@article{ref1,
title="Mid-calf skeletal muscle density and its associations with physical activity, bone health and incident 12-month falls in older adults: the Healthy Ageing Initiative",
journal="Bone",
year="2019",
author="Scott, David and Johansson, Jonas and McMillan, Lachlan B. and Ebeling, Peter R. and Nordström, Anna and Nordström, Peter",
volume="120",
number="",
pages="446-451",
abstract="BACKGROUND: Lower skeletal muscle density, indicating greater infiltration of adipose tissue into muscles, is associated with higher fracture risk in older adults. We aimed to determine whether mid-calf muscle density is associated with falls risk and bone health in community-dwelling older adults. <br><br>METHODS: 2214 community-dwelling men and women who participated in the Healthy Ageing Initiative (Sweden) study at age 70 were included in this analysis. Mid-calf muscle density (mg/cm<sup>3</sup>) at the proximal tibia, and volumetric bone mineral density (vBMD) and architecture at the distal and proximal tibia and radius, were assessed by peripheral quantitative computed tomography. Whole-body lean and fat mass, lumbar spine and total hip areal bone mineral density (aBMD) were assessed by dual-energy X-ray absorptiometry. Participants completed seven-day accelerometer measurements of physical activity intensity, and self-reported falls data were collected 6 and 12 months later. <br><br>RESULTS: 302 (13.5%) participants reported a fall at the 6- or 12-month interview, and 29 (1.3%) reported a fall at both interviews. After adjustment for confounders, lower mid-calf muscle density was associated with a trend towards greater likelihood of experiencing a fall (OR 1.13; 95% CI 1.00, 1.29 per SD lower) and significantly greater likelihood of multiple falls (1.61; 1.16, 2.23). Lower muscle density was not associated with total hip aBMD, and was associated with higher lumbar spine aBMD (B = 0.012; 95% CI 0.004, 0.019 per SD lower) and lower proximal cortical vBMD (-2.86; -4.95, -0.78) at the radius. At the tibia, lower muscle density was associated with lower distal total and trabecular vBMD, and proximal total and cortical vBMD, cortical thickness, cortical area and stress-strain index (all P < 0.05). Only moderate/vigorous intensity physical activity, not sedentary time or light activity, was associated with higher mid-calf muscle density (0.086; 0.034, 0.138). <br><br>CONCLUSIONS: Lower mid-calf muscle density is independently associated with higher likelihood for multiple incident falls and appears to have localised negative effects on bone structure in older adults.<br><br>Copyright © 2018. Published by Elsevier Inc.<p /> <p>Language: en</p>",
language="en",
issn="8756-3282",
doi="10.1016/j.bone.2018.12.004",
url="http://dx.doi.org/10.1016/j.bone.2018.12.004"
}