Prevalence of Diabetes Complications in Adolescents With Type 2 Compared With Type 1 Diabetes 

Eppens MC, Craig ME, Cusumano J, et al. Diabetes Care. 2006;29:1300-1306.

Few studies have addressed the prevalence of diabetic microvascular complications (DMC) among patients with youth-onset type 2 diabetes. A comparative clinic-based study conducted from 1996-2005 assessed the prevalence of complications among patients aged <18 years with type 1 or type 2 diabetes treated in the Diabetes Complications Assessment service at the Children’s Hospital in Westmead, Australia. Included were 1,433 patients with type 1 and 68 with type 2 diabetes.

There was no difference in age between patients with type 1 and type 2 diabetes at the conclusion of this study (both groups averaged approximately 15 years of age), but those with type 1 had significantly longer duration of diabetes (6.8 vs 1.3 years, P<.0001). A1C level was statistically higher among patients with type 1 (8.5%) than type 2 diabetes (7.3%, P<.0001). Compared to those with type 1 diabetes, significantly more patients with type 2 were obese (56% vs 7%), had microalbuminuria (28% vs 6%), and hypertension (36% vs 16%, P<.00001 for each parameter). Only diabetic retinopathy was more common among patients with type 1 than type 2 diabetes (20% vs 4%, P = .043). Diabetic peripheral and autonomic neuropathies did not differ between the groups. Notably, approximately 21% of patients with type 2 diabetes had peripheral nerve abnormalities and more than half had autonomic neuropathy after only 1.3 years of diabetes.

Further analyses of data obtained during this trial revealed that higher A1C was the only significant risk factor for microalbuminuria among patients with type 2 diabetes; however, dsylipidemia was also frequent, with hypercholesterolemia found in ~33% and hypertryglyceridemia in >50% of type 2 diabetes patients. The authors concluded that since the duration of type 2 diabetes is often difficult to determine due to long presymptomatic periods, the high rates of hypertension, microalbuminuria, and nerve abnormalities observed in this study confirmed the need for screening for complications at the time of initial diagnosis of diabetes. Another key finding of this study is the high rates of complications among patients with type 2 diabetes even though their average A1C was 7.3%, indicating that the target A1C of 7.5% for youths with type 1 diabetes may be too high to prevent development of microvascular complications among those with type 2.