Recent prospective studies indicate endothelial dysfunction and increased risk for cardiovascular events in patients with serological evidence of multiple infections. Soluble CD14 (sCD14) plays a key role in the neutralization of lipopolysaccharide (LPS), a well-established bacterial product inducing endothelial dysfunction. Insulin resistance was recently identified as a significant factor influencing circulating sCD14 concentration. Thus, we investigated the association of circulating sCD14 and endothelial dysfunction in subjects with well-established insulin resistance (patients with type 2 diabetes, n = 40) compared to control nondiabetic subjects (n = 100). To further explore the underlying mechanisms, we also analysed C-reactive protein and circulating NO2-/NO3- and cyclic GMP in the diabetic group. Serum sCD14 concentration (ELISA) was found to be differently associated with endothelium-dependent vasodilatation (EDVD, high-resolution ultrasound) in diabetic and non-diabetic subjects. In non-diabetic subjects, serum sCD14 and C-reactive protein correlated negatively with EDVD (r = 0.21, p = 0.03, and r = 0.21, p = 0.03, respectively). In a partial correlation analysis, these associations remained significant after controlling for age and weight (sCD14 and EDVD, r = 0.23, p = 0.023; C-reactive protein and EDVD, r = 0.21, p = 0.03; sCD14 and C-reactive protein, r = 0.30, p = 0.002). In contrast, sCD14 was positively associated with EDVD in type 2 diabetic patients (r = 0.37, p = 0.019). Interestingly, sCD14 was also associated with NO2-/NO3- in this group (r = 0.62, p = 0.001, n = 22). EDVD also correlated with cyclic GMP (r = 0.47, p = 0.03, n = 22). In summary, circulating sCD14 is associated with endothelial function. While in non-diabetic subjects sCD14 behaves as an acute phase reactant, its role in type 2 diabetic patients should be further clarified. These findings need to be confirmed in further studies with larger number of patients.
Print ISSN: 0340-6245
Volume: 94, 09/2005
Pages: 615 - 619