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02-10-2020 | Osteoarthritis | News

Turmeric extract may reduce knee osteoarthritis pain

Author: Laura Cowen


medwireNews: Treatment with Curcuma longa (turmeric) extract may reduce pain but not swelling among patients with symptomatic knee osteoarthritis and knee effusion–synovitis, Australian researchers report.

Benny Antony (University of Tasmania, Hobart) and co-investigators found that the mean visual analog scale (VAS; 0–100 mm) pain score fell by 23.8 mm from a baseline of 55.6 mm following 12 weeks of randomly assigned treatment with turmeric extract 500 mg twice daily (n=36).

By comparison, mean VAS pain score fell by 14.6 mm, from 54.4 mm at baseline, during 12 weeks of treatment with placebo (n=34).

Writing in the Annals of Internal Medicine, Antony et al say that the mean difference of 9.1 mm between the two groups was statically significant, but “may be of uncertain clinical importance” because the “modest effect size” was smaller than the prespecified minimal clinically important difference of 18.0 mm.

However, the authors note that “the first recommended drug therapy in most knee osteoarthritis treatment guidelines until 2019 was paracetamol [acetaminophen], which reportedly showed only a 3.7-mm difference on a 100-mm scale and had a less favorable safety profile [than Curcuma longa].”

The researchers also found that the patients who received turmeric extract experienced a significantly greater mean improvement in WOMAC knee pain (84.2 vs 37.0 mm reduction) and function (292.0 vs 179.7 mm reduction) scores and were more likely to be OARSI-OMERACT responders than those who received placebo (62.9 vs 38.2%).

Conversely, there was no significant difference between the two groups in the mean change in magnetic resonance imaging-assessed effusion–synovitis volume (1.1 vs –2.1 mL) or lateral femoral cartilage T2 relaxation time (–0.2 vs 0.2 ms).

Post-hoc analyses indicated that the reductions in pain were limited to participants with a lower baseline effusion–synovitis volume, which could be because “participants with a higher effusion–synovitis volume may have more severe disease,” Antony and team remark.

They point out, however, that this finding is “contrary to our original hypothesis that [Curcuma longa] may work best in persons with more local inflammation.”

The authors conclude: “Overall, these results suggest that the modest effect on knee pain in our study may be clinically relevant and that [Curcuma longa] may be a treatment option for managing knee osteoarthritis symptoms.”

They add: “Multicenter trials with larger sample sizes are needed to assess the clinical significance of these findings.”

medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2020 Springer Healthcare Ltd, part of the Springer Nature Group

Ann Intern Med 2020; doi:10.7326/M20-0990