Postchallenge Hyperglycemia in a National Sample of U.S. Adults With Type 2 Diabetes

Abstract

OBJECTIVE—Postchallenge hyperglycemia (PCH) is known to contribute to suboptimal glycemic control in adults with non–insulin-requiring type 2 diabetes. The objective of this study was to estimate the prevalence of PCH among individuals with diabetes. RESEARCH DESIGN AND METHODS—We conducted a cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey (1988–1994) in adults aged 40–74 years with diabetes who were not using insulin (i.e., they used oral hypoglycemics or received no pharmacological therapy). Each respondent underwent a standard 75-g oral glucose tolerance test. PCH was defined as a 2-h glucose level ≥200 mg/dl. RESULTS—Overall, PCH was present in 74% of those with diagnosed diabetes. Although it was present in virtually all (99%) of the diabetic adults under suboptimal glycemic control (HbA_1c ≥7.0%), PCH was also common (39%) among those under optimal control (HbA_1c <7.0%). Likewise, among sulfonylurea users, PCH was present in 99% of those under suboptimal control and in 63% of those under good control. Similar patterns were observed in those with undiagnosed diabetes. Isolated PCH (2-h glucose ≥200 mg/dl and fasting glucose <126 mg/dl) was present in 9.8% of the adults with diagnosed diabetes. CONCLUSIONS—These data suggest that PCH is common among diabetic adults in the U.S., even in the setting of “optimal” glycemic control and sulfonylurea use. Interventions designed to lower postprandial glucose excursions may help improve overall glycemic control in the general population of U.S. adults with diabetes.