Abstract
Purpose :
Our lab previously demonstrated mitochondrial haplogroup H to be a risk factor proliferative diabetic retinopathy (PDR) and haplogroup Uk to be protective against PDR among diabetics with retinopathy (DR). The purpose of this study was to determine whether haplogroups H and Uk are also associated with risk and protection from DR, and more specifically nonproliferative DR (NPDR), among patients with diabetes mellitus (DM).
Methods :
Medical records for Caucasian patients with DM (223 with DR, 414 without DR) were obtained from BioVU, Vanderbilt’s electronic, deidentified DNA databank. International Statistical Classification of Diseases (ICD-9) codes for DM with or without DR were used to identify subjects with available chip-level genotype data. BioVU records were manually reviewed, and diagnoses of DM, DR, NPDR, and PDR as well as demographics, DM type and duration, and hemoglobin A1c (HgbA1c) level, were determined. An additional 197 DM patients (91 with DR, 106 without DR) with full medical records were recruited from the Vanderbilt Eye Institute (VEI). VEI patients were genotyped using a Sequenom pool, and the mitochondrial haplogroup of all subjects was determined with HaploGrep. DM without DR was compared to DR and to NPDR by chi-square tests and by multivariate logistic regression adjusting for sex, DM type, duration of DM, and HgbA1c level.
Results :
The percentage of DM patients with DR did not differ among the haplogroups (H=38%, Uk=41%, Other=35%; p=0.42). There was also no significant effect of haplogroup H (p=0.45) or haplogroup Uk (p=0.77) on the presence of DR among diabetics when adjusting for sex, DM type, duration of DM, and HgbA1c. In unadjusted analyses, diabetics with haplogroup Uk were more likely to have NPDR than diabetics with haplogroups H or Other (H=19%, Uk=30%, Other=21%; p=0.021). However, there was no significant effect of haplogroup H (p=0.11) or haplogroup Uk (p=0.22) on the presence of NPDR among diabetics after adjusting for covariates.
Conclusions :
In this cohort, when adjusting for demographic and clinical covariates, there was no association between mitochondrial haplogroup H or Uk and the presence of DR or NPDR among diabetics. Taken together with previous data from our lab, this suggests that haplogroups H and Uk are not likely to influence the stepwise progression from DM without DR to NPDR to PDR, but are associated primarily with the transition from NPDR to PDR.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.