OSA induces an altered proteomic profile linked to cardiovascular and organ damage in nocturnal hypertension

<bold>Background:</bold> Patients with nocturnal hypertension (NH) present increased cardiovascular (CV) risk. Obstructive sleep apnea (OSA) is highly prevalent in this population and is associated with CV and organ damage. The pathological implications of OSA on CV health of NH patients is not completely understood. Proteomic analyses could significantly contribute to evaluate heightened CV damage associated to OSA in NH patients. <bold>Objective:</bold> To assess the proteomic profile of CV and organ damage linked to OSA in patients with NH. <bold>Methods:</bold> This exploratory study included patients referred to the sleep unit diagnosed with NH (mean night blood pressure (BP)≥120/70 mmHg) through 24-hour ambulatory BP monitoring. OSA was confirmed by polysomnography. NH patients with severe OSA (apnea-hypopnea index (AHI)≥30 events·hr⁻¹) were matched with patients without OSA (AHI<15 events·hr^-1) by age, sex, BMI and night mean blood pressure (MBP). Plasma levels of 344 proteins associated with CV and organ damage were analyzed using proximity extension assay technology (Olink®, Sweden). <bold>Results:</bold> Each group comprised 29 patients (median age: 48 years, median BMI: 29.5 kg/m², 70.7% males and median nocturnal MBP: 91.8 mmHg). Proteomic analysis unveiled changes in the levels of 18 proteins in the OSA group, of which 13 were linked to organ damage. First component of Sparse Partial Least Squares (sPLS) selected all differentially expressed proteins and identified a cluster of proteins associated with OSA. Furthermore, the first component of sPLS demonstrated an adjusted dose-response association with the AHI. <bold>Conclusion:</bold> In patients with NH, OSA triggers a modified proteomic profile linked to CV and organ damage.