A 6-year nationwide cohort study of glycaemic control in young people withType 1 diabetes - Risk markers for the development of retinopathy, nephropathy, and neuropathy

The study aimed to identify risk markers (present at the start of the study in 1989) for the occurrence and progression of microvascular complications 6 years later (in 1995) in a Danish nationwide cohort of children and adol escents with Type 1 diabetes (average age at entry 13.7 years). Probabiliti es for the development of elevated albumin excretion rate (AER), retinopath y, and increased vibration perception threshold (VPT) could then be estimat ed from a stepwise logistic regression model. A total of 339 patients (47% of the original cohort) were studied. Sex, age, diabetes duration, insulin regimen and dose, height, weight, HbA(1c), blood pressure, and AER were rec orded. In addition, information on retinopathy, neuropathy (VPT), and anti- hypertensive treatment was obtained at the end of the study. HbA(1c) (norma l range 4.3-5.8, mean 5.3%) and AER (upper normal limit < 20 <mu>g min(-1)) in two, timed overnight urine collections were analysed centrally. Eye exa mination was performed by two-field fundus photography. Determination of VP T was assessed by biothesiometry. Increased AER (greater than or equal to 2 0 mug min(-1)) was found in 12.8% of the patients in 1995, and risk markers for this were increased AER and high HbA(1c), in 1989 (both p < 0.001). Re tinopathy was present in 57.8% of patients in 1995, for which the risk mark ers were long duration of diabetes (p < 0.0001), age (p < 0.01), and high H bA(1c), (p < 0.0001) in 1989. Elevated VPT (>6.5 V) was found in 62.5% of p atients in 1995, for which the risk markers were male sex (p < 0.05), age ( p < 0.0001), and increased AER (p < 0.05) in 1989. This study confirms that hyperglycaemia plays a major role for the development of microvascular com plications in kidneys and eyes, and emphasises the need for optimal glycaem ic control in children and adolescents with Type 1 diabetes. (C) 2000 Elsev ier Science Inc. All rights reserved.