Racial and ethnic differences in glycemic control of adults with type 2 diabetes

OBJECTIVE - To evaluate glycemic control in a representative sample of U.S, adults with type 2 diabetes. RESEARCH DESIGN AND METHODS - The Third National Health and Nutrition Exami nation Survey included national samples of non-Hispanic whites, non-Hispani c blacks, and Mexican Americans aged greater than or equal to 20 years. Inf ormation on medical history and treatment of diabetes was obtained to deter mine those who had been diagnosed with type 2 diabetes by a physician befor e the survey (n = 1,480). Easting plasma glucose and HbA(1c) were measured, and the frequencies of sociodemographic and clinical variables related to glycemic control were determined. RESULTS - A higher proportion of non-Hispanic blacks were treated with insu lin and a higher proportion of Mexican Americans were treated with oral age nts compared with non-Hispanic whites, but the majority of adults in each r acial or ethnic group (71-83%) used pharmacologic treatment for diabetes. U se of multiple daily insulin injections was more common in whites. Blood gl ucose self-monitoring was less common in Mexican Americans, but most patien ts had never self-monitored. HbA(1c) values in the nondiabetic range were f ound in 26% of non-Hispanic whites, 17% of non-Hispanic blacks, and 20% of Mexican Americans. Poor glycemic control (HbA(1c) >8%) was more common in n on-Hispanic black women (50%) and Mexican-American men (45%) compared with the other groups (35-38%),but HbA(1c) for both sexes and for all racial and ethnic groups was substantially higher than normal levels. Those with HbA( 1c) >8% included 52% of insulin-treated patients and 42% of those taking or al agents. There was no relationship of glycemic control to socioeconomic s tatus or access to medical care in any racial or ethnic group. CONCLUSIONS - These data indicate that many patients with ripe 2 diabetes i n the U.S. have poor glycemic control, placing them at high risk of diabeti c complications. Non-Hispanic black women, Mexican-American men, and patien ts treated with insulin and oral agents were disproportionately represented among those in poor glycemic control. Clinical, public health, and researc h efforts should focus on more effective methods to control blood glucose i n patients with diabetes.