Obstructive sleep apnea risk and subclinical atherosclerosis in South Asians living in the United States

Racial and ethnic influences on carotid atherosclerosis: Epidemiology and risk factors

Carotid atherosclerosis-related stenosis, marked by atherosclerotic plaque formation in the carotid artery, significantly increases ischemic stroke risk. Its prevalence varies across ethnic groups, reflecting racial disparities. Epidemiological studies have highlighted different susceptibilities to carotid stenosis among racial groups. Native Americans and Whites show greater vulnerability, indicating genetic and environmental influences. The impact of carotid stenosis is more severe in Hispanic and Black populations, with a higher incidence of related brain injuries, underscoring the need for targeted interventions. Comparative imaging studies between Chinese and White individuals reveal unique patterns of carotid stenosis, enhancing understanding of its pathophysiology and management across ethnicities. This review also categorizes risk factors, distinguishing those with racial disparity (such as genetic loci, sleep apnea, and emotional factors, socioeconomic status) from those without. In summary, racial disparities affect carotid stenosis, leading to varying susceptibilities and outcomes among ethnic groups. Recognizing these differences is essential for developing effective prevention, diagnosis, and management strategies. Addressing these disparities is critical to reducing ischemic stroke's burden across populations. Continued research and targeted interventions are crucial to improve outcomes for individuals at risk of carotid stenosis and its complications.

Circadian rhythms of risk factors and management in atherosclerotic and hypertensive vascular disease: Modern chronobiological perspectives of an ancient disease

Atherosclerosis, a chronic inflammatory disease of the arteries that appears to have been as prevalent in ancient as in modern civilizations, is predisposing to life-threatening and life-ending cardiac and vascular complications, such as myocardial and cerebral infarctions. The pathogenesis of atherosclerosis involves intima plaque buildup caused by vascular endothelial dysfunction, cholesterol deposition, smooth muscle proliferation, inflammatory cell infiltration and connective tissue accumulation. Hypertension is an independent and controllable risk factor for atherosclerotic cardiovascular disease (CVD). Conversely, atherosclerosis hardens the arterial wall and raises arterial blood pressure. Many CVD patients experience both atherosclerosis and hypertension and are prescribed medications to concurrently mitigate the two disease conditions. A substantial number of publications document that many pathophysiological changes caused by atherosclerosis and hypertension occur in a manner dependent upon circadian clocks or clock gene products. This article reviews progress in the research of circadian regulation of vascular cell function, inflammation, hemostasis and atherothrombosis. In particular, it delineates the relationship of circadian organization with signal transduction and activation of the renin-angiotensin-aldosterone system as well as disturbance of the sleep/wake circadian rhythm, as exemplified by shift work, metabolic syndromes and obstructive sleep apnea (OSA), as promoters and mechanisms of atherogenesis and risk for non-fatal and fatal CVD outcomes. This article additionally updates advances in the clinical management of key biological processes of atherosclerosis to optimally achieve suppression of atherogenesis through chronotherapeutic control of atherogenic/hypertensive pathological sequelae.

Leading Predictors of COVID-19-Related Poor Mental Health in Adult Asian Indians: An Application of Extreme Gradient Boosting and Shapley Additive Explanations

During the COVID-19 pandemic, an increase in poor mental health among Asian Indians was observed in the United States. However, the leading predictors of poor mental health during the COVID-19 pandemic in Asian Indians remained unknown. A cross-sectional online survey was administered to self-identified Asian Indians aged 18 and older (N = 289). Survey collected information on demographic and socio-economic characteristics and the COVID-19 burden. Two novel machine learning techniques-eXtreme Gradient Boosting and Shapley Additive exPlanations (SHAP) were used to identify the leading predictors and explain their associations with poor mental health. A majority of the study participants were female (65.1%), below 50 years of age (73.3%), and had income ≥ $75,000 (81.0%). The six leading predictors of poor mental health among Asian Indians were sleep disturbance, age, general health, income, wearing a mask, and self-reported discrimination. SHAP plots indicated that higher age, wearing a mask, and maintaining social distancing all the time were negatively associated with poor mental health while having sleep disturbance and imputed income levels were positively associated with poor mental health. The model performance metrics indicated high accuracy (0.77), precision (0.78), F1 score (0.77), recall (0.77), and AUROC (0.87). Nearly one in two adults reported poor mental health, and one in five reported sleep disturbance. Findings from our study suggest a paradoxical relationship between income and poor mental health; further studies are needed to confirm our study findings. Sleep disturbance and perceived discrimination can be targeted through tailored intervention to reduce the risk of poor mental health in Asian Indians.

Cardiovascular diseases and sleep disorders in South Asians: A scoping review

BACKGROUND

South Asians comprise 20% of the world population. There is a high prevalence of cardiovascular diseases among South Asians, and sleep disorders may be a key risk factor.

OBJECTIVE

The review examined literature about cardiovascular and sleep disorders in South Asian countries and in the United States, United Kingdom, Canada, and the Netherlands.

METHODS

Methods from Arksey and O'Malley's framework and Peter et al. were used to synthesize findings from 23 research studies.

RESULTS

The studies addressed sleep disorders with hypertension, heart failure, diabetes, and obesity. Obstructive sleep apnea and short sleep duration were common and associated with cardiovascular morbidity and mortality at early ages in South Asians. Researchers analyzed polysomnography-derived sleep measures, vascular functions, polymorphisms, C-reactive protein levels, public knowledge about cardiovascular health, and sleep-related questionnaire scores. Most studies were conducted in major metropolitan areas; no data were available about people living in locations with limited health care resources. Among migrant South Asians, researchers did not explore the role of acculturation on sleep patterns and cardiovascular outcomes.

CONCLUSIONS

The review highlights important considerations for researchers who plan to investigate cardiovascular conditions in South Asian communities. There is a need for more knowledge about sleep-related risk factors, and researchers should also examine cultural, political, and socioeconomic factors that affect health care access. This knowledge will be imperative for designing effective and tailored disease prevention strategies for South Asian populations.

Angiopoietin-like proteins 8 knockout reduces intermittent hypoxia-induced vascular remodeling in a murine model of obstructive sleep apnea

OBJECTIVE

Obstructive sleep apnea (OSA) is a major risk factor for cardiovascular mortality. Apnea-induced chronic intermittent hypoxia (CIH) is a primary pathophysiological manifestation of OSA that promotes various cardiovascular alterations, such as aortic vascular remodeling. In this study, we investigated the association between angiopoietin-like proteins 8 (ANGPTL8) and CIH-induced aortic vascular remodeling in mice.

METHODS

C57BL/6J male mice were divided into four groups: Normoxia group, ANGPTL8^-/- group, CIH group, CIH + ANGPTL8^-/- group. Mice in the normoxia group and ANGPTL8^-/- group received no treatment, while mice in the CIH and CIH + ANGPTL8^-/- group were subjected to CIH (21%-5% O₂, 180 s/cycle, 10 h/day) for 6 weeks. At the end of the experiments, intima-media thickness (IMT), elastin disorganization, and aortic wall collagen abundance were assessed in vivo. Immunohistochemistry and Western-blot were used to detect endoplasmic reticulum stress (ERS) and aortic vascular smooth muscle cell proliferation. ANGPTL8 shRNA and ANGPL8 overexpression were used in aortic vascular smooth muscle cells to investigate the mechanism of ANGPTL8 in CIH.

RESULTS

Compared to the control group, CIH exposure significantly increased intima-media thickness (IMT), elastic fibers disorganization, and aortic wall collagen abundance. CIH also significantly increased blood pressure, induced hyperlipidemia, as well as the expression of ERS protein activating transcription factor-6 (ATF6) and aortic vascular smooth muscle cell proliferation. Contrary, ANGPTL8^-/- significantly mitigated the CIH-induced vascular remodeling; ANGPTL8^-/- decreased CIH-induced hypertension and hyperlipidemia, inhibited the protein expression of ATF6, and aortic vascular smooth muscle cell proliferation. Moreover, our in vitro study suggested that CIH could induce ANGPTL8 expression via hypoxia-inducible factor (HIF-1α); ANGPTL8 induced proliferation of aortic vascular smooth muscle cells via the ERS pathway.

CONCLUSION

ANGPTL8^-/- can prevent CIH-induced aortic vascular remodeling, probably through the inhibition of the ERS pathway. Therefore, ANGPTL8 might be a potential target in CIH-induced aortic vascular remodeling.

Snoring Sound Characteristics are Associated with Common Carotid Artery Profiles in Patients with Obstructive Sleep Apnea

BACKGROUND

Obstructive sleep apnea (OSA) and snoring have been reported to be modifiable risk factors for thick carotid intima-media thickness (CIMT) and carotid atherosclerosis, which are closely linked to cardiovascular disease.

METHODS

This cross-sectional study prospectively recruited 70 participants with OSA and without a history of carotid artery disorder, who primarily sought surgical Intervention. OSA and snoring were assessed with the Epworth Sleepiness Scale, Snore Outcomes Survey, polysomnography, and snoring sound recording. The carotid arteries were evaluated with ultrasonography and divided into three types of carotid artery profiles (normal carotid artery, thick CIMT, or significant carotid atherosclerosis). Multivariate linear/logistic/categorical regressions were performed with the forward selection approaches/logistic least absolute shrinkage and selection operator, as appropriate.

RESULTS

Normalized snoring sound energy (301-850 Hz) was independently associated with the carotid intima-media thickness (regression coefficient [β] = 0.01, standard error [SE] = 0.004, P = 0.03; R ² = 0.067) and type of carotid profile (β = 0.40, SE = 0.09, P < 0.001; R ² = 0.156). Normalized snoring sound energy (4-300 Hz) (β = -0.10, SE = 0.04, P = 0.01) and female sex (β = 1.90, SE = 0.94, P = 0.04) were independently related to the presence of carotid stenosis (R ² = 0.159). The optimal regression model of the type of carotid artery profile included normalized snoring sound energy (301-850 Hz) (β = 0.33, SE = 0.14, P = 0.03), snoring time (β = 0.26, SE = 0.13, P = 0.047), female sex (β = 0.26, SE = 0.13, P = 0.047), and increased age (β = 0.20, SE = 0.10, P = 0.04) under the control of the Snore Outcomes Survey score, 3% oxygen desaturation index, snoring sound energy (4-1500 Hz), normalized snoring sound energy (851-1500 Hz), cigarette smoking, and hyperlipidemia (R ² = 0.427).

CONCLUSION

Our findings suggested that snoring sound characteristics are associated with carotid artery profiles among early OSA patients who cannot be noticed by ultrasound because organic changes of the carotid artery have not yet started. Future studies are warranted to verify the clinical significance of the results.

Targeting subclinical organ damage in obstructive sleep apnea: a narrative review

Subclinical abnormalities in cardiac and vascular structure reflect the adverse effects triggered by a variety of risk factors on the cardiovascular (CV) system thereby representing an intermediate step in the cardiovascular continuum; such alterations are recognized as reliable markers of increased cardiovascular risk in different clinical settings including obstructive sleep apnea (OSA). The mechanisms underlying subclinical organ damage (OD) in the OSA setting are multifactorial. Hypoxemia and hypercapnia, induced by repeated collapses of upper airways, have been suggested to trigger a cascade of events such as activation of the sympathetic tone, renin-angiotensin-aldosterone system leading to endothelial dysfunction, vasoconstriction, myocardial and vascular remodeling, and hypertension. Furthermore, coexisting non-haemodynamic alterations such as increased oxidative stress, release of inflammatory substances, enhanced lipolysis and insulin resistance have been reported to play a role in the pathogenesis of both cardiac and extra-cardiac OD. In this article we reviewed available evidence on the association between OSA and subclinical cardiac (i.e., left and right ventricular hypertrophy, left atrial dilatation) and extra-cardiac organ damage (i.e., carotid atherosclerosis, arterial stiffness, microvascular retinal changes, and microalbuminuria). This association is apparently stronger for cardiac and carotid subclinical damage than for other markers (i.e., arterial stiffness and retinal changes) and mostly evident in the setting of severe OSA.