Does diabetes mellitus affect the mortality and morbidity rates after coronary artery bypass surgery?

Introduction

Although diabetes mellitus (DM) is one of the major risk factors of developing atherosclerosis, its effects on mortality and morbidity after cardiac surgery are still not clear. We aimed to determine the effects of DM on hospital mortality and morbidity rates.

Methods

A total of 1245 consecutive patients undergoing coronary artery operations with or without cardiopulmonary bypass from September 2003 to July 2004 were followed to determine risk factors on mortality and morbidity in patients with diabetes and nondiabetes. The statistical analysis was realised by it test for parametric variables and chi-square test for nonparametric variables. P < 0.05 was considered statistically significant.

Results

Twenty percent of all patients were diabetics. According to demographic data and coexisting diseases, there were significant differences between the diabetics and nondiabetics, in sex (female), body mass index (obesity), carotid arterial disease, hypertension, preoperative urea and creatinine levels (P < 0.001). Although we found that the inotropic usage of the diabetics were significantly higher (P < 0.005), there were no differences in operation, bypass and cross-clamping time between the two groups, In the ICU period, we could not find any difference in intubation time, blood products usage, reoperation and ICU stay. Duration of hospital stay was significantly longer in diabetics (P < 0.01). Postoperative complications and mortality rates are presented in Table 1.

Table 1 Postoperative complications and mortality rates

Conclusion

It was interesting to see that although there were no differences in operative and postoperative data between the two groups, factors that could affect the morbidity and the mortality rate were significantly higher in diabetics. In our opinion this was because diabetics unfortunately have more coexisting diseases such as hypertension or renal insufficiency.