Association of upper airway surgery and improved cardiovascular biomarkers and risk in OSA

Obstructive sleep apnea hypopnea syndrome and vascular lesions: An update on what we currently know

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is the most prevalent sleep and respiratory disorder. This syndrome can induce severe cardiovascular and cerebrovascular complications, and intermittent hypoxia is a pivotal contributor to this damage. Vascular pathology is closely associated with the impairment of target organs, marking a focal point in current research. Vascular lesions are the fundamental pathophysiological basis of multiorgan ailments and indicate a shared pathogenic mechanism among common cardiovascular and cerebrovascular conditions, suggesting their importance as a public health concern. Increasing evidence shows a strong correlation between OSAHS and vascular lesions. Previous studies predominantly focused on the pathophysiological alterations in OSAHS itself, such as intermittent hypoxia and fragmented sleep, leading to vascular disruptions. This review aims to delve deeper into the vascular lesions affected by OSAHS by examining the microscopic pathophysiological mechanisms involved. Emphasis has been placed on examining how OSAHS induces vascular lesions through disruptions in the endothelial barrier, metabolic dysregulation, cellular phenotype alterations, neuroendocrine irregularities, programmed cell death, vascular inflammation, oxidative stress and epigenetic modifications. This review examines the epidemiology and associated risk factors for OSAHS and vascular diseases and subsequently describes the existing evidence on vascular lesions induced by OSAHS in the cardiovascular, cerebrovascular, retinal, renal and reproductive systems. A detailed account of the current research on the pathophysiological mechanisms mediating vascular lesions caused by OSAHS is provided, culminating in a discussion of research advancements in therapeutic modalities to mitigate OSAHS-related vascular lesions and the implications of these treatment strategies.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Homocysteine Levels in Severe OSA Patients Before and After TORS-OSA Surgery

OBJECTIVE

The increased risk of cardiovascular diseases owing to a high level of serum homocysteine has been widely reported. Literature has demonstrated that patients with obstructive sleep apnea/hypopnea syndrome (OSA) had a higher homocysteine level than control group. This study aimed to investigate the alteration of serum homocysteine levels in severe OSA patients receiving transoral robotic surgery (TORS).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic medical center.

METHODS

Data of polysomnography (PSG) and serum homocysteine levels before and at least 3 months after the surgery were collected and analyzed via paired t tests. A subgroup analysis based on the preoperative homocysteine level (≥15 mcmol/L, as hyperhomocysteinemia group) was conducted to compare the intergroup differences of homocysteine decrease. Pearson's correlation was used to survey the relationships between the changes of major PSG parameters and the levels of homocysteine decrease at baseline and after TORS-OSA surgery.

RESULTS

Two hundred sixty-one patients with severe OSA were enrolled. There were significant improvements in major PSG parameters after TORS-OSA surgery. Homocysteine levels significantly decreased from 12.1 ± 3.9 to 11.4 ± 3.7 mcmol/L (difference = -0.7 ± 2.8 mcmol/L, p = .001) postoperatively, which was shown in the hyperhomocysteinemia group (difference = -2.9 ± 4.7 mcmol/L, p = .007) to a greater extent. Pearson's correlation revealed that ΔODI (oxygen desaturation index/h) was the predominant estimate with a positive association with Δhomocysteine (r = 0.525, p = .012).

CONCLUSION

TORS-OSA surgery could decrease homocysteine levels in OSA patients. The effects were more relevant in severe OSA patients with abnormal preoperative homocysteine levels.

Long-term effects of obstructive sleep apnea and its treatment on open-angle glaucoma: a big-data cohort study

STUDY OBJECTIVES

The relationship between open-angle glaucoma (OAG) and obstructive sleep apnea (OSA) is unclear. The long-term risk for OAG after OSA diagnosis has not been investigated. Therefore, we assessed the risk for OAG among patients with OSA over a 12-year follow-up period using nationwide, population-based data.

METHODS

The OSA group was randomly selected from among 3.5 million individuals registered with the National Health Insurance Service. The non-OSA group was obtained through propensity score matching considering several variables. The primary endpoint was glaucoma diagnosis.

RESULTS

The OSA and non-OSA groups both included 6,369 individuals. The overall hazard ratio for OAG in the OSA group was 1.42 (95% confidence interval [CI]: 1.19-1.69). In subgroup analysis, the hazard ratio for OAG was 1.94 (95% CI: 1.57-2.41) for those aged > 60 years, 1.50 (95% CI: 1.20-1.89) for those with diabetes mellitus, 1.53 (95% CI: 1.26-1.86) for those with hypertension, and 0.71 (95% CI: 0.52-0.96) for those with a history of OSA surgery.

CONCLUSIONS

Over the 12-year follow-up, the risk for OAG increased after OSA diagnosis. Further research will be necessary to determine if treating OSA can mitigate this association.

CITATION

Lee T-E, Kim JS, Yeom SW, Lee MG, Lee JH, Lee H-J. Long-term effects of obstructive sleep apnea and its treatment on open-angle glaucoma: a big-data cohort study. J Clin Sleep Med. 2023;19(2):339-346.

Association between mean platelet volume and obstructive sleep apnea-hypopnea syndrome in children

To evaluate the correlation between mean platelet volume (MPV) and obstructive sleep apnea-hypopnea syndrome (OSAHS) in children, and to explore the diagnostic value of MPV for OSAHS. Children with OSAHS diagnosed by polysomnography (PSG) at Fuyong People's Hospital of Bao'an District/Shenzhen Children's Hospital from January 2020 to January 2021 were enrolled in this study. MPV in peripheral venous blood of the enrolled children was detected. Based on the PSG results (apnea-hypopnea index [AHI] and lowest oxygen saturation [LSaO2]), illness severity was classified, and correlations between the 2 parameters were statistically analyzed. A total of 190 children (males = 135, females = 55) with OSAHS were enrolled in the study. There were no significant correlations between AHI, LSaO2, white blood cell count, red blood cell count, blood platelets, hemoglobin, and packed cell volume (P > .05), but there was a significant positive correlation between AHI and MPV (R > 0, P < .05). There was a significant negative correlation between the LSaO2 index and MPV (R > 0, P < .05). In addition, the receiver operating characteristic (ROC) curve indicated that the best cutoff value for MPV to diagnose mild and moderate-to-severe disease conditions was 9.35 fl, and the coincidence rates for these 2 disease conditions were 93% and 80%, respectively. The ROC curve was also optimal for the diagnosis of mild and moderate-to-severe hypoxia. The critical value was 8.85 fl, and the coincidence rates for these 2 conditions were 96.4% and 76.3%, respectively. In children with OSAHS, MPV is positively correlated with AHI and negatively correlated with the LSaO2 index of PSG. Based on the results of ROC curve analysis, MPV can be used as an auxiliary diagnostic index to judge the severity of OSAHS and the degree of hypoxia in children.

Impact of the COVID-19 pandemic on obstructive sleep apnea: recommendations for symptom management

STUDY OBJECTIVES

In the context of the current COVID-19 pandemic situation, we address the following important questions: (1) How can patients be identified for possible OSA while sleep clinic testing is temporarily unavailable or limited? and (2) What measures can be suggested to improve sleep health until proper diagnosis and treatment become safe and available again?

METHODS

As a proxy for home or in-laboratory testing, validation of a symptom-based measure of OSA risk is presented, based on an ongoing larger prospective study of 156 family medicine patients with OSA (88 women, 68 men; mean age, 57 years) and 60 control participants (36 women, 24 men; mean age, 54 years) recruited from the community. Participants completed the Sleep Symptom Checklist (SSC) and a range of other self-report measures; primary care patients also underwent a polysomnographic sleep study.

RESULTS

Results showed that (1) individuals with OSA reported more symptoms on the SSC related to insomnia, daytime symptoms, sleep disorders, and psychological maladjustment than did the control group (all P < .001), and (2) their sleep-related symptoms were significantly more severe than those of the control patients. In addition, several polysomnographic indices in recently diagnosed untreated individuals with OSA were significantly correlated with SSC measured sleep disorder symptoms, and SSC scores significantly distinguished participants with OSA from control participants.

CONCLUSIONS

Our findings suggest that family practitioners can effectively prescreen patients for possible OSA by inquiring about 5 items that form the SSC sleep disorders subscale. If OSA is suspected, then we can recommend a range of behavioral techniques to improve symptoms. The current pandemic causes us to reflect that the provisional targeting of symptoms and guidance regarding mitigation strategies while waiting for specialist care could serve patients well at any time.

Bariatric surgery may provide better protection than uvulopalatopharyngoplasty against major adverse cardiovascular events in obese patients with obstructive sleep apnea

BACKGROUND

The major adverse cardiovascular events (MACE) risk is unclear among Asian obese patients with obstructive sleep apnea (OSA) who undergo bariatric surgery (BS) or uvulopalatopharyngoplasty (UPPP).

OBJECTIVES

We aimed to evaluate differences between Asian obese patients with OSA who underwent BS or UPPP regarding MACE.

SETTING

The Longitudinal Health Insurance Database, a subset of the NHI Research Database (NHIRD) originated from the National Health Insurance (NHI) program in Taiwan, which comprises information from 2 million randomly sampled individuals between 2000 and 2015.

METHODS

Participants aged 18-55 years whose diagnoses corresponded with codes in the International Classification of Diseases, Ninth Revision, Clinical Modification for BS, UPPP, obesity, and OSA were included in this population-based, matched cohort study of Taiwan's insurance claims data gathered between 2000 and 2015. Obese patients with OSA who underwent BS or UPPP were propensity score matched; the study's outcome was MACE.

RESULTS

A total of 1336 patients, comprising 668 in each of the BS and UPPP cohorts, were enrolled. After a mean follow-up period of 8.51 years, 166 patients, comprising 52 in the BS cohort and 114 in the UPPP cohort, experienced MACE. The adjusted hazard ratio (aHR) for MACE was .592 (95% confidence interval [CI] = .324-.789; P < .001). The BS cohort had lower risks of stroke (aHR = .663; 95% CI = .312-.890; P < .001), myocardial infarction (aHR = .116; 95% CI = .052-.135; P < .001), and mortality (aHR = .779; 95% CI = .423-.948; P = .001) than the UPPP cohort.

CONCLUSION

BS may provide greater protection against MACE than UPPP in Asian obese patients with OSA. Additional mechanistic research is needed to clarify differences between BS and UPPP in these patients.

Association between Upper-airway Surgery and Ameliorative Risk Markers of Endothelial Function in Obstructive Sleep Apnea

The objective of our study was to evaluate the effects of upper-airway surgery on improvement of endothelial function-related markers in patients with obstructive sleep apnea (OSA). Subjects with moderate to severe OSA who underwent upper-airway surgery, with a follow-up duration of at least 6 months, were included. Pre- and postoperative polysomnographic variables and endothelial function-related markers were compared. Subgroup and correlation analyses were conducted to find possible indicators for better endothelial function-related markers after upper-airway surgery. In total, 44 patients with OSA were included. The mean follow-up duration was 1.72 ± 0.92 years. Serum VEGFA [-20.29 (CI: -35.27, -5.31), p < 0.05], Ang2 [-0.06 (CI: -0.16, 0.03), p < 0.05], E-selectin [-7.21 (CI: -11.01, -3.41), p < 0.001], VWF [-58.83 (CI: -103.93, -13.73), p < 0.05], VWFCP [-33.52 (CI: -66.34, -0.70), p < 0.05], and TM [-0.06 (CI: -0.09, -0.03), p < 0.05] were significantly lower after upper-airway surgery. However, other risk markers of endothelial function, such as Ang1, ICAM1, VEGFR1, and VCAM, did not change significantly. Correlations between improved endothelial function-related markers and ameliorated oxyhemoglobin saturation and glucolipid metabolism were established. Upper-airway surgery might be associated with an improvement in endothelial function in patients with OSA. These changes may be associated with improved oxygen saturation after upper-airway surgery.