Factors affecting peak bone density in Japanese women

Both genetic and environmental factors have been shown to contribute to the determination of bone density. To clarify the interaction between genetic and environmental factors affecting peak bone mass, we investigated the cor relation between bone mineral density (BMD) and physical constitution, vita min D receptor (VDR) genotype, age, age of menarche, history of menstrual d ysfunction, and exercise in 157 healthy young Japanese women. History of ex ercise and menstrual dysfunction were significant independent predictors of BMD. The VDR genotype also affects peak bone density. Exercise has been sh own to increase BMD in a similar way for each VDR genotype including those women who have the particular genotype associated with low bone density. Th is data indicate that there are complex gene-environmental interactions par ticularly in relation to menstrual history, exercise, and genetic factors d uring childhood/adolescence that may have implications for the development of adult BMD in women.