Issue 155 Item 15 Poor Glycemic Control Predicts Increase in C-Reactive Protein

High concentrations of HbA1c are associated with increased concentrations of CRP. A group of researchers led by Dr Dana King of the Medical University of South Carolina in Charleston, USA, analyzed the relationship between concentrations of HbA1c and C-reactive protein (CRP). Data were reviewed from 1,018 adults with nongestational diabetes who had participated in the National Health and Nutrition Examination Survey III from 1988 to 1994. Patients were stratified according to concentration of HbA1c: low (<7.0%) or high (>9.0%). Increased concentration of CRP ( >0.3mg/dL) was the main primary outcome.

The researchers found that patients with high concentrations of HbA1c were more likely to have an increased concentration of CRP(p<0.001). Concentrations of HbA1c greater than 9.0% and 11.0% were associated with a significantly greater probability of having increased concentrations of CRP (odds ratios 2.15 and 4.40, respectively) after adjusting for age, race, sex, smoking, time since diagnosis of diabetes, insulin, and body mass index. High concentrations of HbA1c also predicted increased concentrations of CRP when HbA1c was analyzed as a continuous variable (odds ratio 1.20). The researchers conclude that high concentrations of HbA1c are associated with increased concentrations of CRP, which suggests that glycemic control is associated with systemic inflammation in patients with diabetes. Diabetes Care 2003;26:1535-9