Positive airway pressure therapy and daytime hypercapnia in patients with sleep-disordered breathing

The effect of positive airway pressure therapy on neurocognitive functions, depression and anxiety in obesity hypoventilation syndrome

Background

The aim of this study is to evaluate the presence of neurocognitive dysfunctions, depression and anxiety and the effect of positive airway pressure (PAP) therapy on these alterations in Obesity Hypoventilation Syndrome (OHS) patients.

Methods

Ten healthy normal and obese controls, 10 OHS and 10 OSAS patients were included in the study. Short form-36, Beck Depression Scale and State-Trade Anxiety Inventory (STAI 1-2) were performed. Wisconsin Card Sorting Test (WCST), Montreal Cognitive Assessment Scale (MOCA), Enhanced Cued Recall (ECR) and Mini Mental Test (MMT) were used for neurocognitive evaluation. All tests were repeated after one night PAP therapy in OHS and OSAS groups.

Results

OHS patients had the lowest scores of physical (PF) and social functioning (SF) in SF-36. The total number of persistent errors and incorrect answers were the highest in OHS group in WCST. The scores of MOCA, ECR and MMT were lower; depression and anxiety scores were higher in OHS group than in controls (p = 0,00). There was a significant increase in the completed categories in OHS after PAP therapy (p = 0,03). There were also significant increases in MOCA, ECR and MMT scores and significant decreases in depression and anxiety scores with respect to PAP therapy.

Conclusions

Cognitive dysfunction, depression and anxiety are important under-recognized comorbidities in OHS. It is suggested that short term PAP therapy had positive effects on neurocognitive functions, depression and anxiety but further multicentre, prospective studies with large number of cases are needed to evaluate the effect of long term PAP therapy on these parameters.

Obesity hypoventilation syndrome

Obesity is becoming a major medical concern in several parts of the world, with huge economic impacts on health- care systems, resulting mainly from increased cardiovascular risks. At the same time, obesity leads to a number of sleep-disordered breathing patterns like obstructive sleep apnea and obesity hypoventilation syndrome (OHS), leading to increased morbidity and mortality with reduced quality of life. OHS is distinct from other sleep- related breathing disorders although overlap may exist. OHS patients may have obstructive sleep apnea/hypopnea with hypercapnia and sleep hypoventilation, or an isolated sleep hypoventilation. Despite its major impact on health, this disorder is under-recognized and under-diagnosed. Available management options include aggressive weight reduction, oxygen therapy and using positive airway pressure techniques. In this review, we will go over the epidemiology, pathophysiology, presentation and diagnosis and management of OHS.