Effect of exercise therapy combined with branched-chain amino acid supplementation on muscle strengthening in persons with osteoarthritis.

Background: Improving lower limb muscle strength is important in preventing progression of osteoarthritis (OA) and its symptoms. Exercise with branched-chain amino acid (BCAA) supplementation has been reported to affect protein anabolism in young and elderly persons. However, few studies provided daily BCAAs for patients with OA.

Objective: This study examined the effects of combined BCAAs and exercise therapy on physical function improvement in women with hip OA scheduled for total hip arthroplasty.

Methods: The subjects were 43 women with OA (age: 64.2 $\pm$ 9.4). The participants were randomly divided into two groups: BCAA ( $n=21$ ) and control ( $n=22$ ). The combined therapy was carried out for one month. Exercise intervention involved hip abductor muscle exercise in both groups. For the nutritional intervention, 6 g of BCAAs or 1.2 g of starch were consumed within 10 min before starting the exercise.

Results: There was a marginally significant difference in the main effect between the groups in 10-m timed gait time. The improvement rate in hip abductor muscle strength of the contralateral side was significantly greater in the BCAA group.

Conclusion: By combining BCAA intake and exercise therapy, a significant improvement in hip abductor muscle strength of the contralateral side was achieved in women with OA.