Epidemiologic Methods to Estimate Insufficient Sleep in the US Population.

This study explored the divergence in population-level estimates of insufficient sleep (<6 h) by examining the explanatory role of race/ethnicity and contrasting values derived from logistic and Poisson regression modeling techniques. We utilized National Health and Nutrition Examination Survey data to test our hypotheses among 20-85 year-old non-Hispanic Black and non-Hispanic White adults. We estimated the odds ratios using the transformed logistic regression and Poisson regression with robust variance relative risk and 95% confidence intervals (CI) of insufficient sleep. Comparing non-Hispanic White (10176) with non-Hispanic Black (4888) adults (mean age: 50.61 ± 18.03 years, female: 50.8%), we observed that the proportion of insufficient sleepers among non-Hispanic Blacks (19.2-26.1%) was higher than among non-Hispanic Whites (8.9-13.7%) across all age groupings. The converted estimated relative risk ranged from 2.12 (95% CI: 1.59, 2.84) to 2.59 (95% CI: 1.92, 3.50), while the estimated relative risks derived directly from Poisson regression analysis ranged from 1.84 (95% CI: 1.49, 2.26) to 2.12 (95% CI: 1.64, 2.73). All analyses indicated a higher risk of insufficient sleep among non-Hispanic Blacks. However, the estimates derived from logistic regression modeling were considerably higher, suggesting the direct estimates of relative risk ascertained from Poisson regression modeling may be a preferred method for estimating population-level risk of insufficient sleep.

Sleep Apnea Symptoms and Cardiovascular Disease Risks among Haitian Medical Students.

Sleep apnea is a prevalent sleep disorder that disproportionately affects blacks and has been previously studied among Caribbean-born blacks in Brooklyn, New York, but there has been negligible research in the Caribbean, specifically Haiti, and developing countries on this pressing health issue. A total of 373 medical students (mean age=20.6 years ± 2.3 years) from a medical school in Haiti participated in this study. Participants were administered a questionnaire assessing their sleep health and cardiovascular outcomes. The rate of sleep apnea symptoms was: snoring (13.2%), excessive daytime sleepiness (73.7%), and difficulty maintaining sleep (25.3%). Many reported falling asleep while watching television (68.2%) or while driving (7.8%). Based on logistic regression analysis, reported nocturnal breathing pauses was the most important predictor of the likelihood of reporting a history of cardiac disease (14.96; 95% CI=1.27-76.07). Findings suggest that more aggressive effort should be made to increase screening of sleep apnea among Haitians, thereby increasing the likelihood for early detection and treatment to reduce sleep-related risk of cardiovascular disease.

Gray Matter Correlates of Cognitive Performance Differ between Relapsing-Remitting and Primary-Progressive Multiple Sclerosis.

Multiple Sclerosis (MS) is a chronic inflammatory/demyelinating and neurodegenerative disease of the central nervous system (CNS). Most patients experience a relapsing-remitting (RR) course, while about 15-20% of patients experience a primary progressive (PP) course. Cognitive impairment affects approximately 40-70% of all MS patients and differences in cognitive impairment between RR-MS and PP-MS have been found. We aimed to compare RR-MS and PP-MS patients in terms of cognitive performance, and to investigate the MRI correlates of cognitive impairment in the two groups using measures of brain volumes and cortical thickness. Fifty-seven patients (42 RR-MS, 15 PP-MS) and thirty-eight matched controls underwent neuropsychological (NP) testing and MRI. PP-MS patients scored lower than RR-MS patients on most of the NP tests in absence of any specific pattern. PP-MS patients showed significantly lower caudate volume. There was no significant difference in MRI correlates of cognitive impairment between the two groups except for a prevalent association with MRI measures of cortical GM injury in RR-MS patients and with MRI measures of subcortical GM injury in PP-MS patients. This suggests that although cognitive impairment results from several factors, cortical and subcortical GM injury may play a different role depending on the disease course.