The longitudinal relationship between thigh muscle mass and the development of knee osteoarthritis

Abstract

Objective Greater quadriceps strength has been found to reduce risk for symptomatic knee osteoarthritis (SxKOA) and knee joint space narrowing (JSN). However, this finding could relate to muscle mass or activation pattern. The purpose of this study was to assess whether greater thigh muscle mass protects against (1) incident radiographic (RKOA), (2) incident SxKOA or (3) worsening of knee JSN by 30-month follow-up. Design Multicenter Knee Osteoarthritis (MOST) study participants, who underwent dual energy x-ray absorptiometry (DXA) at the Iowa site were included. Thigh muscle mass was calculated from DXA image sub-regions. Sex-stratified, knee-based analyses controlled for incomplete independence between limbs within subjects. The effect of thigh lean mass and specific strength as predictors of ipsilateral RKOA, SxKOA and worsening of JSN were assessed, while controlling for age, BMI, and history of knee surgery. Results A total of 519 men (948 knees) and 784 women (1453 knees) were included. Mean age and BMI were 62 years and 30 kg/m2. Thigh muscle mass was not associated with risk for RKOA, SxKOA or knee JSN. However, in comparison with the lowest tertile, those in the highest and middle tertiles of knee extensor specific strength had a lower risk for SxKOA and JSN (OR 0.29–0.68). Conclusions Thigh muscle mass does not appear to confer protection against incident or worsening knee OA. These findings suggest that future studies of risk for knee OA should focus on the roles of knee extensor neuromuscular activation and muscle physiology, rather than the muscle mass.

Low Skeletal Muscle Mass in the Lower Limbs Is Independently Associated to Knee Osteoarthritis

“…Segal et al . also reported that thigh muscle mass does not appear to confer protection or worsening knee OA and insisted that knee extensor neuromuscular activation and muscle physiology were more important than muscle mass itself [48]. Instead of measuring muscle strength, we calculated and compared the physical activity derived from the IPAQ-K, although it cannot be a perfect substitute for muscle strength.…”

Risk of Knee Osteoarthritis With Obesity, Sarcopenic Obesity, and Sarcopenia

“…Fat and muscle mass were estimated from whole‐body dual x‐ray absorptiometry (DXA) (Horizon DXA System, software version 12.0; Hologic) obtained at baseline using a published protocol . Variables of fat and lean muscle mass (referred to hereafter as muscle mass) were recorded in kilograms from DXA.…”

Thigh Muscle Specific‐Strength and the Risk of Incident Knee Osteoarthritis: The Influence of Sex and Greater Body Mass Index

“…In relation to incident RKOA, the influence of poor muscle specific‐strength on the risk of RKOA development is unclear but is clinically important, since muscle specific‐strength (i.e., muscle strength per unit anatomical cross‐sectional area [ACSA]) is a potentially modifiable risk factor. Segal et al observed that poor knee extensor–specific strength did not predict incident RKOA over 30 months in the Multicenter Osteoarthritis Study (MOST). However, specific strength was calculated using entire thigh muscle mass obtained from dual X‐ray absorptiometry (DXA) and not specifically the quadriceps ACSA that is responsible for providing knee extensor strength .…”