Serum CRP levels are equally elevated in newly diagnosed type 2 diabetes and impaired glucose tolerance and related to adiponectin levels and insulin sensitivity

Abstract 

Aims

To measure the serum highly sensitive C-reactive protein (hs-CRP) and adiponectin levels, assess insulin sensitivity index (SI) and acute insulin response (AIR) in normal control (NC) subjects, patients with impaired glucose tolerance (IGT) and newly diagnosed type 2 diabetes mellitus (DM), and further explore the possible correlation between hs-CRP and SI, AIR and adiponectin in IGT and newly diagnosed type 2 DM groups.

Methods

Age and sex matched 28 normal subjects, 31 patients with IGT, and 31 patients with newly diagnosed type 2 DM were included in the study. SI and AIR were assessed by the reduced sample number of Bergman's minimal model method with intravenous glucose tolerance test in subjects of each group.

Results

Compared with NC group, serum hs-CRP was significantly increased in IGT and type 2 DM groups (p<0.001), although there was no significant difference between the latter groups. Hs-CRP was negatively correlated with high density lipoprotein cholesterol (HDL-C), SI and adiponectin levels (p<0.05 to p<0.001), and positively correlated with systolic blood pressure (SBP), fasting plasma glucose (FPG), BMI, waist-to-hip ratio (WHR), postprandial 2h plasma glucose (2hPG), fasting serum insulin (FINS) and postprandial serum insulin (PSI) in IGT and newly diagnosed type 2 DM groups (p<0.05 to p<0.001). In general multivariate regression, only adiponectin was the significantly independent determinant for serum hs-CRP (regression coefficient −1.380; 95% CI −2.062 to 0.698, p<0.001); meanwhile, TG, SI, hs-CRP, FINS, 2hPG and WHR were significantly independent determinants for serum adiponectin concentration (p<0.05 to p<0.001).

Conclusions

Elevated serum hs-CRP may play a role in the development of insulin resistance syndrome and type 2 diabetes. This elevation is accompanied by the opposite changes of adiponectin.

Abbreviations: WHO, World Health Organization, IGT, impaired glucose tolerance, DM, diabetes mellitus, SI, insulin sensitivity index, AIR, acute insulin response, CRP, C-reactive protein

Keywords: Impaired glucose tolerance (IGT), Diabetes mellitus (DM), Insulin sensitivity index (SI), Acute insulin response (AIR), Highly sensitive C-reactive protein (hs-CRP)