Hyperhomocysteinemia is a risk factor for coronary arteriosclerosis in Japanese patients with type 1 diabetes

OBJECTIVE - An increased plasma homocysteine level is an important risk fac tor for vascular disease, including coronary atherosclerosis, in the genera l population. However. the role of hyperhomocysteinemia in the development of coronary artery disease (CAD) in patients with type 2 diabetes is unknow n. Therefore, we hale endeavored to determine the relationship between plas ma homocysteine levels and the presence of coronary arteriosclerosis in pat ients with type 2 diabetes. RESEARCH DESIGN AND METHODS - The study group consisted of 145 Japanese pat ients (95 men and 50 women) who underwent routine coronary angiography to a ssess chest pain or suspected CAD. Plasma total homocysteine level, lipid l evel, and parameters of fibrinolytic activity were measured. All patients w ere identified as diabetic or nondiabetic by the new American Diabetes Asso ciation (ADA) criteria. The diagnoses of all patients studied were confirme d by coronary angiography. The severity of coronary artery stenosis was qua ntified using CAD scoring on the basis of prior reports, and subjects were graded as nonstenotic, stenotic single-vessel, stenotic two-vessel, or sten otic three-vessel based on the number of stenotic coronary arteries. Patien ts were classified into two groups: those with stenotic vessels and these w ithout stenotic vessels. RESULTS - The plasma homocysteine level was significantly higher in patient s with than in patients without stenotic vessels (13.8 +/- 3.9 vs. 11.7 +/- 3.9 mu mol/l, respectively; P = 0.0009). The number of stenotic coronary a rteries, which was used to grade each case as nonstenotic, stenotic single- vessel, stenotic two-vessel, or stenotic three-vessel, was related only to the total homocysteine level in the diabetic (diabetes mellitus [DM]) group , but it was associated with lipoprotein(a) in the nondiabetic (non-diabete s mellitus [non-DM]) group. Spearman's rank correlation test demonstrated t hat the plasma homocysteine level was strongly correlated with CAD score, b oth in the entire study group and in the DM group (P = 0.003 for the entire group and P = 0.011 for the DM group). Hyperhomocysteinemia, which was def ined as total homocysteine level >14.0 mu mol/l. was seen in 57 (39.3%) of the patients. The CAD score was highest in diabetic patients with hyperhomo cysteinemia (P < 0.05). CONCLUSIONS - There seems to be a clear relationship between hyperhomocyste inemia and an increased risk of coronary arteriosclerosis in Japanese patie nts with type 2 diabetes.