HbA1c is a biomarker of the presence and severity of diabetes mellitus (DM). High sensitivity serum C-reactive protein (hs-CRP) is a marker of systemic inflammation. Elevated levels of both have been shown to be independently associated with cardiovascular disease.

The STOP trial randomized patients with Type II-DM and presence of coronary plaque on CCTA to Semaglutide/placebo. Baseline HbA1c and CRP were measured. Multivariate linear regression analysis was used to examine the association of baseline HbA1C with hs-CRP.

In 107 subjects, mean age was 56.5±8.3 yrs, 67 (63%) were male. Mean duration of diabetes was 16.1±7.5 years, mean HbA1C was 9±1.90, 89 subjects (83%) were on lipid-lowering medications, and 89 (83%) were on antihypertensives. 14 (13%) were current smokers and 41 (38%) were former smokers. Spearman correlation demonstrated a significant correlation between A1C and hs-CRP at baseline (R=0.28 p=0.0036). In unadjusted linear regression analysis, compared to subjects with a CRP of <1, those with a CRP >1 had 1-unit higher A1C levels (p=0.02) and those with CRP >3 had 1.2-unit higher A1C (p=0.01). When adjusting for age, gender, BMI, hyperlipidemia, hypertension, and smoking, the association was no longer significant in CRP<1 versus >1 (p=0.21) and CRP<1 versus CRP>3 (p=.099), suggesting a trend towards an association.

Higher HbA1c levels were associated with increased hs-CRP, demonstrating that poorly-controlled DM is associated with increased systemic inflammation. The lack of statistical significance on multivariate adjusted analysis with a trend towards an association could be due to the relatively small sample size.