Variation in Protein Expression Depending on the Severity of Sleep Apnoea-Hypopnoea Syndrome

Objective: A prospective study with a consecutive sample and a control group to determine whether protein expression in patients with sleep apnoea-hypopnoea syndrome (SANS) is different from that of the control group (IAH <= 5). Patients and methods: A total of 32 patients aged between 35 and 60 years who had a polysomnograph performed were included. Patients with an acute or chronic were excluded. The first dimension of the proteomic study was carried out on IPG strips (18 cm, pH 4-7) and the second on SDS-PAGE gels in triplicate for each group. The gels were stained with SYPRO-Ruby (Bio-Rad (R)), the images obtained with an FX-Imager laser scanner and the spots were analysed using ProteomWeaver v. 4.0 (Bio-Rad (R)) software. Significant changes between the gels were analysed by replicates and separately, being considered a significant change if the relative intensity of the spots was three times higher or lower than that of the control and if it was observed in 2 of the 3 replicates of each group, with a coefficient of variation of <20%. Results: The patients were divided into 8 subjects per group (control, mild, moderate and severe). The comparison of the gels showed significant differences between the control group and the 3 clinical groups, with significant over-expression being observed in 3 spots, and under-expression in 7 spots in the control group. Conclusion: There are significant changes in protein expression between a control group and patients in different stages of disease. The proteomic study can identify biomarkers associated with the diagnosis and severity of the SAHS. (C) 2009 SEPAR. Published by Elsevier Espana, S.L . All rights reserved.