Mortality in diabetic patients participating in an ophthalmological control and screening programme

The aim of this follow-up study has been to assess retinopathy and change of treatment to insulin therapy as risk factors for mortality in diabetic patients participating in a control and screening programme for retinopathy. A total of 3220 diabetic patients, 483 with an age at diagnosis <30 years, and 2737 with an age at diagnosis ≤30 years, were included. Retinopathy was graded on fundus photographs using the Wisconsin Scale, and the visual acuity was assessed. The average HbA(₁c) value was calculated for each patient for the previous 8 years to estimate long-term glycaemic control. Mortality data were obtained from death certificates. Two hundred and sixty-three diabetic patients (8.2 %) died during the mean follow-up time of 3.4 years, 13 (2.7 %) of those with younger-onset (<30 years) and 250 (9.1%) of those with older-onset (≤30 years) diabetes. Of them, 148 (56.3 %) died from cardiovascular and 23 (8.7 %) from cerebrovascular disorders. After adjusting for differences in age and sex, more severe retinopathy and the use of antihypertensive drugs were associated with a decreased overall survival rate as well as an increased mortality from cardiovascular and cerebrovascular diseases. A statistically significant association between HbA(tc) values in the highest quartile, i.e. ≤8.4 %, and cardiovascular and all cause mortality did not remain when retinopathy was entered into the multivariate analyses. Duration of diabetes, but not change of treatment to insulin therapy, was associated with higher cardiovascular mortality in patients whose diabetes was diagnosed after the age of 30 years. We conclude that severe retinopathy, use of antihypertensive drugs, and poor glycaemic control predicted death from cardiovascular disease in diabetic patients participating in an ophthalmological screening programme.