Associations between self-reported sleep duration and cardiometabolic risk factors in young African-origin adults from the five-country Modeling the Epidemiologic Transition Study (METS)

To investigate associations between self-reported sleep duration and cardiometabolic (CM) risk factors in African-origin adults residing in five countries spanning the epidemiologic transition. Cross-sectional. Ghanaian (n = 491), South African (n = 503), Jamaican (n = 508), Seychellois (n = 501) and American (n = 480) men and women. Self-reported sleep duration was obtained using questionnaires. Sex- and site-stratified logistic regression analyses investigated relationships between sleep duration, individual CM risk factors and a binary CM risk variable (presence of ≥3 CM risk factors), adjusting for age, physical activity and education. Sleep duration distributions varied by cohort: 44.5%, 41.4%, 35.9%, 16.8% and 2.5% of American, Jamaican, Seychellois, Ghanaian and South African men reported <7 h sleep per night respectively (p < 0.001). Similarly, 42.6%, 28.6%, 25.2%, 12.8% and 1.5% of American, Jamaican, Seychellois, Ghanaian and South African women reported <7 h sleep respectively (p < 0.001). American men reporting ≤6 h sleep were more likely to be in the elevated CM risk group (OR: 2.52, 95%CI: 1.02, 6.22, p = 0.045) and to have a high waist circumference (OR: 2.44, 95%CI: 1.07, 5.57, p = 0.034) compared to those reporting 8 h sleep. Jamaican women reporting ≤6 h sleep (OR: 2.53, 95%CI: 1.19, 5.36, p = 0.016) and American women reporting 7 h sleep (OR: 2.71, 95%CI: 1.17, 6.26, p = 0.002) were more likely to be obese than those reporting 8 h sleep. Associations between short sleep and CM risk factors were only evident in the American men and women and Jamaican women. Future interventions to address CM risk and sleep health may need to be country-specific when targeting high-risk populations

Sex-specific associations between self-reported sleep characteristics and 10-year cardiovascular disease risk in men and women of African descent living in a low socioeconomic status environment

BackgroundRisk factors for cardiovascular disease (CVD) and sleep health are well-known to be sex- and race-specific. To build on the established relationship between sleep duration and CVD risk, this cross-sectional study aimed to describe sex-specific associations between CVD risk and other sleep characteristics (sleep quality, sleep timing and sleep onset latency) in low-income adults of African descent.MethodsSelf-reported sleep (Pittsburgh Sleep Quality Index [PSQI], Epworth Sleepiness Scale [ESS], Insomnia Severity Index [ISI]), demographic and lifestyle data were collected in 412 adults (56% women, 35.0±7.6y, 40% employed) living in an informal settlement in South Africa. CVD risk was determined using the BMI-modified Framingham 10-year CVD risk formula.ResultsLogistic regression analyses, adjusted for employment, alcohol use and physical activity, indicated that men reporting poor sleep quality (OR: 1.9[95%CI: 1.1-3.5],p=0.025) and earlier bedtimes (0.54[0.39-0.74],p&lt;0.001) were more likely to belong to a higher 10-year CVD risk score quintile. Women reporting earlier bedtimes (0.72[0.55-0.95],p=0.020) and wake-up times (0.30[0.1-0.7],p=0.007), longer sleep-onset latency (1.5[1.4-1.9],p=0.003), shorter total sleep times (0.84[0.7-0.9],p=0.029), higher PSQI global scores (1.9[1.3-2.9],p=0.001) and more moderate to severe symptoms of insomnia (ISI≥15)(3.24[1.04-10.04],p=0.016) were more likely to belong to higher 10-year CVD risk score quintile.ConclusionIn addition to sleep duration, we found that sleep quality, sleep timing and sleep onset latency are additional risk factors for CVD in adults of African descent. Sex-specific differences in the sleep-CVD-risk relationship observed suggests that future studies and recommendations about sleep health in relation to CVD should take sex into account.<br/

Associations between fears related to safety during sleep and self-reported sleep in men and women living in a low-socioeconomic status setting

South Africans living in low socioeconomic areas have self-reported unusually long sleep durations (approximately 9–10 h). One hypothesis is that these long durations may be a compensatory response to poor sleep quality as a result of stressful environments. This study aimed to investigate whether fear of not being safe during sleep is associated with markers of sleep quality or duration in men and women. South Africans (n = 411, 25–50 y, 57% women) of African-origin living in an urban township, characterised by high crime and poverty rates, participated in this study. Participants are part of a larger longitudinal cohort study: Modelling the Epidemiologic Transition Study (METS)–Microbiome. Customised questions were used to assess the presence or absence of fears related to feeling safe during sleep, and the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index were used to assess daytime sleepiness, sleep quality and insomnia symptom severity respectively. Adjusted logistic regression models indicated that participants who reported fears related to safety during sleep were more likely to report poor sleep quality (PSQI &gt; 5) compared to participants not reporting such fears and that this relationship was stronger among men than women. This is one of the first studies outside American or European populations to suggest that poor quality sleep is associated with fear of personal safety in low-SES South African adults