Hyperhomocysteinaemia is associated with coronary events in type 2 diabetes

Objectives. Amongst nondiabetic individuals, a high serum homocysteine concentration is an independent but relatively weak risk factor for coronary events. However, it is not known whether homocysteine increases risk of coronary events in type 2 diabetes. Therefore, we examined the combined effect of homocysteine and type 2 diabetes on risk of fatal and nonfatal coronary events. Subjects. We assessed the 10-year risk of coronary events associated with homocysteine amongst diabetic (n = 140) and nondiabetic (n = 361) individuals. Design. We did this in the Hoorn Study, a population-based study of glucose tolerance and related complications in Caucasian men and women aged 50-75 years. Results. The incidence rate for coronary events was 2.63 (29 of 140) per 100 person-years amongst diabetic and 1.29 (42 of 361) amongst nondiabetic individuals. Amongst diabetic individuals, risk of coronary events increased 28% for each 5-μmol L^-1 increment of homocysteine (hazard ratio, 1.28:95% CI, 1.02-1.58). This risk was independent of age, sex, hypertension, total cholesterol, HDL-cholesterol, cigarette smoking, body mass index and glomerular filtration rate. In nondiabetic participants, homocysteine was not associated with an increased risk of coronary events (hazard ratio for each 5-μmol L^-1 increment of homocysteine, 0.86; 0.52-1.41). Conclusions. These data suggest that homocysteine is significantly associated with coronary events in individuals with type 2 diabetes, independent of traditional cardiovascular risk factors. Investigation of the effect of treatment with vitamin B on prognosis of individuals with type 2 diabetes is warranted.