Resting Energy Expenditure In Men Research Articles

Association of Serum Adipokines and Resting Energy Expenditure in Patients With Chronic Kidney Disease

Background and AimMetabolic disorders are prevalent in patients with chronic kidney disease (CKD) and may lead to protein energy wasting (PEW). Adipokines improve connections between PEW and energy metabolism. We aimed to determine the relationship between adipokine levels and resting energy expenditure (REE) in patients with CKD.MethodsA total of 208 patients in non-dialyzed CKD stages 3–5 were enrolled in this cross-sectional study. Serum adipokines (leptin, adiponectin, and interleukin 6 (IL-6) were measured using enzyme-linked immunosorbent assay. Patient's REE was measured using indirect calorimetry. Fat mass (FM) and lean tissue mass (LTM) were measured using multiple-frequency bioimpedance analysis. Spearman correlation analyses and multivariate linear regression models were used to assess the association between serum adipokines and REE.ResultsThe mean age was 52.7 ± 14.6 years, and 26.9, 26.4, and 46.7% of our participants had CKD stages 3, 4, and 5, respectively. The median values of serum adiponectin, leptin, and IL-6 were 470.4 (range, 291.1–802.2), 238.1 (range, 187.9–418.4), and 4.0 (range, 2.4–9.5) pg/mL, respectively. The male participants had significantly lower FM% (P = 0.001) and lower leptin levels (P < 0.001) than the female participants. After adjusting for age, diabetes, high-sensitivity C-reactive protein, intact parathyroid hormone, LTM, and FM, multiple linear regression analysis revealed that serum leptin levels were significantly positively associated with REE in men rather than in women (P < 0.05). Serum adiponectin levels were inversely associated with REE in men, but this association disappeared while FM was additionally adjusted. Adiponectin levels in women were not correlated with REE (P > 0.05). IL-6 was not significantly associated with REE in either men or women.ConclusionsA sex-specific relationship between serum adipokines (leptin and adiponectin) and REE was observed in patients with CKD stages 3–5, which was partly confounded by FM.

Age-related changes in resting energy expenditure in normal weight, overweight and obese men and women

ObjectivesAging is associated with changes in resting energy expenditure (REE) and body composition. We investigated the association between age and changes in REE in men and women stratified by body mass index (BMI) categories (normal weight, overweight and obesity). We also examined whether the age-related decline in REE was explained by concomitant changes in body composition and lifestyle factors. Study designCross-sectional. Main outcome measures3442 adult participants (age range: 18–81 y; men/women: 977/2465) were included. The BMI range was 18.5–60.2kg/m2. REE was measured by indirect calorimetry in fasting conditions and body composition by bioelectrical impedance. Regression models were used to evaluate age-related changes in REE in subjects stratified by sex and BMI. Models were adjusted for body composition (fat mass, fat free mass), smoking, disease count and physical activity. ResultsIn unadjusted models, the rate of decline in REE was highest in obese men (slope=−8.7±0.8kcal/day/year) whereas the lowest rate of decline was observed in normal weight women (−2.9±0.3kcal/day/year). Gender differences were observed for the age of onset of REE adaptive changes (i.e., not accounted by age related changes in body composition and lifestyle factors). In women, adaptive changes appeared to occur in middle-age (∼47 y) across all BMI groups whereas changes seemed to be delayed in obese men (∼54 y) compared to overweight (∼43 y) and normal weight (∼39 y) men. ConclusionsSex and BMI influenced the rate and degree of the age-related decline in REE. Critical age windows have been identified for the onset of putative mechanisms of energy adaptation. These findings require confirmation in prospective studies.

Effects of Estrogen and Testosterone on Resting Energy Expenditure in Older Men

The mechanisms by which sex hormones cause changes in body composition are unclear. Sex steroid deficiency might directly reduce energy expenditure/fat oxidation and thereby predispose to increased body fat. Alternatively, sex steroid deficiency could result in lean tissue loss and thus reduced energy expenditure. Our objective was to examine the independent and combined effects of acute testosterone and estrogen withdrawal on respiratory exchange ratio (RER) and resting energy expenditure (REE) in men. The objective of the study was to examine the independent and combined effects of acute estrogen and testosterone withdrawal on RER and REE in men. A total of 54 men aged 50-80 years, BMI range of 17-35 kg/m(2) underwent a 3-week eugonadal run-in hormone-treatment period involving suppression of endogenous sex steroids using letrozole and leuprolide acetate (Lupron) while sex steroid concentrations were maintained with transdermal testosterone (T) and estradiol (E). A second Lupron injection was then given and participants were randomized to one of the following four 3-week treatment groups: group A (-T, -E), group B (-T, +E), group C (+T, -E), and group D (+T, +E). REE and RER were measured via indirect calorimetry before and after the 3-week treatment period. Three-week suppression and/or repletion of estrogen or testosterone did not produce changes in RER or REE within or between groups. We conclude that abrupt changes in sex steroids does not change resting substrate oxidation, indicating that changes that can be observed after more prolonged periods of deficiency are most likely due to direct effects of sex steroids on body composition.