Appendicular Lean Mass, Grip Strength, and the Development of Knee Osteoarthritis and Knee Pain Among Older Adults

OBJECTIVE: The association of sarcopenia with development of knee osteoarthritis (OA) or knee pain in older adults is uncertain. We examined the relationship of grip strength and appendicular lean mass (ALM) with the likelihood of developing knee OA and knee pain in older adults in the Health ABC (Health, Aging, and Body Composition) Study. METHODS: ALM and grip strength were assessed at baseline by dual‐energy x‐ray absorptiometry and handheld dynamometry, respectively. Incident clinically diagnosed, symptomatic knee OA, defined as new participant report of physician‐diagnosed knee OA and concurrent frequent knee pain, and incident frequent knee pain over 5 years of follow‐up were examined. Separate regression analyses, stratified by sex, modeled associations of baseline ALM and grip strength with the likelihood of incident clinically diagnosed, symptomatic knee OA and incident knee pain over follow‐up, adjusting for covariates. RESULTS: Among the 2779 subjects without OA at baseline, 95 men (6.9%) and 158 women (11.3%) developed clinically diagnosed, symptomatic knee OA, and, among the 2182 subjects without knee pain at baseline, 315 men (28.3%) and 385 women (36.1%) developed knee pain over follow‐up. Among men only, each SD decrement of ALM was associated with decreasing likelihood of incident knee OA (odds ratio [OR] per SD decrement: 0.68; 95% confidence interval [CI]: 0.47‐0.97), and each SD decrement of grip strength was associated with increasing likelihood of incident knee pain (OR per SD decrement: 1.20; 95% CI: 1.01‐1.42). CONCLUSION: In older men, ALM and grip strength may be associated with the development of knee OA and knee pain, respectively.