Presented at the 18th Annual meeting of the American Society of Bone and Mineral Reseach, September 1996, Seattle, WA, U.S.A.
Genetic Influences on Muscle Strength, Lean Body Mass, and Bone Mineral Density: A Twin Study†
Article first published online: 1 DEC 1997
Copyright © 1997 ASBMR
Journal of Bone and Mineral Research
Volume 12, Issue 12, pages 2076–2081, December 1997
How to Cite
Arden, N. K. and Spector, T. D. (1997), Genetic Influences on Muscle Strength, Lean Body Mass, and Bone Mineral Density: A Twin Study. J Bone Miner Res, 12: 2076–2081. doi: 10.1359/jbmr.19220.127.116.116
- Issue published online: 4 DEC 2009
- Article first published online: 1 DEC 1997
- Manuscript Accepted: 28 JUL 1997
- Manuscript Revised: 21 JUL 1997
- Manuscript Received: 28 APR 1997
Lean body mass and muscle strength are both associated with bone mineral density (BMD), which is known to be under strong genetic control. In this classical twin study, we examine the size of the genetic component of both muscle strength and lean body mass and to what degree they account for the genetic component of BMD. In all, 706 postmenopausal women were examined; 227 pairs of monozygous (MZ) twins and 126 pairs of dizygous (DZ) twins. Grip strength was measured using a hand-help grip bulb and leg strength using a dynamic leg extensor power rig. Lean body mass and BMD at multiple sites were measured by dual-energy X-ray absorptiometry. BMD correlated with both leg extensor strength (r = 0.16–0.26) and grip strength (r = 0.12–0.21). Lean mass was significantly correlated with BMD at all sites (r = 0.20–0.39). All three muscle variables have a moderate genetic component with heritability estimates of 0.52 for lean body mass, 0.46 for leg extensor strength, and 0.30 for grip strength (all p < 0.05). The genetic component of BMD was not significantly reduced after adjusting for lean mass and muscle strength, with less than 20% of the genetic variance of BMD explained by the muscle variables. In conclusion, these data suggest that the three muscle variables have a modest genetic component, suggesting the potential for clinical intervention and lifestyle modifications. The genetic component to muscle bulk and strength accounts for little of the genetic component to BMD, confirming the rationale for research into bone-specific genes.