Bone mineral density in old age: the influence of age at menarche, menopause status and habitual past and present physical activity

INTRODUCTION: In this study, the hypothesis that bone mineral density (BMD) of peri-, pre- and postmenopausal women is associated with the current level of habitual physical activity, as well as past physical activity, at the age of building peak bone mass, was tested. MATERIAL AND METHODS: The study involved 500 Polish women aged 40 to 70. For the assessment of BMD and bone mineral content (BMC) the densitometry method (dual-energy X-ray absorptiometry, DXA) of the forearm bone was used. The International Physical Activity Questionnaire (IPAQ) was used to assess the present level of physical activity. The assessment of past physical activity was related to adolescence. RESULTS: There was a significant, strong influence on the norm BMD in the distal forearm sections values in the distal forearm sections of such variables as: older age of the first menstruation (OR = 1.37; p = 0.002), sufficient present physical activity (OR = 1.57; p = 0.001), and particularly high past physical activity (OR = 6.77; p = 0.003). Significantly lower chances for the norm BMD dis were found in women with the oldest hormonal status (OR = 0.09; p < 0.001). In the proximal segment, the analogous conditions of the norm BMD, and in addition the chances for good mineralization, were increased by higher body mass index (OR = 1.11; p < 0.001). Sufficient present activity increased the chances of good forearm mineralization in the proximal part more than four times (OR = 4.2; p < 0.001), and a high level of past physical activity increased these chances several dozen times (OR = 69.9; p < 0.001). CONCLUSIONS: Physical activity proved to be one of the most important factors determining the statistically significant correct mineralization of bone tissue of women.