Biological evidence suggests that ethno-racial differences in morning evening type are possible, whereby Blacks may be more likely to be morning type compared to Whites. However, population-level evidence of ethno-racial difference in morning evening type is limited. In an earlier study, we reported that morning type was more prevalent in Blacks compared to Whites in the United Kingdom (UK) Biobank cohort (N = 439,933). This study aimed to determine if these ethno-racial differences persisted after accounting for an even broader range of social, environmental and individual characteristics and employing an analytic approach that simulates randomization in observational data, propensity score modeling. Data from UK Biobank participants whose self-identified race/ethnicity was Black/Black British or White; who did not report daytime napping, shift work or night shift work; who provided full mental health information; and who were identified using propensity score matching were used (N = 2,044). Each sample was strongly matched across all social, environmental and individual characteristics as indicated by absolute standardized mean differences <0.09 for all variables. The prevalence of reporting nocturnal short, adequate and long sleep as well as morning, intermediate and evening type among Blacks (n = 1,022) was compared with a matched sample of Whites (n = 1,022) using multinomial logistic regression models. Blacks had a 62% greater odds of being morning type [odds ratio (OR) = 1.620, 95% confidence interval (CI): 1.336 1.964, p < .0001] and a more than threefold greater odds of reporting nocturnal short sleep (OR = 3.453, 95% CI: 2.846 4.190, p < .0001) than Whites. These data indicate that the greater prevalence of morning type and short nocturnal sleep in Blacks compared to Whites is not fully explained by a wide range of social and environmental factors. If sleep is an upstream determinant of health, these data suggest that ethno-racially targeted public health sleep intervention strategies are needed.
Effects of Chronotype on Sleep Duration and Body Composition Variables
Body composition changes with age. These changes include decreases in fat-free mass and increases in fat mass and central fat accumulation. Improving body composition will augment efforts to lower obesity rates and cardio-metabolic diseases (e.g. type 2 diabetes). Sleep may be a determinant of body composition, whereby shortened sleep duration predicts weight gain. However, evidence is inconsistent. Differences in chronotype (the extent to which an individual is a ?morning? or an ?evening? person) may explain these inconsistent findings. This study will examine the extent to which chronotype modifies the association between sleep duration, fat mass, and fat-free mass in adults. Obesity is associated with leading causes of death and chronic disease (e.g. cardiovascular disease). To elucidate the relationship between obesity and sleep, this study will explore sleep duration, with an emphasis on chronotype-specific differences in eating habits, physical activity, fat mass, and fat free mass. This is aligned with the UK Biobank?s purpose because if chronotype modifies the relationship between sleep and obesity, it may be used to predict who is at greatest risk for obesity onset. These findings may also provide insight into chronotype based weight management interventions. We will examine the hypothesis that chronotype modifies the effect between sleep duration and obesity. Obesity will be regressed on the indicator for whether or not someone is a ?morning? person or an ?evening? person and sleep duration to determine this relationship. Then to determine potential causal pathways through which sleep duration impacts body composition, chronotype-specific differences in eating habits, physical activity, and body composition will be quantified using structural equation modeling. This approach will allow us to quantify the relationship of other potentially influential variables such as person, demographic, and environmental factors. Data from the full UK Biobank cohort, stratified and balanced on sex, will be used to elucidate the relationship between chronotype, sleep duration and body composition.
|Lead investigator:||Dr Alexandra Hanlon|
|Lead institution:||University of Pennsylvania|
3 related Returns
|Return ID||App ID||Description||Archive Date|
|534||3474||Ethnic differences in sleep duration and moring-evening type in a population||5 Jun 2017|
|536||3474||Interactive effects of sleep duration and morning/ evening preference on cardiovascular risk factors||5 Jun 2017|
|535||3474||Smoking, screen-based sedentary behaviour, and diet associated with habitual sleep duration and chronotype: data from the UK Biobank||5 Jun 2017|
|1471||Differences in morning-evening type and sleep duration between black and white adults: Results from a propensity-matched UK Biobank sample||Malone, S.K.||2017||Chronobiology International. 2017|