Effect of nasal continuous positive airway pressure on inflammatory mediators in patients with overlap syndrome

Impact of sleep-disordered breathing treatment on upper airway anatomy and physiology

Sleep-disordered breathing (SDB) is a major public health problem. Various anatomic, pathophysiologic, and environmental changes contribute to SDB. The successful treatment of SDB reverses many of these abnormal processes. The present article discusses the current clinical evidence that supports the reversibility and its potential application in the management of SDB. Continuous positive airway pressure reduces angiogenesis and inflammatory edema, increases pharyngeal size, and improves surrogate markers of vascular inflammation and tongue muscle fiber types. Mandibular advancement devices lead to favorable maxillary and mandibular changes, increase pharyngeal area, and improve hypertension. Uvulopalatopharyngoplasty increases posterior airway space and pharyngeal volume, reduces nasal and oral resistance, and lowers response to high CO2. Weight loss reduces nasopharyngeal collapsibility, critical closing pressure of the airway, apnea-hypopnea index, and improves oxygen saturations. Potential clinical benefits of these changes in the management of SDB and patient compliance with treatment are discussed.

Inflammatory processes and effects of continuous positive airway pressure (CPAP) in overlap syndrome

We aimed to compare serum levels of the inflammatory mediators including C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and asymmetric dimethylarginine (ADMA) in chronic obstructive pulmonary disease (COPD), obstructive sleep apnea syndrome (OSAS), and their coexistence called overlap syndrome (OVS). In addition, we planned to investigate changes of these mediators with the treatment of continuous positive airway pressure (CPAP) in OSAS and OVS. CRP, TNF-α, and ADMA levels were analyzed by ELISA method from blood samples withdrawn from patients with COPD (N = 25), OVS (N = 25), and moderate- to severe-stage OSAS (N = 25). First blood samples were taken in the morning after polysomnography application, and second blood samples were taken from OSAS and OVS patients who underwent regular CPAP treatment. In comparison of three groups prior to CPAP treatment, ADMA level in OSAS were significantly lower than in COPD (p = 0.009), but CRP and TNF-α were similar among groups. When we compared the parameters before and after CPAP treatment, the level of CRP in both OSAS and OVS decreased significantly (p = 0.02, p = 0.04), whereas TNF-α and ADMA levels did not display any significant differences. A decrease of serum CRP level in OVS and OSAS groups following effective CPAP treatment shows that CPAP is an effective treatment method for systemic inflammation.