High body mass index (BMI) and LDL-cholesterol are associated with the presence of retinopathy 17 years after diagnosis of diabetes - in the Diabetes Incidence Study in Sweden (DISS).

Abstract

Purpose: To estimate the prevalence and severity of diabetic retinopathy (DR) median 17 (14-19) years after diagnosis in a nationwide population-based cohort study of 444 patients with diabetes diagnosed 1987-1988 at the age of 15-34 years, and to identify risk factors associated with the presence of retinopathy.

Methods: Since 1983 the Diabetes Incidence Study in Sweden (DISS) has registered patients diagnosed with diabetes as young adults (age of 15-34 years). The study includes patients with both type 1 and type 2 DM. Analyses of islet antibodies (ICA or GADA) at diabetes diagnosis was used to classify the type of diabetes. Retinal photographs in 444 patients were collected and centrally graded. The 11 steps of the alternative classification of the Wisconsin study were used to classify the degree of retinopathy. Level 10 represents no retinopathy, levels 21-51 nonproliferative diabetic retinopathy (NPDR) of increasing severity, and level 60+ all forms of proliferative retinopathy (PDR), with and without laser treatment. The eye with the more severe level of retinopathy decided the patient’s retinopathy level.

Results: 120 (27%) patients had no retinopathy, 281 (63%) non proliferative retinopathy and 43 (10%) proliferative retinopahy. The prevalence of any retinopathy was 73%. No differences in prevalence between type 1 and type 2 DM was found. Patients with retinopathy had a significantly higher systolic (128 vs. 122 mmHg) and diastolic (77 vs. 74 mmHg) blood pressure, body mass index (26.6 vs. 24.8), triglycerides (1.4 vs. 1.0 mmol/l) and HbA1c (67 vs. 58 mmol/mol) than those without retinopathy (all p-values <0.01). LDL-cholesterol also was higher (2.9 vs. 2.7 mmol/l, p=0.04). Using logistic regression analysis, higher systolic blood pressure, BMI, LDL and HbA1c remained as risk factors for having any retinopathy after 17 years of diabetes duration.

Conclusions: High blood pressure and glucose level are well known risk factors associated with development and progression of diabetic retinopathy. Interestingly also a higher BMI and LDL cholesterol were independent predictors for having retinopathy median 17 (15-19) years after diagnosis of diabetes, indicating that diabetic retinopathy has a complex etiology involving also risk factors related to macrovascular disease.

Keywords: 499 diabetic retinopathy • 463 clinical (human) or epidemiologic studies: prevalence/incidence • 464 clinical (human) or epidemiologic studies: risk factor assessment