Changes in axial bone density with age: a twin study.

Abstract

Bone mineral density in adult life, which is an important determinant of fracture risk, is determined by peak adult bone density, achieved in early adulthood and subsequent rates of change during adult life. Cross-sectional twin and family studies indicate that the majority of population variation in bone density may be explained by genetic factors. Although there is evidence for a genetic effect on peak bone mass, it is unknown whether there is a genetic effect on rates of changes in bone density with age. Changes in lumbar spine and femoral neck bone density determined by dual-photon absorptiometry (Lunar DP3) were examined in a cohort of monozygotic (MZ, n = 21, 3 male and 18 female pairs..