Resting energy expenditure and fat-free mass do not decline during aging in severely obese women.

BACKGROUND & AIMS: Few studies have investigated the age-related modification of resting energy expenditure (REE) and free fat mass (FFM) in severe obesity. This cross-sectional study analyzed REE and FFM in severely and moderately obese women and in lean subjects at different ages to find the possible differences between obese and lean subjects during aging. METHODS: Sedentary women (n=261) were divided into three groups with different body mass indexes (BMIs): 20.0-24.9; 30-34.9; >40 kg/m(2). Each group was then divided into five subgroups: 20-29; 30-39; 40-49; 50-59; 60-69 years. REE was measured with an indirect calorimetric device. The FFM was calculated by bioelectric impedance. RESULTS: The REE in severely obese women was higher than the REE in lean or moderately obese women. The FFM of severely obese women was lower than that of moderately obese or lean women. The aging induced reductions of the REE and FFM in lean and moderately obese subjects, but not in women with severe obesity. CONCLUSIONS: This experiment indicates that REE and FFM do not decline during aging in women with BMI>40, suggesting that the severe obesity induces different age-related adaptations of metabolism and body composition.

Activity of autonomic nervous system is related to body weight in pre-menopausal, but not in post-menopausal women.

This study analyzed vegetative modulation, expressed as heart rate variability (HRV) power spectral analysis, in lean and obese women at pre-menopausal or post-menopausal age to reveal possible differences in menopause-related autonomic activity in lean and obese subjects. Sedentary women (n = 40) were divided in four groups: pre-menopausal lean and obese women, post-menopausal lean and obese subjects. The HRV-power spectrum was evaluated on a 5-min long ECG recording. The absolute values of the spectrum were summed in the following frequencies: a low-frequency (0.04-0.15 Hz; LF) and high-frequency (0.15-0.40; HF) range. LF and HF were values used to estimate the sympathetic and parasympathetic activity. LF and HF values of pre-menopausal obese women are lower than values of lean women. The menopause induced a same decrease in LF and HF values in lean and obese subjects, so that no difference was found in post-menopausal groups. This experiment indicates that modifications of autonomic modulation can be included among factors related to obesity in pre-menopausal, but not post-menopausal women.

Plasma 1,25 hydroxycholecalciferol concentrations and net intestinal calcium, phosphate and magnesium absorption in man.

We evaluated the relationship between plasma concentrations of the renal hormone (I,25(OH)2 vitamin D and net intestinal CA,PO4 and Mg absorption in healthy volunteers eating similar diets. Net intestinal CA absorption was positively correlated to plasma I,25(OH)2D concentrations. By contrast, there was no significant correlation between PO4 and Mg absorption and plasma I,25(OH)2D concentrations. We conclude that net intestinal Ca absorption is critically dependent upon the availability of renal homone, while other factors must play a dominant role in regulating net intestinal PO4 and MG absorption.

Serum alpha-tocopherol, lipids, potassium and creatine phosphokinase in normal and patients with malabsorption.

Serum alpha-tocopherol, lipids, potassium and creatine phosphokinase levels we-remeasured in 20 adult male control patients and 120 malabsorption patients. The malabsorption group had significantly lower serum alpha-tocopherol levels than the control group. The change was independent of serum total lipid levels that were not significantly different among the two groups. Serum potassium and creatine phosphokinase did not correlate with serum alpha-tocopherol levels in either control and malabsorption group. Body mass indices that are directly relate to adiposity increased with increase of serum alpha-tocopherol and total lipids of serum.