Retinopathy in subjects with impaired fasting glucose: the NANSY-Eye baseline report

Network for Pharmacoepidemiology (NEPI) Antidiabetes Study-Eye is a randomized placebo-controlled Swedish trial investigating if treatment with sulphonylurea, in addition to dietary regulation and increased exercise, delays the development of retinopathy in subjects with impaired fasting glucose (IFG).

Subjects were surveyed in primary care with repeated fasting blood glucose measurements. Those with a mean of two consecutive values >or=5.6 and <6.1 mmol/l were invited to participate. Baseline physical examination included blood pressure and body mass index (BMI). Fundus photos were taken in two fields using 35-mm diafilm. The alternative classification of the Wisconsin Epidemiologic Study of Diabetic Retinopathy was used to classify the retinopathy level.

At baseline, 90 men and 64 women with IFG were photographed. Of these, 16 subjects (10%) had mild or very mild retinopathy. There was no difference in occurrence of retinopathy between subjects with known diagnosis of hypertension or not. However, subjects with retinopathy had significantly higher systolic (154 vs. 141 mmHg, p = 0.013) and diastolic (86 vs. 81 mmHg, p = 0.008) blood pressure levels independent of differences in age, sex and known hypertension. There was a corresponding difference in BMI, being greater in subjects with than in those without retinopathy (32.4 vs. 29.2 kg/m(2), p = 0.013). There were no associations between levels of fasting blood glucose or haemoglobin A1c, on the one hand, and retinopathy, on the other.

Retinopathy may be present even before type 2 diabetes is manifest. It is associated with higher blood pressure levels and higher BMI values, that is, with predominant features of the metabolic syndrome.