Author's reply.

To the Editor,

We would like to thank the authors for their contribution to our study entitled “Obesity is still a risk factor in coronary artery bypass surgery” published in Anatol J Cardiol 2014; 14: 631-7. (1) and their valuable comments. They have mentioned that, as outlined in Table 3, some preoperative demographic characteristics in obese and non-obese groups differed. They have also stated that these factors could play a role in postoperative morbidity and mortality. However, we know that female gender, diabetes, and hypertension are comorbidities of obesity. It is not easy to say that these factors played a direct role on adverse effects. It would be more reliable to state that the comorbidities of obesity increase these adverse outcomes. However, multivariate analysis could have been performed to increase reliability. We have re-analyzed the effect of each mentioned parameter on adverse effects (female gender, hypertension, diabetes, and smoking) and did not find any statistically significant effects (p>0.05 each) on adverse outcomes except for increased rates of postoperative atrial fibrillation (POAF) in patients with diabetes (p=0.03).

The authors have also stated that they find the lower rates of POAF in obese group very conflicting. But, as mentioned in the original article, obese patients are more prone to insulin resistance which mandates increased use of perioperative insulin for strict blood glucose control. Insulin causes decrease in the occurrence rates of POAF (2). We find this explanation for the lower rates of POAF satisfactory.