Research Article Reduced Systemic Levels of IL-10 Are Associated with the Severity of Obstructive Sleep Apnea and Insulin Resistance in Morbidly Obese Humans Sonia Leon-Cabrera, 1 Yoaly Arana-Lechuga, 2 Enrique Esqueda-León, 2 Guadalupe Terán-Pérez, 2 Antonio Gonzalez-Chavez, 3 Galileo Escobedo, 4 and Javier Velázquez Moctezuma 2 1 Unidad de Biomedicina, Facultad de Estudios Superiores-Iztacala, Universidad Nacional Aut´ onoma de M´ exico, Avenida de los Barrios 1, Los Reyes Iztacala, 54090 Tlalnepantla, MEX, Mexico 2 Departamento de Biolog´ ıa de la Reproducci´ on y Cl´ ınica de Trastornos de Sue˜ no, Universidad Aut´ onoma Metropolitana-Iztapalapa, 09340 M´ exico, DF, Mexico 3 Servicio de Medicina Interna, Hospital General de M´ exico, 06726 M´ exico, DF, Mexico 4 Unidad de Medicina Experimental, Facultad de Medicina, Universidad Nacional Aut´ onoma de M´ exico, Hospital General de M´ exico, 06726 M´ exico, DF, Mexico Correspondence should be addressed to Javier Vel´ azquez Moctezuma; jvm@xanum.uam.mx Received 20 January 2015; Revised 23 March 2015; Accepted 23 March 2015 Academic Editor: Mark R. Zielinski Copyright © 2015 Sonia Leon-Cabrera et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Obstructive sleep apnea (OSA) has been related to elevation of infammatory cytokines and development of insulin resistance in morbidly obese (MO) subjects. However, it is still unclear whether the systemic concentration of anti-infammatory mediators is also afected in MO subjects directly related to the severity of OSA and level of insulin resistance. Normal weight and MO subjects were subjected to overnight polysomnography in order to establish the severity of OSA, according to the apnea-hypopnea index (AHI). Blood samples were obtained for estimation of total cholesterol and triglycerides, insulin, glucose, insulin resistance, tumor necrosis factor alpha (TNF-), interleukin 12 (IL12), and interleukin 10 (IL-10). Serum levels of IL-10 were signifcantly lower in MO subjects with OSA than in MO and control individuals without OSA. Besides being inversely associated with serum TNF-  and IL-12, decreased IL-10 levels were signifcantly related to increased AHI, hyperinsulinemia, and insulin resistance. Serum IL-10 is signifcantly reduced in morbidly obese subjects with severe OSA while also showing a clear relationship with a state of hyperinsulinemia and insulin resistance probably regardless of obesity in the present sample. It may be of potential clinical interest to identify the stimulatory mechanisms of IL-10 in obese individuals with OSA. 1. Introduction Obstructive sleep apnea (OSA) is a condition that threatens health, which is characterized by complete or partial upper airway collapse occurring repeatedly during sleep. OSA is a common health problem afecting 10% of men and 3% of women in the general population, with a considerably high prevalence (∼40%) among morbidly obese (MO) individuals [1, 2]. Recurrent episodes of upper airway obstruction, progressive hypoxemia, and sleep fragmentation during OSA have been related to the advent of neural, cardiovascular, and metabolic disturbances mainly in extremely obese subjects [3–5]. Recently, some studies have demonstrated that OSA signifcantly increases the risk of developing insulin resis- tance and type 2 diabetes in individuals with morbid obesity [6, 7]. Moreover, it has been reported that the presence of OSA is associated with a signifcant increase of cardiovascular and cerebrovascular disease in MO individuals [8–11]. Tus, OSA is an important risk factor that contributes to the incidence of cardiovascular and metabolic disease mainly Hindawi Publishing Corporation Mediators of Inflammation Volume 2015, Article ID 493409, 9 pages http://dx.doi.org/10.1155/2015/493409