Effectiveness of nasal continuous airway pressure therapy in patients with obstructive sleep apnea

A Prospective Study on Obstructive Sleep Apnea, Clinical Profile and Polysomnographic Variables

Background: Obstructive sleep apnea (OSA) is characterized by recurring episodes of pharyngeal collapse, which can partially or completely block airflow during sleep and cause cardiorespiratory and neurological imbalances. Therefore, the purpose of this study was to assess OSA and the relationship between AHI and polysomnographic characteristics in OSA patients. Methodology: A prospective study was conducted at the Department of Pulmonology and Sleep Medicine for two years. All 216 participants underwent polysomnography, and 175 of them were reported to have OSA (AHI ≥ 5), while 41 of them did not (AHI < 5). ANOVA and Pearson's correlation coefficient test were performed. Results: In terms of the study population's average AHI, Group 1 had 1.69 ± 1.34, mild OSA had 11.79 ± 3.55, moderate OSA had 22.12 ± 4.34, and severe OSA was found to have 59.16 ± 22.15 events/hour. The study group's average age was 53.77 ± 7.19 out of 175 OSA patients. According to AHI, the BMI for mild OSA was 31.66 ± 8.32 kg/m², for moderate OSA, it was 30.52 ± 3.99 kg/m², and for severe OSA, it was 34.35 ± 8.22 kg/m². The average number of oxygen desaturation events and snoring duration were 25.20 ± 18.63 and 24.61 ± 28.53 min, respectively. BMI (r = 0.249, p < 0.001), average oxygen saturation (r = -0.387, p < 0.000), oxygen desaturation (r = 0.661, p < 0.000), snoring time (r = 0.231, p < 0.002), and the number of snores (r = 0.383, p < 0.001) were the polysomnographic variables that showed significant correlations with AHI in the study group. Conclusions: In this study, a substantial prevalence of obesity and a high OSA frequency were found in men. Our research showed that individuals with obstructive sleep apnea experience nocturnal desaturations. Polysomnography is the primary test for early detection of this treatable condition.

The effect of continuous positive airway pressure treatment on inflammatory parameters and periostin levels in patients with obstructive sleep apnea syndrome

BACKGROUND

The purpose of the study was to examine the effects of continuous positive airway pressure (CPAP) treatment on inflammation parameters in patients with obstructive sleep apnea syndrome (OSAS).

METHODS

Patients aged 18 to 65 years who underwent polysomnography (PSG) in the sleep clinic between January 1, 2019, and December 31, 2019, were included in the study. Patients with severe OSAS initiated treatment with CPAP. Patients and control subjects were assessed for levels of periostin, TNF-alpha, TGF-beta, and IL-6. Patients were re-evaluated 3 months later. Comparisons for the serum markers were made between controls and patients of different severity of OSAS. Comparisons of serum markers were also made between baseline and 3 month follow-up.  RESULTS: A total of 92 patients were enrolled in the study, including 25 controls (apnea-hypopnea index or AHI < 5/h), 39 patents with mild to moderate OSAS who did not receive CPAP, and 28 patients with severe OSAS receiving CPAP treatment. When all three groups were compared, levels of periostin, TNF-alpha, TGF-beta, and IL-6, as inflammatory markers, were higher in the OSAS group, though not at a statistically significant level. In patients with severe OSAS, there were statistically significant decreases in the TGF-beta 1, TNF-alpha, and IL-6 values between baseline values and the same measures taken after 3 months of CPAP treatment. Periostin values also decreased after treatment, but this decrease was not at a significant level.

CONCLUSION

Inflammatory parameters of patients with OSAS were significantly higher compared with healthy participants. Regression of inflammation was detected after CPAP treatment.

Bidirectional relationship between sleep and Alzheimer's disease: role of amyloid, tau, and other factors

As we age, we experience changes in our nighttime sleep and daytime wakefulness. Individuals afflicted with Alzheimer's disease (AD) can develop sleep problems even before memory and other cognitive deficits are reported. As the disease progresses and cognitive changes ensue, sleep disturbances become even more debilitating. Thus, it is imperative to gain a better understanding of the relationship between sleep and AD pathogenesis. We postulate a bidirectional relationship between sleep and the neuropathological hallmarks of AD; in particular, the accumulation of amyloid-β (Aβ) and tau. Our research group has shown that extracellular levels of both Aβ and tau fluctuate during the normal sleep-wake cycle. Disturbed sleep and increased wakefulness acutely lead to increased Aβ production and decreased Aβ clearance, whereas Aβ aggregation and deposition is enhanced by chronic increased wakefulness in animal models. Once Aβ accumulates, there is evidence in both mice and humans that this results in disturbed sleep. New findings from our group reveal that acute sleep deprivation increases levels of tau in mouse brain interstitial fluid (ISF) and human cerebrospinal fluid (CSF) and chronic sleep deprivation accelerates the spread of tau protein aggregates in neural networks. Finally, recent evidence also suggests that accumulation of tau aggregates in the brain correlates with decreased nonrapid eye movement (NREM) sleep slow wave activity. In this review, we first provide a brief overview of the AD and sleep literature and then highlight recent advances in the understanding of the relationship between sleep and AD pathogenesis. Importantly, the effects of the bidirectional relationship between the sleep-wake cycle and tau have not been previously discussed in other reviews on this topic. Lastly, we provide possible directions for future studies on the role of sleep in AD.