Abstract
Purpose :
The high prevalence of diabetic retinopathy (DR) under conventional insulin therapy increases with duration of diabetes mellitus type 1 (TDM1) and HbA1c. We evaluated the prevalence of DR and its correlation with a new HbA1c load defining parameter HbA1c years as well as conventional parameters in T1DM adults treated with intensified insulin therapy (IIT) from the onset of disease.
Methods :
Cross sectional analysis of 151 adults with T1DM (5-30 years duration) treated at two university-based diabetic centers (Basel/Zurich, Switzerland) with IIT from the onset of disease. Imaging according to standard study procedures included ETDRS 7-field color stereoscopic photography/fluorescein angiography, SD-Optical coherence tomography. Grading of images was carried out by the Vienna Reading Center. DR was graded from 0 to 4: 0=no DR, 1=mild non-proliferative DR (NPDR), 2= moderate NPDR, 3=severe NPDR, 4= proliferative DR (PDR). The maximum DR status (worse eye) as well as the mean of DR status of both eyes of each patient were used to perform uni-/multivariate analyses regarding the influence of blood glucose control, duration of T1DM and the total HbA1c load over the whole duration of disease (HbA1c years).
Results :
The mean duration of T1DM was 14.3±5.8 years, mean actual HbA1c 7.58±1.21%, mean of individual mean HbA1c 7.45±1.10%, mean HbA1c years 21.7±18.0. 39% of patients had no signs of DR in both eyes, in 28% the maximum DR stage was 1, in 27% 2, in 5% 3 and only one patient showed in one eye PDR. The following parameters showed a significant correlation with the maximum DR status (worse eye): actual HbA1c (p=0.0240), individual longterm mean HbA1c (p=0.0024), duration of T1DM (p<0.0001). Using the mean DR status of both eyes of each patient revealed even stronger significance for the same parameters (p=0.0025, p<0.0001, p<0.0001). The new parameter expressing the total HbA1c load, HbA1c years, was found to correlate highly significant with the DR status (p<0.0001), regardless if the worse eye DR status or the mean DR status of both eyes was used. The influence of HbA1c values and HbA1c load remained significant after adjusting for age, sex and duration of diabetes.
Conclusions :
The prevalence of DR in patients with T1DM treated with IIT from onset of the disease is low and highly correlated with the new parameter HbA1c years.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.