Obstructive sleep apnoea and inflammation in age-dependent cardiovascular disease

A mediation analysis of metabolic and inflammatory factors in the severe sleep apnea-coronary heart disease association

BACKGROUND

It is unclear whether metabolic and inflammatory factors mediate the association between severe sleep apnea and coronary heart disease (CHD) in observational studies based on the large-scale population. This study aims to assess the association between severe sleep apnea and CHD and to explore the extent to which this association is mediated by metabolic factors and C-reactive protein (CRP).

METHODS

In UK Biobank, 213 442 CHD-free (mean age: 55.00) adults were followed up for 15 years to detect incident CHD. Metabolic factors included hyperglycemia, hypertension, dyslipidemia, hypertriglyceridemia, and hyperuricemia. A higher CRP concentration level was defined as a cutoff point of >3.0 mg/l. Data were analyzed using Cox proportional hazards models and the generalized structural equation model.

RESULTS

During follow-up, 9278 participants developed incident CHD (4.3%). The multi-adjusted hazard ratio and 95% confidence interval of CHD related to severe sleep apnea were 1.76 (1.44-2.15). In the mediation analysis, the strongest indirect association was for dyslipidemia, accounting for 20.8% of the association between severe sleep apnea and CHD (β = 0.22, 95% confidence interval = 0.16-0.28), followed by hypertriglyceridemia (12.3%). The proportion of mediation increased to 29.1% when CRP was added to the metabolic mediators.

CONCLUSIONS

Severe sleep apnea was associated with an increased risk of CHD. Lipid factors might play an essential role in the severe sleep apnea-CHD relationship. CRP increased the magnitude of mediation effects of overall metabolic factors. What is already known on this topic It is unknown whether the association between severe sleep apnea and CHD among the large population-based cohort study. Evidence on the mediating effect of metabolic and inflammatory factors in the severe sleep apnea-CHD association remains unclear. What this study adds Lipid factors were the biggest mediation driver in the severe sleep apnea-CHD path. C-reactive protein increased the magnitude of mediation effects of overall metabolic factors. How this study might affect research, practice or policy Investigating mediation analyses not only enhances comprehension of the pathophysiological connection between severe sleep apnea and CHD but also offers valuable insights into preventing CHD.

The neutrophil-to-lymphocyte ratio is a potential biomarker for the occurrence of atrial fibrillation in patients with obstructive sleep apnea: A BIOMARKER OF AF IN OSA PATIENTS

BACKGROUND

Obstructive sleep apnea (OSA) affects the occurrence of atrial fibrillation (AF) and usually coexists with AF. Chronic inflammation has been identified as an important factor in the development of AF, and the neutrophil-to-lymphocyte ratio (NLR) has been identified as a biomarker that positively correlates with the degree of inflammation. However, little information regarding how NLR correlates with AF in OSA patients.

METHODS

Our study enrolled 368 patients with OSA between September 2018 and April 2023. All data were collected after admission. Independently associated factors were assessed by multivariate logistic regression and then constructed a nomogram to predict AF risk. Nomogram's calculation model was evaluated using receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). The correlation between CHA2DS2-VASc scores and NLR was assessed using Spearman correlation.

RESULTS

Multivariate logistic regression showed that high level log-transformed NLR (OR, 1.664; 95% CI, 1.026-2.699; P = 0.039) was independently associated with the presence of AF in patients with OSA. The concordance index (0.817, 95% CI, 0.770-0.864), ROC curve, calibration curve, and DCA of the nomogram indicated this model had well clinical utility. Also, the nomogram's calculation model could identify patients who are at a higher risk of developing AF, and the CHA2DS2-VASc score was positively correlated with NLR in patients with AF (P < 0.05).

CONCLUSION

The elevated NLR may serve as a promising biomarker for assessing the risk of AF in individuals with OSA. The nomogram's calculation model may be utilized as a tool to estimate the probability of AF occurrence in OSA patients.

Obstructive Sleep Apnea and Cardiovascular Risk: The Role of Dyslipidemia, Inflammation, and Obesity

Introduction: The present study aimed to establish the role of lipid abnormalities and inflammatory markers for developing cardiovascular risk, as well as to address the importance of obesity as a common comorbidity in patients with obstructive sleep apnea (OSA).

Methods: The study was conducted as a prospective cohort study including 120 patients with newly diagnosed OSA between 2019 and 2020, at University Clinical Hospital Center “Bezanijska kosa”, Belgrade, Serbia. The diagnosis was established by polysomnography. In all patients, sociodemographic data, respiratory, lipid, and inflammatory parameters were collected and complete echocardiographic study and 24-h blood pressure monitoring were performed.

Results: The mean patient age was 55.7 ± 13.8 years. Study population was mostly male (70.0%) and obese (56.7%). At least 30 apneas or hypopneas per hour were present in 39.0% of patients. A strong positive correlation was found between OSA severity and BMI (r = 0.562, p < 0.001), both associated with lipid, inflammatory and respiratory parameters, and cardiovascular profile of patients with OSA (p < 0.05 for all). Echocardiographic study and 24-h blood pressure monitoring parameters were in turn correlated with lipid and inflammatory markers (p < 0.05 for all).

Conclusion: The results of this study support the important role of dyslipidemia and inflammation, as well as coexistence of obesity in the pathogenesis of numerous conditions linked with an increased risk of cardiovascular morbidity and mortality in patients with OSA.

The gut microbiome as a target for adjuvant therapy in obstructive sleep apnea

Introduction: Gut dysbiosis is assumed to play a role in obstructive sleep apnea (OSA)-associated morbidities. Pre- and probiotics, short chain fatty acids (SCFA) and fecal matter transplantation (FMT) may offer potential as novel therapeutic strategies that target this gut dysbiosis. As more mechanisms of OSA-induced dysbiosis are being elucidated, these novel approaches are being tested in preclinical and clinical development. Areas covered: We examined the evidence linking OSA to gut dysbiosis and discuss the effects of pre- and probiotics on associated cardiometabolic, neurobehavioral and gastrointestinal disorders. The therapeutic potential of SCFA and FMT are also discussed. We reviewed the National Center for Biotechnology Information database, including PubMed and PubMed Central between 2000 - 2020. Expert opinion: To date, there are no clinical trials and only limited evidence from animal studies describing the beneficial effects of pre- and probiotic supplementation on OSA-mediated dysbiosis. Thus, more work is necessary to assess whether prebiotics, probiotics and SCFA are promising future novel strategies for targeting OSA-mediated dysbiosis.