Diabetic Nephropathy among Adult Patients with Type 2 Diabetes Mellitus in Saudi Arabia

Abstract

Background: the occurrences of diabetes mellitus and diabetic nephropathy have increased quickly in the past few decades and have become an economic burden to the healthcare system in KSA. Diabetic nephropathy is a major complication of diabetes mellitus and is a primary cause of end-stage renal disease (ESRD). The occurrence of non-diabetic renal disease (NDRD) in diabetic patients has been increasingly recognized in recent years. It is generally believed that it is difficult to reverse diabetic nephropathy, whereas some cases of non-diabetic renal disease are readily treatable and remittable. However, diabetic nephropathy is known to co-exist with non-diabetic renal disease in a poorly defined population of patients with type 2 diabetes mellitus. This study estimated the pervasiveness of co-existing diabetic nephropathy and non-diabetic renal disease in Saudi patients. Methods:data were retrospectively analyzed from 122 patients with type 2 diabetes mellitus who had experienced a renal biopsy between February 2014 and June 2017 at King Abdulaziz Hospital, region(s), KSA. Male patients numbered 75 (61.5%) of the study population. The biopsies were performed as urinary abnormalities or renal functions were atypical of a diagnosis of diabetic nephropathy. Biopsy samples were examined using light, immunofluorescence (IF) and electron microscopy (EM). Clinical parameters were recorded for each patient at the time of biopsy. Results: nineteen of 122 diabetic patients (8%) had co-existing diabetic nephropathy and non-diabetic renal disease. These patients showed clinical features and pathologic characteristics of diabetic nephropathy, containing a high prevalence of diabetic retinopathy (88.8%), a long duration of diabetes, increased thickness of the glomerular basement membrane (GBM) and mesangial expansion. Nonetheless, they similarly presented with clinical findings which were inconsistent with diabetic nephropathy, such as hematuria, rapidly progressive renal failure and marked proteinuria. Immunoglobulin A (IgA) nephropathy was apparent in 5 out of the 10 patients (50%), tubulointerstitial lesions were found in two patients (20%), membrano-proliferative glomerulonephritis (MPGN) in two patients (20%) and membranous nephropathy (MN) in one patients (10%). Conclusion: retrospective analysis of biopsy data suggests that approximately 8% of Saudi patients with type 2 diabetes mellitus may have co-existing diabetic nephropathy and non-diabetic renal disease. The most common histological diagnosis in our small series was IgA nephropathy.