Impact of gender difference on vitamin D status and its relationship with the extent of coronary artery disease

Background and aim: There has been a surge of interest in the cardiovascular effects of vitamin D (25(OH)D), preventing the processes leading to vascular wall degeneration and coro- nary artery disease (CAD). Gender differences have been suggested for vitamin D status, with a higher rate of deficiency occurring especially in post-menopausal women, increasing the risk of bone fractures and osteoporosis. However, to date, few studies have evaluated the differences in 25(OH)D levels according to gender and their impact on the extent of CAD, which was therefore the aim of the present study. Methods and results: In patients undergoing coronary angiography, fasting samples were collected for the assessment of 25(OH)D levels. Significant CAD was defined as at least one vessel stenosis >50%, while severe CAD was defined as left main and/or three-vessel disease. Of the 1811 patients included, 530 (29.3%) were females, who displayed older age (p < 0.001), higher rate of renal failure (p < 0.001), hypertension (p Z 0.05), treatment with angiotensin- receptor blockers (p Z 0.03) and diuretics (p < 0.001), acute presentation (p < 0.001), higher platelet count (p < 0.001), glycosylated haemoglobin (p Z 0.02) and cholesterol (p Z 0.001), but an inverse relationship with smoking (p < 0.001), previous cardiovascular events (p < 0.001), treatment with statins and acetylsalicylic acid (ASA) (p < 0.001), body mass index (p Z 0.002), haemoglobin (p < 0.001), leucocytes (p Z 0.03) and triglycerides (p < 0.001). Female gender was associated with lower vitamin D levels (14.5 10.9 vs. 15.9 9.5, p Z 0.007) and independently associated with severe vitamin D deficiency (41.9% vs. 30.4%, p < 0.001; adjusted odds ratio (OR) (95% confidence interval (CI)) Z 1.42 (1.08e1.87), p Z 0.01). Lower tertiles of vitamin D were associated with an increased prevalence and severity of CAD in females (adjusted OR (95% CI Z 1.26 (1.10e1.44), p Z 0.001 for CAD; adjusted OR (95% CI) Z 1.6 (1.39e1.87), p < 0.001 for severe CAD). In males, vitamin D status was independently related to the prevalence (adjusted OR (95% CI) Z 1.28 (1.02e1.61), p Z 0.03) of CAD, but not the extent of CAD (adjusted OR (95% CI) Z 1.02 (0.86e1.2), p Z 0.84). Conclusion: Gender significantly affects vitamin D status. The lower 25(OH)D levels observed in females, as compared to males, play a more relevant role in conditioning the severity of CAD.