Abstract
Purpose :
India is burdened with ~70 million diabetics as of 2015 with an expected increase to 100 million by 2030. With an epidemic of this magnitude, diabetic retinopthy (DR) presents an expanding burden of avoidable blindness. India is a critical population as those of South Asian descent are more likely to develop DM and DR. DM causes fragility of red blood cells(RBC) leading to anemia, a well-known risk factor for microvascular complications, and can affect DR risk and severity.The Aditya Jyot Diabetic Retinopathy in Urban Mumbai Slums Study demonstrated prevalence of DR among DM as 15.37%. To examine the role of RBC parameters in understanding risk of DR we compared standard clinical chemistry measures in DM with and without DR in this population.
Methods :
DR cases (n = 26) and DM only controls (n = 90) collected in 18 slum wards in Mumbai were evaluated for a number of clinical chemistry variables. DM was assessed using the American Diabetes Association (ADA) diagnostic criteria of fasting (8 hours) plasma glucose (PG) > 126 mg/dL in individuals >40 years old. DR was evaluated using dilated fundus exams and 7 field fundus photograph. Demographic variables (age, sex), duration of DM and complete blood count and chemistry, including counts, shape and size of white blood cells (WBC), RBC's, and platelets were collected.
Results :
Glycemic control was poor for both DR cases (glycosylated hemoglobin [HbA1c] mean ± SD = 8.8 ± 2.2%) and DM controls (8.3 ± 2.0%), although there is a slight (insignificant) tendency towards higher levels in cases. Adjusting for age, sex and duration of DM, DR patients had significantly lower total RBCs on average (mean=4.56 × 106/µl vs. 4.82 × 106/µl in controls; p = 0.018 ), and also lower hemoglobin (Hb) (mean = 12.1 g/dL, vs. 12.6 in controls), tending towards greater proportion of anemia in cases. DM and DR patients showed similar profiles for WBC and platelet measures.
Conclusions :
In the slums of Mumbai, DM patients have two factors that can exacerbate outcomes such as DR. First, DM is uncontrolled due to inability to afford treatment, and the second is a high rate of concurrent anemia due to poor nutrition. Together these two factors can amplify the effect of RBC destruction, an underlying process in diabetics, to increase risk of DR in this population. As anemia-related traits associate with DR in this population, it is possibly a key factor in mediating risk of DR.
This is a 2020 ARVO Annual Meeting abstract.