
Among individuals with type 2 diabetes (T2D), those with higher serum 25-hydroxyvitamin D (25[OD]D) appear to have a lower risk of heart failure (HF), with the Mendelian randomization (MR) analysis pointing to a possible causal relationship.
In this study, more than 15,000 individuals with T2D aged 40–72 years from the UK Biobank were included in the observational analyses. Electronic health records were used to confirm HF incidence.
The investigators used Cox proportional hazard regression models to estimate hazard ratios (HRs) and 95 percent confidence intervals (CIs) for the association of serum 25(OH)D with HF risk in T2D patients. They also performed MR analyses among 11,260 unrelated participants with T2D.
Finally, 62 confirmed genome-wide variants were used to generate a weighted genetic risk score for genetically predicted 25(OH)D concentration.
The mean serum 25(OH)D concentration was 43.4 nmol/L. Some 836 incident HF events occurred during a median follow-up of 11.3 years.
Serum 25(OH)D showed a nonlinear and inverse relationship with HF, with the decreasing risk plateauing at the 50-nmol/L level. Compared with participants with 25(OH)D <25 nmol/L, those with 25(OH)D 50.0–74.9 nmol/L (adjusted HR, 0.67, 95 percent CI, 0.54–0.83) and >75 nmol/L (adjusted HR, 0.71, 95 percent CI, 0.52–0.98) showed a lower risk of HF.
MR analysis revealed a 36-percent reduced risk of HF for each 7-percent increment in genetically predicted 25(OH)D among individuals with T2D (HR, 0.64, 95 percent CI, 0.41–0.99).
“These findings indicate a role of maintaining adequate vitamin D status in the prevention of HF among individuals with T2D,” the investigators said.