Untreated Obstructive Sleep Apnea Is Associated With Myocardial Injury Independent of Blood Pressure Control in Hypertension

Advanced Oxidation Protein Products in Obstructive Sleep Apnea Hypopnea Syndrome-A Systematic Review and Meta-Analysis

BACKGROUND

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a prevalent sleep-breathing disorder affecting both adults and children. Although previous studies have suggested a potential association between OSAHS and oxidative stress biomarkers, particularly advanced oxidation protein products (AOPP), their conclusive relationship remains unclear. This systematic review and meta-analysis aims to quantitatively synthesise existing evidence on the association between AOPP levels and OSAHS.

METHODS

We comprehensively searched PubMed, Wiley Online Library, Cochrane Library, CBM, and CNKI databases up to October 2023. Two independent researchers screened studies investigating AOPP-OSAHS correlations, followed by data extraction and quality assessment. Statistical analyses were performed using Stata, with standardised mean differences (SMDs) calculated for pooled estimates.

RESULTS

Nine studies comprising 608 patients and 770 controls were included. The meta-analysis demonstrated significantly elevated AOPP concentrations in OSAHS patients compared to controls (SMD = 1.66 , 95% CI = 1.02-2.29; I2 = 96%, p < 0.001). Meta-regression identified significant associations between effect sizes and publication year (β = 0.32, p = 0.016) as well as BMI (β = 0.25, p = 0.028), independent of geographic region, sample type, or analytical methods. Secondary analyses of oxidative stress markers revealed consistent elevations in SOD and MDA levels among OSAHS patients, whereas GSH showed no significant difference.

CONCLUSION

The meta-analysis confirmed a substantial increase in AOPP concentration in OSAHS patients compared to the control group, suggesting that the protein oxidation marker AOPP plays a role in the development of OSAHS and offering valuable insights for future clinical research.

The impact of obstructive sleep apnoea on post-operative outcomes

BACKGROUND

Unrecognised obstructive sleep apnoea (OSA) has been associated with adverse cardiorespiratory perioperative outcomes. However, with changing anaesthetic and perioperative management, there is ongoing uncertainty about the importance of OSA as a risk factor for post-operative complications.

METHODS

A cohort study involving subjects undergoing elective surgery was conducted. OSA was diagnosed with a limited channel sleep monitor. In subjects undergoing routine perioperative care, complications were identified based on the assessment of the attending clinical team. The primary outcome was a composite end-point of cardiorespiratory outcomes comprising myocardial infarction, atrial fibrillation, other arrhythmias, bradycardia, need for inotropic support, unplanned intensive care unit admission, pneumonia or respiratory failure.

RESULTS

Four hundred seventy-two subjects were recruited, with 356 being included in the analyses; 281 (79%) had OSA and 66 (19%) had severe OSA. Subjects with OSA did not have a significantly higher incidence of complications (5.7%) compared to those without (2.7%, adjusted relative risk 1.89 (0.23-15.67)). Additionally, complications were not increased in those with severe OSA.

CONCLUSIONS

Unrecognised OSA was not associated with an increase in clinically evident cardiorespiratory complications in this cohort. The lower complication rates compared with earlier studies suggest that increased use of less invasive surgical techniques, improved pain management and increased awareness of OSA have had an impact in reducing postoperative complications in this group. Further research is needed to clarify the impact of severe OSA on post-operative outcomes in different surgical cohorts with varying risk profiles in order to develop optimal perioperative pathways.

The association between endothelial dysfunction and subclinical myocardial injury in male obstructive sleep apnoea patients

Background

Endothelial dysfunction was shown to contribute significantly to the elevated cardiovascular risk observed in the general population. However, the relationship between endothelial dysfunction and subclinical myocardial injury in obstructive sleep apnoea (OSA) patients remains unclear.

Methods

This cross-sectional study recruited 165 consecutive male patients diagnosed with OSA. All participants underwent overnight polysomnography to confirm the diagnosis and assess the severity of OSA. Subclinical myocardial injury was evaluated using high-sensitivity cardiac troponin I (hs-cTnI) measurements, while endothelial dysfunction was assessed through the peripheral arterial tonometry.

Results

Endothelial dysfunction was present in 80 (48.5%) of the subjects and hs-cTnI was detectable in 147 (89.1%) of the participants. When compared with OSA patients without endothelial dysfunction, those with endothelial dysfunction exhibited significantly lower percentages of hypertension (23.8% versus 43.5%, p=0.007) and abdominal obesity (76.3% versus 88.2%, p=0.043). Patients with endothelial dysfunction frequently manifest a lower apnoea-hypopnoea index and oxygen desaturation index. Despite comparable median hs-cTnI levels, a higher proportion of subjects with detectable hs-cTnI levels was observed among those with endothelial dysfunction (95% versus 83.5%, p=0.018). Logistic regression analysis indicated that endothelial dysfunction was significantly associated with a detectable level of hs-cTnI after adjustment for multiple confounders.

Conclusions

In male OSA patients, endothelial dysfunction appears to be potentially correlated with an increased risk of subclinical myocardial injury, as evidenced by the higher prevalence of detectable hs-cTnI levels. Further investigations are warranted to elucidate the role of endothelial dysfunction in predicting future cardiovascular mortality in this population.

Predictors and markers of the cardiovascular impact of obstructive sleep apnoea

PURPOSE OF REVIEW

Obstructive sleep apnoea (OSA) is the most common form of sleep-disordered breathing and has been linked to cardiovascular health. However, some of the findings supporting this are controversial. These discrepancies might be a result of heterogeneity among OSA patients, and thus, additional information would be required to better stratify OSA patients according to cardiovascular risk. In this review, we aim to discuss the potential of biomarkers to fulfil this role.

RECENT FINDINGS

Randomized controlled trials have been unable to confirm whether OSA treatment with continuous positive airway pressure (CPAP) has a positive effect on cardiovascular outcomes. Emerging physiology-based metrics of OSA seem to be more suitable for identifying patients at higher risk of cardiovascular disease and predicting the effects of CPAP outcomes on cardiovascular health. Similarly, blood-based molecular markers have gained attention in this context over the last few years.

SUMMARY

Accurate cardiovascular risk stratification and appropriate treatment allocation for OSA patients remain challenging. However, significant efforts are being made to develop novel tools to address these important issues.

Continuous positive airway pressure improves blood pressure and serum cardiovascular biomarkers in obstructive sleep apnoea and hypertension

RATIONALE

The impact of treatment for obstructive sleep apnoea (OSA) on reduction of cardiovascular risk is unclear. This study aimed to examine the effect of continuous positive airway pressure (CPAP) on ambulatory blood pressure (BP) and subclinical myocardial injury in subjects with OSA and hypertension.

METHODS

Subjects with hypertension requiring at least three anti-hypertensive medications and moderate-severe OSA were enrolled. Eligible subjects were randomized (1:1) to receive either CPAP treatment or control (no CPAP) for eight weeks. Changes in ambulatory BP and serum biomarkers were compared. Stratified analysis according to circadian BP pattern was performed.

MAIN RESULTS

Ninety two subjects (75% men; age, 51±8 years; apnoea-hypopnoea index 40±8 events·h^-1, taking average of 3.4 anti-hypertensive drugs [range 3-6]) were randomised. The group on CPAP treatment, compared to the control group, demonstrated significant reduction in 24-h systolic BP (-4.4 mmHg, 95% CI -8.7 to -0.1, p=0.046), 24-h diastolic BP (-2.9 mmHg, 95% CI -5.5 to -0.2, p=0.032), daytime systolic BP (-5.4 mmHg, -9.7 to -1.0, p=0.016) and daytime diastolic BP (-3.4 mmHg, 95% CI -6.1 to -0.8, p=0.012). CPAP treatment was associated with significant BP lowering only in non-dippers, but not in dippers. Serum troponin I (mean difference -1.74 pg·mL^-1, 95% CI -2.97 to -0.5, p=0.006) and brain natriuretic peptide (-9.1 pg·mL^-1, 95% CI -17.6 to -0.6, p=0.036) were significantly reduced in CPAP compared to control group.

CONCLUSION

In a cohort with OSA and multiple cardiovascular risk factors including difficult-to-control hypertension, short-term CPAP treatment improved ambulatory BP and alleviated subclinical myocardial injury and strain.

Evaluation of Surgical Learning Curve Effect on Obstructive Sleep Apnea Outcomes in Upper Airway Stimulation

OBJECTIVE

An increasing number of facilities offer Upper Airway Stimulation (UAS) with varying levels of experience. The goal was to quantify whether a surgical learning curve exists in operative or sleep outcomes in UAS.

METHODS

International multi-center retrospective review of the ADHERE registry, a prospective international multi-center study collecting UAS outcomes. ADHERE registry centers with at least 20 implants and outcomes data through at least 6-month follow-up were reviewed. Cases were divided into two groups based on implant order (the first 10 or second 10 consecutive implants at a given site). Group differences were assessed using Mann-Whitney U-tests, Chi-squared tests, or Fisher's Exact tests, as appropriate. A Mann-Kendall trend test was used to detect if there was a monotonic trend in operative time. Sleep outcome equivalence between experience groups was assessed using the two one-sided tests approach.

RESULTS

Thirteen facilities met inclusion criteria, contributing 260 patients. Complication rates did not significantly differ between groups (P = .808). Operative time exhibited a significant downward trend (P < .001), with the median operative time dropping from 150 minutes for the first 10 implants to 134 minutes for the subsequent 10 implants. The decrease in AHI from baseline to 12-month follow-up was equivalent between the first and second ten (22.8 vs 21.2 events/hour, respectively, P < .001). Similarly, the first and second ten groups had equivalent ESS decreases at 6 months (2.0 vs 2.0, respectively, P < .001). ESS outcomes remained equivalent for those with data through 12-months.

CONCLUSIONS

Across the centers' first 20 implants, an approximately 11% reduction operative time was identified, however, no learning curve effect was seen for 6-month or 12-month AHI or ESS over the first twenty implants. Ongoing monitoring through the ADHERE registry will help measure the impact of evolving provider and patient specific characteristics as the number of implant centers increases.

Obstructive Sleep Apnea and Cardiovascular Morbidities: A Review Article

In obstructive sleep apnea (OSA), there are brief episodes of partial or total upper airway obstruction during sleep, which leads to apnea or hypopneas. Much attention is required to understand OSA's effects on the human body, owing to how common but under-diagnosed this disorder remains. Though the role of OSA in cardiovascular (CV) disease is commonly discussed, it remains unclear how it induces changes in the human body. The intermittent and recurrent hypoxia occurring at the cellular level in this condition is critical for the dramatic changes observed. Vascular endothelial cell (VEC) injury and other mechanisms seen in OSA lead to changes in the CV system. OSA can take a toll on a person's overall functioning, especially with so much importance in today's time on preventing and treating cardiac-related deaths. A total of 31 published articles were included from the PubMed database for our literature review. Most of the studies showed a strong association of OSA with hypertension, especially resistant hypertension. Findings were consistent with OSA's independent role in causing CV diseases, included heart failure, coronary artery disease (cardiac ischemia), arrhythmias, and ischemic stroke. Continuous Positive Airway Pressure (CPAP) is one of the reliable and beneficial treatments for OSA patients. OSA is a treatable and modifiable risk factor for cardiac events and related deaths. The primary purpose of our review article was to address any existing gaps between OSA and its effect on the human body with particular emphasis on cardiovascular changes.