Association of Low Levels of Vitamin D with Chronic Stable Angina: A Prospective Case-Control Study.
BACKGROUND
Coronary artery disease (CAD) is a major cause of death and disability in developed countries. Chronic stable angina is the initial manifestation of CAD in approximately 50% of the patients. Recent evidence suggests that vitamin D is crucial for cardiovascular health. The prevalence of vitamin D deficiency in our region is 83%. A low level of vitamin D is associated with chronic stable angina.


OBJECTIVE
This study was aimed at supporting or refuting this hypothesis in our population.


METHODS
The study was a prospective case-control study. We studied 100 cases of chronic stable angina and compared them with 100 matched controls. Vitamin D deficiency was defined as <20 ng/mL, vitamin D insufficiency as 20-30 ng/mL and normal vitamin D level as 31-150 ng/mL.


RESULTS
The prevalence of vitamin D deficiency among cases and controls was 75% and 10%, respectively. 75% of the cases were vitamin D-deficient (<20 ng/mL); 12% were vitamin D-insufficient (20-30 ng/mL), and 13% had normal vitamin D levels (31-150 ng/mL). None had a toxic level of vitamin D. Among the controls, 10% were vitamin D-deficient, 33% were vitamin D-insufficient, and 57% had normal vitamin D levels. The mean vitamin level among cases and controls was 15.53 ng/mL and 40.95 ng/mL, respectively, with the difference being statistically significant (P ≤ 0.0001). There was no statistically significant relation between the disease severities, i.e., on coronary angiography (CAG) with vitamin D level. Among the cases, we found that an increasing age was inversely related to vitamin D levels (P = 0.027).


CONCLUSIONS
Our study indicates a correlation between vitamin D deficiency and chronic stable angina. Low levels may be an independent, potentially modifiable cardiovascular risk factor.
Department of Internal Medicine, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India.
Ab Hameed
AH
Raina
Department of Cardiology, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India.
Mohammad Sultan
MS
Allai
Department of Immunology, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India.
Zafar Amin
ZA
Shah
Department of Internal Medicine, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India.
Khalid Hamid
KH
Changal
Department of Clinical Biochemistry, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India.
Manzoor Ahmad
MA
Raina
Department of Internal Medicine, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India.
Fayaz Ahmad
FA
Bhat
Chronic stable angina; North India; coronary artery disease (CAD); prevention of coronary artery disease; vitamin D