Comparative Efficacy of Nutritional Supplements in Modulating Lung Function and Exercise Capacity in COPD Patients: A Network Meta-Analysis.

Objective: To compare the effects of nutritional supplements on lung function and exercise tolerance in chronic obstructive pulmonary disease (COPD).

Methods: We searched PubMed, Embase, Cochrane Library, and Web of Science for randomized controlled trials (RCTs) on nutritional supplements in COPD patients, with the search ending December 31, 2023. Two authors independently screened studies, extracted data, and assessed quality using the Cochrane risk of bias tool. Data were analyzed using RevMan 5.4 and R 4.2.3.

Results: Forty-eight studies with 2481 COPD patients were included. Network meta-analysis showed six supplements significantly improved the 6-minute walk distance (6MWD) (all p<0.05), with the top three being: Coenzyme Q10+ Creatine [MD=63, 95% CI (36, 90)], L-carnitine [MD=53, 95% CI (24, 82)], and anabolic steroids [MD=44, 95% CI (7.1, 82)]. Four supplements improved FEV₁%(all p<0.05): nanocurcumin [MD=13, 95% CI (7.7, 18)], Vitamin D [MD=7.5, 95% CI (5.1, 9.9)], probiotics [MD=7.1, 95% CI (5.2, 9.1)] and BSO [MD=4.9, 95% CI (1.6, 8.3)]. In pairwise comparisons, nanocurcumin outperformed BSO and Probiotics. Nanocurcumin [MD=12, 95% CI (4.6, 19), p<0.05] improved FEV₁/FVC, and nitrate [MD=26, 95% CI (9.7, 42), p<0.05] was effective for the Incremental Shuttle Walk Test (ISWT). Traditional Chinese Medicine (TCM) products [MD=-1.3, 95% CI (-1.9, -0.67)], melatonin (MLT) [MD=-0.9, 95% CI (-1.6, -0.21)] and Calcitriol [MD=-0.66, 95% CI (-0.93, -0.39)] improved the modified Medical Research Council(mMRC) dyspnea score (all p<0.05), with comparable efficacy among them.

Conclusion: Nutritional supplements improve lung function and exercise endurance in COPD. Coenzyme Q10+Creatine is most effective for endurance, while Nanocurcumin has the greatest impact on lung function.