Relation between adiponectin and bone mineral density in elderly post-menopausal women: role of body composition, leptin, insulin resistance, and dehydroepiandrosterone sulfate.

INTRODUCTION: Adipocytokines have been proposed as new mediators of the protective effects of fat mass on the skeleton. The aim of this study was to test the relationship between adiponectin, leptin, and bone mineral density (BMD), independently of body composition, insulin resistance, and other factors known to affect bone metabolism. METHODS: Thirty-six post-menopausal non-diabetic elderly women, with ages ranging from 66 to 77 yr took part in the study. In all subjects we evaluated body weight, height, body mass index (BMI), waist circumference, adiponectin, leptin, insulin, DHEAS, and homeostasis model assessment of insulin resistance (HOMA), as well as yr since menopause. Total body fat mass (FM) and BMD at whole body and femoral level were measured with Dual energy X-ray Absorptiometry (DXA). Volumetric BMD was defined as the ratio between total body BMD and height. RESULTS: Leptin was positively and adiponectin negatively related with whole body and femoral BMD. Positive associations between insulin, HOMA, DHEAS, and BMD measures were also found. After adjusting for FM, only adiponectin maintained a significant relation with whole body and femoral BMD; the strength of this association was reduced after adjustment for insulin resistance, estimated by HOMA. In stepwise multiple linear regression analyses adiponectin explained 11.7% of total BMD variance, 17.4% of femoral neck BMD variance, and 30.7% of volumetric BMD variance, independently of BMI, FM, leptin, HOMA, and DHEAS. CONCLUSIONS: The present study may suggest possible involvement of adiponectin in bone metabolism, independently of FM and insulin resistance even in elderly post-menopausal women.

Homocysteine and life-style in the elderly.

Elevated homocysteine increases the risk of vascular diseases but little information is available about this issue in the elderly. The aim of this cross-sectional study was to evaluate the relationships between homocysteinemia and gender, anthropometric, and life-style characteristics in a community-dwelling elderly population (65 men and 120 women; 67-78 years). Basal plasma homocysteine levels were determined by High Performance Liquid Chromatography (HPLC). Clinical records, and nutritional and anthropometric variables were collected in all subjects. Body composition was evaluated in all subjects by Dual energy X-ray Absorptiometry (DXA). Thirty-three percent of women and 66% of men had hyper-homocysteinemia. In women, a positive correlation was present between homocysteinemia, age, diastolic blood pressure and plasmatic creatinine, and a negative correlation between homocysteine, fiber intake and folates. In males, there was a positive correlation between plasma homocysteine, age, and body mass index. Multiple regression analysis showed that fat-free mass, cigarette smoking, fiber intake, vitamin B6 and total kcal intake accounted for 18% of homocysteine variance in males (R2 = 0.18, p<0.05). Significantly higher homocysteine values were found in women with a history of cardiovascular disease than in those without (16.6 +/- 9.4 vs 13.8 +/- 4.4 micromol/L, p<0.05). Homocysteinemia was significantly higher in elderly men compared to women (16.7 +/- 4.7 vs 15.3 +/- 7.6; p<0.05). Gender differences in homocysteine disappeared after adjusting for fat-free mass. This study confirms the age-related increase in plasma homocysteine. Life-style characteristics seem to influence significantly homocysteine levels in the elderly. Our study shows that gender effects on homocysteine may be attributed to differences in body composition.

Sagittal abdominal diameter as a practical predictor of visceral fat.

OBJECTIVE: To evaluate the relationships between the supine sagittal abdominal diameter (SAD) and visceral fat, as well as to evaluate intra- and inter-observer reliability of sagittal diameter measurement. PATIENTS: Twenty-eight women ranging in age from 27-78 y with a body mass index (BMI) ranging from 16.9-48.1 kg/m2 and 23 men ranging in age from 32-75 y with BMI ranging from 20-41.6 kg/m2. MEASUREMENT: Body fat distribution was measured by waist circumference, waist to hip ratio (WHR), SAD, anthropometrically assessed and a single slice of computed tomography (CT) at the L4-L5 level. RESULTS: In both genders, a significant association was found between visceral adipose tissue (AT) and SAD, as evaluated by CT (women r = 0.80; men r = 0.83, P < 0.001), and SAD by anthropometry (women r = 0.76; men r = 0.82, P < 0.001), as well as between visceral AT and waist circumference (women r = 0.76, men r = 0.86, P < 0.001) and WHR (women r = 0.57, P < 0.01, men r = 0.80, P < 0.001). A significant association was also found between subcutaneous AT and SAD by anthropometry (women r = 0.79, men r = 0.74, P < 0.001). After adjusting for BMI, the association between subcutaneous AT and SAD was no longer significant in men and only moderately significant in women (r = 0.42, P < 0.05), while the association between visceral AT and SAD by anthropometry remained significant in both genders (women r = 0.63, P < 0.001; men r = 0.66, P < 0.001). When the subjects were divided into two groups according to BMI (lean to moderately overweight women with BMI < 28 and men with BMI < 30 and obese women with BMI > 28 and men with BMI > 30) we found that the relationships between SAD by anthropometry, as well as SAD by CT and visceral AT, were higher in lean to moderately overweight subjects than in those who were obese. High inter-observer correlation was found concerning SAD measurement (r = 0.99, P < 0.001). Intra- and inter-observer precision as evaluated by coefficient of variation and intraclass correlation coefficient for SAD measurement was very high. CONCLUSION: Our study shows the usefulness of SAD by anthropometry to predict visceral fat and its very high inter- and intra-observer precision.

Interrelationships between weight loss, body fat distribution and sex hormones in pre- and postmenopausal obese women.

OBJECTIVES: Relationships between regional body fat distribution and sex hormones as well as changes in sex hormones after weight loss were evaluated. SETTING: All subjects were hospitalized in the Institute of Internal Medicine of the University of Verona. SUBJECTS: Twenty-six premenopausal (age 33.7 +/- 10.2 years) and 15 postmenopausal (age 57.9 +/- 5.9 years) obese women. INTERVENTIONS: Body weight, body-mass index, waist and hip circumferences, visceral fat by computed tomography and sex hormones were evaluated before and after 4 weeks on a very low energy diet. RESULTS: Body-mass index was higher in pre-than in postmenopausal women, although the difference was not significant. Total and free testosterone were significantly higher in the pre- than in the postmenopausal group (P < 0.001). Significant negative correlations were found between age and total testosterone (r = -0.65; P < 0.001), free testosterone (r = -0.54; P < 0.001), androstenedione (r = -0.46; P < 0.01) and urinary cortisol excretion (r = -0.50; P < 0.01). A negative correlation was found between visceral fat and total testosterone (r = -0.41; P < 0.01). After adjusting for age, the negative correlation between total testosterone and visceral fat encountered both in the subject group as a whole and in premenopausal women was no longer significant, whilst a significant negative association between visceral fat and sex hormone binding globulin (SHBG) (r = -0.56; P < 0.001) was always found. When step-down regression analysis was used to evaluate the joint effect of age, menopausal status, and anthropometric and metabolic variables on sex hormones, age was the most powerful independent variable for predicting total testosterone, free testosterone and androstenedione levels, whilst menopausal status was the most powerful predictor of FSH and LH levels. Changes in hormones after VLED were analysed separately in pre- and postmenopausal women. None of the hormones changed significantly after VLED in the postmenopausal group, except for FSH values. LH, free testosterone and urinary cortisol excretion values decreased significantly after VLED in the premenopausal group. CONCLUSIONS: Our data show that age, to a greater extent than visceral fat, seems to be negatively associated with steroid sex hormones. Weight loss seems to be associated with changes in sex hormones only in premenopausal women.