Microalbuminuria in type 1 diabetes: relation to duration, glycemic control and other microvascular coplications: a crosssectional and longitudinal study

ABSTRACT

Without early detection and specific intervention, about 80% of patients with type 1 diabetes who develop sustained microalbuminuria enter into overt nephropathy over a period of 10-15 years. With the aim of studying the prevalence of microalbuminuria and its risk factors and the role of angiotensin converting enzyme inhibitors, this retrospective and prospective study was done at the Diabetic Endocrine Metabolic Pediatric Unit, Cairo University over period of 5 years A total of 500 patients with duration of 3 years or more were included in the study. Their mean age was 13.95 +/- 4.96 years and mean duration of diabetes 6.99 +/- 4.21 years. Longitudinal study included only 100 patients of them who were-compliant and accepted to be followed up for 5 years. Albumin excretion rate [AER] by radioimmunoassay was estimated at the start of the study while albumin/creatinine ratio by nephelometry was later on, assessed. Microalbuminuria was considered positive f in two of three samples in 6 months time AER is >30 mg/d or>20 ug/min, or album in/creatinine >30 mg/mg. Patients were also screened for other diabetic complications as neuropathy, retinopathy and cardiovascular autonomic neuropathy. Prevalence of microalbuminuria in this study varied between 13.7% at the start of the study to 9.8% at the end. Twenty-five patients, had positive microalbuminuria, all were pubertal. They showed significantly higher mean systolic and diastolic blood pressure, higher incidence of neuropathy as well as cardiovascular autonomic neuropathy [p=0.03, 0.03, 0.01 and 0.01 respectively] than patients with microalbuminuria. In the longitudinal study, 9 patients with positive microalbuminuria were followed up on caplopril therapy and strict metabolic control, 7 regressed and 2 persisted. Another five cases developed microalbuminuria during follow up and then regressed later, on the same regimen. Metabolic control was highly correlated to the progression as well as regression of microalbuminuria [r=0.35, p=0.02]. Screening for microalbuminuria is recommended in diabetics with duration more than 3 years. Angiotensin converting enzyme inhibitors together with strict metabolic con trot can cause regression of microalbuminuria