The differences in the relationships of bone mineral density to physical exercise habits and dietary habits among different sites of lumbar vertebrae

• Published in: Japanese Journal of Health and Human Ecology Vol. 67; no. 4; pp. 147 - 155
• Main Authors: SEKINE, Yasuko, ISHIKAWA, Mamoru, KOKAZE, Akatsuki, YOSHIDA, Masao, TAKASHIMA, Yutaka
• Format: Journal Article
• Language: English
• Published: The Japanese Society of Health and Human Ecology 2001
• Subjects: age, bone mineral density, dietary habits, lifestyle
• ISSN: 0368-9395; 1882-868X
• DOI: 10.3861/jshhe.67.147

To examine possible differences in the relationship between bone mineral density (BMD) and lifestyle-related factors in the 2nd, 3rd and 4th lumbar vertebrae (L2, L3 and L4) of middleaged elderly females, the associations between BMD and several lifestyle-related factors were epidemiologically analyzed according to age class in fifty-seven Japanese females, aged 30 to 60, using health check-up data obtained in 1999 in Mito, Japan. The lifestyle-related factors consisted of physical exercise habits, preference of soybean or soybean products, preference of milk or dairy products, and preference of animal protein-rich foods (beef, chicken, pork, fish, processed foods or eggs). The BMD was estimated by the DEXA method using QDR-1000. The BMD in L2, L3, and L4 decreased markedly after the age of 50, whereas no significant differences in any of the three vertebrae were observed for the 30-39 and 40-49 age groups. In all of the age groups (30-39, 40-49, 50-59, and 60-), the BMD was highest for L4, intermediate for L3 and lowest for L2. In individuals younger than 50 (before menopause), the relationship between the adjusted mean BMD and physical exercise habits showed little difference for L2, L3 and L4: the positive association of physical exercise and BMD was strong for L2 and L3, and weak for L4. While preferences for soybean or soybean products and milk or dairy products had a weak positive association with the adjusted mean BMD for each vertebrae, preferencescores for animal protein-rich foods were clearly inversely associated with the adjusted mean BMD of each of the three vertebrae, especially in individuals over the age of 50 (after menopause). These results suggest that the relationship between BMD and lifestyle-related fac tors may differ for each lumbar vertebrae as well as the individual's age. We propose that the excessive intake of animal protein-rich foods may have an adverse effect on BMD in elderly women after menopause, whereas physical exercise before menopause may be beneficial for the prevention of osteoporosis.