Faculty Bibliography

One-third of women worrying about breast cancer report impaired ability to function daily. It is unclear whether women who worry about breast cancer would experience more sleep problems than those who do not. Data were obtained from a cross-sectional study of black and white women to investigate the association between breast cancer worry and insomnia complaints. Several questionnaires were administered during face-to-face interviews to elicit health and sociodemographic data. The present analyses focused on black and white women (n = 1,038; age range = 50-70 years) with no cancer antecedents or history. Overall, 62% of the women worried about breast cancer, and 49% reported insomnia complaints. Logistic regression analyses, adjusting for effects of age, ethnicity, family history, and perceived risk of developing breast cancer, yielded an odds ratio for insomnia complaints of 1.52 (95% CI: 1.15-2.02, p < .001) among women reporting breast cancer worry. More than one half of the women worrying about breast cancer were likely to report insomnia complaints, notwithstanding the fact that those women did not have a history of cancer. Although fewer black women reported breast cancer worry and insomnia complaints, they were as affected as white women by the impact of worry on mood and daily activities.

Obstructive sleep apnea (OSA) is a prevalent sleep disorder that disproportionately affects blacks. While clinical and epidemiologic data indicate intraethnic differences in several medical diseases, little is known about whether OSA symptoms differ within the black ethnic group. We estimated the rate of OSA symptoms in a community-based sample of Caribbean-born black men and women. We also ascertained which sociodemographic and/or medical factors were associated with OSA risk. A total of 554 patients (mean age = 48.17 +/- 16.75 years) participated in the study; 55% were women. Data were collected in four primary-care clinics in Brooklyn, NY. A health educator explained the purpose of the study to interested patients and assisted consenting participants in completing questionnaires, which required 15 min to complete. Participants reporting habitual snoring, excessive daytime sleepiness, and sleep fragmentation were considered at high OSA risk. The rate of OSA symptoms was: snoring (45%), excessive daytime sleepiness (33%), and difficulty maintaining sleep (34%). Many reported falling asleep while watching television (47%) or while driving (14%). Based on logistic regression analysis, a history of heart disease was the most important predictor of the likelihood of expressing OSA symptoms, with a corresponding multivariate-adjusted odds ratio of 11 (95% confidence interval = 3.03-40.63). Findings suggest the need to investigate whether Caribbean-born blacks are at greater risk for developing OSA than African Americans and whites. Caribbean-born blacks with a history of heart disease should be a prime target for interventions that promote adequate screening and timely OSA diagnosis.

OBJECTIVES: Few minority patients with sleep apnea have been evaluated or treated. This study ascertained adherence rate to referrals for sleep apnea evaluation by primary care physicians in a community-based sample of black patients; it also examined baseline characteristics likely to influence adherence rates. METHODS: A retrospective chart audit was conducted at a hospital-based sleep clinic. Scrutiny was limited to male and female patients between the ages of 20 and 80 years. Data obtained for this analysis included baseline characteristics from a detailed sleep history and/or screening questionnaires and polysomnographic parameters. RESULTS: Of the 421 patients referred by their private care physicians, 38% (n=160) adhered to the recommendation for a sleep consultation, but all who showed up for their appointment underwent polysomnographic studies. Logistic regression analyses showed that obesity and daytime sleepiness were the most important factors predicting adherence, with multivariate-adjusted odds ratios of 2.69 [95% CI: 1.54-4.71, p < 0.001] and 6.98 [95% CI: 3.86-12.64, p < 0.001], respectively. Of the patients who underwent a polysomnographic sleep evaluation, 91% received a sleep apnea diagnosis and were treated. CONCLUSIONS: Black patients may be underutilizing available sleep services, but direct comparisons with other ethnic groups could not be made because of insufficient archival data. While the present study does not identify specific barriers to accessing services for sleep problems, it indicates that blacks who are obese and/or are experiencing daytime sleepiness are likely to adhere to recommendations of their physician. Targeted culturally congruent educational interventions to increase awareness of sleep apnea in black communities might help to increase adherence rate.

Although obstructive sleep apnea and cardiovascular disease have common risk factors, epidemiologic studies show that sleep apnea increases risks for cardiovascular disease independently of individuals' demographic characteristics (i.e., age, sex, and race) or risk markers (i.e., smoking, alcohol, obesity, diabetes, dyslipidemia, atrial fibrillation, and hypertension). Individuals with severe sleep apnea are at increased risk for coronary artery disease, congestive heart failure, and stroke. The underlying mechanisms explaining associations between obstructive sleep apnea and cardiovascular disease are not entirely delineated. Several intermediary mechanisms might be involved including sustained sympathetic activation, intrathoracic pressure changes, and oxidative stress. Other abnormalities such as disorders in coagulation factors, endothelial damage, platelet activation, and increased inflammatory mediators might also play a role in the pathogenesis of cardiovascular disease. Linkage between obstructive sleep apnea and cardiovascular disease is corroborated by evidence that treatment of sleep apnea with continuous positive airway pressure reduces systolic blood pressure, improves left ventricular systolic function, and diminishes platelet activation. Several systematic studies are necessary to explicate complex associations between sleep apnea and cardiovascular disease, which may be compounded by the involvement of diseases comprising the metabolic syndrome (i.e., central obesity, hypertension, diabetes, and dyslipidemia). Large-scale, population-based studies testing causal models linking among sleep apnea, cardiovascular morbidity, and metabolic syndrome are needed.

INTRODUCTION: Epidemiologic studies have shown the importance of habitual sleep duration as an index of health and mortality risks. However, little has been done to ascertain ethnic differences in sleep duration in a national sample. This study compares sleep duration in a sample of black and white participants in the National Health Interview Survey (NHIS). METHOD: Data were collected from 29,818 Americans (age range 18-85 years) who participated in the 2005 NHIS. The NHIS is a cross-sectional household interview survey that uses a multistage area probability design, thus permitting representative sampling of U.S. households. During face-to-face interviews conducted by trained interviewers from the U.S. Census Bureau, respondents provided demographic data and information about physician-diagnosed chronic conditions, estimated habitual sleep duration and functional capacity, and rated their mood. RESULTS: Fisher's exact test results indicated that blacks were less likely than whites to report sleeping 7 hours (23% vs. 30%; chi2 = 94, p < 0.0001). Blacks were more likely to experience both short sleep (< or = 5 hours) (12% vs. 8%, chi2 = 44, p < 0.0001) and long sleep (> or = 9 hours) (11% vs. 9%, chi2 = 23, p < 0.0001). Logistic regression analysis, adjusting for differences in sociodemographic factors, depression, functional capacity and medical illnesses, demonstrated that black ethnicity was a significant predictor of extreme sleep duration (Wald = 46, p < 0.0001; OR = 1.35, 95% CI: 1.24-1.47). DISCUSSION: Independent of several sociodemographic and medical factors, blacks had more prevalent short and long sleep durations, suggesting greater variation in habitual sleep time. Therefore, blacks might be at increased risks of developing medical conditions associated with short and long sleep.

The absence of circadian zeitgebers in the social environment causes circadian misalignment, which is often associated with sleep disturbances. Circadian misalignment, defined as a mismatch between the sleep-wake cycle and the timing of the circadian system, can occur either because of inadequate exposure to the light-dark cycle, the most important synchronizer of the circadian system, or reduction in light transmission resulting from ophthalmic diseases (e.g., senile miosis, cataract, diabetic retinopathy, macular degeneration, retinitis pigmentosa, and glaucoma). We propose that glaucoma may be the primary ocular disease that directly compromises photic input to the circadian time-keeping system because of inherent ganglion cell death. Glaucomatous damage to the ganglion cell layer might be particularly harmful to melanopsin. According to histologic and circadian data, a subset of intrinsically photoresponsive retinal ganglion cells, expressing melanopsin and cryptochromes, entrain the endogenous circadian system via transduction of photic input to the thalamus, projecting either to the suprachiasmatic nucleus or the lateral geniculate nucleus. Glaucoma provides a unique opportunity to explore whether in fact light transmission to the circadian system is compromised as a result of ganglion cell loss.

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.

BACKGROUND: Few studies have characterized ethnic variations in standard ophthalmic measures. We tested the hypothesis that nerve fiber layer thickness would show characteristic differences between white and black individuals. We also examined whether ophthalmic measures would show intraethnic differences. METHODS: Seventy participants (mean age: 68.27+/- 5.97 years; blacks: 59% and whites: 41%) were recruited from Brooklyn communities. Sociodemographic and medical data were obtained, and eligible volunteers underwent eye examinations at SUNY Downstate Medical Center. RESULTS: ANCOVA showed that blacks were characterized by significantly worse visual acuity (F=4.14, p=0.05), larger horizontal and vertical cup-to-disk ratios (F=4.53, p=0.04; F=6.08, p=0.02, respectively), and thinner nerve fiber layer than their white counterparts (F=22.61, p=0.009). Within the black ethnicity itself, Caribbean Americans showed significantly thinner nerve fiber layer than did African Americans (F=7.52, p=0.01). CONCLUSION: Findings are consistent with previous reports of racial/ethnic differences in ophthalmic measures. Moreover, they suggest that black ethnicity may not be homogeneous regarding ophthalmic variables, particularly when examining nerve fiber layer thickness. Studies investigating ethnic differences in eye diseases should examine intragroup factors that could influence interpretation of clinical data.