Abstract
Purpose:
To determine the prevalence and risk factors for retinopathy in a population-based study of African Americans (AA) with impaired fasting glucose (IFG) and type 2 diabetes (T2D).
Methods:
Participants with IFG and T2D in the Jackson Heart Study (JHS) were invited to participate in an ancillary study of retinopathy. Dilated, bilateral, digital, seven-field fundus photography was obtained in each participant. The photographs were scored by two masked readers using the Early Treatment Diabetic Retinopathy (ETDRS) adaptation of the modified Airlie House classification. Risk factor measurements including duration of diabetes, hemoglobin A1C (HbA1C), blood pressure, body mass index (BMI) and lipid levels were obtained from each participant’s most recent JHS visit. Grade of retinopathy was defined as the higher grade of the two eyes. Logistic regression (SAS 9.3, SAS Institute Inc., Cary, NC) was used to estimate the association between presence of any retinopathy (ETDRS grade ≥ 14) and traditional risk factors.
Results:
Three hundred and eighty-four participants with IFG and 515 participants with T2D were enrolled in this ancillary study of retinopathy. The prevalence of any retinopathy among participants with IFG was 9.8%. The overall prevalence rates of any retinopathy and proliferative retinopathy were 37.3% and 5.5%, respectively, in the participants with T2D. Among those with IFG, presence of retinopathy was associated with a higher BMI (35.2 kg/m2 vs. 31.4 kg/m2, p=0.03). Among those with T2D, presence of retinopathy was associated with a higher HbA1C level (6.8% vs. 6.2%, p=0.002) and longer duration of diabetes (16.5 years vs. 8.9 years, p<0.0001). Overall, the odds of having any retinopathy were 1.63 (95% confidence interval: 1.08, 2.47) higher in participants with HbA1C ≥ 6.5% compared with those with a HbA1C < 6.5%. No other statistically significant associations with other traditional risk factors were identified.
Conclusions:
The prevalence rates of any retinopathy in AA with IFG and T2D in the JHS are similar to those in other populations. Among participants with IFG, higher BMI is a modifiable risk factor for retinopathy that deserves further investigation. Duration of diabetes and HbA1C level, the two most strongly associated retinopathy risk factors in other ethnicities, were also associated with retinopathy in JHS participants with T2D.
Keywords: 499 diabetic retinopathy •
463 clinical (human) or epidemiologic studies: prevalence/incidence •
464 clinical (human) or epidemiologic studies: risk factor assessment