Objective: To determine whether premenopausal daughters of women with postmenopausal osteoporosis have lower peak bone mass than the daughters of normal women the same age, and to analyze the related risk factors affecting bone mass variation.
Methods: 126 pairs of mother with postmenopausal osteoporosis and her premenopausal daughter, and 136 pairs of normal postmenopausal mother and her premenopausal daughter selected for 410 core families including one healthy premenopausal daughter aged 20 - 40, all of Han ethnicity living in Shanghai recruited by advertisement and lectures. A questionnaire survey was conducted to investigate their dietary custom, Dual-energy X-ray absorptiometry at lumber spine 1 - 4 (L(1 - 4)) and proximal femur was conducted to measure the values of bone mineral density (BMD).
Results: The BMD values in L(1 - 4), femoral neck, and greater trochanter of the daughters of mothers with osteoporosis were 0.68 g/cm(2) +/- 0.07 g/cm(2), 0.59 g/cm(2) +/- 0.08 g/cm(2), and 0.47 g/cm(2) +/- 0.07 g/cm(2) respectively, all significantly lower than those of the daughters of normal mothers (0.86 g/cm(2) +/- 0.14 g/cm(2), 0.70 g/cm(2) +/- 0.11 g/cm(2), and 0.57 g/cm(2) +/- 0.10 g/cm(2) respectively, all P < 0.001). The average body weight of the daughters of mothers with osteoporosis was lighter then that of the daughters of normal mothers by 4.8% (P < 0.05). Multivariate regression analysis showed that age, body height, age of menarche, and milk intake were not influencing factors of BMD value, however, body weight was most significantly associated with BMD of the premenopausal daughters, contributing to the BMD variation at L(1 - 4), femoral neck, and greater trochanter by 9.4%, 16.5%, and 16.6% respectively. When body weight was excluded in the model, lower BMD of mother became the most important factors affecting the BMD variation, contributing to the BMD variation at L(1 - 4), femoral neck, and greater trochanter by 5.1%, 5.3%, and 4.2% respectively.
Conclusion: The daughters of mothers with osteoporosis have reduced peak bone mass. It is likely due to the lower body weight of the daughter and the lower bone mass of the mother.