Cross sectional study of the relationship between bone density to diet and life style using ultrasound bone densitometry

: The relationship between bone density to diet and life style was investigated in pre- and postmenopausal women in Kyoto Prefecture in 1994 by a cross-sectional study. Bone densities of 453 women aged 30-86 years were measured by ultrasound bone densitometry. History of pregnancy and delivery, menstruation, medical history, bone and arthral symptoms, life style, food intake frequency, current and past intake of dairy products, and physical activity were examined by self-administered questionnaire. Analysis of covariance and multiple-regression analysis were performed to determine the relation between bone density and life style adjusted for age and obesity index among 151 premenopausal women (PRE), 244 postmenopausal but not sedentary (under 65 years of age) women (POST), and 58 sedentary (older than 65 years of age) women (SED). The results were as follows; 1) A marked age-related decline in bone density was observed at 45-55 years of age. The correlation coefficient between age and bone density was significant at -0.65 (p < 0.01). 2) Obesity index and bone density were positively correlated in each group. 3) Among the PRE group women, there was no relation between life style and bone density. Those who experienced bone fractures tended toward low bone density. Among the POST group, time since menopause, exercise, and current milk intake were significantly correlated with bone density. In the SED group, women with arthralgia showed significantly lower densities. 4) From multiple-regression analysis, age, obesity index, and milk intake during childhood were shown to be related to bone density in each group.