Sarcopenia in knee osteoarthritis: the association with clinical and sonographic findings, physical function, and nutrition.

Abstract

The purposes of this study were to examine to (1) the relation between OA and sarcopenia and to identify the most practical, easily accessible, and inexpensive method for investigating sarcopenia; (2) evaluation of sarcopenia risk factors in patients with OA. One hundred two patients with clinical and radiological diagnosis of knee osteoarthritis and 33 healthy control subjects were included in the study and all subjects were evaluated for sarcopenia. Dual-X-ray absorptiometry (DEXA) is used to measure body composition parameters and muscle thickness measurements with ultrasonography for diagnosis of sarcopenia. The mean age of the group with sarcopenia was statistically higher than the other two groups (p < 0.001). The weight, body mass index (BMI), waist circumference, upper-mid-arm circumference, thigh, and leg circumference of osteoarthritis (OA) patients with sarcopenia were statistically lower than those of non-sarcopenic and control group (p < 0.01, p < 0.001). Body composition parameter results showed that sarcopenic patients had statistically lower values as fat mass, lean body mass, and skeletal muscle index (p < 0.001, p = 0.001, p < 0.001, respectively) than those of non-sarcopenic and control group and fat mass index values (p = 0.012) are lower than the non-sarcopenic group. With respect to sarcopenia, the effect of adiponectin and leptin levels were not detected. It was determined that body composition values measured with DEXA, ultrasonographic measures, isokinetic muscle strength assessment, handgrip strength, and gait speed had predictive values for sarcopenia. We found that patients with sarcopenic OA were older, weaker, undernourished, and restricted in their level of physical activity in the study. Among the methods of determining sarcopenia, ultrasound becomes prominent with its practical, cheap, and easily accessible features. We think that our results will increase the awareness of the presence of sarcopenia in OA patients.