Diabetol Metab Syndr. 2025 Dec 16. doi: 10.1186/s13098-025-02058-z. Online ahead of print.
ABSTRACT
OBJECTIVE: To investigate the separate, joint, as well as interactive associations of serum 25-hydroxyvitamin D [25(OH)D] concentrations and oxidative balance score (OBS) with mortality among individuals with metabolic syndrome (MetS).
METHODS: The analysis included 12,078 participants with MetS from the National Health and Nutrition Examination Survey (NHANES) 2001-2018. Mortality was ascertained by linkage to National Death Index records through 31 December 2019.
RESULTS: During 99,690 person-years of follow-up, 2357 deaths were documented, including 654 cardiovascular disease (CVD) deaths and 518 cancer deaths. A pronounced “L-shaped” nonlinear relationship was observed between 25(OH)D and mortality; the hazard ratio (HR) [95% confidence interval (CI)] for 25(OH)D ≥ 75.0 vs. < 50.0 nmol/L (reference) were 0.71 (0.61, 0.82), 0.65 (0.48, 0.86), and 0.77 (0.57, 1.05) for all-cause, CVD, and cancer mortality, respectively. A reverse linear relationship was demonstrated between OBS and mortality; the HRs (95% CI) for high OBS vs. low OBS (reference) were 0.76 (0.68, 0.86), 0.70 (0.58, 0.85), and 0.75 (0.60, 0.94) for all-cause, CVD, and cancer mortality, respectively. In the joint analyses, the combination of 25(OH)D ≥ 75.0 nmol/L and high OBS was associated with the lowest risk of all-cause (HR 0.57, 0.46-0.70) and CVD mortality (HR 0.48, 0.34-0.69). In contrast, participants with 25(OH)D levels of 50.0-74.9 nmol/L and high OBS presented the lowest risk of cancer mortality (HR 0.52, 0.34-0.81). A significant synergistic additive interaction between OBS and sufficient 25(OH)D levels on CVD mortality was observed [relative excess risk due to interaction (RERI) = 0.29, 95% CI: 0.02-0.57], with 47% of the total protective effect attributable to their interaction.
CONCLUSIONS: Adequate 25(OH)D and higher OBS are significantly associated with lower risk of mortality and exhibit enhanced protective effects on CVD mortality risk.
PMID:41402956 | DOI:10.1186/s13098-025-02058-z
