Major Electrocardiographic Abnormalities and 25‐Hydroxy Vitamin D Deficiency: Insights from National Health and Nutrition Examination Survey‐ III

Background We explored the relationship between major electrocardiogram (ECG) abnormalities (mECG) and 25‐hydroxy (25‐OH) vitamin D deficiency (VDD) and the effect of mECG abnormalities on all‐cause and cardiovascular mortality in a healthy cohort with 25‐OH vitamin D insufficiency and deficiency. Hypothesis Lower levels of serum 25‐OH vitamin D are associated with increased prevalence of mECG on resting ECG. Methods We identified 5108 individuals from the National Health and Nutrition Examination Survey‐III. mECG abnormalities included: major Q‐QS wave abnormalities, ST depression/elevation, negative T waves, Wolff‐Parkinson‐White pattern, and ventricular conduction defect. Our cohort was divided into 3 groups based on 25‐OH vitamin D levels: Group 1 (referent): >40 ng/mL; group 2 (insufficient): ≥20.01 to ≤40 ng/mL; and group 3 (deficient): ≤20 ng/mL. Logistic regression and Cox proportional hazards regression models were built. Results The prevalence of major ECG abnormalities across 25‐OH vitamin D sufficiency, insufficiency, and deficiency was 5.9%, 11%, and 13 %, respectively ( P  = 0.01). VDD was an independent predictor of mECG abnormalities after adjusting for traditional risk factors (continuous variable odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.97‐0.99, P  = 0.007; categorical variable group 3 vs group 1 OR: 2.36, 95% CI: 1.1‐5.12, P  = 0.03). Baseline major ECG abnormalities were predictive of long‐term all‐cause (hazard ratio [HR]:1.52, 95% CI: 1.23‐1.89), composite cardiovascular (HR: 1.7, 95% CI: 1.34‐2.15), cardiovascular (HR: 1.64, 95% CI: 1.27‐2.12), and ischemic heart disease mortality (HR: 1.98, 95% CI: 1.46‐2.69) in individuals with 25‐OH vitamin D levels ≤40 ng/mL. Conclusions VDD is associated with increased prevalence of major ECG abnormalities. Well‐structured trials are needed to assess progression/resolution of mECG abnormalities with vitamin D supplementation in deficient individuals.