Association of Vitamin D Status With Mental Stress–Induced Myocardial Ischemia in Patients With Coronary Artery Disease

Background Mental stress–induced (MSIMI) or physical stress–induced (PSIMI) myocardial ischemia portends a worse prognosis in patients with coronary artery disease (CAD). Vitamin D insufficiency is associated with adverse cardiovascular outcomes, but its relationship to myocardial ischemia remains unclear. We hypothesized that vitamin D insufficiency will be associated with a higher prevalence of myocardial ischemia in patients with CAD. Methods In 255 patients with stable CAD, myocardial perfusion imaging was performed to assess ischemia in response to mental and physical stress protocols. Vitamin D insufficiency was defined as serum 25-hydroxyvitamin D [25(OH)D] levels below 30 ng/ml, collected on the day of stress testing. Results Mean (standard deviation) 25(OH)D level was 30.8 (12.8) ng/ml, and 139 (55%) patients had vitamin D insufficiency. MSIMI occurred in 30 (12%) patients and PSIMI in 67 (27%). Individuals with MSIMI had significantly lower levels of 25(OH)D as compared with those without MSIMI (24.0 [8.6] versus 31.7 [12.9], p = .002). The prevalence of MSIMI was higher in those with as compared with those without vitamin D insufficiency (17% versus 6%, p = .009). Moreover, low 25(OH)D levels remained independently associated with MSIMI after adjusting for potential confounders. Conversely, 25(OH)D levels were similar between those with or without PSIMI (29.8 [13.0] versus 31.4 [12.7], p = .37), as was the prevalence of PSIMI in those with or without vitamin D insufficiency (29% versus 24%, p = .42). Conclusions Vitamin D insufficiency is associated with a higher prevalence of MSIMI but not PSIMI among stable patients with CAD. Whether this association serves as a potential mechanism linking low vitamin D status to adverse cardiovascular outcomes warrants further investigation.