Depression and Memory Loss in African Americans with Diabetic Retinopathy.

Abstract

To the Editor: Eleven million adults aged 65 and older have type 2 diabetes mellitus. Approximately 25% of them have clinically significant depression, which reflects the personal burdens and neurobiological effects of the disease.1 Approximately 25% of those with diabetes mellitus also have cognitive impairment, which reflects vascular brain injury or a neurodegenerative process.2 Depression and cognitive impairment both predict poor glycemic control, which increases the risk of diabetic retinopathy (DR).3 This risk disproportionately affects blacks because they have higher rates of untreated depression, cognitive impairment, and diabetes mellitus than whites.4 Despite their greater risk, neuropsychiatric factors that contribute to DR in blacks remain unexplored. This study assessed mood, memory, and diabetes mellitus self-management in blacks with DR. Participants were recruited from the retina clinics of two tertiary care hospitals, whose institutional review boards approved study procedures. Eligibility criteria were black race, aged 65 and older, and DR (nonproliferative or proliferative). The following variables were assessed. The average age of participants (n = 62) was 71.9 ± 5.4; 37 (59.7%) were female; mean years of education was 12.2 ± 2.9. Forty participants (64.5%) had nonproliferative DR, and 22 (35.5%) had proliferative DR. Thirty-one (50%) participants had mild or worse depression. Twenty participants (32.3%) had impaired memory. Table 1 compares the diabetes mellitus self-management scores of participants with at least mild depression with the scores of those with no depression, and of participants with impaired memory with those with normal memory. Participants with depression had significantly lower diabetes mellitus self-management scores (53.8 ± 12.4) than those without (64.0 ± 11.3) (F1,60 = 11.53, P < .001) but were similar in age, education, sex, and rates of memory impairment and proliferative DR. Participants with impaired memory had lower diabetes mellitus self-management scores (51.2 ± 11.1) than those with normal memory (61.9 ± 12.1) (F1,58 = 10.99, P = .002) but were similar in age, education, sex, and rates of depression and proliferative DR. Diabetes mellitus self-management scores differed significantly in participants with depression and memory impairment, with neither, and with depression or memory impairment (f = (3,56) = 9.7; P ≤ .001). Participants with depression and memory impairment had significantly lower mean scores (46.6 ± 12.5) than those with neither depression nor memory impairment (66.9 ± 11.8) but did not differ from participants with depression (55.8 ± 9.4) or memory impairment (56.9 ± 5.7). DR is a major cause of vision loss in the United States, affecting 210,000 older blacks, a number that will rise to more than 1,000,000 by 2050, dramatically increasing the prevalence, disability, and costs of DR.4 Almost half of older blacks with DR had at least mild depression, and one-third had impaired memory, two factors that compromise diabetes mellitus self-management and predict progression of DR. The uncertain generalizability and the use of rating scales rather than clinical examinations to identify depression, and neuropsychological examinations to characterize memory, limit these findings. The findings nevertheless have important implications. Older blacks with impaired memory or depression are less likely to adhere to prescribed medications, eye examinations, and treatment for DR, and are less often treated for depression or recognized as cognitively impaired than whites.4, 8 These disparities add to worse glycemic control and difficulty communicating with ophthalmologists as reasons why blacks are twice as likely to become blind from DR as whites.9 A mental health–ophthalmological intervention to improve glycemic control in older blacks with DR is being developed (ClinicalTrials.gov NCT02121340). The intervention is integrated into retina practices and addresses access to care, health literacy, depression, cognition, and beliefs about diabetes mellitus. The rates of depression and impaired memory found in this study support the need for this intervention, and the National Eye Institute's goal of preventing blindness in minority populations.10 The authors wish to acknowledge the Wills Eye AMD Study Group for assistance with recruitment of the sample and data collection. Members include William Benson, MD, Gary C. Brown, MD, Jay L. Federman, MD, Mitchell S. Fineman, MD, David H. Fischer, MD, Sunir J. Garg, MD, Allen C. Ho, MD, Jason Hsu, MD, Richard S. Kaiser, MD, Alfred C. Lucier, MD, Joseph I. Maguire, MD, Carl H. Park, MD, Carl D. Regillo, MD, Lov K. Sarin, MD, Arunan Sivalingam, MD, and Marc Spirn, MD. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Rovner, Casten, Haller: study concept and design, data analysis and interpretation, manuscript preparation. Murchison, Ho, Henderer: acquisition of subjects, data analysis and interpretation, manuscript preparation. Sponsor's Role: Wills Eye Hospital and the Pennsylvania Department of Health had no role in the design, methods, subject recruitment, data collections, analysis, or preparation of this paper.