Effects of sleep on breakfast behaviors in recently unemployed adults

OBJECTIVES

Skipping meals is linked to negative cardiometabolic health outcomes. Few studies have examined the effects of breakfast skipping after disruptive life events, like job loss. The present analyses examine whether sleep timing, duration, and continuity are associated with breakfast eating among 186 adults who recently (past 90 days) experienced involuntary unemployment from the Assessing Daily Activity Patterns Through Occupational Transitions (ADAPT) study.

METHODS

We conducted both cross-sectional and 18-month longitudinal analyses to assess the relationship between actigraphic sleep after job loss and breakfast eating.

RESULTS

Later sleep timing was associated with a lower percentage of days breakfast was eaten at baseline (B = -0.09, SE = 0.02, P < .001) and longitudinally over 18 months (estimate = -0.04; SE = 0.02; P < .05). No other sleep indices were associated with breakfast consumption cross-sectionally or prospectively.

CONCLUSIONS

Unemployed adults with a delay in sleep timing are more likely to skip breakfast than adults with an advancement in sleep timing. Future studies are necessary to test chronobiological mechanisms by which sleep timing might impact breakfast eating. With the understanding that sleep timing is linked to breakfast eating, the advancement of sleep timing may provide a pathway for the promotion of breakfast eating, ultimately preventing cardiometabolic disease.

Association of nocturnal sleep duration and sleep midpoint with osteoporosis risk in rural adults: a large-scale cross-sectional study

BACKGROUND

Evidence has suggested the linkage between sleep habits and several metabolic diseases, but the association of sleep factors with bone health remains unclear, especially in regions with low economic levels. Thus, this study aimed to investigate the relationship of nocturnal sleep duration and sleep midpoint with the osteoporosis risk in a rural population.

METHOD

Eligible subjects were derived from the Henan Rural Cohort Study. The Pittsburgh Sleep Quality Index was applied to collect sleep information including sleep initiating time and wake-up time. The bone mineral density of the calcaneus was measured by the ultrasonic bone density apparatus. Multivariable logistic regression models and restricted cubic splines were utilized to evaluate the odds ratio (OR) and 95% confidence intervals (95% CI).

RESULTS

For 8033 participants, 1636 subjects suffered from osteoporosis. Compared with the reference group (7 ~ h group), the ORs and 95% CI of osteoporosis associated with duration of nocturnal sleep were 1.32 (1.10, 1.56), 1.59 (1.25, 2.01), and 1.82 (1.25, 2.65) in the 8 ~ h, 9 ~ h, and ≥ 10 h group, respectively. Additionally, the adjusted ORs and 95% CI were 1.20 (1.01, 1.44) in the early sleep midpoint group and 1.09 (0.92, 1.29) in the intermediate sleep midpoint, compared with the late. Furthermore, there was a joint effect of long duration of nocturnal sleep and the early sleep midpoint on osteoporosis.

CONCLUSION

Long duration of nocturnal sleep and early sleep midpoint were independently and jointly associated with higher risk of osteoporosis in rural areas.

TRIAL REGISTRATION

The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 06 July 2015. http://www.chictr.org.cn/showproj.aspx?proj=11375.

Nonlinear relationship between sleep midpoint and depression symptoms: a cross-sectional study of US adults

BACKGROUND

Despite the close relationship between sleep-wake cycles and depression symptoms, the relationship between sleep midpoint and depression symptoms in adults remains understudied.

METHODS

In this cross-sectional study, 18280 adults aged ≥ 18 years from the National Health and Nutrition Examination Survey (NHANES) 2015-2020 were analyzed. Covariates included age, sex, race/ethnicity, education level, marital status, family income, body mass index, smoking status, drinking status, physical activity, comorbid condition, sleep duration, and sleep disturbance were adjusted in multivariate regression models.

RESULTS

Weighted restricted cubic spline based on the complex sampling design of NHANES showed that in participants with a sleep midpoint from 2:18 AM to 6:30 AM, the prevalence of depression symptoms increased by 0.2 times (adjusted odds ratio [OR] = 1.20, 95% confidence interval [CI]: 1.08-1.33) per 1-h increment in sleep midpoint compared to the reference point of 2:18 AM. For participants with a sleep midpoint after 6:30 AM and before 2:18 AM the next day, the relationship between sleep midpoint and depression symptoms was not significant after adjusting for all covariates (adjusted OR = 1.01, 95% CI: 0.99-1.03).

CONCLUSIONS

The findings indicate a significant nonlinear association between sleep midpoint and depression symptoms in a nationally representative sample of adults.

The mediating effect of DNA methylation in the association between maternal sleep during pregnancy and offspring adiposity status: a prospective cohort study

Background

Childhood overweight/obesity is a global public health concern. It is important to identify its early-life risk factors. Maternal poor sleep is common in late pregnancy, and previous studies indicated that poor sleep may influence the offspring’s adiposity status. However, very few studies in humans investigated the effect of the different sleep parameters (sleep quantity, quality, and timing) on the offspring’s adiposity indicators, and long-term studies are even more scarce. In addition, the underlying mechanism remains unclear. The present study therefore aimed to examine the association between the three maternal sleep dimensions in the late pregnancy and the offspring adiposity indicators and to explore the potential mediating effect of the cord blood DNA methylation in the above association.

Methods

Included participants in the current study were 2211 healthy pregnant women with singleton gestation from the Shanghai Birth Cohort (SBC) and Shanghai Sleep Birth Cohort (SSBC). Maternal nighttime sleep duration, quality, and midpoint (an indicator of circadian rhythm) were assessed by the same instrument in both cohorts during late pregnancy, and the offspring’s body mass index (BMI) and subcutaneous fat (SF) were measured at 2 years old. Additionally, in 231 SSBC samples, the genome-wide DNA methylation levels were measured using the Illumina Infinium Methylation EPIC BeadChip. The multivariate linear regression was used to determine the associations between the maternal sleep parameters and the offspring adiposity indicators. The epigenome-wide association study was conducted to identify the maternal sleep-related CpG sites. The mediation analysis was performed to evaluate the potential intermediate role of DNA methylation in the association between maternal sleep and offspring adiposity indicators.

Results

The mean maternal nighttime sleep duration and the sleep midpoint for combined cohorts were 9.24 ± 1.13 h and 3.02 ± 0.82, respectively, and 24.5% of pregnant women experienced poor sleep quality in late pregnancy. After adjusting for the covariates, the maternal later sleep midpoint was associated with the increased SF in offspring (Coef. = 0.62, 95% CI 0.37–0.87, p < 0.001) at 2 years old. However, no significant associations of the nighttime sleep duration or sleep quality with the offspring adiposity indicators were found. In the SSBC sample, 45 differential methylated probes (DMPs) were associated with the maternal sleep midpoint, and then, we observed 10 and 3 DMPs that were also associated with the offspring’s SF and BMI at 2 years, of which cg04351668 (MARCH9) and cg12232388 significantly mediated the relationship of sleep midpoint and SF and cg12232388 and cg12225226 mediated the sleep midpoint–BMI association, respectively.

Conclusions

Maternal later sleep timing in late pregnancy was associated with higher childhood adiposity in the offspring. Cord blood DNA methylation may play a mediation role in that relationship.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-022-01284-w.

Genetic variants for morningness in relation to habitual sleep-wake behavior and diurnal preference in a population-based sample of 17,243 adults

OBJECTIVE

Associations of eveningness with health hazards benefit from analyzing to what extent the polygenic score for morningness correlates with the assessments of the behavioral trait of morningness-eveningness and chronotype.

METHODS

With a population-based sample of 17,243 Finnish adults, aged 25-74 years, this study examines the associations of four feasible assessment methods of chronotype, a) biological the genetic liability based on the polygenic score for morningness (PGS_morn), b) the widely-used single item for self-assessed morningness/eveningness (MEQ_i19) of the original Morningness-Eveningness Questionnaire (MEQ), c) the behavioral trait of morningness-eveningness as assessed with the score on the shortened version (sMEQ) of the original MEQ, and d) the phase of entrainment as assessed with the habitual midpoint of sleep based on the self-reported sleep-wake schedule during weekend (Sleep_mid-wknd) as well as the sleep debt corrected midpoint of sleep (Sleep_mid-corr).

RESULTS

All self-report measures correlated with each other, but very weakly with the PGS_morn, which explained 1-2% of the variation in diurnal preference or habitual sleep-wake schedule. The influence of age was greater on Sleep_mid-wknd and Sleep_mid-corr than on the sMEQ or MEQ_i19, indicating that the diurnal preference might be a more stable indicator for morningness-eveningness than the sleep-wake schedule. Analyses of the discrepancies between sMEQ and MEQ_i19 indicated that eveningness can be over-estimated when relying on only the single-item self-assessment.

CONCLUSIONS

The current polygenic score for morningness explains only a small proportion of the variation in diurnal preference or habitual sleep-wake schedule. The molecular genetic basis for morningness-eveningness needs further elucidation.

Timing and variability of postpartum sleep in relation to daytime performance

Postpartum women have highly disturbed sleep, also known as sleep fragmentation. Fragmentation extends their total sleep period, also disrupting sleep timing. A stable and earlier sleep period among non-postpartum populations is related to better performance, physical health, and mental health. However, sleep timing has not been examined among postpartum women who are also vulnerable to daytime impairment. The study objective was to examine how the timing and regularity of sleep during the early postpartum period are related to daytime functioning across postpartum weeks 2-13. In this field-based study, 71 primiparous women wore an actigraph, a small wrist-worn device that monitors sleep and sleep timing, for the 12-week study period. Mothers self-administered a 5-min psychomotor vigilance test (PVT) each morning to evaluate the number of >500ms response lapses. They also completed a Morningness-Eveningness scale at the beginning of the study to identify chronotype. After controlling for maternal age, earlier sleep timing was associated with significantly fewer PVT lapses at postpartum weeks 9,12; a more stable sleep midpoint was associated with significantly fewer PVT lapses at postpartum weeks 2,5-13. Earlier sleep midpoints were related to more stable sleep midpoints at postpartum week 2 and a morning-type chronotype. An earlier sleep midpoint was also associated with a reduced slope of worsening PVT lapses across weeks. Across the first 12 postpartum weeks, women with earlier or more stable sleep periods had less daytime impairment than women with later or more variable sleep midpoints. Postpartum women with earlier sleep midpoints also showed less severe decrements in performance across time, which has been attributed to cumulative impacts of sleep disturbance. These data suggest that the sleep period, in addition to sleep duration and fragmentation, should be more closely examined, particularly among vulnerable women, as it may affect the neurobehavioral performance of new mothers.