Effects of ramadan fasting on diabetic nephropathy in patients with type 2 diabetes

Background: Many patients with type 2 diabetes (T2D) insist to fast during the holy month of Ramadan against medical advice. Aims and Objectives: The study aimed to evaluate the effects of Ramadan fasting on diabetic nephropathy in patients with T2D. Materials and Methods: The present study was conducted on ninety patients with T2D who intended to fast Ramadan; they were divided into the following groups: Group 1: 30 patients with T2D, without albuminuria (normoalbuminuria); Group 2: 30 patients with T2D, with microalbuminuria; and Group 3: 30 patients with T2D, with macroalbuminuria. Laboratory tests including fasting plasma glucose, 2-h postprandial plasma glucose, haemoglobin A1c, serum creatinine, blood urea and urinary albumin/creatinine ratio (UACR) were measured 2 weeks before Ramadan fasting and then repeated within 2 weeks after Ramadan. Results: On comparing data before and after Ramadan, there was a significant increase in creatinine and urea levels, while there was a significant decrease in the estimated glomerular filtration rate (eGFR) and UACR in all the study groups. There was no significant difference between the study groups regarding the percentage of increase in creatinine (P = 0.204) and urea (P = 0.505), while the percentage of decrease in eGFR was significantly higher in the macroalbuminuria group (P = 0.038), and the percentage of decrease in UACR was significantly higher in the normoalbuminuria group (P = 0.001). Conclusion: Ramadan fasting adversely affects the renal function and causes a decrease in the eGFR in type 2 diabetic patients with diabetic nephropathy. Fasting should be under close medical supervision with strict attention to fluid intake and daily activity, as well as adjustment of drug regimens.