Genetic and environmental determinants of bone mineral density in Chinese women

Using stepwise multiple linear regression analyses, body weight was the strongest predictor for BMD in premenopausal women (n = 262), which accounted for 15.9% of the variance at the spine, 20% at femoral neck, 17.1% at trochanter, 24.3% at total hip and 10.9% at the Ward's triangle. Other significant predictors were ESR1 Ivs1-397T/C genotype (2.2% at the spine); LRP5 2220C/T genotype (1.3% at the spine, 1.6% at the trochanter); LRP5 266A/G genotype (1.1% at Ward's triangle); age at menarche (1.3% at trochanter) and age (2.0% at Ward's triangle). As for postmenopausal women (n = 269), body weight (∼25% at various sites) and age (∼16% at femoral neck, trochanter, total hip and Ward's triangle sites) were the strongest predictors of BMD. Other significant predictors were age at menarche (4.4% at spine, 0.7% at femoral neck, 1.4% at trochanter, and 1.4% at Ward's triangle); weight bearing physical activity (2.1% at trochanter and 1% at total hip); calcium intake (1.1% at femoral neck, 0.9% at trochanter, and 1.7% at total hip) ; height (0.7% at trochanter); and ESR2 1082A/G genotype (0.8% at trochanter). We conclude that BMD at various sites and at different time span of a woman is modified by different genetic and lifestyle factors, suggesting that BMD is highly dependent on gene-environmental interactions.