According to a recent study published in 'Rheumatology International', lower protein intake found to be associated with lower upper leg muscle strength.  This study aimed to describe the dietary protein intake and examine the association between dietary protein intake and upper leg muscle strength in patients with knee osteoarthritis (OA). The baseline data from the OA was used in a cross-sectional study. All the patients were diagnosed with symptomatic and radiographic knee OA. The Block Brief 2000 food frequency questionnaire (g/kg body weight) was used to calculate the daily dietary protein intake. The Good Strength chair test was used to examine the sum of knee flexion and extension strength of the index knee (N/kg body weight). The connection between dietary protein intake and muscle strength was evaluated using the linear regression analysis, adjusting for relevant confounders.  The data from 1316 patients with a mean age 61.4 ± SD 9.1 years and out of which 57.0% were female was considered. Mean protein intake was 0.72 ± SD 0.30 g/kg body weight per day. Around 65.1% of the subjects had a protein intake lower than the recommended daily allowance (RDA) of 0.8 g/kg body weight. Mean muscle strength was 5.4 ± SD 2.1 N/kg body weight. Lower protein intake was significantly connected with lower muscle strength. Many patients with knee OA had a dietary protein intake lower than the RDA.

"Longitudinal observational and interventional studies are required in future to study the relationship of dietary protein intake as causitive factor for decreased muscle strength in subjects with knee OA", said the study authors (A. H. de Zwart et al.).