DIFFUSE NARROWING OF CORONARY-ARTERIES IN DIABETIC-PATIENTS - THE EARLIEST PHASE OF CORONARY-ARTERY DISEASE

Coronary arteries in diabetic patients appear to be narrower than in n ormal subjects, but this has not been examined systematically. To inve stigate this hypothesis we reviewed the data of 711 consecutive patien ts with angiographically 'normal coronary arteries'. Excluded were pat ients with valvular, myocardial or pericardial disease, and patients w ith hypertension or hyperlipidemia. Thirteen diabetic patients (10 men ) and 22 nondiabetic persons (8 men) constituted the study and control groups, respectively. The diameters of the coronary arteries and thei r branches were measured and adjusted for body surface area. The sum o f the proximal left anterior descending (LAD), circumflex and right co ronary arteries (RCA) was calculated and defined as total coronary dia meter (TCD). The sum of the distal LAD, first diagonal, first marginal and distal RCA was calculated and defined as total distal coronary di ameter (dTCD). The clinical data of both groups were comparable. Adjus ted TCD for body surface area was 5.4 +/- 1.1 and 6.5 +/- 1.1 mm/m(2) (p < 0.05) in diabetics and nondiabetics, respectively, and adjusted d TCD was 4.9 +/- 1.2 and 6.1 +/- 1.2 mm/m(2) (p = 0.01) in diabetics an d normal subjects, respectively. Specific arteries and branches that w ere significantly smaller in diabetics included: left main coronary ar tery, distal LAD, first diagonal, proximal RCA, distal RCA, right vent ricular branch, and posterolateral and posterior descending artery of RCA origin. Gender was not a confounding factor since the control grou p had a larger proportion of women and still larger arteries than the diabetic group. In conclusion, coronary arteries and their branches in diabetic patients have smaller diameters than normal subjects. This m ay be due to increased coronary tone, diffuse mild atherosclerosis or both.