Analysis of risk factors for progression of diabetic nephropathy in patients with type 2 diabetes

Introduction/Objective. The aim of the study was to examine the progression of diabetic nephropathy (DN) in a prospective three-year period as well as to establish the risk factors for DN progression. Methods. The study involved 45 patients with type 2 diabetes and DN (26 males, aged 18?62 years) followed up for three years. All the patients underwent physical examination and laboratory analysis at each visit. Laboratory analyses included complete blood count, serum glucose, urea, creatinine, protein, lipid concentration, glycosylated hemoglobin (HbA1c) and urine protein, albumin and creatinine concentration. Glomerular filtration rate (GFR) was calculated using Modification of Diet in Renal Disease formula. Kidney length and parenchymal thickness were measured by ultrasound. Results. Fasting serum glucose concentration (12.0 ? 2.79 vs. 9.50 ? 2.22, p < 0.001) and HbA1c (7.99 ? 1.43 vs. 7.49 ? 1.29, p < 0.031) were decreased over the three years. Albuminuria increased (43.75 ? 10.83 vs. 144.44 ? 52.70 mg/l, p < 0.001) and GFR (63 vs. 58.3 ml/min/1.73 m2) decreased significantly during the study, but serum lipid concentration remained unchanged. Mean kidney length and parenchymal thickness decreased during the three years. Linear regression analysis found systolic blood pressure, fasting glycemia, HbA1c as positive and kidney length and parenchymal thickness as negative predictors of proteinuria increase, but proteinuria as negative and serum iron and albumin concentrations as positive predictors of annual change in GFR. Conclusion High blood pressure and high HbA1c are selected as significant risk factors for increasing proteinuria, which is a significant predictor of GFR decreasing in patients with DN.