Prevalence of diabetes complications in adolescents with type 2 compared with type 1 diabetes

OBJECTIVE - To compare the prevalence of diabetes complications and their risk factors in youth with type 1 versus type 2 diabetes. RESEARCH DESIGN AND METHODS - We performed a comparative clinic-based study of 1,433 patients with type 1 diabetes and 68 patients with type 2 diabetes aged < 18 years from New South Wales, Australia. Retinopathy was assessed by seven-field stereoscopic retinal photography; albumin excretion rate from three consecutive, timed, overnight urine collections; peripheral neuropathy by thermal and vibration threshold; and autonomic neuropathy by pupillometry. HbA(1c) (A1C) and lipids were measured in all patients and C-peptide in patients with type 2 diabetes. RESULTS - in patients with type 1 versus type 2 diabetes, median (interquartile range) age was 15.7 years (13.9-17.0) and 15.3 years (13.6-16.4), respectively (P = 0.2), whereas median diabetes duration was 6.8 years (4.7-9.6) and 1.3 years (0.6-3.1), respectively (P < 0.0001). Retinopathy was significantly more common in patients with type I diabetes (20 vs. 4%, P = 0.04), while microalbuminuria and hypertension were significantly less common (6 and 16% in type 1 diabetes vs. 28 and 36% in type 2 diabetes). Rates of peripheral and autonomic neuropathy were similar (27 and 61% in type 1 diabetes vs. 21 and 57% in type 2 diabetes), In multivariate analyses, microalbuminuria was significantly associated with older age (odds ratio 1.3 [95% CI 1.2-1.5], P < 0.001) and systolic hypertension (3.63 [2.0-6.3], P < 0.001) in type I diabetes, while only higher A1C (1.7[1.3-2.9], P = 0.002) was significant in patients with type 2 diabetes. CONCLUSIONS - Youth with type 2 diabetes have significantly higher rates of microalbuminuria and hypertension than their peers with type I diabetes, despite shorter diabetes duration and lower A1C. The results of this study support recommendations for early complications screening and aggressive targeting of glycemic control in patients with type 2 diabetes.