Distribution characteristics of intestinal flora in patients with OSAHS and the relationship between different intestinal flora and sleep disorders, hypoxemia and obesity

OBJECTIVE

To investigate the distribution characteristics of intestinal flora in patients with obstructive sleep apnoea hypopnea syndrome (OSAHS) of different severities and the relationship between different intestinal flora and sleep structure disorder, hypoxemia and obesity.

METHODS

A total of 25 healthy volunteers and 80 patients with OSAHS were enrolled in this study. The control group was healthy, and the experimental group comprised patients with OSAHS. The apnoea-hypopnea index (AHI), minimum saturation of peripheral oxygen (SpO2min), mean saturation of peripheral oxygen, body mass index, maximum apnoea time and other indicators were collected in clinical practice. The patients with OSAHS were divided into 20 mild and 42 moderate OSAHS cases, as well as 18 patients with severe OSAHS according to the AHI classification. Bioinformatics-related statistics were analysed using the QIIME2 software, and clinical data were analysed with the SPSS 22.0 software.

RESULTS

The changes in microbial alpha diversity in the intestinal flora of patients with OSAHS showed that richness, diversity and evenness decreased, but the beta diversity did not change significantly. The Thermus Anoxybacillus, Anaerofustis, Blautia, Sediminibacterium, Ralstonia, Pelomonas, Ochrobactrum, Thermus Sediminibacterium, Ralstonia, Coccidia, Cyanobacteria, Anoxic bacilli and Anaerobes were negatively correlated with AHI (r = -0.38, -0.36, -0.35, -0.33, -0.31, -0.29, -0.22, -0.18) and positively correlated with SpO2min (r =0.38, 0.2, 0.25, 0.22, 0.24, 0.11, 0.23, 0.15).

CONCLUSION

Some bacteria showed a significant correlation with clinical sleep monitoring data, which provides a possibility for the assessment of disease risk, but the mechanisms of their actions in the intestinal tract are not clear at present. Further research and observations are needed.

[Effect of mandibular advancement device upon nuclear factor κB and tumor necrosis factor α, interleukin 6 in genioglossus of rabbit with obstructive sleep apnea hypopnea syndrome]

Objective: To investigate the effects of mandibular advancement device (MAD) upon nuclear factor κB (NF-κB), tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) in the genioglossus. Methods: Eighteen New Zealand white rabbits (male, six months old), in accordance with the random number table, were equally divided into three groups, the control group, obstructive sleep apnea hypopnea syndrome (OSAHS) group and MAD group. All animals were induced to sleep in supine position for 2 hours every morning in the next 8 weeks. The specimens of genioglossus were prepared. The relative expression of NF-κB p65 was measured with Western blotting and the mass concentration of TNF-α and IL-6 was determined with enzyme-linked immunosorbent assay. Results: The relative expressions of NF-κB p65 protein in genioglossus in the control group, OSAHS group and MAD group were 0.24±0.07, 0.44±0.08 and 0.30±0.09, respectively. The mass concentrations of TNF-α in genioglossus in the control group, OSAHS group and MAD group were (0.065±0.020), (0.097±0.018) and (0.071±0.020) μg/L, respectively. The mass concentrations of IL-6 in genioglossus in the control group, OSAHS group and MAD group were (0.063±0.013), (0.093±0.017), and (0.069±0.014) μg/L, respectively. For the above indicators, the data in OSAHS group were all significantly higher than that in MAD group and the control group (P<0.05). No significant difference was found between MAD group and the control group (P>0.05). Conclusions: Treatment of OSAHS with MAD decreased the mass concentration of TNF-α and IL-6 leading to fatigue of genioglossus, reduced the activation of NF-κB and played a significant role in protecting genioglossus.

The importance of obstructive sleep apnoea and hypopnea pathophysiology for customized therapy

The objective of this study is to highlight the importance of anatomical and not-anatomical factors' identification for customized therapy in OSAHS patients. The data sources are: MEDLINE, The Cochrane Library and EMBASE. A systematic review was performed to identify studies that analyze the role of multiple interacting factors involved in the OSAHS pathophysiology. 85 out of 1242 abstracts were selected for full-text review. A variable combinations pathophysiological factors contribute to realize differentiated OSAHS phenotypes: a small pharyngeal airway with a low resistance to collapse (increased critical closing pressure), an inadequate responses of pharyngeal dilator muscles (wakefulness drive to breathe), an unstable ventilator responsiveness to hypercapnia (high loop gain), and an increased propensity to wake related to upper airway obstruction (low arousal threshold). Identifying if the anatomical or not-anatomical factors are predominant in each OSAHS patient represents the current challenge in clinical practice, moreover for the treatment decision-making. In the future, if a reliable and accurate pathophysiological pattern for each OSAHS patient can be identified, a customized therapy will be feasible, with a significant improvement of surgical success in sleep surgery and a better understanding of surgical failure.