Impact of Overweight on Chronic Microvascular Complications in Type 1 Diabetic Patients

OBJECTIVE —To investigate a possible association of BMI with retinopathy and neuropathy in type 1 diabetes. Retinopathy and neuropathy may not only be related to glycemic control and diabetes duration but also to blood pressure and BMI. RESEARCH DESIGN AND METHODS —A total of 592 type 1 diabetic patients without nephropathy were studied (M/F: 324/268; age: 41 ± 12 years; duration: 19 ± 11 years; HbA 1c [A1C]: 7.9 ± 1.1%). Patients were subdivided according to BMI: 168 men and 146 women with BMI 2 , and 156 men and 122 women with BMI ≥25 kg/m 2 . Retinopathy was examined by fundoscopy and neuropathy by electromyography. RESULTS —Hypertension (>130/85 mmHg) was present in 40%, retinopathy in 53%, and neuropathy in 43% of patients. Overweight subjects had more retinopathy (63 vs. 45%, P P = 0.008, OR = 1.6) than normal-weight patients. Patients with retinopathy were older (45 ± 12 vs. 37 ± 11 years, P P P = 0.001), and a higher BMI (25.8 ± 4.1 vs. 24.7 ± 4.2 kg/m 2 , P = 0.001) than individuals without retinopathy. The same results are found in neuropathy. Logistic regression analysis showed that diabetes duration (β = 0.15, P P = 0.0047), and A1C (β = 0.24, P = 0.01), but not BMI, lipid levels, sex, or age, were independent risk factors for retinopathy. Likewise, duration (β = 0.05, P P = 0.0001), A1C (β = 0.35, P P = 0.0001) but not BMI, lipid levels, or hypertension were independently associated with neuropathy. Men had more neuropathy than women (50 vs. 34%, P CONCLUSIONS —Retinopathy and neuropathy are more prevalent in overweight (BMI ≥25 kg/m 2 ) type 1 diabetic subjects. However, logistic regression analysis showed that diabetes duration and A1C remain the main determinants for retinopathy and neuropathy.