Inflammatory Markers and Obstructive Sleep Apnea in Obese Children: The NANOS Study

Introduction. Obesity and obstructive sleep apnea syndrome (OSA) are common coexisting conditions associated with a chronic low-grade inflammatory state underlying some of the cognitive, metabolic, and cardiovascular morbidities. Aim. To examine the levels of inflammatory markers in obese community-dwelling children with OSA, as compared to no-OSA, and their association with clinical and polysomnographic (PSG) variables. Methods. In this cross-sectional, prospective multicenter study, healthy obese Spanish children (ages 4-15 years) were randomly selected and underwent nocturnal PSG followed by a morning fasting blood draw. Plasma samples were assayed for multiple inflammatory markers. Results. 204 children were enrolled in the study; 75 had OSA, defined by an obstructive respiratory disturbance index (RDI) of 3 events/hour total sleep time (TST). BMI, gender, and age were similar in OSA and no-OSA children. Monocyte chemoattractant protein-1 (MCP-1) and plasminogen activator inhibitor-1 (PAI-1) levels were significantly higher in OSA children, with interleukin-6 concentrations being higher in moderate-severe OSA (i.e., AHI > 5/hrTST; P < 0.01), while MCP-1 levels were associated with more prolonged nocturnal hypercapnia (P < 0.001). Conclusion. IL-6, MCP-1, and PAI-1 are altered in the context of OSA among community-based obese children further reinforcing the proinflammatory effects of sleep disorders such as OSA. This trial is registered with ClinicalTrials.gov NCT01322763.Leila Kheirandish-Gozal and David Gozal are supported by a Grant HL-65270 from the National Institutes of Health. The NANOS study was supported by the Spanish Respiratory Society (SEPAR) and Mutua Madrilena. The authors thank the subjects and their parents for their participation and the Basque Biobank For Research-OEHUN for their collaboration. The authors would like to thank the members of the Spanish Sleep Network: Estrella Ordax Carbajo, M. D. (Hospital Universitario de Burgos); Ana Isabel Navazo-Eguia, M. D. (Hospital Universitario de Burgos); Marian Martinez Martinez, M. D. (Hospital Universitario Valdecilla, Santander); Odile Romero Santo-Tomas, MD (Hospital Val D'Hebron); Fernando Masa-Jimenez, M. D. (Hospital San Pedro de Alcantara, Caceres); Cristina Martinez Null (Hospital Universitario Araba, Vitoria); Antonia Barcelo-Bennassar, Ph.D. (Hospital Son Dureta, Palma de Mallorca)