Diabetic nephropathy in children with type 1 diabetes mellitus in Bahrain

OBJECTIVE: Children and adolescent patients with type 1 diabetes mellitus (T1DM) may have an increased risk of developing diabetic nephropathy (DNP). The incidence of DNP varies with glycemic control, and peaks after 15-20 years of diabetes and decline thereafter. Microalbuminuria is uncommon before puberty, and usually occurs after 5 years of diabetic duration. Once overt DNP is established, a progressive decline in the glomerular filtration rate and elevation in arterial blood pressure occurs, and it is the most important disorder leading to renal failure in adult patients with diabetes in developed countries. The purpose of this study was to screen all the children and adolescent with T1DM of 5 years duration or more for DNP.

METHODS: Between April 2000 and February 2001, all patients with T1DM of more than 5 years, who were diagnosed between years 1985 to 1995 and followed by pediatricians at Salmaniya Medical Complex, Kingdom of Bahrain, were screened for DNP. Medical records were reviewed for demographical data, blood for hemoglobin A1c (HbA1c), fasting sugar and renal function test. The presence of DNP, retinopathy and neuropathy and the medications were also reviewed. DNP was diagnosed by urine microscopy, overnight urine collection for albumin to creatinine ratio, or 24-hour urine for protein, and the medications

RESULTS: Diabetic nephropathy was diagnosed in 10 patients (31%), 2 with microalbuminuria (incipient nephropathy), and 8 with proteinuria (clinical nephropathy). Diabetic nephropathy was diagnosed at a mean of 10.5 years after the onset of T1DM. The mean age was 18 years for the DNP. Mean HbA1c was 11.8% for DNP and 10.2% for non-nephropathy group. All the patients with DNP were treated with an angiotensin converting enzyme inhibitor, 5 of them had hypertension. None developed renal failure or retinopathy.

CONCLUSION: Microalbuminuria is uncommon before 5 years of the onset of T1DM. Screening for microalbuminuria should be performed in adolescent over 12 years of age, with diabetes of more than 5 years duration and persistent hyperglycemia (HbA1c > 11 %)