Glomerular filtration rate calculated by modification of diet in renal disease formula can be an indicator of impaired glucose tolerance and diabetes in coronary artery disease

Abstract

Background: There is an increased risk for coronary artery disease (CAD) at modestly elevated levels of blood glucose which is still below the present threshold for type 2 diabetes mellitus (T2DM). In the present study, we aimed to define impaired glucose tolerance (IGT) and T2DM in patients with stable CAD and observe the relationship between clinical and laboratory findings. Materials and Methods: A total of 132 patients who had stable CAD and who had not been diagnosed as glucose intolerance or diabetes were enrolled. In one of the groups, there were patients with IGT or T2DM results and the other one consisted of patients with normal oral glucose tolerance test (OGTT) results. The Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was investigated in patients with fasting plasma glucose (FPG) <100 mg/dl. Results: The prevalance of IGT and T2DM was 30.3%. In IGT + T2DM group, waist/hip ratio and creatinin level were significantly higher and estimated glomerular filtration rate (eGFR) was low. Only eGFR calculated by Modification of Diet in Renal Disease (MDRD) formula was a reliable parameter. MDRD eGFR ≤70 ml/dk/m2 independently predicted IGT + T2DM diagnosis with 50% sensitivity but with 82% specificity. Although it is insufficient to use it as an optimal screening test because of lower sensitivity, it can be a reliable indicator of IGT + DM in patients who had eGFR ≤70. Insulin resistance was diagnosed in 29% of patients whose pretest values were FPG <100 mg/dl. Conclusion: MDRD eGFR can be an indicator for IGT + T2DM. OGTT irrespective of FPG level should be used to determine the presence of IGT + T2DM in stable CAD.

Keywords

• Coronary artery disease
• diabetes mellitus
• estimated glomeruler filtration rate
• glucose intolerance
• Modification of Diet in Renal Disease