Supplementing a strengthening exercise program for knee osteoarthritis with creatine

Stronger muscles could make exercises for osteoarthritis more effective
Osteoarthritis (OA), or the wearing away of a protective substance called articular cartilage on the end of joints, is far and away the most common form of arthritis, and it affects more women than men. Patients who suffer from OA, particularly knee OA, experience pain and disability that usually worsens with weight-bearing and improves with rest. In addition, it has been noted that weakness of the quadriceps (main thigh muscle) is associated with more functional impairments from knee OA, suggesting that a stronger quadriceps could prevent the progression of OA while also reducing pain and improving function. Therefore, measures that enhance the effects of exercises on muscle strength and function could be extremely helpful for knee OA patients. Creatine is a natural organic compound found in fish and red and white meat, and it plays an important role in rapid energy provision during muscle contraction. Creatine supplementation has the potential to increase the amount of creatine and phosphorylcreatine (PCR) in the muscles, which can enhance energy provision, and consequently, muscle strength and function. With this concept in mind, a study was conducted that evaluated the effectiveness of creatine supplementation along with a lower limb resistance-training program in women with knee OA.

Small group of women divided into two groups
Women between 50-65 with a diagnosis of knee OA were sought and evaluated using inclusion criteria. Patients were excluded if they participated in physical exercise training during the past year, or if they had a body mass index (BMI) higher than 35, cardiovascular diseases and/or musculoskeletal disturbances. Of 128 patients who were screened, 24 met the criteria and were randomly placed into either a creatine or placebo group. All patients underwent the same program, which consisted of lower limb resistance strengthening exercises (leg presses, leg extensions, and half-squats), under the supervision of a professional, three times a week for 12 weeks. Subjects in the creatine group were additionally given regular doses of creatine for the duration of the program, while those in the placebo group received the same dose of dextrose. Patients were assessed prior to the start of the program, then again at its completion, using a series of questionnaires. The most important measure taken was the change in physical function of patients, while lean mass, muscle strength, quality of life and pain and stiffness were also assessed for supporting data.

Creatine supplementation shown to have a number of positive effects on patients
According to results from the questionnaires, creatine supplementation produced a number of benefits in patients over the placebo. For physical function – the primary measure of the study – patients in the creatine group improved at significantly higher levels than the placebo group, moving from a score of 15.7 to 18.1 on questionnaires compared to the placebos going from 15.0 to only 15.2. Both groups did manage to demonstrate significant reductions in pain, but those in the creatine group also showed improvements in stiffness, while those in the placebo group did not. In addition, only the creatine group reported improvements in quality of life as well as lower limb lean mass, while the placebo group didn’t experience any meaningful changes in those categories. Finally, creatine supplementation was not shown to have any adverse effects, which means it can also be considered a safe form of treatment.

Using resistance-strengthening exercises to build muscle has already been regarded as an effective method to treat patients with knee OA, as it appears to stabilize the region and makes patients less prone to risks that can exacerbate their condition. Judging by the results of this study, it can also be said that adding creatine to one of these programs is a safe way to further improve physical function, lower limb mean mass and quality of life for women with knee OA. This study lends evidence to the usefulness of adding creatine to a strengthening program for knee OA. Further research is needed to help further solidify clinical guidelines, but these findings should encourage patients with knee OA to inquire about creatine supplementation, and prompt physical therapists to consider adding creatine supplements to exercise programs.

-Summarized by Greg Gargiulo

-As reported in the August ’11 edition of Medicine & Sports in Sports & Exercise