Effects of NAD+ precursors on blood pressure, C‐reactive protein concentration and carotid intima‐media thickness: A meta‐analysis of randomized controlled trials

Abstract Background There are contradictory effects regarding the effect of NAD+ precursor on blood pressure and inflammation. In order to obtain a better viewpoint from them, this study aimed to comprehensively investigate the effects of NAD+ precursor supplementation on blood pressure, C‐reactive protein (CRP) and carotid intima‐media thickness (CIMT). Methods PubMed/MEDLINE, Web of Science, SCOPUS and Embase databases were searched using standard keywords to identify all controlled trials investigating the effects of NAD+ precursor on blood pressure, CRP and CIMT. Pooled weighted mean difference (WMD) and 95% confidence intervals (95% CI) were achieved by random‐effects model analysis for the best estimation of outcomes. Results Twenty‐nine articles (with 8664 participants) were included in this article. Results from meta‐analyses of RCTs from random‐effects models indicated a significant reduction in systolic (SBP) (weighted mean difference (WMD): −2.54 mmHg, p < .001) and diastolic blood pressure (DBP) (WMD: −2.15 mmHg, p < .001), as well as in CRP (WMD: −.93 mg/L, 95% CI −1.47 to −.40, p < .001) concentrations and CIMT (WMD: −.01 mm, 95% CI −.02 to −.00, p = .005) with the NAD+ precursors supplementation compared with the control group. In addition, a greater effect of supplementation with NAD+ precursors in reducing blood pressure (BP) were observed with the highest dose (≥2 g) and duration of the intervention (>12 weeks), as well as with NA supplementation when compared to NE. Conclusions Overall, these findings suggest that NAD+ precursor supplementation might have a beneficial effect on cardiovascular risk factors such as BP, CRP concentration and CIMT.