Early onset type 2 diabetes mellitus: a harbinger for complications in later years-clinical observation from a secondary care cohort

Background: Little is known about the complication burden in later years among early onset type 2 diabetes mellitus (T2DM). Aim: To determine the magnitude of diabetes complications and adequacy of risk factor management and to test the hypothesis that diabetes duration is an important contributing factor to these complications. Design: A cross-sectional study of secondary care diabetes population. Methods: Data on glycaemic control, cardiovascular risk factors (overweight/obesity, hypertension, dyslipidaemia), cardiovascular disease (CVD) and microvascular complications among those diagnosed before (early onset) and after (later onset) 40 years of age at different diabetes durations (<10, 10-20 and >20 years) were analysed. Results: A total of 2733 subjects were identified, of which 527 had diabetes diagnosed below the age of 40 years. By the sixth decade of life, early onset cohort experienced high complication burden (CVD: 37.2%, retinopathy: 59.3% and neuropathy: 53.1%). Complication prevalence increased with diabetes duration but the increment rate was greater among early onset cohort. Compared with those diagnosed after 40, early onset cohort experienced similar burden of microvascular complications similar to 13-20 years earlier. Diabetes duration was a significant predictor for microvascular and CVD complications. Prevalence of CVD risk factors was high (similar to 80-93%) regardless of the age of diagnosis and diabetes duration. Early onset subjects were more likely to have poorer glucose control (similar to 70-78%), untreated hypertension (26.3%) and a substantial number did not receive statin treatment for primary prevention (34.8%). Discussion: Early onset T2DM subjects are at substantial risk of developing diabetes complications in later years but at an earlier stage than later onset cohort and prolonged exposure to adverse diabetic milieu is an important contributing factor. Management of risk factors for diabetes complications was inadequate among early onset subjects.