Beneficial effect of creatine supplementation in knee osteoarthritis.

Abstract

The aim of this study was to investigate the efficacy of creatine (CR) supplementation combined with strengthening exercises in knee osteoarthritis (OA). A randomized, double-blind, placebo-controlled trial was performed. Postmenopausal women with knee OA were allocated to receive either CR (20 g·d(-1) for 1 wk and 5 g·d(-1) thereafter) or placebo (PL) and were enrolled in a lower limb resistance training program. They were assessed at baseline (PRE) and after 12 wk (POST). The primary outcome was the physical function as measured by the timed-stands test. Secondary outcomes included lean mass, quality of life, pain, stiffness, and muscle strength. Physical function was significantly improved only in the CR group (P = 0.006). In addition, a significant between-group difference was observed (CR: PRE = 15.7 ± 1.4, POST = 18.1 ± 1.8; PL: PRE = 15.0 ± 1.8, POST = 15.2 ± 1.2; P = 0.004). The CR group also presented improvements in physical function and stiffness subscales as evaluated by the Western Ontario and McMaster Universities Osteoarthritis Index (P = 0.005 and P = 0.024, respectively), whereas the PL group did not show any significant changes in these parameters (P > 0.05). In addition, only the CR group presented a significant improvement in lower limb lean mass (P = 0.04) as well as in quality of life (P = 0.01). Both CR and PL groups demonstrated significant reductions in pain (P < 0.05). Similarly, a main effect for time revealed an increase in leg-press one-repetition maximum (P = 0.005) with no significant differences between groups (P = 0.81). CR supplementation improves physical function, lower limb lean mass, and quality of life in postmenopausal women with knee OA undergoing strengthening exercises.