The potentially poor response to outpatient diabetes care in urban African-Americans

HbA1c levels can be reduced in populations of diabetic patients, but some individuals may exhibit little improvement. To search for reasons underlying differences in HbA1c outcome, we analyzed patients managed in an outpatient diabetes clinic.

African-Americans with type 2 diabetes were categorized as responders, intermediate responders or poor responders according to their HbA1c level after 1 year of care. Logistical regression was used to determine baseline characteristics that distinguished poor responders from responders. Therapeutic strategies were examined for each of the response categories.

The 447 patients had a mean age and disease duration of 58 and 5 years, respectively, and BMI of 32 kg/m2. Overall, the mean HbA1c level fell from 9.6 to 8.1% after 12 months. Mean HbA1c levels improved from 8.8 to 6.2% in responders, and from 9.5 to 7.9% in intermediate responders. In poor responders, the average HbA1c level was 10.8% on presentation and 10.9% at 1 year. The odds of being a poor responder were significantly increased with longer disease duration, higher initial HbA1c level, and greater BMI. Although doses of oral agents and insulin were significantly higher among poor responders at most visits, the acceleration of insulin therapy did not occur until late in the follow-up period.

Clinical diabetes programs need to devise methods to identify patients who are at risk for persistent hyperglycemia. Whereas patient characteristics explain some heterogeneity of HbA1c outcome (and may aid in earlier identification of patients who potentially may not respond to conventional treatment), insufficient intensification of therapy may also be a component underlying the failure to achieve glycemic goals.