Relation of lifestyle factors to metacarpal bone mineral density was different depending on menstrual condition and years since menopause in Japanese women.

OBJECTIVE

To examine whether the relation between lifestyle and metacarpal bone mineral density (BMD) varied with life-stages.

DESIGN

Cross-sectional study.

SETTING

Taking questionnaires related to lifestyle and examining metacarpal BMD by computed X-ray densitometry at a local health care center.

SUBJECTS

Out of 750 Japanese women aged 40-69 y old who underwent screening for osteoporosis, we selected 535 healthy subjects without medical conditions or lifestyle factors known to affect bone metabolism.

RESULTS

A cross-sectional comparison of BMD and years since menopause (YSM) resulted in a logarithmic regression model (BMD=2. 539-0.149xloge YSM, r2=0.418), indicating that a prominent reduction in metacarpal BMD appears up to 4-6 y after menopause. In premenopausal women with regular menstruation, those who engaged in regular physical activity during adolescence showed significantly greater BMD than those who did not. In 1-5-y postmenopausal women, those with current calcium intake of more than 800 mg/d, current milk intake greater than 900 ml/week, daily consumption of milk and/or dairy products, or frequent consumption of small fish showed significantly greater BMD. In 6-15-y postmenopausal women, those who took more than 6000 or 8000 steps/day showed significantly greater BMD.

CONCLUSIONS

The relation between lifestyle and BMD differed with life-stages in Japanese women. It was suggested that to perform lifestyle modifications for the prevention of osteoporosis, life-stages should be taken into consideration.

SPONSORSHIP

Grant for Research on Health Service from Ministry of Health and Welfare, Japan and grant from The National Dairy Promotion and Research Association of Japan. European Journal of Clinical Nutrition (2000) 54, 9-13