Thigh muscle strength in women linked to knee osteoarthritis
Poor thigh muscle strength was associated with incident radiographic knee osteoarthritis in women, according to a press release and results of a recently published study.
“Our results highlight the importance of maintaining thigh muscle strength to reduce the risk of knee osteoarthritis development, particularly in women,” Adam G. Culvenor, PT, PhD, at the Institute of Anatomy at Paracelsus Medical University Salzburg & Nuremburg in Austria, said in the release.
Culvenor and colleagues assessed 161 Osteoarthritis Initiative patients with incident radiographic knee osteoarthritis (RKOA) — 62% were female — who had a Kellgren-Lawrence grade of 0/1 at baseline, and an osteophyte and joint space narrowing grade of at least 1 by year 4. Researchers matched these patients with 186 controls, 58% of whom were female. Researchers determined thigh muscle anatomical cross-sectional areas (ACSAs) at baseline with axial MRI scans. In addition, they measured isometric extensor and flexor muscle strength at baseline then divided this number by the ACSA to calculate specific strength. They used logistic regression to examine the association between risk for knee osteoarthritis and muscle-specific strength, with and without an adjustment for BMI.
For women, researchers found a significant association between the risk for incident RKOA and reduced specific strength in the knee extensor (odds ratio = 1.47) and flexor (odds ratio = 1.41). However, the significance went away after adjustment for BMI. In addition, lower specific strength was associated with higher BMI in women (r = –0.29), but not in men; however, absolute strength was associated with higher BMI in men (r = 0.28), but not in women.
“The different relationships we observed between muscle weakness, muscle size, BMI and knee osteoarthritis development in men and women suggest that the mechanism by which BMI increases the risk of knee osteoarthritis is sex-specific and may require distinct treatment approaches,” Culvenor said. – by Will Offit
Disclosures: Culvenor reports no relevant financial disclosures. Please see the full study for a list of all other relevant disclosures.