Combined Effects of Insulin Resistance and Inflammation on Comorbidities of Type 2 Diabetes

Abstract

Background: Insulin resistance (IR) and inflammation are closely related to each other and share common pathophysiological and metabolic mechanisms. We aimed to investigate the combined effect of IR and inflammation on comorbidities of type 2 diabetes mellitus (T2DM). Methods: A total 3,758 patients with T2DM were recruited through Huh’s Diabetes Center from January 2003 to June 2009. Insulin sensitivity was measured by a rate constant for plasma glucose disappearance (<i>Kitt</i> , %/min) using short insulin tolerance test. High sensitivity C-reactive protein (hs-CRP) was used as a surrogate for inflammation.Results: Patients with the lowest tertile of <i>Kitt</i> (IR group) showed worse cardio-metabolic parameters while those with the highest tertile of hs-CRP levels had worse cardio-metabolic parameters. The prevalence of metabolic syndrome, fatty liver, albuminuria, and carotid atherosclerosis decreased with <i>Kitt</i> tertile, but increased with hs-CRP tertile. In multiple regression analysis, both <i>Kitt</i> and hs-CRP were independent risk factors for comorbidities of T2DM. In addition, they showed synergistic effects on these comorbidities. Conclusion: Both IR and inflammation were significantly associated with comorbidities of T2DM in a dose dependent manner. In addition, the coexistence of IR and inflammation may synergistically contribute to increased comorbidities of T2DM.