Effects of glucosamine and chondroitan supplementation in women with knee osteoarthritis participating in a fitness and weight loss program

30 sedentary women (54±9 yrs, 163±7 cm; 89±13 kg; 46±3% body fat) with knee osteoarthritis (OA) participated in a 14‐week exercise and diet program and ingested either a supplement containing glucosamine (1,500 mg/d), chondroitan sulfate (1,200 mg/d), MSM (900 mg/d), and white willow bark (180 mg/d) or a placebo. Participants were assigned to follow isoenergenic high protein (HP) or a high carbohydrate (HC) diets. Subjects participated in a supervised 30‐min Curves® circuit training program 3‐d per week. At 0, 2, 10, and 14 weeks, subjects completed a battery of assessments. Data were analyzed by repeated measures ANOVA and are presented as means ± SD from baseline. Results indicated that both groups experienced significant reductions in body mass (−3±4%), fat mass (−6±8%), body fat (−4±3%), knee pain (−112 ±317%), stiffness (−70±234%), and limitations in physical function (−96±1,356%) while 1RM muscular strength (+11±12%), muscular endurance (+13±12%), isokinetic strength (+10–25±4%), physical functioning (+37±52%), energy/fatigue (+55±69%), social functioning (+40±76%), mental health (+22%±84) and functional balance/stability markers significantly increased. Supplementation tended to decrease perceptions of pain, with no statistically significant improvement in strength or functional status. However, a strong effect size (d=1.1) was observed in VAS knee pain and moderate effect sizes were observed in WOMACTM pain (d=0.4), left knee flexion (d=0.53), 1RM max (d=0.53), and total work (d=0.72). Results indicate that women with OA benefit from an exercise and weight loss program and that G/C supplementation may have therapeutic benefits.