Science

Dana E. King, Arch G. Mainous III, Thomas A. Buchanan, William S. Pearson

OBJECTIVE — Recent evidence suggests that poor glycemic control is significantly associated with the development of macrovascular complications of diabetes. Studies have indicated that C-reactive protein (CRP) is an important risk factor for cardiovascular disease. The purpose of this study was to determine the relation between CRP and HbA1c in a large national sample of individuals with diabetes.
RESEARCH DESIGN AND METHODS — A nationally representative sample of non- institutionalized U.S. adults aged 17 years and over with nongestational diabetes was derived from the National Health and Nutrition Examination Survey III (1988–1994) (n = 1,018). Respondents with diabetes were stratified by HbA1c level. The main outcome measure was elevated (>0.30 mg/dl) CRP.
RESULTS — In unadjusted analyses, respondents with diabetes who had elevated HbA1c levels (>9.0%) had a significantly higher percent of elevated CRP than people with low (9.0%(OR2.15,95%CI1.07–4.32)and for HbA1c >11.0% (4.40, 1.87–10.38). Higher HbA1c also predicted elevated CRP in the regression model when HbA1c was analyzed as a continuous variable (1.20, 1.07–1.34).
CONCLUSIONS — In this study, the likelihood of elevated CRP concentrations increased with increasing HbA1c levels. These findings suggest an association between glycemic control and systemic inflammation in people with established diabetes.