Background: An increased level of plasma homocysteine is being recognized as a new risk factor for coronary artery disease. Since there are not enough data about its importance in Indians with coronary artery disease, we aimed to assess the significance of plasma homocysteine as a coronary risk factor in South Indian patients.
Methods and results: In a case-control study, fasting plasma homocysteine levels were estimated in 565 subjects, of whom 221 were cases and 344 were controls. Of the 221 clinically defined cases, 112 underwent coronary angiography while 107 of the 344 controls had angiographically proven normal coronary arteries. Ninety healthy volunteers from the community were also included as controls. Fluorescent polarization immunosorbent assay was used to measure plasma homocysteine levels. In 12 patients, this method was compared to high pressure liquid chromatography and was found to give comparable results. The mean plasma homocysteine level was 18.30 +/- 10.08 micromol/L in clinically defined cases and 18.04 +/- 10.69 micromol/L in controls. Similarly, in angiographicallyproven coronary arterydisease patients, the mean plasma homocysteine levelwas 18.49 +/- 10.04 micromol/L and in individuals with angiographically normal coronary arteries, it was 19.16 +/- 11.38 micromol/L.
Conclusions: There is no statistically significant difference in plasma homocysteine levels between controls and cases with coronary artery disease. The mean plasma homocysteine levels in controls as assessed by fluorescent polarization immunosorbent assay in the present study population are higher as compared to other published reports.