Alberto R. Ramos

Sleep-disordered Breathing in Hispanic/Latino Individuals of Diverse Backgrounds. The Hispanic Community Health Study/Study of Latinos

RATIONALE Hispanic/Latino populations have a high prevalence of cardiovascular risk factors and may be at risk for sleep-disordered breathing (SDB). An understanding of SDB among these populations is needed given evidence that SDB increases cardiovascular risk. OBJECTIVES To quantify SDB prevalence in the U.S. Hispanic/Latino population and its association with symptoms, risk factors, diabetes, and hypertension; and to explore variation by sex and Hispanic/Latino background. METHODS Cross-sectional analysis from the baseline examination of the Hispanic Community Health Study/Study of Latinos. MEASUREMENTS AND MAIN RESULTS The apnea-hypopnea index (AHI) was derived from standardized sleep tests; diabetes and hypertension were based on measurement and history. The sample of 14,440 individuals had an age-adjusted prevalence of minimal SDB (AHI ≥ 5), moderate SDB (AHI ≥ 15), and severe SDB (AHI ≥ 30) of 25.8, 9.8, and 3.9%, respectively. Only 1.3% of participants reported a sleep apnea diagnosis. Moderate SDB was associated with being male (adjusted odds ratio, 2.7; 95% confidence interval, 2.3-3.1), obese (16.8; 11.6-24.4), and older. SDB was associated with an increased adjusted odds of impaired glucose tolerance (1.7; 1.3-2.1), diabetes (2.3; 1.8-2.9), and hypertension. The association with hypertension varied across background groups with the strongest associations among individuals of Puerto Rican and Central American background. CONCLUSIONS SDB is prevalent in U.S. Latinos but rarely associated with a clinical diagnosis. Associations with diabetes and hypertension suggest a large burden of disease may be attributed to untreated SDB, supporting the development and evaluation of culturally relevant detection and treatment approaches.

Sleep disorders and stroke.

The purpose of this review is to highlight existing literature on the epidemiology, pathophysiology, and treatments of stroke sleep disorders. Stroke sleep disorders are associated with many intermediary vascular risk factors leading to stroke, but they may also influence these risk factors through direct or indirect mechanisms. Sleep disturbances may be further exacerbated by stroke or caused by stroke. Unrecognized and untreated sleep disorders may influence rehabilitation efforts and poor functional outcomes following stroke and increase risk for stroke recurrence. Increasing awareness and improving screening for sleep disorders is paramount in the primary and secondary prevention of stroke and in improving stroke outcomes. Many vital questions about the relationship of sleep disorders and stroke are still unanswered and await future well-designed studies.

Insomnia characteristics and clinical correlates in Operation Enduring Freedom/Operation Iraqi Freedom veterans with post-traumatic stress disorder and mild traumatic brain injury: An exploratory study

BACKGROUND There is limited data on chronic insomnia in Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) veterans, in whom post-traumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) often co-exist. Our aim was to compare sleep characteristics of three groups of OEF/OIF veterans: (1) healthy sleepers (HS), (2) those with insomnia associated with PTSD and mTBI (PTSD-mTBI), and (3) those with insomnia associated with PTSD alone. METHODS Consecutive veterans with insomnia complaints (> 6 months) were recruited over 6 months from the Miami VA Post Deployment clinic. Participants completed a sleep disorders clinical interview, medical history, and questionnaires about insomnia, sleepiness, pain, fatigue, depression, PTSD, and health-related quality of life. They underwent polysomnography (PSG) with 2 weeks of actigraphy (ACT) and sleep diaries. RESULTS There were no differences in demographics or most questionnaire responses between PTSD and PTSD-mTBI groups. Subjective daytime sleepiness was significantly greater in PTSD-mTBI subjects compared with HS and PTSD participants. Significant co-morbid sleep disorders were noted in insomnia patients. PSG and ACT wake after sleep onset was significantly shorter in PTSD-mTBI subjects as compared with PTSD participants. CONCLUSION Insomnia patients with PTSD-mTBI were subjectively sleepier despite spending less time awake during the night than PTSD subjects, possibly as a consequence of head trauma.

Association between sleep duration and the mini-mental score: The northern manhattan study

BACKGROUND Short and long sleep duration are associated with increased mortality and worse global cognitive function, but is unclear if these relations persist after accounting for the risk of sleep disordered breathing (SDB). The aim of our study is determine the association between short and long sleep duration with worse global cognitive function in a racially/ethnically diverse elderly cohort. METHODS We examined sleep hours and global cognitive function cross-sectionally within the population-based Northern Manhattan Study cohort. We conducted nonparametric and logistic regression to examine associations between continuous, short (< 6 h) and long (≥ 9 h) sleep hours with performance on the Mini Mental State Examination (MMSE). RESULTS There were 927 stroke-free participants with data on self-reported sleep hours and MMSE scores (mean age 75 ± 9 years, 61% women, 68% Hispanics). The median (interquartile range) MMSE was 28 (10-30). Sleep hours (centered at 7 h) was associated with worse MMSE (β = -0.01; SE [0.004], p = 0.0113) adjusting for demographics, vascular risk factors, medications, and risk for SDB. Reporting long sleep (≥ 9 h) compared to 6 to 8 h of sleep (reference) was significantly and inversely associated with MMSE (adjusted β = -0.06; SE [0.03], p = 0.012), while reporting short sleep was not significantly associated with MMSE performance. Long sleep duration was also associated with low MMSE score when dichotomized (adjusted OR: 2.4, 95% CI: 1.1-5.0). CONCLUSION In this cross-sectional analysis among an elderly community cohort, long sleep duration was associated with worse MMSE performance.

Sleep duration is associated with white matter hyperintensity volume in older adults: the Northern Manhattan Study

Self‐reports of long or short sleep durations have indicated an association with cardiovascular morbidity and mortality, but there are limited data evaluating their association with white matter hyperintensity volume (WMHV), a marker of cerebral small vessel disease. We conducted a cross‐sectional analysis of self‐reported sleep duration to test for a correlation with white matter hyperintensities, measured by quantitative magnetic resonance imaging (MRI), in the Northern Manhattan Study. We used multivariable linear regression models to assess associations between both short (<6 h) and long (≥9 h) sleep durations and log‐transformed WMHV, adjusting for demographic, behavioural and vascular risk factors. A total of 1244 participants, mean age 70 ± 9 years, 61% women and 68% Hispanics were analysed with magnetic resonance brain imaging and self‐reported sleep duration. Short sleep was reported by 23% (n = 293) and long sleep by 10% (n = 121) of the sample. Long sleep (β = 0.178; P = 0.035), but not short sleep (β = −0.053; P = 0.357), was associated with greater log‐WMHV in fully adjusted models. We observed an interaction between sleep duration, diabetes mellitus and log‐WMHV (P = 0.07). In fully adjusted models, stratified analysis showed that long sleep duration was associated with greater WMHV only in those with diabetes (β = 0.78; P = 0.0314), but not in those without diabetes (β = 0.022; P = 0.2), whereas short sleep was not associated with white matter hyperintensities in those with or without diabetes. In conclusion, long sleep duration was associated with a greater burden of white matter lesions in this stroke‐free urban sample. The association was seen mainly among those with diabetes mellitus.

Social and Health Correlates of Sleep Duration in a US Hispanic Population: Results from the Hispanic Community Health Study/Study of Latinos.

STUDY OBJECTIVES To define the prevalence of poor sleep patterns in the US Hispanic/Latino population, identify sociodemographic and psychosocial predictors of short and long sleep duration, and the association between sleep and cardiometabolic outcomes. DESIGN Cross-sectional analysis. SETTING Community-based study. PARTICIPANTS Adults age 18-74 y free of sleep disorders (n = 11,860) from the Hispanic Community Health Study/Study of Latinos baseline examination (2008-2011). INTERVENTIONS N/A. MEASUREMENTS AND RESULTS The mean self-reported sleep duration was 8.0 h per night with 18.6% sleeping less than 7 h and 20.1% sleeping more than 9 h in age- and sex-adjusted analyses. Short sleep was most common in individuals of Puerto Rican heritage (25.6%) and the Other Hispanic group (27.4%). Full-time employment, low level of education, and depressive symptoms were independent predictors of short sleep, whereas unemployment, low household income, low level of education, and being born in the mainland US were independent predictors of long sleep. After accounting for sociodemographic differences, short sleep remained significantly associated with obesity with an odds ratio of 1.29 [95% confidence interval 1.12-1.49] but not with diabetes, hypertension, or heart disease. In contrast, long sleep was not associated with any of these conditions. CONCLUSIONS Sleep duration is highly variable among US Hispanic/Latinos, varying by Hispanic/Latino heritage as well as socioeconomic status. These differences may have health consequences given associations between sleep duration and cardiometabolic disease, particularly obesity.

Reproducibility of a Standardized Actigraphy Scoring Algorithm for Sleep in a US Hispanic/Latino Population.

STUDY OBJECTIVES While actigraphy is considered objective, the process of setting rest intervals to calculate sleep variables is subjective. We sought to evaluate the reproducibility of actigraphy-derived measures of sleep using a standardized algorithm for setting rest intervals. DESIGN Observational study. SETTING Community-based. PARTICIPANTS A random sample of 50 adults aged 18-64 years free of severe sleep apnea participating in the Sueño sleep ancillary study to the Hispanic Community Health Study/Study of Latinos. INTERVENTIONS N/A. MEASUREMENTS AND RESULTS Participants underwent 7 days of continuous wrist actigraphy and completed daily sleep diaries. Studies were scored twice by each of two scorers. Rest intervals were set using a standardized hierarchical approach based on event marker, diary, light, and activity data. Sleep/wake status was then determined for each 30-sec epoch using a validated algorithm, and this was used to generate 11 variables: mean nightly sleep duration, nap duration, 24-h sleep duration, sleep latency, sleep maintenance efficiency, sleep fragmentation index, sleep onset time, sleep offset time, sleep midpoint time, standard deviation of sleep duration, and standard deviation of sleep midpoint. Intra-scorer intraclass correlation coefficients (ICCs) were high, ranging from 0.911 to 0.995 across all 11 variables. Similarly, inter-scorer ICCs were high, also ranging from 0.911 to 0.995, and mean inter-scorer differences were small. Bland-Altman plots did not reveal any systematic disagreement in scoring. CONCLUSIONS With use of a standardized algorithm to set rest intervals, scoring of actigraphy for the purpose of generating a wide array of sleep variables is highly reproducible.

Obstructive sleep apnea and neurocognitive function in a Hispanic/Latino population

Objective: We evaluated the association between obstructive sleep apnea (OSA) and neurocognitive function among community-dwelling Hispanic/Latino individuals in the United States. Methods: Cross-sectional analysis of the Hispanic Community Health Study/Study of Latinos middle-aged and older adults, aged 45 to 74 years, with neurocognitive test scores at baseline measurements from 2008 to 2011. Neurocognitive scores were measured using the Word Fluency (WF) Test, the Brief–Spanish English Verbal Learning Test (SEVLT), and the Digit Symbol Substitution (DSS) Test. OSA was defined by the apnea-hypopnea index (AHI). Multivariable linear regression models were fit to evaluate relations between OSA and neurocognitive scores. Results: The analysis consisted of 8,059 participants, mean age of 56 years, 55% women, and 41% with less than high school education. The mean AHI was 9.0 (range 0–142; normal AHI <5/h). There was an association between the AHI and all 4 neurocognitive test scores: Brief-SEVLT–sum (β = −0.022) and –recall (β = −0.010), WF (β = −0.023), and DSS (β = −0.050) at p < 0.01 that was fully attenuated by age. In the fully adjusted regression model, female sex was a moderating factor between the AHI and WF (β = −0.027, p < 0.10), SVELT-sum (β = −0.37), SVELT-recall (β = −0.010), and DSS (β = −0.061) at p < 0.01. Conclusion: OSA was associated with worse neurocognitive function in a representative sample of Hispanic/Latino women in the United States.

Race-Ethnic Differences of Sleep Symptoms in an Elderly Multi-Ethnic Cohort: The Northern Manhattan Study

Background: Sleep disorders are associated with stroke and may vary among elderly Hispanics, Blacks and Whites. We evaluated differences in sleep symptoms by race-ethnicity in an elderly population-based urban community sample. Methods: Snoring, daytime sleepiness and reported sleep duration were ascertained by standardized interviews as a part of the Northern Manhattan Study, a prospective cohort study of vascular risk factors and stroke risk in a multi-ethnic urban population. Sleep symptoms were compared amongst race-ethnic groups using logistic regression models. Results: A total of 1,964 stroke-free participants completed sleep questionnaires. The mean age was 75 ± 9 years, with 37% men, with 60% Hispanics, 21% Blacks and 19% Whites. In models adjusted for demographic and vascular risk factors, Hispanics had increased odds of frequent snoring (odds ratio, OR: 3.6, 95% confidence interval, CI: 2.3–5.8) and daytime sleepiness (OR: 2.8, 95% CI: 1.7–4.5) compared to White participants. Hispanics were more likely to report long sleep (≧9 h of sleep, OR: 1.8, 95% CI: 1.1–3.1). There was no difference in sleep symptoms between Black and White participants. Conclusion: In this cross-sectional analysis among an elderly community cohort, snoring, sleepiness and long sleep duration were more common in Hispanics. Sleep symptoms may be surrogate markers for an underlying sleep disorder which may be associated with an elevated risk of stroke and may be modified by clinical intervention.

Relation Between Long Sleep and Left Ventricular Mass (from a Multiethnic Elderly Cohort)

Short-sleep and long-sleep duration are associated with prevalent hypertension, poor cardiovascular health, and mortality. The relation of sleep hours with increased left ventricular (LV) mass, a strong correlate of elevated blood pressure (BP) values, is not established. We conducted a cross-sectional analysis among the participants of the population-based Cardiovascular Abnormalities and Brain Lesions study. LV mass was estimated by transthoracic echocardiography. Sleep duration was assessed by reported hours of sleep on a diary kept during 24-hour BP monitoring. Multivariate linear regression models were constructed to assess the relation between sleep hours and LV mass index (LV mass divided by body surface area). Analysis of sleep hour categories (short and long sleep) was performed. Among 756 participants (mean age 71 ± 9 years, 60% women, and 71% Hispanics), the mean sleep duration was 8.6 ± 1.8 hours, and LV mass index was 103 ± 26 g/m². A J-shaped relation between sleep hours squared and LV mass index was observed adjusting for demographics and cardiovascular risk factors. Categorical analysis showed an association between long-sleep duration (>11 hours) and LV mass index (β = 7.4; p = 0.013). Long sleepers had higher diurnal systolic BP (p = 0.012) and nocturnal systolic BP (p <0.001) compared with the reference group. A great part of the variance between sleep duration and LV mass was explained by 24-hour systolic BP (β = 0.45; p <0.0001). In conclusion, self-reported long-sleep duration was associated with increased LV mass. Higher systolic BP, especially nocturnal, may account for part of the observed association.