Introduction
It is known that coronary artery bypass surgery is the most effective treatment method for angina pectoris seen in coronary artery diseases and increases long-term survival(1). Although it is widely used for this purpose worldwide, it causes end organ damages, multiple organ ischemia, necrosis, and consequently mortality and morbidity(2). The vast majority of coronary artery bypass surgeries are performed on-pump and various proinflammatory effects such as non-pulsatile blood flow, low mean blood pressure, and hypothermia occur(3). Neurological, pulmonary and renal dysfunctions, superficial and deep tissue infections can be seen as a result of cardio pulmonary bypass(4, 5, 6, 7).
Classically, microalbuminuria is known as a parameter indicating renal damage. Barriers in the glomeruli prevent macromolecules such as albumin passing into the ultrafiltrate. Albumin which passes to the ultrafiltrate in a small amount is reabsorbed from the proximal tubules and some of it is metabolized and broken down into amino acids. Hence there is a small amount of albumin in the urine. If the glomerular barrier and proximal tubule reabsorption is impaired, the amount of urine albumin increases. This shows us proximal tubule damage and indirectly interstitial inflammation and functional loss in the kidney(8).
Following the consensus that microalbuminuria indicates the loss of kidney function, new hypotheses developed on the idea that urinary albumin excretion is a parameter that increases the risk of cardiovascular disease. Among them, it has come to the fore that microalbuminuria is associated with the loss of general vascular functions and consequently it is an indicator of a high level of cardiovascular disease and kidney function loss (9). Based on this, it was thought that loss of vascular endothelial function might be a cause of vascular albumin leakage and it was concluded that albumin leakage in renal vessels was related to general vascular permeability(10).
Diabetes is known as an independent risk factor for cardiovascular diseases(11). In addition, every 1% increase in Hemoglobin A1c (HbA1c) level in diabetic diseases causes an increase of about 11% in coronary artery diseases(12). Especially in patients with insulin-dependent diabetes microalbuminuria is considered as a sign of nephropathy and a marker of the prevalence of atherosclerosis(13).
The aim of this study is to compare the mortality and morbidity results on type 2 diabetes patients receiving insulin medications or taking oral antidiabetics, all with microalbuminuria and normal creatinine values after on-pump coronary artery bypass (CABG).