DOCSLIB.ORG

Resistance to Thyroid Hormone Is Associated with Raised Energy Expenditure, Muscle Mitochondrial Uncoupling, and Hyperphagia

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Resistance to Thyroid Hormone Is Associated with Raised Energy Expenditure, Muscle Mitochondrial Uncoupling, and Hyperphagia Resistance to thyroid hormone is associated with raised energy expenditure, muscle mitochondrial uncoupling, and hyperphagia Catherine S. Mitchell, … , Krishna Chatterjee, Kitt Falk Petersen J Clin Invest. 2010;120(4):1345-1354. https://doi.org/10.1172/JCI38793. Research Article Metabolism Resistance to thyroid hormone (RTH), a dominantly inherited disorder usually associated with mutations in thyroid hormone receptor β (THRB), is characterized by elevated levels of circulating thyroid hormones (including thyroxine), failure of feedback suppression of thyrotropin, and variable tissue refractoriness to thyroid hormone action. Raised energy expenditure and hyperphagia are recognized features of hyperthyroidism, but the effects of comparable hyperthyroxinemia in RTH patients are unknown. Here, we show that resting energy expenditure (REE) was substantially increased in adults and children with THRB mutations. Energy intake in RTH subjects was increased by 40%, with marked hyperphagia particularly evident in children. Rates of muscle TCA cycle flux were increased by 75% in adults with RTH, whereas rates of ATP synthesis were unchanged, as determined by 13C/31P magnetic resonance spectroscopy. Mitochondrial coupling index between ATP synthesis and mitochondrial rates of oxidation (as estimated by the ratio of ATP synthesis to TCA cycle flux) was significantly decreased in RTH patients. These data demonstrate that basal mitochondrial substrate oxidation is increased and energy production in the form of ATP synthesis is decreased in the muscle of RTH patients and that resting oxidative phosphorylation is uncoupled in this disorder. Furthermore, these observations suggest that mitochondrial uncoupling in skeletal muscle is a major contributor to increased REE in patients with RTH, due to tissue selective retention of […] Find the latest version: https://jci.me/38793/pdf Research article Resistance to thyroid hormone is associated with raised energy expenditure, muscle mitochondrial uncoupling, and hyperphagia Catherine S. Mitchell,1 David B. Savage,1 Sylvie Dufour,2 Nadia Schoenmakers,1 Peter Murgatroyd,1 Douglas Befroy,3 David Halsall,4 Samantha Northcott,1 Philippa Raymond-Barker,1 Suzanne Curran,1 Elana Henning,1 Julia Keogh,1 Penny Owen,5 John Lazarus,5 Douglas L. Rothman,6 I. Sadaf Farooqi,1 Gerald I. Shulman,2,3,7 Krishna Chatterjee,1 and Kitt Falk Petersen3 1University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom. 2Howard Hughes Medical Institute and 3Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut. 4Department of Clinical Biochemistry, Addenbrooke’s Hospital. 5Department of Medicine, University of Cardiff, United Kingdom. 6Department of Diagnostic Radiology and 7Department of Cellular and Molecular Physiology, Yale University School of Medicine. Resistance to thyroid hormone (RTH), a dominantly inherited disorder usually associated with mutations in thyroid hormone receptor β (THRB), is characterized by elevated levels of circulating thyroid hormones (including thyroxine), failure of feedback suppression of thyrotropin, and variable tissue refractoriness to thyroid hormone action. Raised energy expenditure and hyperphagia are recognized features of hyperthy- roidism, but the effects of comparable hyperthyroxinemia in RTH patients are unknown. Here, we show that resting energy expenditure (REE) was substantially increased in adults and children with THRB mutations. Energy intake in RTH subjects was increased by 40%, with marked hyperphagia particularly evident in chil- dren. Rates of muscle TCA cycle flux were increased by 75% in adults with RTH, whereas rates of ATP synthesis were unchanged, as determined by 13C/31P magnetic resonance spectroscopy. Mitochondrial coupling index between ATP synthesis and mitochondrial rates of oxidation (as estimated by the ratio of ATP synthesis to TCA cycle flux) was significantly decreased in RTH patients. These data demonstrate that basal mitochon- drial substrate oxidation is increased and energy production in the form of ATP synthesis is decreased in the muscle of RTH patients and that resting oxidative phosphorylation is uncoupled in this disorder. Further- more, these observations suggest that mitochondrial uncoupling in skeletal muscle is a major contributor to increased REE in patients with RTH, due to tissue selective retention of thyroid hormone receptor α sensitivity to elevated thyroid hormone levels. Introduction subset of affected individuals can exhibit some clinical features Thyroid hormone action is mediated by the products of 2 human of hyperthyroidism, suggesting greater central or pituitary RTH genes (thyroid hormone receptor α [THRA] and thyroid hormone (PRTH) than in peripheral tissues. Although imprecise, this clini- receptor β [THRB]), which are alternately spliced to generate 3 cal distinction may remain useful in the management of the dis- highly homologous nuclear receptor isoforms (TRα1, TRβ1, and order (8). The basis of and mechanisms underlying variable tissue TRβ2) with differing tissue distributions (1). Resistance to thy- resistance in RTH are not fully understood. roid hormone (RTH) is an uncommon disorder, characterized by It is well recognized that the thyroid hormone is a major deter- elevated circulating thyroid hormones with nonsuppressed thyro- minant of energy expenditure, including basal metabolic rate tropin (TSH) levels, reflecting resistance within the hypothalam- (BMR) (9); indeed, even small changes in thyroid hormone levels in ic-pituitary-thyroid axis but variable refractoriness to hormone patients receiving hormone replacement are associated with effects action in peripheral tissues (2). Usually dominantly inherited, on resting energy expenditure (REE) (10). Markedly increased RTH is associated with diverse, heterozygous THRB gene muta- appetite is considered to be a clinical feature of hyperthyroidism, tions impairing hormone binding and/or transcriptional activ- and hyperphagia and enhanced energy intake have indeed been ity of receptors (3–5). In addition, mutant receptors inhibit the formally documented in thyrotoxicosis (11). action of their wild-type counterparts in a dominant-negative We have identified a large cohort of subjects with RTH, defined manner when they are coexpressed (6, 7). The clinical phenotype genetically with THRB gene mutations, with lifelong elevation of RTH is variable: most subjects are either asymptomatic or have of circulating thyroid hormones to levels comparable to conven- nonspecific symptoms and are deemed to be in a compensated tional thyrotoxicosis. To determine whether such hyperthyroxin- euthyroid state termed generalized RTH (GRTH); in contrast, a emia is associated with changes in energy balance, we have evalu- ated whole-body energy expenditure by indirect calorimetry, food Authorship note: Catherine S. Mitchell and David B. Savage contributed equally to intake using an ad libitum test meal (12), and quantified hunger this work. and satiety using visual analogue scores during energy balance Conflict of interest: The authors have declared that no conflict of interest exists. feeding in adults and children with RTH. As skeletal muscle is the Citation for this article: J Clin Invest. 2010;120(4):1345–1354. doi:10.1172/JCI38793. major determinant of energy expenditure in humans (13), we have The Journal of Clinical Investigation http://www.jci.org Volume 120 Number 4 April 2010 1345 research article Table 1 Demographic, anthropometric, and biochemical characteristics of control, adult patients with RTH, and thyrotoxic patients studied by venti- lated hood calorimetry Control RTH Thyrotoxic ANOVA P value P value (16 M, 29 F) (22 M, 32 F) (3 M, 8 F) P value (RTH vs. control) (RTH vs. thyrotoxic) Age (yr) 37.5 ± 1.7 40.6 ± 2.0 44.1 ± 4.2 0.25 NS NS Weight (kg) 69.3 ± 2.1 71.9 ± 2.0 64.8 ± 2.7 0.27 NS NS BMI (18.5–25 kg/m2) 24.5 ± 0.7 26.2 ± 0.7 23.7 ± 0.8 0.10 NS NS Fat to lean mass ratio 0.49 ± 0.04 0.60 ± 0.04 0.61 ± 0.06 0.06 <0.05 NS TSH (0.4–4.0 mU/l) 1.56 ± 0.12 4.06 ± 0.56 <0.03 <0.01 <0.01 <0.01 fT4 (9–20 pmol/l) 13.7 ± 0.3 33.7 ± 1.6 38.9 ± 6.7 <0.01 <0.01 NS fT3 (3–7.5 pmol/l) 5.5 ± 0.1 13.3 ± 0.6 25.8 ± 3.2 <0.01 <0.01 <0.01 Sleeping heart rate (bpm) 60 ± 1 67 ± 1 79 ± 4 <0.01 <0.01 <0.01 HOMA-IR (1.0) 1.3 ± 0.2 1.9 ± 0.2 1.2 ± 0.1 0.02 <0.05 NS FFA (280–920 μmol/l) 268 ± 18 359 ± 21 479 ± 47 <0.01 <0.01 <0.05 Total cholesterol (mmol/l) 4.7 ± 0.2 4.8 ± 0.1 4.1 ± 0.3 0.10 NS NS LDL cholesterol (mmol/l) 2.8 ± 0.1 3.0 ± 0.1 2.5 ± 0.2 0.13 NS NS Triglycerides (mmol/l) 1.2 ± 0.1 1.5 ± 0.1 1.0 ± 0.1 0.11 NS NS HDL cholesterol (mmol/l) 1.5 ± 0.1 1.2 ± 0.1 1.2 ± 0.1 <0.05 0.01 NS SHBG 48.1 ± 4.0 34.1 ± 3.1 129.6 ± 15.4 <0.01 <0.01 <0.01 Data were analyzed using ANOVA with post-hoc Dunnett’s analyses. P values of less than 0.05 were considered significantly. The number 1.0 for HOMA- IR is based on the assumption that normal-weight, healthy subjects aged less than 35 years have an insulin resistance of 1 and β cell function of 100%. M, male; F, female. used 13C/31P magnetic resonance spectroscopy (MRS) to assess firming that the liver is refractory to thyroid hormone action in in vivo resting mitochondrial oxidative phosphorylation activ- this disorder as has been described previously (16). ity noninvasively in a subset of this RTH cohort. The rate of flux Energy expenditure in RTH subjects. REE, measured by indirect through the TCA cycle, a direct measure of mitochondrial oxida- calorimetry and expressed per kilogram LBM to allow for dif- tive function, was determined using 13C MRS during an infusion ferences in body composition between groups, was significantly of [2-13C] acetate.
Load more

Recommended publications
  • Association Between Basal Metabolic Rate and Handgrip Strength in Older Koreans
    International Journal of Environmental Research and Public Health Article Association between Basal Metabolic Rate and Handgrip Strength in Older Koreans 1, 1, 2 3 1, Sung-Kwan Oh y, Da-Hye Son y , Yu-Jin Kwon , Hye Sun Lee and Ji-Won Lee * 1 Department of Family Medicine, Yonsei University College of Medicine, 50 Yonsei-ro Seodaemun-gu, Seoul 03722, Korea; [email protected] (S.-K.O.); [email protected] (D.-H.S.) 2 Department of Family Medicine, Yong-In Severance Hospital, 23 Yongmunno (405 Yeokbuk-dong), Gyeonggi 17046, Korea; [email protected] 3 Biostatistics Collaboration Unit, Department of Research Affairs, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Korea; [email protected] * Correspondence: [email protected] These authors contributed equally to this paper. y Received: 16 October 2019; Accepted: 8 November 2019; Published: 9 November 2019 Abstract: We investigated the relationship between the basal metabolic rate (BMR) and muscle strength through measurement of handgrip strength. We conducted a cross-sectional study of a population representative of older Korean from the 2014–2016 Korean National Health and Nutrition Examination Survey. A total of 2512 community-dwelling men and women aged 65 years and older were included. The BMR was calculated with the Singapore equation and handgrip strength was measured using a digital dynamometer. The patients were categorized into handgrip strength quartiles and a weighted one-way analysis of variance (ANOVA) for continuous variables and a weighted chi-squared test for categorical variables were performed. Pearson, Spearman correlation analysis, univariate, and multivariate linear regression were performed.
    [Show full text]
  • Cardiac Basal Metabolism
    Japanese Journal of Physiology, 51, 399–426, 2001 REVIEW Cardiac Basal Metabolism C. L. GIBBS and D. S. LOISELLE* Department of Physiology, Faculty of Medicine, Nursing and Health Sciences, Monash University, PO Box 13F, Monash University, Victoria 3800, Australia; and *Department of Physiology, Faculty of Medicine and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand Abstract: We endeavor to show that the me- usage remain unresolved. We consider many of tabolism of the nonbeating heart can vary over the physiological factors that can alter the basal an extreme range: from values approximating metabolic rate, stressing the importance of sub- those measured in the beating heart to values of strate supply. We point out that the protective ef- only a small fraction of normal—perhaps mimick- fect of hypothermia may be less than is com- ing the situation of nonflow arrest during cardiac monly assumed in the literature and suggest that bypass surgery. We discuss some of the techni- hypoxia and ischemia may be able to regulate cal issues that make it difficult to establish the basal metabolic rate, thus making an important magnitude of basal metabolism in vivo. We con- contribution to the phenomenon of cardiac hiber- sider some of the likely contributors to its magni- nation. [Japanese Journal of Physiology, 51, tude and point out that the biochemical reasons 399–426, 2001] for a sizable fraction of the heart’s basal ATP Key words: whole hearts, isolated preparations, biochemical contributors, modifiers, species differ- ence, temperature, substrate, hypoxia. heart operations are performed on arrested hearts I. Definition and Introduction worldwide each year, it would seem imperative that The cardiac basal metabolism is the rate of energy we understand the cellular mechanisms that can expenditure of the quiescent myocardium.
    [Show full text]
  • Energetics of Free-Ranging Seabirds
    University of San Diego Digital USD Biology: Faculty Scholarship Department of Biology 2002 Energetics of Free-Ranging Seabirds Hugh I. Ellis University of San Diego Geir Wing Gabrielsen Follow this and additional works at: https://digital.sandiego.edu/biology_facpub Part of the Biology Commons, Ecology and Evolutionary Biology Commons, Ornithology Commons, and the Physiology Commons Digital USD Citation Ellis, Hugh I. and Gabrielsen, Geir Wing, "Energetics of Free-Ranging Seabirds" (2002). Biology: Faculty Scholarship. 20. https://digital.sandiego.edu/biology_facpub/20 This Book Chapter is brought to you for free and open access by the Department of Biology at Digital USD. It has been accepted for inclusion in Biology: Faculty Scholarship by an authorized administrator of Digital USD. For more information, please contact [email protected]. Energetics of Free-Ranging Seabirds Disciplines Biology | Ecology and Evolutionary Biology | Ornithology | Physiology Notes Original publication information: Ellis, H.I. and G.W. Gabrielsen. 2002. Energetics of free-ranging seabirds. Pp. 359-407 in Biology of Marine Birds (B.A. Schreiber and J. Burger, eds.), CRC Press, Boca Raton, FL. This book chapter is available at Digital USD: https://digital.sandiego.edu/biology_facpub/20 Energetics of Free-Ranging 11 Seabirds Hugh I. Ellis and Geir W. Gabrielsen CONTENTS 11.1 Introduction...........................................................................................................................360 11.2 Basal Metabolic Rate in Seabirds........................................................................................360
    [Show full text]
  • The Effect and Dependency of L-Thyroxine Treatment on The
    THE EFFECT AND DEPENDENCY OF L-THYROXINE TREATMENT ON THE BASAL METABOLIC RATE OF POST-METAMORPHIC XENOPUS LAEVIS. A Report of a Senior Study by Angie M. Castle Major: Biology Maryville College Spring, 2007 Date Approved _____________, by ________________________ Faculty Supervisor Date Approved _____________, by ________________________ Editor ii ABSTRACT One function of thyroid hormones is stimulating both the anabolic and catabolic reactions that make up an organism’s metabolism. However, the thyroid may not function properly resulting in hypothyroidism. One side effect of hypothyroidism is a declination in metabolic rate. This study investigated if the thyroid hormone l-thyroxine (T4) could significantly increase the metabolic rate of Xenopus laevis frogs. It was hypothesized that the thyroxine treated Xenopus would demonstrate an increased metabolic rate and decreases in mass. Further, it was hypothesized that after treatment was halted, the experimental group was expected to demonstrate a decrease in metabolic rate and an increase in mass. Twenty-two Xenopus tadpoles were treated with 1mg of l-thyroxine per liter of water for 21 days, and treatment was withdrawn for 21 days. Similarly, twenty- one control tadpoles were treated with 1%NaOH for 21 days. Throughout the 42-day period, the whole body and mass specific metabolic rate was measured using gas exchange respirometry. There was significant increase (p=0.04) in whole body metabolic rate of T4 treated animals, but the increase was not restricted to the treatment period (p=0.12). There was no significant increase in mass specific metabolic rate. Also, there was no significant difference in mass between the final control and the final thyroxine treated (p=0.16).
    [Show full text]
  • Resting Metabolic Rate and Diet-Induced Thermogenesis During Each Phase of the Menstrual Cycle in Healthy Young Women Summary Th
    J. Clin. Biochem. Nutr., 25, 97-107, 1998 Resting Metabolic Rate and Diet-Induced Thermogenesis during Each Phase of the Menstrual Cycle in Healthy Young Women Tatsuhiro MATSUO,1 * Shinichi SAITOH,2 and Masashige SUZUKI,2 1 Division of Nutrition and Biochemistry, Sanyo Women's College, Hatsukaichi 738-8504, Japan 2 Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-8576, Japan (Received June 20, 1998) Summary The effects of the menstrual cycle on resting metabolic rate (RMR) and diet-induced thermogenesis (DIT) were studied in nine healthy young women aged 18-19 years. All subjects were eumenorrheic, with regular menstrual cycles ranging from 28 to 32 days. RMR and DIT were measured in the mid follicular phase and in the mid luteal phase. On the experimental days, subjects fasted overnight; then the RMR was measured by indirect calorimetry. For the measurement of DIT, subjects were fed a meal containing a uniform amount of energy (2.53 MJ) eaten within 15 min, and then indirect calorimetry was performed during rest for 180 min. The RMR was significantly higher in the luteal phase than in the follicular phase (67.0 vs. 62.5 J/kg/min, p<0.01). DIT was also significantly higher in the luteal phase (4.0 vs. 3.2 kJ/kg/3 h, p<0.01). The postprandial respiratory exchange ratio was slightly lower in the luteal phase than in the follicular phase (0.78 vs. 0.81). These results suggest that the menstrual cycle phase affects both the RMR and DIT. Higher postprandial energy expenditure and fat utilization in the luteal phase may be related to sympathetic and endocrinal actions.
    [Show full text]
  • The Relation of Metabolic Rate to Body Weight and Organ Size
    Pediat.Res. 1: 185-195 (1967) Metabolism basal metabolic rate growth REVIEW kidney glomerular filtration rate body surface area body weight oxygen consumption organ growth The Relation of Metabolic Rate to Body Weight and Organ Size A Review M.A. HOLLIDAY[54J, D. POTTER, A.JARRAH and S.BEARG Department of Pediatrics, University of California, San Francisco Medical Center, San Francisco, California, and the Children's Hospital Medical Center, Oakland, California, USA Introduction Historical Background The relation of metabolic rate to body size has been a The measurement of metabolic rate was first achieved subject of continuing interest to physicians, especially by LAVOISIER in 1780. By 1839 enough measurements pediatricians. It has been learned that many quanti- had been accumulated among subjects of different tative functions vary during growth in relation to sizes that it was suggested in a paper read before the metabolic rate, rather than body size. Examples of Royal Academy of France (co-authored by a professor these are cardiac output, glomerular filtration rate, of mathematics and a professor of medicine and oxygen consumption and drug dose. This phenomenon science) that BMR did not increase as body weight may reflect a direct cause and effect relation or may be increased but, rather, as surface area increased [42]. a fortuitous parallel between the relatively slower in- In 1889, RICHET [38] observed that BMR/kg in rab- crease in metabolic rate compared to body size and the bits of varying size decreased as body weight increased; function in question. RUBNER [41] made a similar observation in dogs. Both The fact that a decrease in metabolism and many noted that relating BMR to surface area provided re- other measures of physiological function in relation to a sults that did not vary significantly with size.
    [Show full text]
  • The Body's Energy Budget
    The Body’s Energy Budget energy is measured in units called kcals = Calories the more H’s a molecule contains the more ATP (energy) can be generated of the various energy pathways: fat provides the most energy for its weight note all the H’s more oxidation can occur eg: glucose has 12 H’s 38ATP’s a 16-C FA has 32 H’s 129ATP’s we take in energy continuously we use energy periodically optimal body conditions when energy input = energy output any excess energy intake is stored as fat average person takes in ~1 Million Calories and expends 99% of them maintains energy stability 1 lb of body fat stores 3500 Calories 454g: 87% fat 395g x 9 Cal/g = 3555 kcal would seem if you burn an extra 3500 Cal you would lose 1 lb; and if you eat an extra 3500 Cal you would gain 1 lb not always so: 1. when a person overeats much of the excess energy is stored; some is spent to maintain a heavier body 2. People seem to gain more body fat when they eat extra fat calories than when they eat extra carbohydrate calories 3. They seem to lose body fat most efficiently when they limit fat calories For overweight people a reasonable rate of wt loss is 1/2 – 1 lb/week can be achieved with Cal intake of ~ 10 Cal/lb of body wt. Human Anatomy & Physiology: Nutrition and Metabolism; Ziser, 2004 5 Quicker Weight Loss: 1. may lose lean tissue 2. may not get 100% of nutrients 3.
    [Show full text]
  • The Metabolic Benefits of Menopausal Hormone Therapy Are Not
    nutrients Article The Metabolic Benefits of Menopausal Hormone Therapy Are Not Mediated by Improved Nutritional Habits. The OsteoLaus Cohort Georgios E. Papadakis 1 , Didier Hans 2, Elena Gonzalez Rodriguez 1,2 , Peter Vollenweider 3, Gerard Waeber 3, Pedro Marques-Vidal 3 and Olivier Lamy 2,3,* 1 Service of Endocrinology, Diabetes and Metabolism, Lausanne University Hospital and University of Lausanne, CH-1011 Lausanne, Switzerland 2 Center of Bone Diseases, CHUV, Lausanne University Hospital and University of Lausanne, CH-1011 Lausanne, Switzerland 3 Service of Internal Medicine, CHUV, Lausanne University Hospital and University of Lausanne, CH-1011 Lausanne, Switzerland * Correspondence: [email protected]; Tel.: +41-213140876 Received: 8 July 2019; Accepted: 14 August 2019; Published: 16 August 2019 Abstract: Menopause alters body composition by increasing fat mass. Menopausal hormone therapy (MHT) is associated with decreased total and visceral adiposity. It is unclear whether MHT favorably affects energy intake. We aimed to assess in the OsteoLaus cohort whether total energy intake (TEI) and/or diet quality (macro- and micronutrients, dietary patterns, dietary scores, dietary recommendations)—evaluated by a validated food frequency questionnaire—differ in 839 postmenopausal women classified as current, past or never MHT users. There was no difference between groups regarding TEI or consumption of macronutrients. After multivariable adjustment, MHT users were less likely to adhere to the unhealthy pattern ‘fat and sugar: Current vs. never users [OR (95% CI): 0.48 (0.28–0.82)]; past vs. never users [OR (95% CI): 0.47 (0.27–0.78)]. Past users exhibited a better performance in the revised score for Mediterranean diet than never users (5.00 0.12 vs.
    [Show full text]
  • Energy Metabolism During the Menstrual Cycle, Pregnancy and Lactation in Well Nourished Indian Women
    ENERGY METABOLISM DURING THE MENSTRUAL CYCLE, PREGNANCY AND LACTATION IN WELL NOURISHED INDIAN WOMEN Leonard Sunil Piers lllllllllllllmiiiiiiii , 0000 0576 0455 Promotor: dr. J.G.A.J. Hautvast Hoogleraar voedingsleer en voedselbereiding Promotor: dr. P.S. Shetty Professor of Physiology St. John's Medical College Bangalore, India. Co-promotor: dr. ir. J.M.A. van Raaij Universitair Hoofddocent Vakgroep Humane Voeding AJ U0g>7©\ , (7 Vf ENERGY METABOLISM DURING THE MENSTRUAL CYCLE, PREGNANCY AND LACTATION IN WELL NOURISHED INDIAN WOMEN Leonard Sunil Piers Proefschrift ter verkrijging van de graad van doctor in de landbouw- en milieuwetenschappen, op gezag van de rector magnificus, dr. C. M. Karssen, in het openbaar te verdedigen op woensdag 2 maart 1994 des namiddags te vier uur in de Aula van de Landbouwuniversiteit te Wageningen Ckw-ÇT«^tónc i aiBLiOTHEf» This study was supported by a grant from The Netherlands Foundation for the Advancement of Tropical Research (WOTRO)(Grant WB96-80 ) CIP-DATA KONINKLIJKE BIBLIOTHEEK, DEN HAAG Piers, Leonard Sunil Energy metabolism during the menstrual cycle, pregnancy and lactation in well nourished Indian women / Leonard Sunil Piers. [S.l.:s.n.]. -11 1 Thesis Wageningen - with ref. - With summary in Dutch. ISBN 90-5485-241-0 Subject headings: Energy metabolism and pregnancy / energy metabolism and menstrual cycle / energy metabolism and lactation Printed at Grafisch Service Centrum, LUW °1994 Piers LS. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical, photocopying, recording, or otherwise, without the permission of the author, or, when appropriate, of the publishers.
    [Show full text]
  • Reply from Dr D. A. Sedlock Thank You for Sharing with Me and Allowing Me to Reply to the Letter Sent to You from Dr J
    LETTERS TO THE EDITOR 497 References SEDLOCK DA , LAVENTURE SJ . Body composition and resting energy expenditure in long term spinal cord injury. Paraplegia 1990;28:448-454. WADE OL, BISHOP JM. Cardiac output and regional blood flow. Oxford: Blackwell, 1962;p 93. COURNANDA, RICHARDS DW . TransAss Amer Phys 1954;67: 162. SILVER JR. The oxygen cost of breathing in tetraplegic patients. Paraplegia 1963:204-214. J. R. Silver Consultant in Spinal Injuries Stoke Mandeville Hospital Aylesbury, UK Reply from Dr D. A. Sedlock Thank you for sharing with me and allowing me to reply to the letter sent to you from Dr J. R. Silver regarding our article entitled 'Body composition and resting energy expenditure in long term spinal cord injury' Paraplegia 1990;28:448-454. Dr Silver provides some evidence I to indicate that skeletal muscle accounts for a substantial proportion of resting oxygen uptake, and therefore disagrees with the statement in our article2 that a spinal lesion below TIO ' ... would affect predominantly lower extremity skeletal muscle, which contributes little to resting energy expenditure'. Although the evidence cited by Dr Silver shows skeletal muscle to account for 30% of resting energy expenditure, I Bray and Atkinson3 report previously published values ranging from 17-25%. Regardless of the actual proportion, these percentages reflect the oxygen consumed by the skeletal musculature of the entire body. If we assume that the lower extremities account for even as much as 60% of the total body skeletal musculature, then it follows that '60 of the estimated 17-30% of skeletal muscle metabolism can be accounted for by this muscle mass.
    [Show full text]
  • Best-Fitting Prediction Equations for Basal Metabolic Rate
    International Journal of Obesity (2013) 37, 1364–1370 & 2013 Macmillan Publishers Limited All rights reserved 0307-0565/13 www.nature.com/ijo REVIEW Best-fitting prediction equations for basal metabolic rate: informing obesity interventions in diverse populations NS Sabounchi1, H Rahmandad2 and A Ammerman3 Basal metabolic rate (BMR) represents the largest component of total energy expenditure and is a major contributor to energy balance. Therefore, accurately estimating BMR is critical for developing rigorous obesity prevention and control strategies. Over the past several decades, numerous BMR formulas have been developed targeted to different population groups. A comprehensive literature search revealed 248 BMR estimation equations developed using diverse ranges of age, gender, race, fat-free mass, fat mass, height, waist-to-hip ratio, body mass index and weight. A subset of 47 studies included enough detail to allow for development of meta-regression equations. Utilizing these studies, meta-equations were developed targeted to 20 specific population groups. This review provides a comprehensive summary of available BMR equations and an estimate of their accuracy. An accompanying online BMR prediction tool (available at http://www.sdl.ise.vt.edu/tutorials.html) was developed to automatically estimate BMR based on the most appropriate equation after user-entry of individual age, race, gender and weight. International Journal of Obesity (2013) 37, 1364–1370; doi:10.1038/ijo.2012.218; published online 15 January 2013 Keywords: basal metabolic rate; resting metabolic rate; prediction; meta-analysis; review; meta-regression INTRODUCTION mass (FFM)),13 gender and race15 on BMR. Most of the developed Obesity is the result of a positive imbalance between energy equations have focused on cross-sectional data from targeted intake and energy expenditure.1 The basal metabolic rate (BMR), sub-populations (for example, the young adults) and have used a 16 defined as the energy required for performing vital body functions specific equation structure.
    [Show full text]
  • Mammalian Basal Metabolic Rate Is Proportional to Body Mass2/3
    Mammalian basal metabolic rate is proportional to body mass2/3 Craig R. White* and Roger S. Seymour Department of Environmental Biology, University of Adelaide, Adelaide 5005, Australia Edited by Knut Schmidt-Nielsen, Duke University, Durham, NC, and approved December 27, 2002 (received for review October 23, 2002) The relationship between mammalian basal metabolic rate (BMR, The problematic inclusion of ruminants was also recognized ml of O2 per h) and body mass (M, g) has been the subject of regular by Kleiber (2), whose compilation included 13 data points investigation for over a century. Typically, the relationship is derived from eight species (two steers, cow, man, woman, sheep, aMb. The male dog, female dog, hen, pigeon, male rat, female rat, and ring ؍ expressed as an allometric equation of the form BMR scaling exponent (b) is a point of contention throughout this body dove). Kleiber addressed the problem by providing b values of literature, within which arguments for and against geometric calculated for all 13 data points and for a subset of 9 data points ,(scaling are made and with ruminants excluded. Using Kleiber’s data (ref. 2; Table 1 (4/3 ؍ and quarter-power (b (3/2 ؍ b) rebutted. Recently, interest in the topic has been revived by exponents of 0.737 (r2 ϭ 0.999) and 0.727 (r2 ϭ 0.999) can be published explanations for quarter-power scaling based on fractal calculated for these groups, respectively. In this case, quarter- nutrient supply networks and four-dimensional biology. Here, a power scaling remained following the exclusion of ruminants, new analysis of the allometry of mammalian BMR that accounts for because of the influence of the four data points for male and variation associated with body temperature, digestive state, and female dogs and humans.
    [Show full text]