L-arginine for Knee Osteoarthritis Patients

Pain is the dominant symptom of knee osteoarthritis (KOA). The main management goal for people with KOA is to control pain without increasing treatment-related adverse effects (AEs). However, the commonly prescribed systemic analgesics have safety concerns, such as increased risk of cardiovascular and gastrointestinal AEs. Therefore, it is urgent to develop safe and effective treatment options.

L-arginine is one of the most commonly used oral nutritional supplements that has been widely used in patients with peripheral arterial disease, cystic fibrosis, and pregnant women with high risk of pre-eclampsia. The supplement has a high safety profile. Previous case-control and cross-sectional studies have found plasma L-arginine levels were lower in patients with knee OA than controls, suggesting that arginine deficiency may increase the risk of OA. The investigators previously observed an inverse dose-response relationship between levels of serum L-arginine and the risk of incident symptomatic KOA. Additionally, the investigators demonstrated that intra-articular injection of L-arginine solution relieved pain symptoms in a surgical rat model of OA. However, there is a paucity of high-quality clinical evidence on the effect of intake of L-arginine supplement on pain relief among patients with symptomatic KOA.

The investigators propose to conduct a randomized, double-blind, placebo-controlled trial to examine the efficacy and safety of oral L-arginine in patients with knee OA.

• Change From Baseline in WOMAC pain score. [Срок оценки: Baseline, Weeks 2, 4 and 8]
• Change From Baseline in Knee pain on a visual analogue scale (VAS). [Срок оценки: Baseline, Weeks 2, 4, 8 and 12]
• Change From Baseline in WOMAC total score. [Срок оценки: Baseline, Weeks 2, 4, 8 and 12]
• Change From Baseline in Change From Baseline in WOMAC stiffness score. [Срок оценки: Baseline, Weeks 2, 4, 8 and 12]
• Change From Baseline in WOMAC function score. [Срок оценки: Baseline, Weeks 2, 4, 8 and 12]
• Change From Baseline in Patient global assessment of osteoarthritis (PGA-OA) score. [Срок оценки: Baseline, Weeks 2, 4, 8 and 12]
• Change From Baseline in SF-12 questionnaire score. [Срок оценки: Baseline, Weeks 2, 4, 8 and 12]
• Change From Baseline in Timed Up and Go Test (TUG). [Срок оценки: Baseline, Weeks 4, 8 and 12]
• Change From Baseline in Chair-stand Test. [Срок оценки: Baseline, Weeks 4, 8 and 12]
• Change From Baseline in Ultrasound-assessed knee synovitis. [Срок оценки: Baseline, Week 12]
• Rescue medicine consumption. [Срок оценки: Weeks 2, 4, 8 and 12]
• Change From Baseline in Level of C-reactive protein (CRP). [Срок оценки: Baseline, Weeks 4, 8 and 12]