Is the risk of diabetic retinopathy greater in non-Hispanic blacks and Mexican Americans than in non-Hispanic whites with type 2 diabetes? A U.S. population study

• Published in: Diabetes care Vol. 21; no. 8; pp. 1230 - 1235
• Main Authors: Harris, M I, Klein, R, Cowie, C C, Rowland, M, Byrd-Holt, D D
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01.08.1998
• Subjects: Adult; African Americans; African Continental Ancestry Group; Associated diseases and complications; Biological and medical sciences; Blood Glucose - analysis; Blood Pressure; Cameras; Diabetes; Diabetes Mellitus, Type 2 - epidemiology; Diabetes Mellitus, Type 2 - physiopathology; Diabetes. Impaired glucose tolerance; Diabetic retinopathy; Diabetic Retinopathy - classification; Diabetic Retinopathy - diagnosis; Diabetic Retinopathy - epidemiology; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; European Continental Ancestry Group; Fasting; Female; Glucose; Glycated Hemoglobin A - analysis; Health Surveys; Hispanic Americans; Humans; Male; Medical sciences; Mexican Americans; Middle Aged; Nutrition; Photography; Plasma; Prevalence; Race; Regression analysis; Research design; Risk Factors; United States - epidemiology; United States; North America; America; United States > US; Endocrinopathy; Human; Ethnic origin; Prevalence; Retinopathy; Negroid; Latinamerican; Non insulin dependent diabetes; Epidemiology; Eye disease; Risk rate; Adult; Complication; Caucasoid; Comparative study
• ISSN: 0149-5992; 1935-5548
• DOI: 10.2337/diacare.21.8.1230

Is the risk of diabetic retinopathy greater in non-Hispanic blacks and Mexican Americans than in non-Hispanic whites with type 2 diabetes? A U.S. population study. M I Harris , R Klein , C C Cowie , M Rowland and D D Byrd-Holt National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA. harrism@ep.niddk.nih.gov Abstract OBJECTIVE: To compare the risk for diabetic retinopathy in non-Hispanic white, non-Hispanic black, and Mexican-American adults with type 2 diabetes in the U.S. population. RESEARCH DESIGN AND METHODS: Representative population-based samples of people aged > or = 40 years in each of the three racial/ethnic groups were studied in the 1988-1994. Third National Health and Nutrition Examination Survey (NHANES III). Diagnosed diabetes was ascertained by medical history interview, and undiagnosed diabetes by measurement of fasting plasma glucose. A fundus photograph of a single eye was taken with a nonmydriatic camera, and a standardized protocol was used to grade diabetic retinopathy. Information on risk factors for retinopathy was obtained by interview and standard laboratory procedures. RESULTS: Prevalence of any lesions of diabetic retinopathy in people with diagnosed diabetes was 46% higher in non-Hispanic blacks and 84% higher in Mexican Americans, compared with non-Hispanic whites. Blacks and Mexican Americans also had higher rates of moderate and severe retinopathy and higher levels of many putative risk factors for retinopathy. Blacks had lower retinopathy prevalence among those with undiagnosed diabetes. In logistic regression, retinopathy in people with diagnosed diabetes was associated only with measures of diabetes severity (duration of diabetes, HbA1c, level, treatment with insulin and oral agents) and systolic blood pressure. After adjustment for these factors, the risk of retinopathy in Mexican Americans was twice that of non-Hispanic whites, but non-Hispanic blacks were not at higher risk for retinopathy. These risks were similar when people with undiagnosed diabetes were included in the logistic regression models. CONCLUSIONS: The prevalence and severity of diabetic retinopathy is greater in non-Hispanic blacks and Mexican Americans with type 2 diabetes in the U.S. population than in non-Hispanic whites. For blacks, this can be attributed to their higher levels of risk factors for retinopathy, but the excess risk in Mexican Americans is unexplained.