Fractional excretion of sodium (FENa): A paraphernalia in incipient nephropathy versus overt nephropathy in Type I Diabetes Mellitus

Abstract

An estimated 40% of patients diagnosed with Type I diabetes and 5–15% of patients with Type II diabetes eventually develop ESRD and diabetes has become the leading cause (44%) of end-stage renal disease in India. There is substantial evidence that early treatment will delay or prevent the onset of diabetic nephropathy, or diabetic kidney disease. In its earliest stage Diabetic nephropathy manifests with low levels of albumin (microalbuminuria) in the urine. This often is referred to as incipient nephropathy. With the progress of disease, urine albumin levels will increase until overt nephropathy (defined as more than 300 mg per 24 hours or more than 200 mcg per minute). The present hospital based observational descriptive study was conducted in Siddhartha Medical College, Vijayawada and Bhaskar Medical College & General Hospital, Moinabad from June 2014 to February 2016. 94 type I diabetes patients on Insulin therapy for 5 years as subjects along with 30 normal people as controls were enrolled in the study. T1D-Overt exhibit significantly increased FENa compared with T1D-Incipient, T1D-normal and Control subjects. Our study illustrates the importance of tubule-glomerular feedback as a major pathway of renal sodium handling in T1D-Overt as well as the important role of ambient glucose levels in kidney functioning. Future studies should determine the clinical role of blocking proximal tubular sodium reabsorption with SGLT2 inhibitors, because these agents have the potential to reduce hyper filtration and blood pressure predominantly in T1D-H, thereby protecting against the initiation and progression of diabetic nephropathy. Early identification of incipient nephropathy in Type I Diabetics with FENa may substantially assist in the early management and prevention of delaying end stage renal disease in Diabetics thus reducing morbidity.