Sleep-disordered breathing and hypertension among African Americans

Ethical and Policy Implications of Racial and Ethnic Healthcare Disparities in Sleep Health

Despite efforts in recent years, including in policy and research, to address health disparities in the United States, many of those disparities continue to fester in marginalized racial/ethnic populations. Understanding sleep health disparities is critical in understanding the health and wellness of these groups. Using obstructive sleep apnea (OSA) in Black populations as a focus, this paper presents the role of race and ethnicity in the clinical understanding of sleep health-related issues by medical practitioners and the implications of the lack of clear policies or best practices to guide medical practitioners' attempts to meet sleep-related needs of marginalized racial/ethnic populations. Furthermore, the knowledge gap may be further complicated by the poor understanding and integration of existing evidence with the many, complex, sleep-associated co-morbidities. Policymaking in this area ought to be based on the ethical implications of disparate sleep-related health outcomes by race and ethnicity. So, we conclude by offering recommendations for developing ethically sound policies for addressing sleep problems in marginalized racial and ethnic populations.

Association of obstructive sleep apnea with microvascular endothelial dysfunction and subclinical coronary artery disease in a community-based population

Studies have reported an association between obstructive sleep apnea (OSA) and cardiovascular disease (CVD) morbidity and mortality. Proposed mechanisms include endothelial dysfunction and atherosclerosis. We aimed to investigate the associations of OSA with endothelial dysfunction and subclinical atherosclerotic coronary artery disease (CAD), and assess the impact of race on these associations. We used data from the Heart Strategies Concentrating on Risk Evaluation (Heart SCORE) study, a community-based prospective cohort with approximately equal representation of black and white participants. OSA severity was measured in 765 individuals using the apnea-hypopnea index (AHI). Endothelial dysfunction was measured using the Endo-PAT device, expressed as Framingham reactive hyperemia index (F_RHI). Coronary artery calcium (CAC), a marker of subclinical CAD, was quantified by electron beam computed tomography. There were 498 (65%) female participants, 282 (37%) black individuals, and 204 (26%) participants with moderate/severe OSA (AHI ≥15). In univariate models, moderate/severe OSA was associated with lower F_RHI and higher CAC, as well as several traditional CVD risk factors including older age, male sex, hypertension, diabetes, higher body mass index, and lower high-density lipoprotein cholesterol levels. In a multivariable model, individuals with moderate/severe OSA had 10% lower F_RHI and 35% higher CAC, which did not reach statistical significance ( p=0.08 for both comparisons). There was no significant interaction of race on the association of OSA with F_RHI or CAC ( p-value >0.1 for all comparisons). In a community-based cohort comprised of black and white participants, moderate/severe OSA was modestly associated with endothelial dysfunction and subclinical atherosclerotic CAD. These associations did not vary by race.

Occupational Health and Sleep Issues in Underserved Populations

Sleep disorders and occupational hazards, injuries, and illnesses impact an individual's overall health. In the United States, substantial racial, ethnic, and socioeconomic disparities exist in sleep and occupational health. Primary care physicians working in underserved communities should be aware of this disparity and target these higher-risk populations for focused evaluation and intervention.

Obstructive sleep apnea and atrial fibrillation: understanding the connection

There is a high incidence of atrial fibrillation (AF) in patients with obstructive sleep apnea (OSA). Whether this represents a causative relationship or is merely an association remains to be determined. This review describes the current understanding of pathophysiologic links supporting a causative relationship between OSA and AF. The management of AF with antiarrhythmics, cardioversion and ablation success depends on compliance with OSA treatment. OSA worsens every risk factor resulting in a higher stroke risk in AF patients. Strategies for early screening and compliance with OSA treatment are the need of the hour.

Obstructive sleep apnea and cardiovascular disease in blacks: a call to action from the Association of Black Cardiologists

Obstructive sleep apnea (OSA) has emerged as a new and important risk factor for cardiovascular disease (CVD). Over the last decade, epidemiologic and clinical research has consistently supported the association of OSA with increased cardiovascular (CV) morbidity and mortality. Such evidence prompted the American Heart Association to issue a scientific statement describing the need to recognize OSA as an important target for therapy in reducing CV risk. Emerging facts suggest that marked racial differences exist in the association of OSA with CVD. Although both conditions are more prevalent in blacks, almost all National Institutes of Health-funded research projects evaluating the relationship between OSA and CV risk have been conducted in predominantly white populations. There is an urgent need for research studies investigating the CV impact of OSA among high-risk minorities, especially blacks. This article first examines the evidence supporting the association between OSA and CVD and reviews the influence of ethnic/racial differences on this association. Public health implications of OSA and future directions, especially regarding minority populations, are discussed.

Resistant hypertension and obstructive sleep apnea in the primary-care setting

We ascertained the prevalence of resistant hypertension (RH) among blacks and determined whether RH patients are at greater risk for obstructive sleep apnea (OSA) than hypertensives. Method. Data emanated from Metabolic Syndrome Outcome Study (MetSO), a study investigating metabolic syndrome among blacks in the primary-care setting. Sample of 200 patients (mean age = 63 ± 13 years; female = 61%) with a diagnosis of hypertension provided subjective and clinical data. RH was defined using the JNC 7and European Society guidelines. We assessed OSA risk using the Apnea Risk Evaluation System ARES), defining high risk as a total ARES score ≥6. Results. Overall, 26% met criteria for RH and 40% were at high OSA risk. Logistic regression analysis, adjusting for effects of age, gender, and medical co morbidities, showed that patients with RH were nearly 2.5 times more likely to be at high OSA risk, relative to those with hypertension (OR = 2.46, 95% CI: 1.03-5.88, P < .05). Conclusion. Our findings show that the prevalence of RH among blacks fell within the range of RH for the general hypertensive population (3-29%). However, patients with RH were at significantly greater risk of OSA compared to patients with hypertension.

Associations of sleep-disordered breathing with excessive daytime sleepiness and blood pressure in Japanese women

Sleep-disordered breathing (SDB) is a recognized risk factor for excessive daytime sleepiness (EDS) and hypertension, but evidence of this association in Asian women is limited. We conducted a cross-sectional study of 3,568 women aged 30-69 years living in three Japanese communities. The 3% oxygen desaturation index (ODI) was selected as the indicator of SDB, and blood oxygen fall was estimated by overnight pulse oximetry. The prevalence of SDB was 20.2% for 3% ODI>or=5, 6.4% for 3% ODI>or=10, and 2.8% for 3% ODI>or=15 among Japanese women aged 30-69 years. The 3% ODI was positively associated with the prevalence of self-reported EDS and mean values of systolic and diastolic blood pressure levels. The multivariate odds ratios for 3% ODI of 5-9, 10-14, and >or=15 in reference to 3% ODI<5 were 1.9 (1.2-3.0), 2.2 (1.0-4.6), and 1.8 (0.7-4.4) (p for trend=0.01), respectively, for EDS and 1.1 (0.9-1.4), 1.2 (0.8-1.8), and 2.2 (1.4-3.4) (p for trend<0.001), respectively, for hypertension. The severity of SDB was significantly associated with EDS and hypertension among Japanese women.

Insomnia symptoms in a multiethnic sample of American women

BACKGROUND

Ethnic disparities in socioeconomic factors, risk markers, and coping styles affect health status. This study examined whether those factors influence insomnia symptoms in a multiethnic sample of urban American women.

METHODS

Women (n = 1440, average age = 59.5 +/- 6.45 years) participating in the study were recruited using a stratified, cluster sampling technique. The sample comprises African Americans (22%), English-speaking Caribbeans (22%), Haitians (22%), Dominicans (12%), Eastern Europeans (11%), and European Americans (11%). Trained staff conducted face-to-face interviews lasting 1.5 hours acquiring demographic, health, and sleep data.

RESULTS

Analysis indicated significant ethnic differences in socioeconomics, risk markers, and health characteristics. The prevalence of insomnia symptoms (defined as either difficulty initiating sleep, difficulty maintaining sleep, or early morning awakening) among African Americans was 71%, English-speaking Caribbeans 34%, Haitians 33%, Dominicans 73%, Eastern Europeans 77%, and European Americans 70%. Hierarchical regression results showed that ethnicity explained 20% of the variance in the insomnia variable. Sociodemographic factors explained 5% of the variance, risk markers explained 5%, medical factors 20%, and coping styles 1%. Goodness-of-fit test indicated the model was reliable [chi-square = 276, p < 0.001], explaining 51% of the variance.

CONCLUSIONS

Findings show interethnic heterogeneity in insomnia symptoms, even among groups previously assumed to be homogeneous. Different factors seemingly influence rates of insomnia symptoms within each ethnic group examined. These findings have direct relevance in the management of sleep problems among women of different ethnic backgrounds. Understanding of ethnic/cultural factors affecting the sleep experience is important in interpreting subjective sleep data.

Sleep apnea: epidemiology, pathophysiology, and relation to cardiovascular risk

Several studies have shown the occurrence of an independent association between obstructive sleep apnea syndrome (OSAS) and cardiovascular disease, including arterial hypertension, ischemic heart disease, and stroke. The pathogenesis of the cardiovascular complications of OSAS is still poorly understood, however. Several mechanisms are likely to be involved, including sympathetic overactivity, selective activation of inflammatory molecular pathways, endothelial dysfunction, abnormality in the process of coagulation, and metabolic dysregulation. The latter may involve insulin resistance and disorders of lipid metabolism. The aim of this review, which reports the data presented at a workshop jointly endorsed by the European Society of Hypertension and by the European Union COST action on OSAS (COST B26), is to critically summarize the evidence available to support an independent association between OSAS and cardiovascular disease.

Insomnia symptoms and repressive coping in a sample of older Black and White women

BACKGROUND

This study examined whether ethnic differences in insomnia symptoms are mediated by differences in repressive coping styles.

METHODS

A total of 1274 women (average age = 59.36 +/- 6.53 years) participated in the study; 28% were White and 72% were Black. Older women in Brooklyn, NY were recruited using a stratified, cluster-sampling technique. Trained staff conducted face-to-face interviews lasting 1.5 hours acquiring sociodemographic data, health characteristics, and risk factors. A sleep questionnaire was administered and individual repressive coping styles were assessed. Fisher's exact test and Spearman and Pearson analyses were used to analyze the data.

RESULTS

The rate of insomnia symptoms was greater among White women [74% vs. 46%; chi2 = 87.67, p < 0.0001]. Black women scored higher on the repressive coping scale than did White women [Black = 37.52 +/- 6.99, White = 29.78 +/- 7.38, F1,1272 = 304.75, p < 0.0001]. We observed stronger correlations between repressive coping and insomnia symptoms for Black [rs = -0.43, p < 0.0001] than for White women [rs = -0.18, p < 0.0001]. Controlling for variation in repressive coping, the magnitude of the correlation between ethnicity and insomnia symptoms was substantially reduced. Multivariate adjustment for differences in sociodemographics, health risk factors, physical health, and health beliefs and attitudes had little effect on the relationships.

CONCLUSION

Relationships between ethnicity and insomnia symptoms are jointly dependent on the degree of repressive coping, suggesting that Black women may be reporting fewer insomnia symptoms because of a greater ability to route negative emotions from consciousness. It may be that Blacks cope with sleep problems within a positive self-regulatory framework, which allows them to deal more effectively with sleep-interfering psychological processes to stressful life events and to curtail dysfunctional sleep-interpreting processes.

Carotid sinus nerve is involved in cardiorespiratory responses to intracarotid injection of capsaicin in the rat

The carotid sinus nerve (CSN), important in cardiorespiratory modulation, mainly contains C fibers (CSCFs). Previous studies have demonstrated that selective stimulation of bronchopulmonary C fibers (PCFs) via right atrial injection of capsaicin (Cap; ∼0.25 μg) results in an apnea (∼3 s) associated with hypotension and bradycardia. The present study was undertaken to determine the effects of activating CSCFs on cardiorespiratory activities. Intracarotid injection of Cap was performed before and after bilateral transection of the CSN in anesthetized and spontaneously breathing rats. Our results showed that 1) low doses of Cap (up to 2 ng) produced an increase in minute ventilation by elevating both tidal volume and respiratory frequency with the threshold dosage at 1.0 ng ( P < 0.05); 2) high doses (4–64 ng) generated an apnea (prolongation of expiratory duration by ∼8-fold) and hypertension ( P < 0.05); 3) bilateral transection of the CSN reduced excitatory and inhibitory respiratory responses by 30 and 81%, respectively, and increased the hypertension by 88% ( P < 0.05); and 4) the same doses of Cap delivered into the right atrium to stimulate PCFs failed to evoke detectable cardiorespiratory responses. Our results suggest that compared with PCFs, CSCFs are more sensitive to Cap stimulation and that activation of these fibers significantly modulates cardiorespiratory activity in anesthetized rats.

Obstructive sleep apnea and hypertension

There is growing evidence of a causal relationship between obstructive sleep apnea (OSA) and hypertension. Untreated OSA may have direct and deleterious effects on cardiovascular function and structure through several mechanisms, including sympathetic activation, oxidative stress, inflammation, and endothelial dysfunction. OSA may contribute to or augment elevated blood pressure levels in a large proportion of the hypertensive patient population. It is important to consider OSA in the differential diagnosis of hypertensive patients who are obese. OSA should be especially considered in those hypertensive patients who respond poorly to combination therapy with antihypertensive medications.