Is risk of diabetic retinopathy lower in Australia's Greek-born migrants?

The standardized cardiovascular disease death rate for the Greek population in Crete has increased since the 1960s, unlike the all-cause and cardiovascular disease death rate for Australia's Greek migrant population, which has remained paradoxically low. A small window of opportunity remains in which the vascular profile of this interesting atypical migrant population can be characterized. This study assessed whether ethnicity modulates the risk of diabetic retinopathy in Greek-born migrants to Australia.

The study design was a community-based cross-sectional study of diabetic retinopathy in 107 Greek-born and Australian-born men with Type 2 diabetes, aged 44-83 years. Diabetic retinopathy was assessed by mydriatic three-field retinal photography.

Prevalence of diabetic retinopathy was lower in Greek-born than in Australian-born participants (22 and 37%, respectively). Despite having a higher mean systolic blood pressure level (148 vs. 137 mmHg), Greek-born men had a significantly lower risk of diabetic retinopathy than Australian-born men, after adjusting for age, duration of diabetes, glycated haemoglobin, systolic blood pressure, diastolic blood pressure, albumin to creatinine ratio, and total cholesterol and triglyceride levels [odds ratio 0.32 (0.10-0.99); r(2) = 0.41, P = 0.047].

Greek ethnicity may confer some protection against diabetic retinopathy to Australia's Greek-born migrants, an effect not explained by established risk factors for diabetic retinopathy. A small window of opportunity remains in which to elucidate the ethnicity-related exposures that modulate vascular risk in this older migrant population.