The influence of maternal heritability on bone density, area and microarchitecture in active young-adult daughters.

Areal bone mineral density (aBMD) is heritable between mothers and daughters; however, there is limited heritability research regarding bone microarchitecture. The primary aim of this study was to determine the heritability of aBMD from dual X-ray absorptiometry (DXA), and volumetric BMD (vBMD), bone area and bone microarchitecture from high-resolution peripheral quantitative computed tomography (HR-pQCT), among young-adult daughters from their menopause-aged mothers. The secondary objective examined the association between daughters' lifestyle and heritability. Thirty-nine mother- (55.4 ±4.2yrs) daughter (23.8 ±4.2yrs SD) pairs completed questionnaires including health history, physical activity and food frequency. Lumbar spine, femoral neck, total hip and whole body aBMD were measured by DXA. Radial and tibial vBMD, bone area and microarchitecture were measured by HR-pQCT. Heritability (½ h2) was determined by linear regression. The heritability-lifestyle interplay was examined using multiple regression. Bone area (½ h2: 31-46%) was more heritable than bone microarchitecture (½ h2: 11-29%) or vBMD (½ h2: 19-23%) by HR-pQCT. DXA aBMDs were not significantly heritable (p>0.05). Maternal heritability and daughters’ lifestyle covariates (e.g., caffeine, dietary calcium, and sedentary time) explained 10-45% of aBMD variance, 11-69% of vBMD variance, 41-66% of area variance by HR-pQCT, and 13-71% of microarchitectural variance in daughters. Two-dimensional aBMD did not show heritability, but the bone parameters that were derived from more sensitive three-dimensional imaging were maternally heritable. Both heritability and lifestyle were explanatory of HR-pQCT-derived bone parameters.