Bone density and body composition in Japanese women

Age-related variations in trunk composition and patterns of regional bone and soft tissue changes in adult Caucasian women by DXA

We explored the regional variations in body composition with advancing age in healthy Caucasian females living in the Mediterranean area. The objectives of this study were to establish body composition values for the trunk in healthy women of a Greek origin and to evaluate the effects of aging on the distribution of truncal bone mass, fat mass (FM) and lean mass (LM). Body composition of the trunk and detailed analysis of its anatomical components-the ribs, the thoracic spine, the lumbar spine and the pelvis, and FM and LM ratios--were calculated in 330 women aged 20-85 years, using DXA. Peak bone mineral density (BMD) of the trunk was attained between ages 30 and 33. The overall truncal BMD reduction with age was 20.7% (p < 0.001). Peak %LM of the trunk was achieved at age 20. The overall reduction of %LM with age for the trunk was 9.8% (p < 0.001). Peak %FM of the trunk was attained between ages 68 and 73, and the overall %FM reduction with age was 2.8% (p > 0.05). Multiple comparative analyses showed that the 51-60 years age group was the landmark age for significant changes of truncal bone mass measures across all age groups (p = 0). For truncal LM and FM metrics, multigroup comparative analysis showed the turning point of significant changes in soft tissue was the 41-50 age bracket (p = 0 and p = 0, respectively). In Greek women, truncal %LM exceeded by far %FM across all ages (p = 0). Our results suggest that aging affects body composition of the trunk in ambulatory healthy women of a Greek origin differently, leading to menopausal loss of bone mass, senior adulthood loss of lean mass, and middle-age storage of fat mass. In adult women, these age-related associations between bone and soft tissue metrics on DXA exams carry implications for the attainment of optimal peak values and shifts in body composition overtime, impacting lifelong skeletal health.

Age-related trends and reference intervals of cross-linked C-telopeptide of type I collagen and procollagen type I N-propeptide from a reference population of Sri Lankan adult women

Refer ence values of bone turnover markers (BTMs) are determined by factors that are country-specific. In Sri Lanka, unavailability of BTM reference data has led to their non-use in management of osteoporosis. The results of this study can be used as reference data for women in Sri Lanka.

INTRODUCTION

This study was performed to establish age-related reference intervals for bone resorption marker; cross-linked C-telopeptide of type I collagen (CTX) and bone formation marker; procollagen type I N-propeptide (PINP) in a group of Sri Lankan adult women.

METHODS

Adult women (n = 347) aged 20-70 years were recruited using age-stratified random sampling technique and categorized into age groups by decades. Serum CTX and PINP concentration were measured using enzyme-linked immunosorbent assay (ELISA). The geometric mean (95% confidence interval) and 2.5th and 97.5th percentiles were calculated. ANOVA was used to compare the means between groups.

RESULTS

Mean CTX levels were relatively low and remained unchanged between 20 and 49 years. After the age of 49 years, mean CTXconcentration elevated significantly until the age of 70 years (43%, p < 0.001). Mean PINP concentrations were not significantly different between age categories (p > 0.05). Reference intervals of CTX and PINP were based on 2.5th and 97.5th percentile values. Reference intervals of CTX for the age groups of 20-29, 30-39, 40-49, 50-59, and 60-70 years were 0.19-0.97 ng/mL, 0.18-0.95 ng/mL, 0.20-1.29 ng/mL, 0.17-2.20 ng/mL, and 0.17-2.85 ng/mL respectively. Reference intervals of PINP for the same age groups were 118-810 pg/mL, 119-772 pg/mL, 116-645 pg/mL, 108-684 pg/mL, and 108-715 pg/mL respectively.

CONCLUSION

In Sri Lanka, bone turnover markers are not used in evaluating patients mainly due to lack of normative data. These values can be used as reference data for women in this age group.

Correlation between bone mineral density and body composition in Japanese females aged 18-40 years with low forearm bone mineral density

OBJECTIVES

To clarify the relationship between bone mineral density (BMD) and body composition in Japanese women aged 18-40 years with low forearm BMD.

METHODS

The subjects were Japanese 199 women who had been selected for inclusion in the study based on a low forearm BMD determined at the Annual Women's Health Examination. The subjects' mean (+/- standard deviation) age, body height, body weight, and body mass index (BMI) were 33.5 (+/-4.3) years, 158.1 (+/-5.1) cm, 49.6 (+/-5.7) kg, and 19.8 (+/-2.1), respectively. The BMD of the lumbar spine, total body, and left arm were measured using dual-energy X-ray absorptiometry (DXA). Fat mass (FM), bone-free lean tissue mass (LTM), and body fat percentage (BF%) were measured simultaneously with DXA.

RESULTS

In the structural equation model, the standardized regression weights for the path from BMI to BMD of all sites were 0.273-0.434. Conversely, the BF% to BMD of the total body and left arm were -0.192 and -0.296, respectively. In multiple regression analysis, the FM index (FMI) was significantly associated with the BMD of the lumbar spine as a weight-bearing site. The LTM index (LTMI) was significantly associated with the BMD of the total body and left arm as a non-weight-bearing site.

CONCLUSIONS

Young females with low forearm BMD had low body weight and BMI. Thinness was shown to be a risk factor for low BMD, in accordance with results reported elsewhere. A gain in body weight may have the effect of increasing BMD, but our results suggest that to increase BMD, the gain in body weight must include increases in LTM, and not FM alone.

Bone mineral mass in males and females with and without Down syndrome

Previous bone comparison studies between subjects with and without Down syndrome (DS) were performed using bone mineral density (BMD) as the dependent variable, and mainly focused on lumbar spine region. The purpose of this study was to compare bone mineral mass adjusted for bone and body size, in limbs, lumbar spine, and femoral neck between males and females with and without DS. Subjects were 66 females (33 with DS) and 68 males (34 with DS) aged 14-40 years. Analysis of covariance (ANCOVA) was used to analyze the main and interaction effects of gender and condition on bone mineral mass. For this purpose, adjusted bone mineral content (BMC) (for bone area, height, and age), volumetric bone mineral density (vBMD) (for age), and composite indices of femoral neck strength (for age), were used as the dependent variables, corrected additionally for body composition variables selected by regression analysis. ANCOVA revealed lower lumbar spine vBMD in DS than in control subjects with (-5%, P = 0.013), or without body weight adjustments (-6%, P = 0.003). In femoral neck, the mean of each strength measure was also lower in DS than in control subjects. Mean differences between groups were, with and without additional adjustments for fat mass, respectively, -8% (P = 0.009), and -13% (P < 0.001) for compressive strength, -11% (P = 0.036), and -16% (P = 0.004) for bending strength, and -7% (P = 0.031), and -11% (P = 0.002) for impact strength. These lumbar spine and femoral neck differences between groups were highest in young adults (> 20 years) and not significant in adolescents. No interaction effect was observed between gender and condition. In conclusion, DS was shown to be a risk factor for low vBMD in lumbar spine, and for diminished bone strength relative to the loads that the femoral neck must bear. Body composition did not reach statistical significance as predictor of bone differences in these sites between subjects with and without DS, suggesting that other factors may be involved in this detrimental bone status, particularly in young adults compared with adolescents.

Body weight change since menopause and percentage body fat mass are predictors of subsequent bone mineral density change of the proximal femur in women aged 75 years and older: results of a 5 year prospective study

Few studies have evaluated risk factors for bone loss in elderly women. We examined risk factors associated with a 5-year longitudinal change in bone mineral density (BMD) at the hip in healthy women aged 75 years and older. The BMD of 276 women from the French EPIDOS (Epidémiologie des Osteoporoses) study was assessed in Montpellier from 1992 to 1993 and again from 1997 to 1998. BMD was measured at the femoral neck, trochanter, and Ward's area using the same Lunar densitometer. We examined the relationship between clinical and behavioral factors at baseline and their variations during follow-up, with percentage BMD change adjusted for baseline BMD. Depending on the femur subregion studied, a significant decrease in BMD (exceeding the least significant difference, i.e., > 2.8 CV) was observed in 36.2% to 51.1% of women. Multivariate analysis showed that both postmenopausal weight change before baseline and baseline percentage of fat mass were positively correlated with BMD change at the Ward's triangle and the trochanter. Yearly absolute and relative weight changes over the follow-up period were significantly associated with change of trochanter and femoral neck BMD. Our results show that maintenance of body weight throughout the postmenopause period and body fat mass play protective roles against bone loss at the proximal femur in women aged 75 years and older and suggest the value in including assessment of weight change throughout postmenopause and percentage body fat mass in screening programs for elderly women who are at higher risk of accelerated bone loss.

Effect of a one-year combined exercise training program on body composition in men with coronary artery disease

Increased fat mass, particularly abdominal fat mass, is associated with poor metabolic profiles and an increase in cardiovascular risk factors. The purpose of this study was to evaluate the effect of a 1-year combined aerobic and strength training regimen, compared to aerobic training only, on body composition in patients with coronary artery disease (CAD). Thirty-six males with CAD were assigned to 3 groups: 13 to weight training plus aerobic training (combined training group [CT]), 13 to aerobic training only (aerobic training group [AT]), and 10 to a control group (no exercise [CG]). Body composition was determined by dual-energy x-ray absorptiometry (DEXA). Differences were observed between groups at the end of the study, controlling for prevalues. The total and trunk percent fat mass (%FM) were lower in CT compared with AT and CG (P<.05). The total %FM in AT was significantly (P<.05) lower than in CG, but the %FM of the trunk did not differ between the 2 groups. Fat-free mass (FFM) was significantly higher in CT than in AT and CG (P<.05). The results suggest that a long-term CT program is more effective than an AT program alone in producing changes in body composition. The percentage changes in total and trunk fat mass were higher in CT (-11% and -12%, respectively) than in AT (-2.4% and -0.7%, respectively). Future studies need to investigate the specific health effects of trunkal fat mass loss in patients with CAD.

Relation between body composition and age in healthy Japanese subjects

OBJECTIVE

To describe the relation between body composition and age measured by dual-energy X-ray absorptiometry (DXA) in healthy Japanese adults.

DESIGN

Cross-sectional study.

SUBJECTS AND MEASUREMENTS

The subjects were 2411 healthy Japanese adults (males 625, females 1786, age 20--79 y) who attended the Fukuoka Health Promotion Center, Fukuoka, Japan for health check-up. Body composition was determined by DXA (QDR-2000, Hologic) for the whole body and three anatomical regions of arms, legs and trunk.

RESULTS

The mean values of body mass index (BMI) and percentage fat mass (%FM) were 23.2+/-3.1 (s.d.) kg/m(2) and 21.8+/-6.8% for males and 22.1+/-3.3 kg/m(2) and 32.0+/-7.5% for females, respectively. For males, curvilinear relations with the peaks in their forties or fifties were seen for the variables associated adiposity, ie BMI, waist and hip circumference, waist-hip ratio, total or regional fat mass (FM), %FM and ratio of trunk FM to leg FM. For females, most of these variables increased linearly in older subjects. Lean mass (LM), bone mineral content (BMC) and bone mineral density (BMD) of the whole body and appendicular LM were relatively constant until the forties and then decreased in both sexes. The rates of decrease in the total or appendicular LM were larger for males than for females, whereas those in BMC or BMD were larger for females than for males.

CONCLUSIONS

This study presents the first detailed data on body composition in Japanese, which may be useful when comparing with populations of different racial and ethnic backgrounds and studying ill subjects.

Relationship between total and regional bone mineral density and menopausal state, body composition and life style factors in overweight Japanese women

OBJECTIVE

To investigate whether menopausal state, body composition and lifestyle factors influence total and regional bone mineral density in overweight Japanese women.

DESIGN

Cross-sectional study of women who were recruited to the weight reduction program held at community-based health promotion center in Tokyo area.

SUBJECTS

A total of 178 women with a mean age of 48 y old (20-69 y) with a clear menstrual history and BMI over 24.

MEASUREMENTS

Total, regional and lumbar spine bone mineral density (BMD) and body composition were measured using DXA (Lunar). Menstrual history was taken by a questionnaire and walking steps per day and energy intake were measured. Physical fitness was assessed by cardio-respiratory fitness and leg extension power. Subjects were divided into pre-menopausal and post-menopausal groups.

RESULTS

Pre-menopausal group had significantly higher total body BMD as well as regional BMD than post-menopausal group. However, no differences in BMI, percentage fat and fat mass (FM) were seen between the two groups. The multiple regression analysis stepwise method revealed that total and regional BMD correlated with menopausal state and total FM independently. Total and regional BMD did not correlate with total non-fat soft tissue mass (NFSM), energy intake, walking steps or physical fitness levels. Trunk and lower extremities BMD correlated with corresponding regional FM and NFSM, and upper extremities BMD correlated with only corresponding body part NFSM after adjusting menopausal state.

CONCLUSION

Total and regional BMD had strong negative correlation with menopausal state rather than total FM in overweight Japanese women. Weight-bearing site BMD correlated with corresponding body part FM and NFSM and non-weight bearing site BMD only correlated with corresponding body part NFSM after adjusting for menopausal state.