A NATIONWIDE CROSS-SECTIONAL STUDY OF RETINOPATHY AND MICROALBUMINURIA IN YOUNG NORWEGIAN TYPE-1 (INSULIN-DEPENDENT) DIABETIC-PATIENTS

A nationwide cohort of Type 1 (insulin-dependent) diabetic patients was studied to determine the prevalence of retinopathy and microalbuminuria and to evaluate the association to various risk factors. Of 600 subjects with mean age of 19.8 years (range 8.0-30.3) and a mean duration of diabetes of 10.5 years (range 6.2-17.3),371 (60 %) volunteered for a clinical examination which included fundus photography, timed overnight urine samples for albumin excretion rate, measurement of arterial blood pressure and determination of HbA1c. Retinopathy was found in 122 of 371 patients (32.8 %). in 3 of 41 (7.3 %) patients aged less than 13 years. The youngest subject with retinopathy was 9.6 years old. Microalbuminuria was found in 44 of 351 patients (12.5 %), in 1 of 41 (2.4 %) patients aged less than 13 years. The youngest subject with microalbuminuria was 11.5 years old. Mean HbA1c was 8.6 % (normal range 4.5-6.1 %). Patients with retinopathy had significantly higher mean age (p = 0.0001), longer mean duration of diabetes (p = 0.0001), higher mean HbA1c (p = 0.009), and higher mean arterial blood pressure (p = 0.0001) compared to patients without retinopathy. In microalbuminuric patients HbA1c (p = 0.0001) and mean arterial blood pressure (p = 0.01) were significantly higher compared to non-microalbuminuric patients, but there was no difference in age or diabetes duration. In a multiple logistic regression model, age, HbA1c, duration of diabetes and mean arterial blood pressure were found to be significantly associated with retinopathy, while HbA1c, mean arterial blood pressure and onset before 13.0 years of age were found to be associated with microalbuminuria. The prevalence of retinopathy and microalbuminuria was relatively low. Both retinopathy and microalbuminuria were strongly associated with blood glucose control and developed at prepubertal age in some patients. The findings indicate that more intense optimization of blood glucose control in children and adolescents with Type 1 diabetes is warranted.