RACE AND ETHNIC DIFFERENCES IN GLYCEMIC CONTROL AMONG ADULTS WITH DIAGNOSED DIABETES IN THE UNITED STATES Sharon Saydah, MHS, PhD; Catherine Cowie, PhD; Mark S. Eberhardt, PhD; Nathalie De Rekeneire, MD; K. M. Venkat Narayan, MD, MSc, MBA, FRCP Objective: Control of blood glucose levels reduces vascular complications among people with diabetes, but less than half of the adults with diabetes in the United States are achieving good glycemic control. This study examines 1999– 2002 national data on the association between race/ethnicity and glycemic control among adults with previously diagnosed diabetes. Design: We analyzed data from the National Health and Nutrition Examination Survey (NHANES) 1999–2002, a cross-sectional survey of a nationally representative sample of the non-institutionalized civilian US population. Participants were non-pregnant adults, 20 years or older, with a previous diagnosis of diabetes, and who had participated in both the interview and examination in NHANES 1999–2002 (N5843). Glycemic control was determined by levels of glycosylated hemoglobin (A1C). We compared glycemic control by race/ethnicity and potential confounders including measures of socioeconomic status, obesity, healthcare access and diabetes treatment. Results: Overall, 44% of adults with previously diagnosed diabetes had good glycemic control (A1C levels , 7%). Mexican Americans and non- Hispanic Blacks were less likely to achieve good control (35.4% and 36.9%, respectively) com- pared with non-Hispanic Whites (48.6%). After multivariable adjustment for measures of socio- economic status, obesity, healthcare access and utilization and diabetes treatment, differences in glycemic control by race/ethnicity remained. Conclusion: Glycemic control is low among all racial/ethnic groups, but is lower among non- Hispanic Blacks and Mexican Americans. These results provide guidance for public health workers and health professionals in targeting programs to improve glycemic control among adults with diagnosed diabetes in the United States. (Ethn Dis. 2007;17:529–535) Key Words: Race, Ethnicity, Diabetes, Gly- cemic Control INTRODUCTION Diabetes affects more than 20.8 mil- lion people in the United States. 1 The disease results in considerable loss of life; patients diagnosed between the ages of 40 and 60 lose a decade or more of life expectancy. 2 Diabetes also results in increased morbidity, economic costs, and reduced quality of life. Individuals with diabetes are at increased risk for both micro-vascular complications (eg, retinopathy, nephropathy), macro-vas- cular complications (eg, coronary heart disease, stroke, peripheral vascular dis- ease) and neuropathy. The disease affects minority popula- tions in the United States disproportion- ately; these populations also experience greater loss of life and rates of complica- tions. 2 Improved glycemic control among individuals with diagnosed di- abetes can reduce the risk of micro- and macrovascular disease and neuropa- thy. 3–5 The American Diabetes Associa- tion (ADA) regards glycemic control as one of the important strategies for the management of diabetes, and hemoglo- bin A1C is the best measure of glycemic level over the previous 3 months. The ADA recommends a goal of A1C ,7% for people with diabetes. 6 Studies have shown that a large proportion of people with diabetes do not achieve optimal glycemic con- trol, 7–14 but only a few of these inves- tigations have been nationally represen- tative. 9,10,12–14 We previously published national data showing that ,40% of US adults with diabetes achieved A1C levels ,7% in 1999–2000. 13 Although studies suggest the associ- ation of several factors (eg, race/ethnic- ity, insurance coverage, insulin use) with glycemic control, the current picture at the national level remains unclear. 15–16 In particular, it is unclear why dispar- ities exist in glycemic control by race/ ethnicity and to what extent such disparities are explained by socioeco- nomic factors, or other factors such as obesity, healthcare access and diabetes severity. A better understanding of these factors may facilitate more precise targeting of public health efforts. The objective of this analysis is to assess the association of race/ethnicity and good (A1C ,7%) glycemic control after controlling for potential confounders Address correspondence and reprint requests to Sharon Saydah, PhD; National Center for Health Statistics; Centers for Disease Control and Prevention; 3311 Toledo Road; Hyattsville, MD 20782. 301- 458-4183; 301458-4036 (fax); ssaydah@ cdc.gov From the National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, Maryland (SS, MSE); National Institute for Digestive and Diabe- tes and Kidney Diseases, Bethesda, Mary- land (CC); Social and Scientific Systems, Silver Spring, Maryland (ND); and the Division of Diabetes Translation, Centers for Disease Control and Prevention, Atlanta, Georgia (KMVN). It is unclear why disparities exist in glycemic control by race/ethnicity and to what extent such disparities are explained by socioeconomic factors, or other factors such as obesity, healthcare access and diabetes severity. Disclaimer: The views and interpreta- tions presented in this paper are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention or the National Institutes of Diabetes, Digestive, and Kidney Diseases. Ethnicity & Disease, Volume 17, Summer 2007 529