In post-myocardial infarction (MI) patients, we examined independent and combined associations of vitamin D status and physical activity (PA) with long-term mortality, including effect modification by health determinants. We conducted a prospective analysis of 4,837 MI patients from the Alpha Omega Cohort. Baseline blood samples (2002-2006) were assessed for plasma 25-hydroxyvitamin D (25[OH]D) levels using LC-MS/MS. PA was assessed using a validated questionnaire. Patients were followed for mortality through December 2022. HRs for CVD and all-cause mortality were obtained across sex-specific tertiles of 25(OH)D and four categories of PA using Cox models, adjusted for sociodemographic and lifestyle factors. Potential effect modification by health determinants was examined through stratification. Patients were 69±5.6 years old, 78% was male, 21% had diabetes, and 10% used vitamin D-containing supplements. Over 14.4 years, 3,206 deaths occurred, including 1,244 from CVD. Median 25(OH)D was 21.1 ng/mL and 44% was vitamin D deficient (<20 ng/mL). Higher 25(OH)D levels were associated with lower CVD (HR:0.63, 95%CI:0.54,0.74) and all-cause mortality (HR:0.68, 95%CI:0.62,0.75). For PA levels (high vs. light), HRs were 0.72 (95%CI:0.61,0.85) for CVD mortality and 0.83 (95%CI:0.75,0.92) for all-cause mortality. Patients with low 25(OH)D and no PA had a threefold higher mortality risk than those with high 25(OH)D levels and high PA. The associations were not significantly modified by sex, comorbidities and other health determinants. Vitamin D status and PA were inversely and independently associated with long-term risk of CVD and all-cause mortality after MI, regardless of other health determinants.
Read full abstract