Hypercapnia impaired cognitive and memory functions in obese patients with obstructive sleep apnoea

Abstract

Obstructive sleep apnoea (OSA) is a sleep disorder involving repeated nocturnal desaturation and sleep fragmentation. OSA can result in decreased daytime alertness and neurocognitive dysfunction. Hypercapnia status is also related to neurocognitive dysfunction in patients with pulmonary diseases. We evaluated the effects of hypercapnia on cognitive performance and memory function in a prospective case-controlled study. We enrolled thirty-nine obese patients with OSA and collected their arterial blood samples. All the participants provided arterial blood samples, and completed two questionnaires (the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale) and six cognitive tasks (the psychomotor vigilance task [PVT], the Stroop task, the Eriksen flanker task, processing speed [DSST], and verbal and visual memory [LM&FM]), which were used to evaluate daytime sleepiness, cognitive function, and memory function within one week of a polysomnographic study. When compared to the OSA without diurnal hypoventilation, the patients with stable hypercapnia (OHS) had increased reaction times in the PVT, Stroop task, and flanker task. Hypercapnic obese patients with OSA also had comparatively significantly lower scores in the processing speed and logical memory tests. OHS had increased reaction times in the attention and cognitive function assessments, and deficits in the logical memory, when compared to those with OSA without diurnal hypoventilation.

Hypoxemia following hospital discharge after fast‐track hip and knee arthroplasty – A prospective observational study subanalysis

“…Previous obstructive sleep apnoea studies have supported a correlation between hypoxemia/hypercapnia and delirium or cognitive impairment 25 . This was not supported by our study, but might be due to low power from POCD occurring rarely in our population, or the fact that the development of POCD is multifactorial including other factors than hypoxemia such as impaired sleep, opioid use 17 and inflammation 26 .…”

“…3,24 Previous obstructive sleep apnoea studies have supported a correlation between hypoxemia/hypercapnia and delirium or cognitive impairment. 25 This was not supported by our study, but might be due to low power from POCD occurring rarely in our population, or the fact that the development of POCD is multifactorial including other factors than hypoxemia such as impaired sleep, opioid use 17 and inflammation. 26 Among other clinical outcomes of specific interest are cardiac injury, which a recent study in abdominal surgery have suggested to correlate with hypoxemia, 3 similar to previous studies observing ischaemic ECG changes during post-operative hypoxemic episodes.…”

Effect of Sleep Disorder on Delirium in Post-Cardiac Surgery Patients

“…[38][39][40] Similarly, OSA-related chronic intermittent hypoxia and hypercapnia can also hinder attention, memory and cognition. 41,42 Specifically, how SPD generates cognitive and behavioural dysfunction is still unclear. A large number of cortisol production induced by hypothalamic-pituitary-adrenal axis hyperactivity may be a possible mechanism that explains how SPD influences cognitive and behavioural dysfunction.…”

Vasomotor influences on glymphatic-lymphatic coupling and solute trafficking in the central nervous system

“…39–41 Recent findings in subjects with OSA suggest that in addition to sleep fragmentation and hypoxemia, hypercapnia may be a key driver of neurocognitive decline. 42,43 The present findings raise the intriguing possibility that transient and chronic hypercapnia may contribute to such cognitive deficits at least in part through the impairment of perivascular clearance of interstitial solutes.…”