Effects of aspirin on serum C-reactive protein and interleukin-6 levels in patients with type 2 diabetes without cardiovascular disease: a randomized placebo-controlled crossover trial

Aim:  Low-grade inflammation plays a pivotal role in atherogenesis in type 2 diabetes. Next to its antithrombotic effects, several lines of evidence demonstrate anti-inflammatory properties of aspirin. We determined the effects of aspirin on inflammation – represented by C-reactive protein (CRP) and interleukin-6 (IL-6) – in type 2 diabetic subjects without cardiovascular disease and assessed differential effects of aspirin 300 mg compared with 100 mg. Methods:  A randomized, placebo-controlled, double-blind, crossover trial was performed in 40 type 2 diabetic patients. In two periods of 6 weeks, patients used 100 or 300 mg aspirin and placebo. Plasma CRP and IL-6 levels were measured before and after both periods. Results:  Use of aspirin resulted in a CRP reduction of 1.23 ± 1.02 mg/l (mean ± s.e.m.), whereas use of placebo resulted in a mean increase of 0.04 ± 1.32 mg/l (P = 0.366). Aspirin reduced IL-6 with 0.7 ± 0.5 pg/ml, whereas use of placebo resulted in a mean increase of 0.2 ± 0.8 pg/ml (P = 0.302). There were no significant differences in effects on CRP and IL-6 between 100 and 300 mg aspirin. Conclusions:  Our results indicate that a 6-week course of aspirin does not improve low-grade inflammation in patients with type 2 diabetes without cardiovascular disease, although a modest effect could not be excluded. No significant differential effects between aspirin 100 and 300 mg were found.