title: Age at diagnosis, glycaemic control and the development of retinopathy in a population-based cohort of Type 1 diabetic subjects in Canterbury, New Zealand.
abstract: The aim was to determine the relationship between age at diagnosis, glycaemic control and the development of retinopathy in a population-based cohort of Type 1 diabetic subjects. At 1 January 1984, there were 286 individuals with Type 1 diabetes (and age of onset<20 years) on the Canterbury, New Zealand population register who had at least 2 prospective HbA(1c) readings (from 1 January 1984). Of these, 107 already had retinopathy. Of the 179 subjects without retinopathy at baseline 63 developed retinopathy during follow-up. After controlling for duration of diabetes (in the whole group), age at diagnosis was found to be a significant predictor of HbA(1c) level (P=0.001), with higher (mean+/-SD) baseline HbA(1c) in the 10-14 age group (7.95+/-2.14%), compared with (7.62+/-1.77%) in the <10 year group and (7.39+/-2.57%) in the >14 year group. The major predictors of retinopathy (in those without retinopathy at baseline), however were duration of diabetes (mean time to development of retinopathy decreases by 14% (95% CI 10-17%) for each year), baseline HbA(1c) (for each unit increase, mean time to development of retinopathy decreased by 23% (95%CI 13-32%) and HbA(1c) slope (average annual change). Peri-pubertal age at diagnosis (10-14 years) did not influence the time to onset of retinopathy over and above that attributed to duration of diabetes and glycaemic control.
authors: Lipid and Diabetes Research Group, Hagley Building, Christchurch Hospital, Christchurch, New Zealand. chrisf@chhlth.govt.nz
authors: C M
authors: CM
authors: Florkowski
authors: R S
authors: RS
authors: Scott
authors: P A
authors: PA
authors: Coope
authors: P J
authors: PJ
authors: Graham
authors: C L
authors: CL
authors: Moir
mesh_terms: D000293:Adolescent; D000375:Aging / Q000502:physiology*; D001786:Blood Glucose / Q000032:analysis*; D002648:Child; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000150:complications*; D003930:Diabetic Retinopathy / Q000209:etiology*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009520:New Zealand; D011379:Prognosis; D011446:Prospective Studies; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin