Association between physical performance and bone mass in community-dwelling postmenopausal Japanese women: The Unzen study.

BACKGROUND: Low bone mass is an independent risk factor for osteoporotic fractures. We examined the association between physical performance and bone mass using quantitative ultrasound in community-dwelling postmenopausal Japanese women. METHODS: We conducted a cross-sectional study on 524 community-dwelling postmenopausal Japanese women who were not being administered osteoporosis medications. Physical performance was assessed on the basis of grip strength, chair stand time, and functional reach. The stiffness index was measured as a quantitative ultrasound parameter for heel bone mass. RESULTS: Physical performance, assessed by grip strength, chair stand time, and functional reach, and the stiffness index significantly decreased with age (both p<0.001). The multiple linear regression analysis showed that grip strength (p = 0.001), chair stand time (p = 0.004), and functional reach (p = 0.048) were significantly associated with the stiffness index after adjusting for age, body mass index, smoking, drinking, and exercise. CONCLUSIONS: Physical performance was significantly associated with heel bone mass in community-dwelling postmenopausal Japanese women.

Association between fat mass by bioelectrical impedance analysis and bone mass by quantitative ultrasound in relation to grip strength and serum 25-hydroxyvitamin D in postmenopausal Japanese women: the Unzen study.

BACKGROUND: Whether fat mass or lean mass affects bone mass in postmenopausal women is controversial. This study aimed to explore the association between body composition measured by bioelectrical impedance analysis (BIA) and bone mass measured by quantitative ultrasound (QUS) in postmenopausal women in Japan. METHODS: We conducted a cross-sectional study, The Unzen Study, on 382 community-dwelling postmenopausal Japanese women (mean (standard deviation) age: 68.2 (7.2) years) who participated in periodic health examinations. The stiffness index (SI) was measured using QUS, and body composition (e.g., fat mass and muscle mass) was measured using BIA. Grip strength was measured. Fasting blood samples were collected, and 25-hydroxyvitamin D (25(OH)D), tartrate-resistant acid phosphatase-5b (TRACP-5b), and parathyroid hormone (PTH) levels were measured. Data on current smoking, alcohol consumption, exercise, and any comorbidities (heart disease, lung disease, stroke, or diabetes mellitus) were collected. RESULTS: The SI increased with increasing quartiles of fat mass and muscle mass (both p for trend <  0.001), respectively. There were positive correlations between SI and log (25(OH)D) or grip strength. Fat mass significantly correlated with grip strength. Multiple linear regression analysis showed that higher fat mass was independently and significantly associated with higher SI after adjusting for age, height, comorbidity, current smoking, alcohol consumption, exercise, log (25(OH)D), log (TRACP-5b), log (PTH), and grip strength (p = 0.001). In contrast, no association was observed between muscle mass and SI. CONCLUSIONS: Fat mass, but not muscle mass, was a significant determinant of SI in community-dwelling postmenopausal Japanese women.

Association between serum 25-hydroxyvitamin D and physical performance measures in middle-aged and old Japanese men and women: The Unzen study.

PURPOSE: Regarding epidemiological studies, the role of vitamin D in musculoskeletal functionality (muscle weakness and physical performance) among elderly people is still controversial. The purpose of the present study was to investigate the associations between 25-hydroxyvitamin D [25(OH)D] and physical performance among community-dwelling middle-aged and old Japanese men and women. METHODS: The subjects were community-dwelling 297 men and 415 women aged 50 years and over. Data on height (m) and weight (kg) were collected. Serum 25(OH)D, parathyroid hormone, calcium, and albumin levels were measured. Serum 25(OH)D was classified into deficiency group: < 20 ng/mL, insufficiency group: 20-30 ng/mL, and sufficiency group: ≧ 30 ng/mL. Physical performance was assessed by grip strength, chair stand time, and functional reach. Information on current smoking, alcohol drinking, regular exercise, any comorbidities (hypertension, heart disease, diabetes mellitus, lung disease, and stroke), and pain (lumbar and knee) was collected. RESULTS: Vitamin D deficiency and insufficiency based on serum 25(OH)D levels were observed in 15.2% and 56.9% of men and 52.0% and 43.6% of women, respectively. In men, higher serum 25(OH)D levels were associated with better grip strength (p for trend = 0.003), chair stand time (p for trend = 0.042), and functional reach (p for trend <0.001). On the other hand, these parameters were not associated with serum 25(OH)D levels in women. CONCLUSION: A higher level of serum 25(OH)D was associated with better physical performance in men but not in women.

Association between vitamin D and bone mineral density in Japanese adults: the Unzen study.

We showed an association between serum concentrations of vitamin D and bone health among community-dwelling adults in Japan after adjustment for confounding factors, with 730 participants in a city, with concentrations of 25(OH) vitamin D, and with parameters of quantitative ultrasound. PURPOSE: The primary objective of this study was to examine the correlation between serum 25-hydroxyvitamin D (25(OH)D) concentration and bone indicators as measured by quantitative ultrasound in middle-aged and older Japanese adults living in low-latitude seaside areas during summer and autumn. METHODS: We conducted a cross-sectional study, the Unzen study, on community-dwelling Japanese adults who participated to periodic health examinations between 2011 and 2013 (during the months of May to November). RESULTS: A total of 301 men (mean (SD) age, 67.9 (8.2) years; range, 50-92 years) and 429 women (mean (SD) age, 67.9 (7.7); range, 50-89 years) participated in this study. Serum 25(OH)D levels and quantitative ultrasound parameters (broadband ultrasound (BUA), speed of sound (SOS), and stiffness index of the calcaneus were measured for the participants. We excluded two men and 28 women from the 730 participants because they were on medication for osteoporosis. So, 299 men and 401 women were included in the final data analysis. The prevalence of vitamin D insufficiency (< 30 ng/ml) was very high: 71.9% in men and 95.5% in women. In women, the log(25(OH)D) positively and significantly correlated with SOS (p = 0.011) and stiffness index (p = 0.028) but not with BUA (p = 0.176). In men, the log(25(OH)D) did not correlate with the BUA, SOS, or stiffness index (p = 0.218, 0.420, and 0.262, respectively). CONCLUSIONS: Serum 25(OH)D levels were associated with SOS or stiffness index in women but not in men.

Association between self-reported walking speed and calcaneal stiffness index in postmenopausal Japanese women.

BACKGROUND: Osteoporosis and related fractures, a worldwide public health issue of growing concern, is characterized by compromised bone strength and an increased risk of fracture. Here we show an association between self-reported walking speed and bone mass among community-dwelling postmenopausal Japanese women aged 50 years and older. DESIGN; CROSS-SECTIONAL STUDY: Setting and Participants; The survey population included 1008 postmenopausal women 50-92 years of age residing in rural communities. METHODS: Self-reported walking speed was ascertained by asking the participants: "Is your walking speed faster than others of the same age and sex?" to which participants responded "yes (faster)" or "no (moderate/slower)." Calcaneal stiffness index was measured. RESULTS: Women with a faster self-reported walking speed were younger and had a lower BMI, higher stiffness index, and higher grip strength than women with a slower walking speed. Multiple linear regression analysis adjusted for age, BMI, grip strength, comorbidity, current smoking, and alcohol drinking status showed a significant association between faster self-reported walking speed and higher calcaneal stiffness index (p <  0.001). CONCLUSIONS: Our findings suggest that questionnaires of walking speed may be useful for predicting bone mass and that a fast self-reported walking may benefit bone health in postmenopausal women.