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.


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 <25 kg/m(2), and 156 men and 122 women with BMI > or =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 < 0.0001, odds ratio [OR] = 2.1) and neuropathy (49 vs. 38%, P = 0.008, OR = 1.6) than normal-weight patients. Patients with retinopathy were older (45 +/- 12 vs. 37 +/- 11 years, P < 0.0001) and had a longer diabetes duration (25 +/- 10 vs. 12 +/- 8 years, P < 0.0001), a higher A1C (8.0 +/- 1.1 vs. 7.7 +/- 1.1%, 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 (beta = 0.15, P < 0.0001), blood pressure (beta = 0.22, P = 0.0047), and A1C (beta = 0.24, P = 0.01), but not BMI, lipid levels, sex, or age, were independent risk factors for retinopathy. Likewise, duration (beta = 0.05, P < 0.0001), age (beta = 0.04, P = 0.0001), A1C (beta = 0.35, P < 0.0001), and sex (beta = 0.74, 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 < 0.0001, OR = 1.9). Leptin and adiponectin levels did not differ between individuals with or without microvascular complications.


CONCLUSIONS
Retinopathy and neuropathy are more prevalent in overweight (BMI > or =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.
Department of Diabetology, Faculty of Medicine, University Hospital Antwerp, Wilrijkstraat 10, B-2650 Edegem, Belgium. christophe.deblock@ua.ac.be
Christophe E M
CE
De Block
Ivo H
IH
De Leeuw
Luc F
LF
Van Gaal
D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D003925:Diabetic Angiopathies / Q000150:complications*; D003929:Diabetic Neuropathies / Q000453:epidemiology*; D003930:Diabetic Retinopathy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio