Association of dietary niacin intake with cardiovascular-kidney-metabolic syndrome risk and mortality

Background: Dietary niacin, an essential nutrient, protects against metabolic diseases; however, its association with Cardiovascular-Kidney-Metabolic (CKM) syndrome and related mortality remains poorly understood. Methods: We examined the associations between dietary niacin intake and the prevalence of advanced CKM syndrome using logistic regression models, as well as the associations between dietary niacin intake and mortality (all-cause, cardiovascular, and cancer) across CKM stages using Cox proportional hazards models, based on data from the National Health and Nutrition Examination Survey. Non-linear relationships were examined using restricted cubic spline (RCS) analyses. Results: Among the 14,282 participants, 14.3% (2,042/14,282) were identified as having advanced-stage CKM syndrome. Higher dietary niacin intake was inversely associated with the prevalence of advanced-stage CKM syndrome (odds ratio [OR] = 0.72, 95% CI: 0.62-0.85). Stronger inverse associations were observed among participants aged over 40 years, those with higher physical activity levels, and those without hyperlipidemia. In patients with CKM stages 0-2, higher niacin intake was inversely associated with the risks of all-cause mortality (hazard ratio [HR] 0.75, 95% CI: 0.61-0.91), cardiovascular mortality (HR 0.53, 95% CI: 0.29-0.94), and cancer mortality (HR 0.70, 95% CI: 0.49-0.93). In patients with CKM stages 3-4, higher niacin intake was negatively associated with the risks of all-cause mortality (HR 0.82, 95% CI: 0.67-0.97) and cancer mortality (HR 0.53, 95% CI: 0.29-0.95). RCS analysis revealed a negative linear relationship of dietary niacin with advanced CKM syndrome and non-linear associations with all-cause, cardiovascular, and cancer mortality among patients in CKM stages 3-4. Conclusion: Dietary niacin intake may be associated with a lower prevalence of advanced-stage CKM syndrome and reduced mortality across all CKM stages, suggesting its potential role in dietary interventions for CKM prevention and management.