Riki Kuwahata

Relative contribution of lean and fat mass component to bone mineral density in males.

Abstract. We investigated the relative contribution of lean body mass (LBM) and body fat mass to bone mineral density (BMD) in 93 healthy Japanese male volunteers (mean age, 33.1 ± 6.9 years; range, 18–54 years). Age, height (Ht), weight (Wt), and body mass index (BMI, Wt/Ht2) were recorded. Body fat mass, percentage of body fat, body fat mass/Ht2, LBM, LBM/Wt, LBM/Ht2, and lumbar spine (L2–L4) and total body BMD (TBBMD) were measured by dual-energy X-ray absorptiometry. On the Pearson correlation test, LBM was positively correlated with L2–L4 BMD. LBM, LBM/Wt, and LBM/Ht2 were positively correlated with TBBMD. However, body fat mass and body fat mass/Ht2 were not correlated with lumbar spine and total body BMD. On the partial correlation test, LBM was still correlated with lumbar spine (r = 0.307, P < 0.05) and total body BMD (r = 0.545, P < 0.0001), irrespective of age and height, whereas body fat mass was not correlated with BMD of these sites (r = −0.069 and −0.169, respectively). We concluded that, in males, LBM is one of the significant determinants of BMD whereas body fat mass is a negligible BMD determinant.

Difference in the effect of adiposity on bone density between pre- and postmenopausal women.

OBJECTIVES Elevated bone mineral density (BMD) in obese women is partially attributable to the higher circulating estrogen levels derived from extraglandular aromatization in adipose tissue. However, it remains unclear whether there is an effect of overall adiposity on BMD in both pre- and postmenopausal women. The difference in the effect of overall adiposity on BMD between pre- and postmenopausal women was investigated. MATERIALS AND METHODS Subjects were 296 premenopausal women with regular menstruation and 233 postmenopausal women. Age, age at menarche, years since menopause (YSM, in postmenopausal women), weight, height, and body mass index were recorded. Total fat mass amount, lean mass amount, and percentage of body fat were measured by whole body scanning with dual-energy X-ray absorptiometry (DEXA). Lumbar spine BMD (L2-L4) was measured by DEXA. In each group, significant determinants of BMD were investigated using univariate and stepwise multiple regression analysis. RESULTS In postmenopausal women, YSM, lean mass amount, total fat mass amount, and height were significant determinants of BMD (R(2)=0.273, P<0.001). In premenopausal women, only two variables including lean mass amount and age at menarche were significant determinants of lumbar spine BMD (R(2)=0.110, P<0.001), but total fat mass amount and percentage of body fat were not significant determinants of BMD. CONCLUSION The effect of overall adiposity on BMD is more prominent in postmenopausal women than in premenopausal women.

Relationship between body fat distribution and bone mineral density in premenopausal Japanese women

Objective To investigate the relationship between body fat distribution and bone mineral density (BMD). Methods Subjects were 282 premenopausal women (mean age ± standard deviation [SD], 38.8 ± 8.5 years; range, 20–51 years) with regular menstrual cycles. Baseline characteristics included age, age at menarche, height, weight, body mass index ([BMI], weight/height2), and parity. Anthropometric characteristics including the ratio of trunk fat mass to leg fat mass (trunk–leg fat ratio), percentage of body fat, and total body lean mass were measured by whole-body scanning with dual-energy x-ray absorptiometry. Lumbar spine BMD (L2–4) was also measured by dual-energy x-ray absorptiometry. Correlations of BMD to baseline and anthropometric characteristics were investigated using univariate and multivariate analysis. Results Although height, trunk–leg fat ratio, and total body lean mass were positively correlated with lumbar spine BMD (r = .18, P < .01; r = .17, P < .01; and r = .25, P < .001; respectively), age at menarche was inversely correlated with BMD (r = −.19, P < .01). On multivariable analysis, trunk–leg fat ratio, height, age at menarche, and total body lean mass were still independently correlated with lumbar spine BMD (P < .05). However, total fat mass was not correlated with BMD. Conclusion Upper body fat distribution rather than overall adiposity is associated with lumbar spine BMD in premenopausal women. Humoral factors associated with body fat mass appear to influence lumbar spine BMD.

Relationship of upper body obesity to menstrual disorders

Background. The purpose of the present study was to investigate the relative contribution of upper and lower body obesity to obesity‐related menstrual disorders.

Relationship of androgens to muscle size and bone mineral density in women with polycystic ovary syndrome.

OBJECTIVE To investigate the relationship of androgens to regional muscle size and bone mineral density (BMD) in women with polycystic ovary syndrome (PCOS). METHODS Seventy‐one amenorrheic and right‐side dominant women with PCOS (mean age ± standard deviation 28.1 ± 6.7 years) were enrolled. Baseline characteristics included age, height, weight, and body mass index (BMI). Regional BMD and lean mass were measured by whole‐body scanning with dual‐energy x‐ray absorptiometry. Serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), and androstenedione were measured by radioimmunoassay. Correlations between regional BMD and variables were investigated using a Pearson correlation test and multiple regression analysis. RESULTS Serum testosterone levels correlated significantly with lean mass of the left arm, right arm, trunk, left leg, and right leg (r = .34, P < .05 to r = .50, P < .01). Regional lean mass correlated significantly with respective regional BMD (r = .30, P < .05 to r = .68, P < .001). These relationships remained significant after adjusting for age, height, and weight. Serum testosterone levels were not correlated with BMD of the bilateral arms and lumbar spine. Although serum testosterone levels correlated with leg BMD (r = .34, P < .05 to r = .45, P < .01), significance did not persist after adjusting for respective regional lean mass. CONCLUSION Testosterone influences regional BMD through increasing regional muscle mass in women with polycystic ovary syndrome.

Body fat distribution and body composition during GnRH agonist therapy.

Objective To identify the effects of GnRH agonist therapy on body composition (lean and fat mass components) and body fat distribution. Methods Fifteen women with uterine leiomyomas were given a GnRH agonist (leuprorelin acetate, 3.75 mg) monthly for 4 months. Weight, height, and body mass index (BMI, weight/height2) were recorded. Regional and total body composition, trunk-leg fat ratio, bone mineral density of the lumbar spine (L2–L4), and total body were assessed by whole-body scanning with dual-energy x-ray absorptiometry before and after treatment. Uterine volume was measured by transabdominal ultrasonography. Results The mean (± standard deviation [SD]) lean mass of total body, trunk, and leg decreased significantly (36.3 ± 4.9 to 35.4 ± 4.4 kg, P < .01; 18.8 ± 2.8 to 18.1 ± 2.8 kg, P < .05; and 11.4 ± 1.8 to 11.1 ± 1.6 kg, P < .05; respectively), whereas body fat mass, percentage of body fat, and trunk fat mass increased significantly (20.8 ± 4.8 to 21.8 ± 4.6 kg, P < .01; 34.9 ± 5.9 to 36.5 ± 5.2%, P < .01; and 8.6 ± 3.0 to 9.3 ± 3.0 kg, P < .01; respectively). Trunk-leg fat ratio increased significantly (1.03 ± 0.32 to 1.12 ± 0.33, P < .05). Weight, BMI, arm tissue composition (lean and fat mass components), and leg fat mass did not change during 4 months of GnRH agonist therapy. Bone mineral density and uterine volume decreased significantly. Conclusion Hypogonadism by GnRH agonist therapy induces lean mass loss, increased adiposity overall, and upper body fat accumulation.

The effects of physical exercise on body fat distribution and bone mineral density in postmenopausal women

OBJECTIVE The present cross-sectional study investigated the effects of physical exercise on body fat distribution and bone mineral density (BMD). METHODS Subjects were 57 postmenopausal women (mean age, 60.5+/-6.4 years) who had exercised regularly for at least 2 years. Controls were 130 age-matched sedentary women. Age, years since menopause (YSM), height, weight, and body mass index (BMI, wt./ht.(2)) were recorded. Total fat mass, percentage of body fat, trunk fat mass, leg fat mass, the ratio of trunk fat mass to leg fat mass (trunk-leg fat ratio), total body lean mass, percentage of body lean, and lumbar spine BMD (L2-L4) were measured by dual-energy X-ray absorptiometry. RESULTS Baseline characteristics and leg fat mass did not differ between the two groups. Total fat mass, percentage of body fat, trunk fat mass, and trunk-leg fat ratio were lower (P<0.05, P<0.01, P<0.01 and P<0.001, respectively), while total body lean mass, percentage of body lean mass, and lumbar spine BMD were higher in exercising women (P<0.05, P<0.05 and P<0.01, respectively). Performing physical exercise was inversely correlated with trunk-leg fat ratio (standardized regression coefficient=-0.178, P<0.01), but positively correlated with BMD (0. 203, P<0.01) irrespective of age, height, YSM, and total fat mass. CONCLUSION Physical exercise has beneficial effects on body fat distribution and BMD in postmenopausal women. Reduction of upper body fat distribution with physical exercise may be more attributable to the decrease in trunk fat mass.

Effect of non–weight-bearing body fat on bone mineral density before and after menopause

Objective To investigate the difference in the effect of non–weight-bearing body fat mass on bone mineral density between premenopausal and postmenopausal women. Methods We studied 252 regularly menstruating pre-menopausal women and 213 postmenopausal women with right side dominance. Age, years since menopause (in post-menopausal women), height, weight, and body mass index were recorded. Bone mineral density of non–weight-bearing sites (ie, arms), weight-bearing sites (ie, lumbar spine including L2–4 and legs), and body fat mass were measured by whole-body scanning with dual-energy x-ray absorptiometry. Body fat mass was also measured by dual energy x-ray absorptiometry. Results Body fat mass did not differ between groups. In postmenopausal women, body fat mass correlated positively with bone mineral density of the left leg (r = .41, P < .001), right leg (r = .36, P < .001), left arm (r = .31, P < .001), and lumbar spine (r = .27, P < .001). The correlation between body fat mass and bone mineral density of the left arm remained significant after adjusting for age, years since menopause, and height. In premenopausal women, body fat mass correlated positively with bone mineral density of left leg (r = .37, P < .001) and right leg (r = 0.31, P < .001), but correlated weakly with bilateral arms (r ≤ .19) and lumbar spine bone mineral density (r = 0.13, P < .05). Conclusion The effect of non–weight-bearing body fat on bone mineral density was greater in postmenopausal than premenopausal women.

Inverse relationship between the changes in trunk lean and fat mass during gonadotropin-releasing hormone agonist therapy

OBJECTIVE The aim of the present study was to investigate the relationship between the changes in lean and fat mass during gonadotropin-releasing hormone agonist (GnRH agonist) therapy. METHODS Subjects were 24 premenopausal women (mean age, 39.5+/-9.4 years; range, 32-52 years) with uterine leiomyomas. They were given GnRH agonist (leuprorelin acetate, 3.75 mg) monthly for 4 months. Age and height were recorded. Body weight, regional and total body composition, and the ratio of trunk fat mass to leg fat mass (trunk-leg fat ratio) were assessed by whole body scanning with dual-energy X-ray absorptiometry. Changes in these variables were investigated. Relationships between the changes in regional lean and fat mass were investigated using Pearsons correlation test. RESULTS Trunk fat mass significantly increased from 8616+/-3538 to 9265+/-3526 g (P<0.01) and trunk-leg fat ratio significantly increased (1.02+/-0.39 to 1.07+/-0.39, P<0.05). Trunk lean mass significantly decreased from 18,509+/-2602 to 17,916+/-2402 g (P<0.01). However, body weight, and lean and fat mass component in the extremities did not change. Change in trunk fat mass was inversely correlated with change in trunk lean mass (r=-0.439, P<0.05), but such relationships were not observed in arm and leg regions. CONCLUSION Inverse relationship between the changes in trunk lean and fat mass is observed during GnRH agonist therapy.

Discordance in the decline in regional lean and bone mass with advancing age

Aim: To investigate whether regional mineral‐free lean mass (lean mass) and bone mineral density (BMD) decrease equally with advancing age.