Effects of RU 486 on energy expenditure and meal tolerance in normal men

Resting Energy Expenditure and Body Composition in Children and Adolescents With Genetic, Hypothalamic, Medication-Induced or Multifactorial Severe Obesity

Background

Pediatric obesity is a multifactorial disease which can be caused by underlying medical disorders arising from disruptions in the hypothalamic leptin-melanocortin pathway, which regulates satiety and energy expenditure.

Aim

To investigate and compare resting energy expenditure (REE) and body composition characteristics of children and adolescents with severe obesity with or without underlying medical causes.

Methods

This prospective observational study included pediatric patients who underwent an extensive diagnostic workup in our academic centre that evaluated endocrine, non-syndromic and syndromic genetic, hypothalamic, and medication-induced causes of obesity. REE was assessed by indirect calorimetry; body composition by air displacement plethysmography. The ratio between measured REE (mREE) and predicted REE (Schofield equations), REE%, was calculated, with decreased mREE defined as REE% ≤90% and elevated mREE ≥110%. Additionally, the influence of fat-free-mass (FFM) on mREE was evaluated using multiple linear regression.

Results

We included 292 patients (146 [50%] with body composition measurements), of which 218 (75%) patients had multifactorial obesity and 74 (25%) an underlying medical cause: non-syndromic and syndromic genetic (n= 29 and 28, respectively), hypothalamic (n= 10), and medication-induced (n= 7) obesity. Mean age was 10.8 ± 4.3 years, 59% were female, mean BMI SDS was 3.8 ± 1.1, indicating severe obesity. Mean REE% was higher in children with non-syndromic genetic obesity (107.4% ± 12.7) and lower in children with hypothalamic obesity (87.6% ± 14.2) compared to multifactorial obesity (100.5% ± 12.6, both p<0.01). In 9 children with pseudohypoparathyroidism type 1a, mean REE% was similar (100.4 ± 5.1). Across all patients, mREE was decreased in 60 (21%) patients and elevated in 69 (24%) patients. After adjustment for FFM, mREE did not differ between patients within each of the subgroups of underlying medical causes compared to multifactorial obesity (all p>0.05).

Conclusions

In this cohort of children with severe obesity due to various etiologies, large inter-individual differences in mREE were found. Consistent with previous studies, almost half of patients had decreased or elevated mREE. This knowledge is important for patient-tailored treatment, e.g. personalized dietary and physical activity interventions and consideration of pharmacotherapy affecting central energy expenditure regulation in children with decreased mREE.

Dexamethasone reduces energy expenditure and increases susceptibility to diet-induced obesity in mice

OBJECTIVE

To investigate how long-term treatment with dexamethasone affects energy expenditure and adiposity in mice and whether this is influenced by feeding on a high-fat diet (HFD).

DESIGN AND METHODS

Mice were placed on a HFD for 2 weeks and started on dexamethasone at 5 mg/kg every other day during the next 7 weeks.

RESULTS

Treatment with dexamethasone increased body fat, an effect that was more pronounced in the animals kept on HFD; dexamethasone treatment also worsened liver steatosis caused by the HFD. At the same time, treatment with dexamethasone lowered the respiratory quotient in chow-fed animals and slowed nightly metabolic rate in the animals kept on HFD. In addition, the acute VO2 acceleration in response to β3 adrenergic-stimulation was significantly limited in the dexamethasone-treated animals, as a result of marked decrease in UCP-1 mRNA observed in the brown adipose tissue of these animals.

CONCLUSIONS

Long-term treatment with dexamethasone in a mouse model of diet-induced obesity decreases brown adipose tissue thermogenesis and exaggerates adiposity and liver steatosis. © 2013 American Institute of Chemical Engineers AIChE J, 2013.

Extra-adrenal regeneration of glucocorticoids by 11beta-hydroxysteroid dehydrogenase type 1: physiological regulator and pharmacological target for energy partitioning

The major glucocorticoid in man, cortisol, plays important roles in regulating fuel metabolism, energy partitioning and body fat distribution. In addition to the control of cortisol levels in blood by the hypothalamic-pituitary-adrenal axis, intracellular cortisol levels within target tissues can be controlled by local enzymes. 11Beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) catalyses the regeneration of active cortisol from inert cortisone, thereby amplifying cortisol levels and glucocorticoid receptor activation in adipose tissue, liver and other tissues. 11Beta-HSD1 is under complex tissue-specific regulation and there is evidence that it adjusts local cortisol concentrations independently of the plasma cortisol concentrations, e.g. in response to changes in diet. In obesity 11beta-HSD1 mRNA and activity in adipose tissue are increased. The mechanism of this up-regulation remains uncertain; polymorphisms in the HSD11B1 gene have been associated with metabolic complications of obesity, including hypertension and type 2 diabetes, but not with obesity per se. Extensive data have been obtained in mice with transgenic over-expression of 11beta-HSD1 in liver and adipocytes, targeted deletion of 11beta-HSD1, and using novel selective 11beta-HSD1 inhibitors; these data support the use of 11beta-HSD1 inhibitors to lower intracellular glucocorticoid levels and treat both obesity and its metabolic complications. Moreover, in human subjects the non-selective 'prototype' inhibitor carbenoxolone enhances insulin sensitivity. Results of clinical studies with novel potent selective 11beta-HSD1 inhibitors are therefore eagerly awaited. The present article focuses on the physiological role of glucocorticoids in regulating energy partitioning, and the evidence that this process is modulated by 11beta-HSD1 in human subjects.

Validation of three predictive equations for basal metabolic rate in adults

Objective

To cross-validate three predictive set of equations for basal metabolic rate (BMR) developed by Schofield (Schofield database), Henry (Oxford database) and Cole (Oxford database) using mean values for age, weight, height and BMR of published studies.

Design

Literature review of studies published from 1985 to March 2002.

Setting

All studies selected used appropriate methods and followed conditions that met the criteria established for basal metabolism, were performed in healthy adults, and were not part of the Schofield or Oxford database.

Subjects

A total of 261 groups of men and women from 175 studies were selected and categorised in three age groups (18.5–29.9, 30.0–59.9, ≥60 years old) and three body mass index (BMI) groups (normal weight, overweight and obese).

Results

Linear regression and concordance correlation analysis showed that the three sets of equations had the same association and agreement with measured BMR, across gender, age, and BMI groups. The agreement of all equations was moderate for men and poor for women. The lowest mean squared prediction errors (MSPRs) were given by Henry equations in men and Cole equations in women. Henry and Cole equations gave lower values than Schofield equations, except for men over 60 years of age. Henry equations were the most accurate in men. None of the three equations performed consistently better in women.

Conclusion

These results support the use of Henry equations in men with a wide range of age and BMI. None of the proposed predictive equations seem to be appropriate to estimate BMR in women.

Inhibition of 11beta-hydroxysteroid dehydrogenase type 1 reduces food intake and weight gain but maintains energy expenditure in diet-induced obese mice

AIMS/HYPOTHESIS

The 11beta-hydroxysteroid dehydrogenase type-1 inhibitor BVT.2733 lowers blood glucose and insulin in mutant mouse models of obesity and diabetes. Its effects on energy balance and body composition, and their contribution to improved glucose homeostasis have received little attention.

MATERIALS AND METHODS

BVT.2733 (100 mg/kg, orally) was given twice daily to lean and diet-induced obese mice for 16 or 17 days. A group of obese mice was pair-fed to the amounts consumed by BVT.2733-treated mice.

RESULTS

In both obese and lean mice, BVT.2733 reduced food intake and weight gain, but increased water intake. Pair-feeding caused almost as great a decrease in body weight as BVT.2733. Energy expenditure was 38+/-8% higher in the BVT.2733-treated obese mice than in the pair-fed mice. Terminal plasma corticosterone was raised, lean body weight reduced and percentage fat unchanged in the pair-fed mice (control, 47.8+/-2.6%; pair-fed, 47.1+/-1.9%), whereas BVT.2733 did not reduce lean mass, but did reduce percentage fat (40.9+/-2.0%). BVT.2733 but not pair-feeding reduced both the glucose tolerance AUC and the plasma insulin concentration 30 min after giving glucose.

CONCLUSIONS/INTERPRETATION

BVT.2733 reduced food intake but prevented a concomitant reduction in lean body mass and energy expenditure. The latter effects may have contributed to improved glucose tolerance.