Faulkner Kimberly A, Cauley Jane A, Roth Stephen M, Kammerer Candace, Stone Katie, Hillier Teresa A, Ensrud Kristine E, Hochberg Marc, Nevitt Michael C, Zmuda Joseph M
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, 130 DeSoto St., A-551, Pittsburgh, PA 15261, USA.
J Appl Physiol (1985). 2010 May;108(5):1142-7. doi: 10.1152/japplphysiol.00128.2009. Epub 2010 Feb 18.
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<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 nonsignificant (P>0.05). Environmental correlations ranged from 0.35 to 0.58 (absolute values), P<0.05 for all.
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 coinfluenced at least to a small degree by shared latent familial or environmental factors; however, up to approximately one-half of the covariation between usual-paced walking speed and rapid step-ups may be due to a common set of genes.
骨折风险中可能存在的家族因素可能是通过反复跌倒的遗传易感性介导的。
我们的分析样本包括186对女性姐妹（n = 401），平均年龄71.9岁（标准差 = 5.0）。使用方差成分模型，我们估计了跌倒风险移动性表型（如从椅子上站起的时间、快速上台阶和正常步速行走速度）以及反复跌倒的残余上限遗传力。我们还估计了成对的跌倒风险移动性表型之间的家族相关性和环境（未测量）相关性。所有模型均针对年龄、身高、体重指数以及医学和环境因素进行了调整。
残余上限遗传力均为中等水平（P < 0.05），范围从正常步速行走速度的0.27到反复跌倒的0.58。确定了正常步速行走速度与快速上台阶之间的家族相关性很强，为0.65（P < 0.01）。正常步速行走速度与从椅子上站起的时间之间的家族相关性（-0.02）以及从椅子上站起的时间与快速上台阶之间的家族相关性（-0.27）均不显著（P > 0.05）。环境相关性范围从0.35到0.58（绝对值），所有P值均< 0.05。
在老年女性姐妹中，跌倒风险移动性表型和反复跌倒存在中等程度的家族相似性，鉴于成年姐妹分开生活，我们预计这主要是遗传性的。所有跌倒风险移动性表型可能至少在一定程度上受到共同的潜在家族或环境因素的共同影响；然而，正常步速行走速度和快速上台阶之间高达约一半的协方差可能归因于一组共同的基因。
