2811] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Healthy older men have reduced testosterone (Te) production and frequent, small irregular LH pulses. Which is cause and which is effect are not known. RATIONALE In model systems, frequent and irregular LH pulses reflect attenuated feedback inhibition by Te. HYPOTHESIS Factors associated with aging impair negative feedback by Te. SUBJECTS AND SETTING Healthy men at an academic medical center were studied. METHODS The study used quantification of the regularity of LH release patterns during blockade of gonadal steroidogenesis and graded transdermal Te addback in 18 healthy men aged 18-65 yr. RESULTS In the cohort as a whole, stepwise Te repletion repressed LH concentrations (P = 0.001) and enhanced the quantifiable orderliness of LH release patterns (P < 0.001). By regression analysis, age attenuated the capability of increasing Te concentrations to regularize LH secretion patterns (P = 0.019). However, after a fixed GnRH stimulus, the effect of Te on LH regularity was invariant of the age factor (P = 0.16), thus pointing to a hypothalamic locus of impaired Te feedback. SUMMARY Aging disrupts the capability of systemic Te concentrations to maintain orderly LH secretion under endogenous, but not exogenous, GnRH drive. CONCLUSIONS Age or factors associated with increased age reduce negative feedback by any given total Te concentration on hypothalamopituitary GnRH-LH outflow, thus contributing to disorderly LH secretion.
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Affiliation(s)
- Peter Y Liu
- Endocrine Research Unit, Mayo Clinic School of Graduate Medical Education, General Clinical Research Center, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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Meier JJ, Kjems LL, Veldhuis JD, Lefèbvre P, Butler PC. Postprandial suppression of glucagon secretion depends on intact pulsatile insulin secretion: further evidence for the intraislet insulin hypothesis. Diabetes 2006; 55:1051-6. [PMID: 16567528 DOI: 10.2337/diabetes.55.04.06.db05-1449] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Type 2 diabetes is characterized by an approximately 60% loss of beta-cell mass, a marked defect in postprandial insulin secretion, and a failure to suppress postprandial glucagon concentrations. It is possible that postprandial hyperglucagonemia in type 2 diabetes is due to impaired postprandial insulin secretion. To address this, we studied eight adult Goettingen minipigs before and after an approximately 60% reduction in beta-cell mass induced by alloxan. Pigs were studied fasting and after ingestion of a mixed meal. Insulin and glucagon secretion were determined by deconvolution of blood hormone concentrations measured at 1-min intervals. The relationship between insulin and glucagon release was analyzed using cross-correlation and forward versus reverse cross-approximate entropy. We report that glucagon and insulin were secreted in approximately 4-min pulses. Prealloxan, postprandial insulin secretion drove an approximately 20% suppression of glucagon concentrations (P < 0.01), through inhibition of glucagon pulse mass. The alloxan-induced approximately 60% deficit in beta-cell mass lead to an approximately 70% deficit in postprandial insulin secretion and loss of the postprandial insulin-driven suppression of glucagon secretion. We conclude that postprandial hyperglucagonemia in type 2 diabetes is likely due to loss of intraislet postprandial suppression of glucagon secretion by insulin.
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Affiliation(s)
- Juris J Meier
- Larry Hillblom Islet Research Center, UCLA David Geffen School of Medicine, 24-130 Warren Hall, 900 Veteran Ave., Los Angeles, CA 90095-7073, USA
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Liu PY, Pincus SM, Takahashi PY, Roebuck PD, Iranmanesh A, Keenan DM, Veldhuis JD. Aging attenuates both the regularity and joint synchrony of LH and testosterone secretion in normal men: analyses via a model of graded GnRH receptor blockade. Am J Physiol Endocrinol Metab 2006; 290:E34-E41. [PMID: 16339924 DOI: 10.1152/ajpendo.00227.2005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Testosterone (T) secretion declines in the aging male, albeit for unknown reasons. From an ensemble perspective, repeated incremental signaling among gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and T is required to maintain physiological androgen availability. Pattern-regularity statistics, such as univariate approximate entropy (ApEn) and bivariate cross-ApEn, provide specific and sensitive model-free measurement of altered multi-pathway control. The present study exploits partial muting of one pathway (GnRH drive) to appraise adaptive regulation of LH and T secretion in young and aging individuals. Analyses comprised 100 paired 18-h LH and T concentration time series obtained in 25 healthy men ages 20-72 yr each administered placebo and three graded doses of a specific GnRH-receptor antagonist. Graded blockade of GnRH drive increased the individual regularity of LH and T secretion and the synchrony of LH-T feedforward and T-LH feedback in the cohort as a whole (P<0.001 for each). However, age markedly attenuated ganirelix-induced enhancement of univariate T orderliness and bivariate LH-T feedback and T-LH feedback synchrony (P <or= 0.0025). In summary, the present analyses support the thesis that aging disrupts coordinate control of T secretion, LH-T feedforward, and T-LH feedback in healthy men. Thus the experimental strategy of stepwise silencing of an agonistic pathway may have utility in dissecting the bases of altered neurohormonal linkages in other systems.
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Affiliation(s)
- Peter Y Liu
- Endocrine Research Unit, Dept. of Internal Medicine, Mayo School of Graduate Medical Education, General Clinical Research Center, Mayo Clinic, Rochester, MN 55905, USA
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Veldhuis JD, Keenan DM, Roelfsema F, Iranmanesh A. Aging-related adaptations in the corticotropic axis: modulation by gender. Endocrinol Metab Clin North Am 2005; 34:993-1014, x-xi. [PMID: 16310635 DOI: 10.1016/j.ecl.2005.07.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Johannes D Veldhuis
- Endocrine Research Unit, Department of Internal Medicine, Mayo School of Graduate Medical Education, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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35
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Liu PY, Iranmanesh A, Nehra AX, Keenan DM, Veldhuis JD. Mechanisms of hypoandrogenemia in healthy aging men. Endocrinol Metab Clin North Am 2005; 34:935-55, ix. [PMID: 16310632 DOI: 10.1016/j.ecl.2005.07.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Peter Y Liu
- Endocrine Research Unit, Department of Internal Medicine, Mayo School of Graduate Education, General Clinical Research Center, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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Liu PY, Swerdloff RS, Wang C. Relative testosterone deficiency in older men: clinical definition and presentation. Endocrinol Metab Clin North Am 2005; 34:957-72, x. [PMID: 16310633 DOI: 10.1016/j.ecl.2005.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Peter Y Liu
- Division of Endocrinology, Department of Medicine, Los Angeles Biomedical Research Institute, Harbor-University of California at Los Angeles Medical Center, 1000 West Carson Street, Torrance, CA 90509, USA
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Liu PY, Takahashi PY, Roebuck PD, Iranmanesh A, Veldhuis JD. Aging in healthy men impairs recombinant human luteinizing hormone (LH)-stimulated testosterone secretion monitored under a two-day intravenous pulsatile LH clamp. J Clin Endocrinol Metab 2005; 90:5544-50. [PMID: 16030163 DOI: 10.1210/jc.2005-0909] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Testosterone (Te) depletion in aging men in principle could reflect deficits in the hypothalamus, pituitary gland, or testis. Available pharmacological studies of possible failure of Leydig cell steroidogenesis remain inconclusive. OBJECTIVE The objective of the study was to assess Te secretion in older and young men in response to near physiological LH stimulation. INTERVENTION Pulsatile i.v. infusion of recombinant human LH was administered for 2 d to stimulate Te secretion during suppression of endogenous LH concentrations with a potent selective GnRH receptor antagonist (ganirelix). SUBJECTS/CONTEXT: Healthy older (aged 60-73 yr, n = 8) and young (19-30 yr, n = 13) men were studied in an academic setting. MEASURES Pulsatile LH and Te concentrations on the second day of exogenous LH stimulation were measured. RESULTS Serum ganirelix concentrations and infused LH pulse increments were similar by age. In contrast, older subjects manifested: 1) reduced mean Te concentrations (P = 0.016), Te peak heights (P = 0.014), increments (P = 0.010), summed areas (P < 0.013), and interpeak Te concentrations (P = 0.023); 2) decreased Te to LH concentration ratios (P = 0.002); 3) diminished LH-Te feed-forward synchrony (P = 0.020); and 4) a blunted amplitude (P = 0.036) and advanced phase (P = 0.013) of diurnal Te rhythms. CONCLUSION A novel regimen of pulsatile LH stimulation for 48 h during GnRH receptor blockade unmasks deficits in pulsatile, basal, synchronous, and nyctohemeral Te secretion in healthy older men. These findings do not exclude concomitant defects in GnRH outflow and/or Te-negative feedback in the aging male.
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Affiliation(s)
- Peter Y Liu
- Endocrine Research Unit, Department of Internal Medicine, Mayo School of Graduate Medical Education, General Clinical Research Center, Mayo Clinic, Rochester, Minnesota 55905, USA
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Liu PY, Pincus SM, Keenan DM, Roelfsema F, Veldhuis JD. Joint synchrony of reciprocal hormonal signaling in human paradigms of both ACTH excess and cortisol depletion. Am J Physiol Endocrinol Metab 2005; 289:E160-5. [PMID: 15727954 DOI: 10.1152/ajpendo.00007.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hypothalamo-pituitary-adrenal axis is a stress-adaptive neuroendocrine ensemble, in which adrenocorticotropin (ACTH) drives cortisol secretion (feedforward) and cortisol restrains ACTH outflow (feedback). Quantifying direction- and pathway-specific adjustments within this and other interlinked systems by noninvasive means remains difficult. The present study tests the hypothesis that forward and reverse cross-approximate entropy (X-ApEn), a lag-, scale-, and model-independent measure of two-signal synchrony, would allow quantifiable discrimination of feedforward (ACTH --> cortisol) and feedback (cortisol --> ACTH) control. To this end, forward X-ApEn was defined by employing serial ACTH concentrations as a template to appraise pair-wise synchrony with cortisol secretion rates and vice versa for reverse X-ApEn. Coupled hormone profiles included normal ACTH-normal cortisol, high ACTH-high cortisol, and high ACTH-low cortisol concentrations in 35 healthy subjects, 21 patients with tumoral ACTH secretion, and 9 volunteers given placebo and a steroidogenic inhibitor, respectively. We used forward and reverse X-ApEn analyses to identify marked and equivalent losses of feedforward and feedback linkages (both P < 0.001) in patients with tumoral ACTH secretion. An identical analytical strategy revealed that ACTH --> cortisol feedforward synchrony decreases (P < 0.001), whereas cortisol --> ACTH feedback synchrony increases (P < 0.001), in response to hypocortisolemia. The collective outcomes establish precedence for pathway-specific adaptations in a major neurohormonal system. Thus quantification of directionally defined joint synchrony of biologically coupled signals offers a noninvasive strategy to dissect feedforward- and feedback-selective adaptations in an interactive axis.
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Affiliation(s)
- Peter Y Liu
- Division of Endocrinology, Department of Internal Medicine, Endocrine Research Unit and General Clinical Research Center, Mayo Clinic, Mayo Medical and Graduate Schools of Medicine, 200 First St. Southwest, Rochester, MN 55905, USA
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