Effect of diabetes mellitus on formation of coronary collateral vessels

Background-Although myocardial ischemia is known to be significantly relate d to the development of coronary collateral vessels (CCVs), there is consid erable variation between patients with ischemic heart disease in the presen ce of collateral development. The nature of this variability is not well kn own. Likewise, it remains unclear whether diabetes mellitus (DM) has any ef fect on CCVs. The aim of this study was to evaluate the effect of DM on CCV s. Methods and Resulfs-Of the patients who underwent coronary angiography duri ng the interval between March 1, 1993, and June 20, 1998, in our institutio n, 306 were diabetic. Those patients in whom coronary angiography is normal or severity of coronary artery stenosis is thought not to be sufficient fo r the development of CCVs (<75%) were excluded from the study. A total of 2 05 patients (mean age, 59 +/- 8 years) met the criteria for the DM group. F or case-control matching, 205 consecutive nondiabetic patients (mean age, 5 8 +/- 9 years) who had greater than or equal to 1 diseased vessel with >75% stenosis were included in the control group. The CCVs were graded accordin g to the Rentrop scoring system, and the collateral score was calculated by summing the Rentrop numbers of every patient. There was no statistical dif ference between patients with and without DM in clinical baseline character istics. The mean number of diseased vessels in the DM group (1.58 +/- 0.68) was higher than that in the nondiabetic group (1.42 +/- 0.65, P = 0.005). The mean collateral score was 2.41 +/- 2.20 in the DM group and 2.60 +/- 2. 39 in the control group. After confounding variables were controlled for, t he collateral score in the diabetic group was significantly different from that in the nondiabetic group (P = 0.034). Conclusions-Our findings suggest that CCV development is poorer in patients with than in patients without DM. Thus, we can speculate that DM is an imp ortant factor affecting CCV development.