Background:
It is unclear whether vitamin D deficiency is associated with a higher risk of cardiovascular disease, and through what biochemical pathways this could occur. We investigated the relationship between serum 25-OH vitamin D and typical cardiovascular risk markers as well as incident myocardial infarction (MI) in a large group of high-risk individuals from the community of Calgary, Alberta, Canada.
Methods:
Calgary Laboratory Services databases were queried for age, sex, body mass index (BMI), personal healthcare number (PHN) and first available serum 25-OH vitamin D measure from patients who received an electrocardiogram or urine creatinine clearance test from 2010-2013. Data was linked by PHN to first available laboratory results for total cholesterol, HDL cholesterol, triglycerides, LDL cholesterol, fasting glucose and HbA1c as well as Alberta Health Services hospital discharge data for first myocardial infarction (ICD-10: I21.1-9) occurring after 25-OH vitamin D measurement. Multiple linear and logistic regression were used to examine all associations.
Results:
There were 36 000-50 000 complete patient records for analysis of each of the risk markers, with a median follow-up of 8-11 months. A 30 mmol/L increase in serum 25-OH vitamin D was associated with significantly (p<0.001) lower total cholesterol (-0.07 mmol/L), LDL cholesterol (-0.06 mmol/L), triglycerides (-0.14 mmol/L), fasting glucose (-0.12 mmol/L), and HbA1c (-0.13% mmol/L), but higher HDL cholesterol (+0.06 mmol/L) after adjusting for age, sex, BMI, monthly hours of sun-exposure and time between measures. Among these individuals, there were 458 cases of MI occurring after 25-OH vitamin D measurement, with a median follow-up of 1 year. In a case-cohort analysis that included 2500 controls, a 30 mmol/L increase in 25-OH vitamin D was associated with a 21% (p<0.001) lower odds of MI after multivariate adjustment. This association was strongly attenuated after adjusting LDL, HDL, fasting glucose and HbA1c.
Conclusion:
In a high-risk group of community patients from Calgary, Alberta, Canada, higher serum 25-OH vitamin D was associated with a lower risk of MI, which was explained by changes in commonly measured cardiovascular risk markers. Further study is needed to determine whether changes in cardiovascular risk markers are causally related to changes in 25-OH vitamin D.
Acute Coronary Syndromes: From the Laboratory Markers to the Coronary Vessels