Renal Function Impairment in Patients with Type 1 Diabetes Mellitus as determined by Biochemical Markers of Chronic Kidney Disease and Renal Ultrasonography in a Nigerian Tertiary Health Institution: A Preliminary Study

Abstract

Background: Chronic kidney disease (CKD) is a long term complication of Diabetes Mellitus (DM). We evaluated renal function in Type 1 DM patients in a tertiary health institution in Nigeria.

Methods: A prospective case-control study.  Fasting blood glucose (FBG), glycated haemoglobin (HbA1c), and serum C-peptide, Islet cell antibody (ICA), Glutamic acid decarboxylase antibody (anti-GAD) were measured. Stages of diabetic nephropathy were defined by estimated glomerular filtration rate, eGFR (Cystatin C-based), albumin/creatinine ratio (ACR) and plasma kidney injury molecule 1 (KIM-1). Resistivity index (RI) was by renal Doppler ultrasound.

Results: Ten patients (aged 15 to 17 yr, IDDM duration 0.2 to 9 yr) were evaluated against ten age-matched controls. Recent and remote poor glycemic control were evidenced by FPG, mean 243.9 ± 105.84mg/dl (13.55 ± 5.88mmol/l) and HbA1c (11.72 ± 1.93%) respectively. Serum C-peptide (0.69 ± 0.09ng/ml) was severely low; ICA (43.10 ± 1.85ng/ml) and anti-GAD (30 ± 26.23ng/ml) were markedly elevated. Serum cystatin C was elevated (1.56 ± 0.78mg/l versus 0.52±0.11, p=0.017). Six patients had a GFR <60 mL/min/1.73m². One patient had stage 1, 3 had stage 2, 4 had stage 3, 2 had stage 4 but none had stage 5 CKD; GFR decline occurred as early as 2.5months. Three patients had normoalbuminuric renal insufficiency; ACR: 3 macroalbuminuric and 3 microalbuminuric. KIM 1 was elevated (3.76± 1.15ng/ml versus 1.15± 0.09, p<0.001); one had increased RI (≥ 0.7).

Conclusion: Moderate CKD is highly prevalent in T1D subjects and commences as early as two and a half years of disease. Poor glycemic control is contributory.