Abstract
Purpose :
There is controversy regarding the importance of blood pressure (BP) in the development of Diabetic Macular Edema (DME). We performed a retrospective, observational study to determine the effect of BP prior to the diagnosis of diabetic retinopathy (DR) on the risk of developing DME.
Methods :
We analyzed twenty years of data (2001-2020) from the Synthetic Derivative, Vanderbilt’s electronic health record de-identified database. Patients with any DR aged 18 and above were included. Systolic and diastolic BP values two years before the diagnosis of DR were extracted and their average was termed “Historic BP” (Figure 1). Using severity classifiers from The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High BP, patients were stratified into four groups: Normotensive, Prehypertension, Stage 1 hypertension (HTN), and Stage 2 HTN. From that point forward, each record was reviewed for DME, defined by the presence of appropriate claims data and review of the primary notes. A Cox proportional hazard model tested the effect of Historic BP severity on the hazard of developing DME adjusting for age at DR diagnosis, sex, race, HbA1c, BMI, and diabetes mellitus type/duration. Vanderbilt’s Institutional Review Board deemed use of this de-identified database to be exempt.
Results :
Of 1,350 patients identified with DR, 285 (21%) developed DME. A likelihood ratio test showed that Historic BP severity was significantly associated with developing DME (p=0.0069). Compared to the Normotensive group, patients with Pre-HTN (HR=1.8; 95%CI 1.1-3.0; p= 0.0145), Stage 1 HTN (HR=2.0; 95%CI 1.2-3.2; p=0.0102), and Stage 2 HTN (HR=3.3; 95%CI 1.6-6.7; p= 0.00087) were associated with an increased DME risk, independent of covariates. Historic HbA1c levels were associated with increased risk of DME (HR=1.2; 95%CI 1.2-1.3; p<0.001). However, other covariates did not increase the risk of DME.
Conclusions :
This data suggests an increased risk of developing DME for patients with progressively more severe HTN levels compared to Normotensive patients. Thus, historical elements beyond the acute presence of HTN, such as chronic degenerative changes in the walls of arteries may predispose individuals to the development of DME. Further investigation of these findings would offer a novel understanding regarding the significance of HTN in DME development.
This is a 2021 ARVO Annual Meeting abstract.