Familial resemblance and shared latent familial variance in recurrent fall risk in older women

A possible familial component to fracture risk may be mediated through a genetic liability to fall recurrently. Our analysis sample included 186 female sibling-ships (n=401) of mean age 71.9 yr (SD=5.0). Using variance component models, we estimated residual upper-limit heritabilities in fall-risk mobility phenotypes (e.g., chair-stand time, rapid step-ups, and usual-paced walking speed) and in recurrent falls. We also estimated familial and environmental (unmeasured) correlations between pairs of fall-risk mobility phenotypes. All models were adjusted for age, height, body mass index, and medical and environmental factors. Residual upper-limit heritabilities were all moderate (P