A review of the association between oral bacterial flora and obstructive sleep apnea-hypopnea syndrome comorbid with cardiovascular disease

Associations between sleep parameters and falls among older adults with and without cardiovascular disease: Evidence from the China Health and Retirement Longitudinal Study (CHARLS)

AIM

Falls are a major global public health concern, requiring early screening and prevention. Cardiovascular disease (CVD) is associated with physical impairments and increased fall risk. Despite the link between CVD and sleep parameters, research on falls and sleep in CVD patients is limited. We aimed to compare the correlation between falls and sleep in populations with and without CVD to develop fall prevention strategies.

METHODS

This longitudinal cohort study utilized data from the China Health and Retirement Longitudinal Study (CHARLS). Baseline data were collected in 2011, with follow-up in 2015. Falls and CVD were assessed based on self-reporting. Sleep parameters, including nighttime and total sleep duration, daytime napping, and sleep disturbance were collected via self-reported questionnaires. Data analysis was conducted using SPSS and R statistical.

RESULTS

A cohort of 4349 individuals with an average age of 68.00 ± 5.97 years was analyzed. From these individuals, 21.5% reported falls during follow-up. Baseline CVD was significantly associated with follow-up falls (P < 0.001). After adjusting for multiple factors, nighttime sleep durations of <6 h (P = 0.004), 8 to 9 h (P = 0.016) and >9 h (P = 0.031) were significantly associated with follow-up falls among the CVD group. Total sleep duration <7 h was significantly associated with follow-up falls in both the total and non-CVD groups (P < 0.05).

CONCLUSIONS

Maintaining a moderate sleep duration is crucial for preventing falls among older adults. Both excessively short and long sleep durations are associated with fall risks, particularly for individuals with CVD. Geriatr Gerontol Int 2025; 25: 38-47.

Sleep disorders as independent predictors of taste dysfunction risk

OBJECTIVES

This study aimed to investigate the association between sleep disorders and the prevalence of taste dysfunction and the mediation effect of oral microbe in adults over 40 years.

MATERIALS AND METHODS

Cross-sectional data were utilized from the National Health and Nutrition Examination Survey (2011-2014). Regression models were employed, adjusting for demographic variables and covariates. Subgroup analyses were conducted based on age, sex, ethnicity, and education level. Multiplicative interactions were assessed through likelihood ratio tests. Additionally, the impact of sleep disturbance on the alpha diversity of the oral microbiome was examined using the rank-sum test (significance threshold: p < 0.05). Mediation analysis based on oral microbiota was conducted.

RESULTS

The analysis included 4869 participants. After adjusting for adjusting for demographic variables and covariates, individuals with sleep disorders exhibited a 36% increased risk of taste dysfunctions compared to those without sleep disorders (OR: 1.36, 95% CI: 1.00-1.84, p = 0.05). Interaction analyses indicated no significant differences between sleep disorders and taste dysfunctions concerning sex, educational level, and age across various models (Crude Model, Model 1, Model 2, and Model 3; p for interaction > 0.05). Furthermore, compared with the non-sleep disorder group, patients with sleep disorders demonstrated decreased numbers of OTUs, Shannon-Wiener indices, and Faith's phylogenetic diversity indices in the oral microbiota (p < 0.05). However, the mediation analysis failed to reveal an indirect effect of oral microbiome on taste dysfunction (p > 0.05.) CONCLUSION: Sleep disorders independently correlate with a higher risk of taste dysfunctions, potentially associated with alterations in oral flora.

The effect of unhealthy lifestyle on the pathogenesis of sick sinus syndrome: A life-guiding review

Sick sinus syndrome (SSS), also known as sinoatrial node dysfunction, has been widely concerned by the medical community. The incidence rate of SSS is increasingly, which poses a great threat to public health. Through decades of repeated research in the medical field, great progress has been made in the pathogenesis of SSS and the interaction mechanism between SSS and other cardiovascular diseases. In this paper, we pay special attention to the mental stimulation factors under various pressures such as society and work, and the influence of smoking, drinking, and unhealthy diet on the pathogenesis of SSS. It also explains the mechanism of negative factors in the pathogenesis of SSS. These unhealthy lifestyle will lead to the occurrence of sinoatrial node disease and arrhythmia, and then induce SSS. Therefore, in the premise of increasing incidence rate of SSS and difficult to cure, how to avoid these harmful factors and ensure a healthy lifestyle is extremely important for preventing and treating SSS. This study also has guiding significance for the daily life of high-risk population of SSS and reducing the mortality of SSS patients.

Changes in the oral and nasal microbiota in pediatric obstructive sleep apnea

Background

Several clinical studies have demonstrated that pediatric obstructive sleep apnea (OSA) is associated with dysbiosis of airway mucosal microbiota. However, how oral and nasal microbial diversity, composition, and structure are altered in pediatric OSA has not been systemically explored.

Methods

30 polysomnography-confirmed OSA patients with adenoid hypertrophy, and 30 controls who did not have adenoid hypertrophy, were enrolled. Swabs from four surface oral tissue sites (tongue base, soft palate, both palatine tonsils, and adenoid) and one nasal swab from both anterior nares were collected. The 16S ribosomal RNA (rRNA) V3-V4 region was sequenced to identify the microbial communities.

Results

The beta diversity and microbial profiles were significantly different between pediatric OSA patients and controls at the five upper airway sites. The abundances of Haemophilus, Fusobacterium, and Porphyromonas were higher at adenoid and tonsils sites of pediatric patients with OSA. Functional analysis revealed that the differential pathway between the pediatric OSA patients and controls involved glycerophospholipids and amino acid metabolism.

Conclusions

In this study, the oral and nasal microbiome of pediatric OSA patients exhibited certain differences in composition compared with the controls. However, the microbiota data could be useful as a reference for studies on the upper airway microbiome.

Relationship between untreated obstructive sleep apnea and breath hydrogen and methane after glucose load

BACKGROUND

Patients with sleep disturbances have gastrointestinal symptoms. Breath hydrogen (H₂) and methane (CH₄) indicating small intestinal bacterial overgrowth (SIBO) might be related with these symptoms. The study was conducted to assess the link between breath profiles and untreated obstructive sleep apnea (OSA).

METHODS

: This prospective study enrolled consecutive patients with OSA using polysomnography. Heart rate variability (HRV) was used as a measurement for the balance of autonomic nervous system during polysomnography. Glucose breath test (GBT) to evaluate breath H₂ and CH₄ and bowel symptom questionnaire to investigate associated intestinal symptoms were performed.

RESULTS

Among 52 patients with OSA, 16 (30.8%) showed positivity to GBT. Although no significant difference was shown in GBT positivity between patients with healthy controls and patients with OSA (13.3% vs 30.8%, P = 0.109), breath H₂ and CH₄ levels in the OSA group were significantly higher than those in controls (P < 0.05). Flatulence was significantly common in OSA groups with GBT positivity than those without GBT positivity. Multivariate analysis demonstrated that waist-to-hip ratio (odds ratio = 12.889; 95% confidence interval (CI): 1.257-132.200; P = 0.031) and low-to-high-frequency ratio of HRV (odds ratio = 1.476; 95% CI: 1.013-2.151, P = 0.042) are independently related to GBT positivity in patients with OSA.

CONCLUSION

: Elevated breath H₂ or CH₄ after glucose load might not be an uncommon finding in patients with untreated OSA. Abdominal obesity and autonomic imbalance dysfunction are significantly associated with GBT positivity in OSA patients. SIBO could be considered as target for therapeutic management in OSA patients.

Altered Salivary Microbiota in Patients with Obstructive Sleep Apnea Comorbid Hypertension

PURPOSE

Microorganisms contribute to the pathogenesis of obstructive sleep apnea (OSA)-associated hypertension (HTN), while more studies focus on intestinal microbiome. However, the relationship between oral microbiota and OSA-associated HTN has yet to be elucidated. This study aimed to identify differences in salivary microbiota between patients with OSA comorbid HTN compared with OSA patients, and furthermore evaluate the relationship between oral microbiome changes and increased blood pressure in patients with OSA.

PATIENTS AND METHODS

This study collected salivary samples from 103 participants, including 27 healthy controls, 27 patients with OSA, 23 patients with HTN, and 26 patients with OSA comorbid HTN, to explore alterations of the oral microbiome using 16S rRNA gene V3-V4 high-throughput sequencing. And ultra-high-performance liquid chromatography was used for metabolomic analysis.

RESULTS

Alpha- and beta-diversity analyses revealed a substantial difference in community structure and diversity in patients with OSA comorbid HTN compared with patients with OSA or HTN. The relative abundance of the genus Actinomyces was significantly decreased in patients with HTN compared with healthy controls, and those with OSA concomitant HTN compared with the patients in OSA, but was not significantly different between patients with OSA and healthy controls. Linear discriminant analysis effect size and variance analysis also indicated that the genera Haemophilus, Neisseria, and Lautropia were enriched in HTN. In addition, Oribacterium was an unique taxa in the OSA comorbid HTN group compared with the control group. Metabolomic analysis of saliva identified compounds associated with cardiovascular disease in patients with OSA comorbid HTN.2-hydroxyadenine, was significantly increased in the group of patients with OSA compared with controls, and L-carnitine was significantly decreased in patients with OSA comorbid HTN compared with OSA patients.

CONCLUSION

This study highlighted noninvasive biomarkers for patients with OSA comorbid HTN. As the first study to find alterations of the salivary microbiome in patients with OSA comorbid HTN, it may provide a theoretical foundation for clinical diagnosis and treatment of this condition.

Blockade of adenosine A2A receptor alleviates cognitive dysfunction after chronic exposure to intermittent hypoxia in mice

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is widely known for its multiple systems damage, especially neurocognitive deficits in children. Since their discovery, adenosine A_2A receptors (A_2ARs) have been considered as key elements in signaling pathways mediating neurodegenerative diseases such as Huntington's and Alzheimer's, as well as cognitive function regulation. Herein, we investigated A_2AR role in cognitive impairment induced by chronic intermittent hypoxia (CIH). Mice were exposed to CIH 7 h every day for 4 weeks, and intraperitoneally injected with A_2AR agonist CGS21680 or A_2AR antagonist SCH58261 half an hour before IH exposure daily. The 8-arm radial arm maze was utilized to assess spatial memory after CIH exposures.To validate findings using pharmacology, the impact of intermittent hypoxia was investigated in A_2AR knockout mice. CIH-induced memory dysfunction was manifested by increased error rates in the radial arm maze test. The behavioral changes were associated with hippocampal pathology, neuronal apoptosis, and synaptic plasticity impairment. The stimulation of adenosine A_2AR exacerbated memory impairment with more serious neuropathological damage, attenuated long-term potentiation (LTP), syntaxin down-regulation, and increased BDNF protein. Moreover, apoptosis-promoting protein cleaved caspase-3 was upregulated while anti-apoptotic protein Bcl-2 was downregulated. Consistent with these findings, A_2AR inhibition with SCH58261 and A_2AR deletion exhibited the opposite result. Overall, these findings suggest that A_2AR plays a critical role in CIH-induced impairment of learning and memory by accelerating hippocampal neuronal apoptosis and reducing synaptic plasticity. Blockade of adenosine A_2A receptor alleviates cognitive dysfunction after chronic exposure to intermittent hypoxia in mice.

Alterations of oral microbiota in patients with obstructive sleep apnea-hypopnea syndrome treated with continuous positive airway pressure: a pilot study

PURPOSE

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is an independent risk factor for cardiovascular diseases, including hypertension. In our previous study, it was demonstrated that oral microbiota alteration in patients with OSAHS, particularly in the genera Aggregatibacter and Porphyromonas, may influence the development of hypertension. Continuous positive airway pressure (CPAP) is the main therapy for OSAHS and OSAHS-associated hypertension. However, the role of oral microbiota post CPAP treatment remains unknown.

METHODS

We conducted 16S rDNA pyrosequencing and bioinformatic analyses to compare the bacterial composition of oral specimens from patients with OSAHS before and after overnight CPAP treatment.

RESULTS

This approach enabled a relatively comprehensive description of oral microbiota, with decreases in Gemella and increases in Staphylococcus, f_Lachnospiraceae, Parabacteroides, and f_Ruminococcaceae after CPAP treatment.

CONCLUSION

Alteration of oral microbiota may shed new insight on the underlying pathogenesis of OSAHS-associated hypertension.