Background: Early detection of diabetic nephropathy is of great importance. Renal functional reserve (RFR) is the difference between glomerular filtration rate (GFR) in basal conditions and GFR after a protein meal.
Objective: To examine renal functional reserve in children with type 1 diabetes mellitus (T1D) in order to detect diabetic nephropathy at early stage.
Method: Case control study included patients with duration of T1D more than 3 years, older than 10 years and normal microalbuminuria. We measured creatinine clearance, cystatin C and calculated RFR after a protein meal (PM) challenge. Study group consisted of 20 patients and control group included 16 children with T1D, who did not give a consent for oral (PM) load. GFR was calculated and 24 hour ambulatory blood pressure was performed in all patients.
Results: Baseline clinical characteristics did not differ between those two groups. Mean age was 15.3±2.2, duration of diabetes 6.8±3.3 years, insulin dose 1.0±0.3 U/kg per day, HbA1c was 8.4±1.8% and GFR was 121.6±26.2. None of patients were hypertensive, but 76.5% were non-dippers. Mean serum creatinine levels and creatinine clearance were within normal values before and after a (PM). Average serum cystatin C was elevated before and after a (PM) and was 1.03±0.56 and 0.37±0.94 mg/l, respectively. Mean RFR was −0.13±9.6% and was reduced in all patients.
Conclusion: Although this was a pilot project and the sample size was small, all patients had reduced RFR. Poor metabolic control might be the reason but all patients were normotensive and had normal microalbuminuria. Those results imply that we need to look for new markers of early nephropathy.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology