Efficacy and safety of curcumin in patients with metabolic phenotype of osteoarthritis: A pilot study

The aim of this study was to assess efficacy and safety of curcumin in metabolic syndrome- associated osteoarthritis (MetS-OA). All patients provided written informed consent. Knee OA was diagnosed according to American College of Rheumatology criteria; MetS was diagnosed according to Russian Scientific Society of Cardiology Guidelines. The study had before-and-after design. The main inclusion criteria were presence of knee OA and MetS, levels of global health assessment and pain assessment more than 50 mm using 0-100 visual analogue scale (VAS). The main outcome was VAS global. The other outcomes were VAS pain, Knee injury and Osteoarthritis Outcome Score (KOOS) consisting of five subscales: pain (KOOS pain), other symptoms (KOOS symptoms), activities in daily living (KOOS ADL), function in sport and recreation (KOOS Sport/Rec) and knee related Quality of life (KOOS QoL). The level of depression was measured using PHQ- 9. For pain, proportion of patients achieving minimal clinically important improvement (MCII) was assessed using the cut-offs of (a) 15 of 100 for absolute improvement and 20% for relative improvement.The treatment consisted of C. longa extract 1000 mg/day for 4 weeks. The assessments were performed on baseline and 4 weeks thereafter. Eighteen women with MetS-OA of the knee were included in the study.At the end of treatment, there were significant improvements in the VAS global scale by an average 33.9 mm (p = 0.001), VAS pain by 25 mm (p = 0.001). There was a trend towards improvement in PHQ-9 by 2.9 (p = 0.05). The mean improvement in KOOS pain was 11 (p = 0.001). KOOS symptoms improved by 9 (p = 0.025), KOOS ADL - by 12.4 (p = 0.001), KOOS Sport/Rec by 10.3 (p = 0.044), and KOOS QOL by 14.4 (p = 0.009). The proportion of patients achieving clinically significant improvement (MCII) were nine (56%) for both global health and pain. There were no adverse events during the study. The findings of this study suggest clinical efficacy and safety of C. Longa in MetS-associated knee OA. There is a need for large controlled studies to confirm these results.