Low Dose Niacin Versus Placebo Treatment for Parkinson's Disease: A Randomized Controlled Trial

Abstract Background Parkinson's Disease (PD) patients have lower niacin levels compared to their spouses. The main objective was to study low-dose daily niacin supplementation on motor symptoms in Parkinson's disease subjects. Methods Forty-Seven PD patients were randomly assigned to receive low-dose niacin or placebo in a randomized, double-blind study for the first six months. After the double-blind phase, all participants received open-label niacin for the next six months. All patients were evaluated at baseline, six months, and one year of treatment. The main outcome measure was the Unified Parkinson's Disease Rating Scale III (UPDRS III) scores. Secondary outcome measures were depression, sleep quality, mental flexibility and cognition, and physical fatigue. Results Niacin treatment was tolerated well by 45 subjects. The baseline mean UPDRS III score was 21.3 ± 15.8 for the niacin group and 22.4 ± 11.8 for placebo. The change with six months of placebo was 1.5 [95% CI, -0.73 to 3.73], and niacin was − 1.06 [95% CI, -3.68 to 1.57]. From six to twelve months, the average UPDRS III score decreased for the placebo group by 2.66 [95% CI, -0.95 to 6.24] and the niacin group by 4.63 [95% CI, 1.42 to 7.83]. Eight subjects withdrew from the study before the 6-month time point and eight more before the one-year time point due to voluntary discontinuation, flushing, or inability to continue (SARS-CoV-2 shut-down). Conclusion Low-dose niacin supplementation may be helpful as an adjunct therapy in improving motor function in PD. Trial registration: Clinicaltrials.gov, NCT03462680. Registered 12 March 2018- Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03462680?term=gpr109A&draw=2&rank=1