Citation

Faulkner KA, Cauley JA, Roth SM, Kammerer CM, Stone K, Hillier TA, Ensrud KE, Hochberg M, Nevitt MC, Zmuda JM. J. Appl. Physiol. (APS Bethesda) 2010; 108(5): 1142-1147.

Affiliation

University of Pittsburgh.

Copyright

(Copyright © 2010, American Physiological Society)

DOI

10.1152/japplphysiol.00128.2009

PMID

20167680

PMCID

PMC2867539

Abstract

Background A possible familial component to fracture risk may be mediated through a genetic liability to fall recurrently. Methods Our analysis sample included 186 female sibling-ships (N=401) of mean age =71.9 years (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, BMI, and medical and environmental factors. Results Residual upper-limit heritabilities were all moderate (p<0.05), ranging from 0.27 for usual-paced walking speed to 0.58 for recurrent falls. A strong familial correlation between usual-paced walking speed and rapid step-ups of 0.65 (p<0.01) was identified. Familial correlations between usual-paced walking speed and chair-stand time (-0.02) and between chair-stand time and rapid step-ups (-0.27) were both non-significant (p>0.05). Environmental correlations ranged from 0.35 to 0.58 (absolute values), p<0.05 for all. Conclusions There exists moderate familial resemblance in fall-risk mobility phenotypes and recurrent falls among older female siblings, which we expect is primarily genetic given that adult siblings live separate lives. All fall-risk mobility phenotypes may be co-influenced at least to a small degree by shared latent familial or environmental factors; however, up to approximately half of the covariation between usual-paced walking speed and rapid step-ups may be due to a common set of genes. Key words: falls, familial correlation, genetics, heritability.

Language: en