Complication characteristics between young-onset type 2 versus type 1 diabetes in a UK population

Background: In the UK, the care of young people with diabetes has focused predominantly on type 1 diabetes (T1D). However, young-onset T2D has become increasingly prevalent. At present, it is unclear which type of diabetes represents the more adverse phenotype to develop complications. This study aims to determine the complication burden and its predictive factors in young-onset T2D compared with T1D. Methods: A cross-sectional study using a hospital diabetes register to identify patients with young-onset T2D and T1D. Young-onset T2D was defined as age of diagnosis below 40 years. The T1D cohort with a similar age of diagnosis was used as a comparator. Data from the last clinic visit was used for analysis. Clinical characteristics and diabetes complications were evaluated at diabetes durations <10, 10-20, and >20 years. Predictive factors for diabetes complications (age, sex, glycated hemoglobin, creatinine, diabetes duration, hypertension, dyslipidemia, and body mass index >25) were determined by logistic regression analysis. Results: Data were collected on 1287 patients, of which 760 and 527 had T1D and T2D, respectively. In all diabetes durations, the T2D cohort had an older age of onset (p<0.0005) with a higher prevalence of obesity, hypertension, and dyslipidemia (all p<0.0005) while glycemic control was similar in both groups. Cardiovascular disease (p<0.005) and neuropathy (p<0.05) were more prevalent in the young-onset T2D cohort in all diabetes durations. There was no difference in retinopathy. Cardiovascular disease was predominantly due to ischemic heart disease. Stroke and peripheral vascular disease became significantly higher in T2D after 20 years duration. After controlling for traditional risk factors, young-onset T2D was an independent predictor for cardiovascular disease (p<0.005) and neuropathy (p<0.05) but not for retinopathy. Conclusions: Young-onset T2D is a more aggressive phenotype than T1D to develop diabetes complications, particularly for ischemic heart disease and neuropathy.