Calprotectin: A protein related to cardiovascular risk in adult patients with obstructive sleep apnea

Introduction: Increased levels of inflammatory mediators, such as hs-CRP, have been detected in patients with obstructive sleep apnea (OSA) and used as cardiovascular risk and disease outcome predictors. Calprotectin is an inflammatory marker regulating atherogenic processes not investigated in adult OSA patients. The aim of the present study as primary objective was to examine the role of calprotectin as an inflammatory molecule, acting through a distinct pathway to the atherogenic process in adult OSA patients and its associations with hs-CRP and the lipidemic profile of the patients. As a secondary objective was the evaluation of the atherogenic markers post-CPAP treatment. Materials and methods: Seventy-four participants underwent full overnight polysomnography. Blood samples were collected for calprotectin, hs-CRP, total cholesterol, triglycerides, LDL, HDL and glucose levels. Thirty-two OSA patients were reexamined 6 months post-CPAP treatment. Results: Out of 74 participants included in the study, 33 had moderate OSA, 27 had severe OSA and 14 were controls. Calprotectin and hs-CRP were significantly increased in patients with moderate and severe OSA compared to controls (p < 0.0001). Calprotectin and hs-CRP levels were positively correlated with apnea-hypopnea index, BMI and total time of sleep with SaO(2) <90% and inversely correlated with Sa02 minimum and mean values. Calprotectin and hs-CRP levels were significantly improved post-CPAP treatment (p < 0.0001). Discussion: Calprotectin may serve as a novel and reliable, biomarker of cardiovascular risk severity in OSA patients. The decrease of calprotectin levels post-CPAP treatment combined with hs-CRP amelioration could provide evidence for reduction of cardiovascular risk post CPAP treatment. (C) 2013 Elsevier Ltd. All rights reserved.