Effect of nicotinamide riboside on airway inflammation in COPD: a randomized, placebo-controlled trial

Abstract

Chronic obstructive pulmonary disease (COPD) is a progressive, incurable disease associated with smoking and advanced age, ranking as the third leading cause of death worldwide. DNA damage and loss of the central metabolite nicotinamide adenine dinucleotide (NAD⁺) may contribute to both aging and COPD, presenting a potential avenue for interventions. In this randomized, double-blind, placebo-controlled clinical trial, we treated patients with stable COPD (n = 40) with the NAD⁺ precursor nicotinamide riboside (NR) for 6 weeks and followed-up 12 weeks later. The primary outcome was change in sputum interleukin-8 (IL-8) from baseline to week 6. The estimated treatment difference between NR and placebo in IL-8 after 6 weeks was -52.6% (95% confidence interval (CI): -75.7% to -7.6%; P = 0.030). This effect persisted until the follow-up 12 weeks after the end of treatment (-63.7%: 95% CI -85.7% to -7.8%; P = 0.034). For secondary outcomes, NR treatment increased NAD⁺ levels by more than twofold in whole blood, whereas IL-6 levels in plasma remained unchanged. In exploratory analyses, treatment with NR showed indications of upregulated gene pathways related to genomic integrity in the airways and reduced epigenetic aging, possibly through a reduction in cellular senescence. These exploratory analyses need to be confirmed in future trials. ClinicalTrials.gov identifier: NCT04990869 .

Fig. 1. CONSORT flow diagram.

The primary outcome IL-8 was assessed in sputum samples from patients with COPD.

Fig. 2. Augmented NAD⁺ levels after NR supplementation in COPD decrease airway inflammation.

a, Study design. b, Changes in the primary outcome IL-8 in sputum from baseline (Pre, n = 30) after 6 weeks of NR/placebo supplementation (Post, n = 26) and at follow-up after 12 weeks (Follow-up, n = 24), along with individual values in patients with COPD: paired pre-intervention to post-intervention sputum samples where available are shown (n = 22). A constrained linear mixed model adjusted for sex and baseline CAT score was used for analysis on log-transformed data, and back-transformed least square means ± 95% CI with two-sided P values are shown. c, Changes in the secondary outcome whole-blood NAD⁺ levels from baseline (Pre, COPD: n = 40, Healthy: n = 18) to 6 weeks (Post, COPD: n = 37, Healthy: n = 18) and at follow-up after 12 weeks (Follow-up, COPD: n = 35, Healthy: n = 18), along with individual values in patients with COPD and lung-healthy controls with paired pre-intervention to post-intervention whole-blood samples (COPD: n = 37, Healthy: n = 18) and NAD⁺ levels at baseline (mean ± s.d.). A constrained linear mixed model adjusted for sex was used for analysis, and least square means ± 95% CI with two-sided P values are shown. d, Changes in the secondary outcome plasma IL-6 levels from baseline (Pre, COPD: n = 40, Healthy: n = 18) to 6 weeks (Post, COPD: n = 36, Healthy: n = 18) and at follow-up after 12 weeks (Follow-up, COPD: n = 35, Healthy: n = 18), along with individual values in patients with COPD and lung-healthy controls with paired pre-intervention to post-intervention whole-blood samples (COPD: n = 36, Healthy: n = 18) and NAD⁺ levels at baseline (mean ± s.d.). A constrained linear mixed model adjusted for sex was used for analysis, and least square means ± 95% CI with two-sided P values are shown. Corrections for multiplicity were not made.

Fig. 3. NR treatment effects on epigenetic aging, transcription signaling and predicted cellular senescence in patients with COPD.

a, Change in the exploratory outcome rate of aging (RoA: epigenetic age/chronological age) from baseline (Pre, n = 36) after 6 weeks of NR/placebo supplementation (Post, n = 31) and after a 12-week follow-up (Follow-up, n = 25) in patients with COPD. Four different epigenetic clocks are shown. A constrained linear mixed model adjusted for sex and baseline CAT score was used for analysis showing least square means ± 95% CI. Forest plot showing differences in RoA between patients with COPD (n = 36) and lung-healthy controls (n = 15) measured in PBMCs. Each line represents the mean ± 95% CI effect size (Cohen’s d) for different epigenetic clocks, with positive values indicating higher RoA in patients with COPD. Blue color indicates non-overlap of 95% CI with zero. b, Exploratory outcome RNA sequencing in nasal epithelial cells. RNA was extracted and sequenced to generate GSEA maps showing functional groups (shaded circles) of gene sets detected (FDR < 0.05) in patients with COPD and lung-healthy controls after 6 weeks of NR treatment. Node size indicates gene set size, and color indicates direction of change, with red being upregulated and blue being downregulated with NR treatment. c, Analysis workflow showing a representative micrograph of a sputum sample and monocyte nuclei detection by the DNNs. Change in the post hoc outcome predicted IR-induced senescence and replicative senescence from baseline (Pre, n = 29) after 6 weeks of NR/placebo supplementation (Post, n = 25) and after a 12-week follow-up (Follow-up, n = 24) in patients with COPD. A similar statistical model as a was used. Corrections for multiplicity were not made.

Extended Data Fig. 1. Correlation between baseline sputum IL-8 and the change in IL-8 following the intervention.

Delta values are Pre- to post-intervention in the NR (n = 7) and placebo (n = 15) group of patients with COPD. Correlations are analyzed using Person’s correlation on log-transformed data with two-sided P-values shown.

Extended Data Fig. 2. Baseline correlations with NAD⁺.

(a) Correlation between baseline NAD⁺ and Forced Expiratory Volume (FEV₁) analyzed using Person’s correlation. (b) Correlation between baseline NAD⁺ and the change in NAD⁺ following the intervention in pooled NR and placebo groups analyzed using Person’s correlation.

Extended Data Fig. 3. Effects of NR treatment on sputum inflammatory markers.

Changes in the post hoc outcomes sputum neutrophil and macrophage differential and absolute count, and neutrophil elastase and interleukin-6 (IL-6) levels from baseline (Pre, n = 30) following six weeks of NR/placebo supplementation (Post, n = 26) and at follow-up after twelve-weeks (Follow-up, n = 24) in patients with COPD. A constrained linear mixed model adjusted for sex and baseline COPD assessment test (CAT) score was used for analysis on log-transformed data and back-transformed least square means ± 95% confidence intervals with two-sided P-values shown. Corrections for multiplicity were not made.

Extended Data Fig. 4. Effects of NR treatment on epigenetic age.

Change in rate of aging (epigenetic age/chronological age) from baseline (Pre, n = 36) following six weeks of NR/placebo supplementation (Post, n = 31) and after a twelve-week follow-up (Follow-up, n = 25) in patients with COPD. The nine different epigenetic clocks included in the ‘System age’ clocks are shown. A constrained linear mixed model adjusted for sex and baseline COPD assessment test (CAT) score was used for analysis with least square means ± 95% confidence intervals with two-sided P-values shown. Corrections for multiplicity were not made.

Extended Data Fig. 5. Effects of NR treatment on gene set enrichment.

(a) Gene Set Enrichment Analysis (GSEA) of top 10 up- and down-regulated gene sets arranged by normalized enrichment score (NES) and Venn diagram of enriched gene sets following 6 weeks of NR supplementation in patients with COPD and (b) lung-healthy controls. (c) Bar graph and Venn diagram of enriched gene sets after a 12-week follow-up period in patients with COPD and (d) lung-healthy controls.

Extended Data Fig. 6. Effects of NR treatment on principal component analysis.

(a) Principal component analysis (PCA) of mean gene expression of nasal epithelial cells in patients with COPD and lung-healthy controls grouped into baseline (BL), post, and follow-up (FU) for NR and placebo (PLC) treated groups. (b) PCA of gene expression of individual subjects at a time point.

Extended Data Fig. 7. Correlations between markers of inflammation, senescence and epigenetic age.

(a) Correlation between baseline sputum IL-8 and predicted IR senescence (n = 29), sputum IL-8 and replicative senescence (n = 29), sputum IL-6 and predicted IR senescence (n = 27) and sputum IL-6 and replicative senescence (n = 27). (b) Correlation between baseline RoA and sputum IL-8 (n = 25) and ionizing radiation-like senescence (n = 25). Correlation between change in RoA and ionizing radiation-like senescence (n = 14) and sputum IL-8 following the intervention (n = 16). Correlations were analyzed using Person’s correlation on log-transformed data with two-sided P-values shown.

Extended Data Fig. 8. Effects of NR in vitro.

(a) NAD⁺ levels and cell viability in human bronchial epithelial cells (BEAS-2b) following exposure to increasing concentrations of menadione for 4 hours co-treated with or without 1 mM NR during exposure and 24 hours after exposure (mean ± standard deviation, n = 3 biological replicates). A main-effects analysis of variance (ANOVA) model was fitted to the data, and the two-tailed P-values for the effect of NR dose are shown. An unpaired t-test was used to test differences in area under the curve (AUC) survival with or without NR with a two-tailed P-value shown. (b) Probability of senescence following exposure to ionizing radiation (IR) and ultraviolet light (UV-C) in primary human fibroblasts (MRC-5, AG08498, GM22159, GM22222) treated with increasing concentrations of NR for 24 hours after exposure (mean ± standard deviation, n = 4, with each cell line used as a biological replicate). A main-effects ANOVA model was fitted to the data, and the two-tailed P-values for the effect of NR dose are shown.