Perimenopausal bone mass and risk factors.

We studied the effect of menopausal status and risk factors on lumbar bone mineral density (BMD) and metacarpal cortical thickness (MCT) in 286 women of 46-55 years of age. Body mass index (height/weight) was measured and the family history of osteoporosis, reproductive history, menopausal status, calcium intake, amount of physical activity and the consumption of tobacco and alcohol were assessed. Lumbar BMD and MCT decreased substantially in the perimenopausal and postmenopausal period. In the premenopausal women a significant (P = 0.03) lower lumbar BMD was observed in the lowest tertile of calcium intake (less than or equal to 900 mg/day) compared to the highest tertile (greater than or equal to 1200 mg/day). This difference was not apparent in the peri- and postmenopausal women. This suggests that dietary calcium intake is more important in the development and/or maintenance of peak bone mass, than in the modulation of postmenopausal bone loss. Apart from menopausal status and low calcium intake, no other significant determinant of bone mass could be identified. We conclude, therefore, that the assessment of risk factor status is not an efficient tool for the identification of perimenopausal women with low bone mass.