The relation of C-reactive protein and impaired fasting glucose: Could it be a predictor for prediabetic state?

The rate of cardiovascular disease is increasing in developed countries progressively with estimates predicting 22 million by 2030. Based on these cardiovascular events lies atherosclerosis, a condition intricately linked to chronic inflammatory processes. Among fundamental clinical biomarkers, C-reactive protein (CRP) stands out as a backbone of inflammatory activity. Notably, the excessive production of CRP, often linked with obesity, plays a pivotal role in the dysregulation of triglyceride apo B-100 fractional catabolism, thus emerging as a significant cardiovascular risk factor. Apart from atherosclerotic processes, the interplay between high CRP levels and impaired fasting glucose (IFG) is also gaining recognition as a messenger of disrupted glucose metabolism, potentially ushering in the onset of a prediabetic state.

Our retrospective analysis scrutinized the biochemical data - namely low-density lipoprotein cholesterol (LDL-C), triglycerides, fasting blood sugar, and CRP levels-of 3500 patients from an internal medicine outpatient clinic seen from August 2006 to May 2007. Our objective was to dissect the correlations among these parameters. Exclusion criteria were omitting individuals with acute or chronic inflammation, known inflammatory diseases, diagnosed diabetes, coronary artery disease, lipid metabolism disorders, those on lipid-lowering agents, and anyone outside the age bracket of 18-65 years. This study was conducted in strict adherence to the ethical principles outlined in the Declaration of Helsinki.

As a result of our study, the ratio of CRP levels above 0.8 was significantly higher in patients with IFG according to the World Health Organization criteria (6.1-6.9 mmol/L or 109-124 mg/dL) than in individuals with normal fasting glucose (70-108 mg/dL). (19.7%, 17.2%, respectively) (p<0.001). In addition, the ratio of CRP levels above 0.8 was also higher in patients with triglyceride levels between 151 and 199 mg/dL) and over 500 mg/dL. (23.2%, 24.1%, respectively) (p<0.012). However, the relationship between CRP levels and LDL-C total cholesterol was not statistically significant (p>0.05).

This retrospective study suggests the imperative for a proactive approach in the clinical evaluation of patients exhibiting elevated CRP, especially in the context of preemptive management of prediabetes. In light of these findings, we think that elevated CRP may be a warning sign for prediabetic status and may be useful in early diagnosis.