Serum vitamin D levels correlate to coronary artery disease severity: a retrospective chart analysis

Background: The pro-atherosclerotic nature of vitamin D deficiency has been shown to increase cardiovascular events. We further emphasized and evaluated the severity of coronary artery disease (CAD) with varying levels of vitamin D in relation to age, gender, ethnicity and baseline confounders. Methods: A retrospective, single-center study of 9,399 patients admitted between 2005 and 2014 for chest pain who underwent coronary angiography. Patients without a vitamin D level, measured as 25-dihydroxyvitamin D (25[OH]D) were excluded from our study. 25(OH)D deficiency and insufficiency were defined by having serum concentration levels of less than 20 ng/ml and 20 to 29.9 ng/ml, respectively, while normal levels were defined as greater than or equal to 30 ng/ml. We assessed levels of 25(OH)D and extent of coronary disease with coronary angiography as obstructive CAD (left main stenosis of ≥50% or any stenosis of ≥70%), non-obstructive CAD (≥1 stenosis ≥20% but no stenosis ≥70%) and normal coronaries (no stenosis >20%). Results: Among 9,399 patients, 1,311 qualified, of which 308 patients (23%) had normal 25(OH)D levels, 552 patients (42%) had 25(OH)D deficiency and 451 patients (35%) had 25(OH)D insufficiency. In an analysis of the extent of coronary disease, we identified 20% of patients having normal coronaries, 55% having obstructive CAD and 25% having non-obstructive CAD. Baseline clinical risk factors and co-morbidities did not differ between the groups. Patients with normal 25(OH)D levels were found to have normal coronaries compared to patients with 25(OH)D deficiency or insufficiency (OR: 7, 95% CI: 5.2 – 9.5, p < 0.0001). Comparing patients with normal 25(OH)D levels, patients with 25(OH)D deficiency or insufficiency (<29 ng/ml), 62% were found to have obstructive CAD (n = 624, OR: 2.9, 95% CI: 2.3-3.7, p < 0.0001) and 25% had non-obstructive CAD (n = 249, OR: 1.5, 95% CI: 1.1-2, p =0.02). Conclusion: Normal coronaries and CAD were shown to correlate with normal and low levels of 25(OH)D, respectively. There is an inverse relationship between the percentage of coronary artery occlusion and serum 25(OH)D concentrations. Vitamin D may provide benefits in risk stratification of patients with CAD and serve as a possible risk factor.