Associations of bedtime, sleep duration, and sleep quality with semen quality in males seeking fertility treatment: a preliminary study.
ABSTRACT: Background:Poor sleep has been linked to a number of adverse health outcomes. Recent studies suggest that late bedtimes, short or long sleep durations, and poor sleep quality may impair semen quality. No study has previously explored all three factors in relation to semen quality. Results:One hundred and four men and their partners treated at three fertility clinics in Denmark between 2010 and 2012 completed an online-version of the Pittsburgh Sleep Quality Index (PSQI). The results of the semen analyses conducted at the fertility clinics were self-reported and categorised as normal or reduced.Early bedtime (
Project description:<h4>Introduction</h4>Hypertension affects up to 5% of children worldwide and predicts later cardiovascular morbidity. Associations of short sleep and hypertension have been frequently reported in adults but less consistently in children. This study aims to examine the role of late bedtimes, a marker of short sleep duration, and potentially misaligned circadian rhythms, on incident elevated blood pressure (BP) in a large cohort of Mexican children.<h4>Methods</h4>Participants included 2,033 adolescents recruited from public schools in Morelos, Mexico, free from elevated BP (<90th sex, age, and height-standardized percentile). Fourteen months later, all adolescents had a second BP assessment. We abstracted baseline habitual bedtimes from questionnaires to evaluate the association between bedtime and elevated BP incidence (?90th percentile). Risk ratios and 95% confidence intervals were estimated with discrete-time mixed survival models, adjusting for potential confounders and accounting for clustering by school.<h4>Results</h4>Participants were 12.5 (SD?=?0.6) years old at baseline. At the follow-up visit 10% of adolescents had developed elevated BP. Compared to participants with a habitual weekday bedtime between 9 and 10 pm, those with a weekday bedtime 11 pm or later had a 1.87 times higher risk of developing elevated BP over the follow-up period (95% CI = 1.09, 2.21), after accounting for confounders. Participants with earlier weekday bedtimes also had a higher risk of elevated BP (RR?=?1.96; 95% CI = 1.27, 3.01). The associations persisted after accounting for wake time.<h4>Conclusion</h4>These data showed a U-shaped association between weekday bedtime and elevated/high BP risk among Mexican adolescents.
Project description:Study Objectives:Having a regular, age-appropriate bedtime and sufficient sleep from early childhood may be important for healthy weight in adolescence. This study aimed to (1) identify heterogeneous groups of children by bedtime and sleep routines and (2) test longitudinal associations of childhood bedtime and sleep routine groups with adolescent body mass index (BMI). Methods:We analyzed longitudinal data from the Fragile Families and Child Wellbeing Study, a national birth cohort from 20 US cities (N = 2196). Childhood bedtime and sleep routines were assessed by mothers' reports of their children's presence and timing of bedtimes, adherence to bedtimes, and habitual sleep duration at ages 5 and 9. At age 15, these adolescents reported their height and weight, which were used to calculate BMI z-score. Results:Latent Class Analysis revealed four groups of childhood bedtime and sleep routines: No Bedtime Routine Age 5 (Group 1), No Bedtime Routine Age 9 (Group 2), Borderline Bedtimes Ages 5 and 9 (Group 3), and Age-Appropriate Bedtime and Sleep Routines Ages 5 and 9 (Group 4, reference). Compared with adolescents in the reference group, those in the No Bedtime Routine Age 9 (Group 2) had +0.38 SD greater BMI (95% CI = [0.13 to 0.63]), above the level for overweight (1.02 SD BMI/85th percentile). Associations persisted after adjusting for age 3 BMI and sociodemographic characteristics. Conclusions:Results demonstrate heterogeneity in childhood bedtime routine groups and their associations with adolescent BMI. Future studies should focus on whether childhood sleep behavior interventions promote healthier sleep and weight in later life course stages.
Project description:Despite proper sleep hygiene being critical to our health, guidelines for improving sleep habits often focus on only a single component, namely, sleep duration. Recent works, however, have brought to light the importance of another aspect of sleep: bedtime regularity, given its ties to cognitive and metabolic health outcomes. To further our understanding of this often-neglected component of sleep, the objective of this work was to investigate the association between bedtime regularity and resting heart rate (RHR): an important biomarker for cardiovascular health. Utilizing Fitbit Charge HRs to measure bedtimes, sleep and RHR, 255,736 nights of data were collected from a cohort of 557 college students. We observed that going to bed even 30?minutes later than one's normal bedtime was associated with a significantly higher RHR throughout sleep (Coeff +0.18; 95% CI: +0.11, +0.26 bpm), persisting into the following day and converging with one's normal RHR in the early evening. Bedtimes of at least 1?hour earlier were also associated with significantly higher RHRs throughout sleep; however, they converged with one's normal rate by the end of the sleep session, not extending into the following day. These observations stress the importance of maintaining proper sleep habits, beyond sleep duration, as high variability in bedtimes may be detrimental to one's cardiovascular health.
Project description:STUDY OBJECTIVES:To investigate the correlation between self-reported and objective measures of total sleep time (TST) in adults and examine whether sex, race/ethnicity, and weight status influence this association. METHODS:Participants were individuals who screened for sleep intervention studies, providing > 7 days of wrist actigraphy sleep data (TSTobj) and reporting sleep duration (TSTPSQI) using the Pittsburgh Sleep Quality Index (PSQI) questionnaire (n = 53 men, 60 women; 59% minority/Hispanics; age 30.9 ± 9.7 years; body mass index 26.2 ± 3.2 kg/m2). In addition, TSTbed/wake was calculated as the difference between bedtime and waketime, minus the time to fall asleep, from the PSQI. Univariate regression analyses were performed to assess the relation between TSTobj and TSTPSQI and TSTbed/wake and compare the relation by sex, race, and ethnicity. Bland-Altman tests were done to assess bias by sex, race/ethnicity, weight status, and sleep quality. RESULTS:TSTbed/wake correlated with TSTobj (r = .57, P < .0001). TSTPSQI and TSTbed/wake were greater than TSTobj (0.63 ± 0.99 hours and 0.79 ± 0.76 hours, respectively, both P < .0001). The difference between TSTPSQI and TSTobj did not vary by sex (? = .12, P = .52), race/ethnicity (? = .15, P = .48), age (? = -.01, P = .27), or body mass index (? = .04, P = .13) whereas that between TSTbed/wake and TSTobj varied by age (? = -.020, P = .0051), BMI (? = .054, P = .0021), race/ethnicity (? = .36, P = .021), and sleep efficiency (? = -.089, P < .0001). CONCLUSIONS:Calculating TST using self-reported bedtimes and wake times provided TST estimate that correlated with TSTobj but greater over-reporting occurred in younger and heavier individuals, non-whites or Hispanics, and those with low sleep efficiency. In clinical and research settings, asking individuals to report bedtimes, wake times, and length of time to fall asleep may more accurately estimate TST than asking about sleep duration alone.
Project description:<b>Objective:</b> To investigate the effect of 1) lockdown duration and 2) training intensity on sleep quality and insomnia symptoms in elite athletes. <b>Methods:</b> 1,454 elite athletes (24.1 ± 6.7 years; 42% female; 41% individual sports) from 40 countries answered a retrospective, cross-sectional, web-based questionnaire relating to their behavioral habits pre- and during- COVID-19 lockdown, including: 1) Pittsburgh sleep quality index (PSQI); 2) Insomnia severity index (ISI); bespoke questions about 3) napping; and 4) training behaviors. The association between dependent (PSQI and ISI) and independent variables (sleep, napping and training behaviors) was determined with multiple regression and is reported as semi-partial correlation coefficient squared (in percentage). <b>Results:</b> 15% of the sample spent < 1 month, 27% spent 1-2 months and 58% spent > 2 months in lockdown. 29% self-reported maintaining the same training intensity during-lockdown whilst 71% reduced training intensity. PSQI (4.1 ± 2.4 to 5.8 ± 3.1; mean difference (MD): 1.7; 95% confidence interval of the difference (95% CI): 1.6-1.9) and ISI (5.1 ± 4.7 to 7.7 ± 6.4; MD: 2.6; 95% CI: 2.3-2.9) scores were higher during-compared to pre-lockdown, associated (all <i>p</i> < 0.001) with longer sleep onset latency (PSQI: 28%; ISI: 23%), later bedtime (PSQI: 13%; ISI: 14%) and later preferred time of day to train (PSQI: 9%; ISI: 5%) during-lockdown. Those who reduced training intensity during-lockdown showed higher PSQI (<i>p</i> < 0.001; MD: 1.25; 95% CI: 0.87-1.63) and ISI (<i>p</i> < 0.001; MD: 2.5; 95% CI: 1.72-3.27) scores compared to those who maintained training intensity. Although PSQI score was not affected by the lockdown duration, ISI score was higher in athletes who spent > 2 months confined compared to those who spent < 1 month (<i>p</i> < 0.001; MD: 1.28; 95% CI: 0.26-2.3). <b>Conclusion:</b> Reducing training intensity during the COVID-19-induced lockdown was associated with lower sleep quality and higher insomnia severity in elite athletes. Lockdown duration had further disrupting effects on elite athletes' sleep behavior. These findings could be of relevance in future lockdown or lockdown-like situations (e.g., prolonged illness, injury, and quarantine after international travel).
Project description:Background Previous studies have suggested that sleep timing is associated with cardiovascular risk factors. However, there is no evidence on the relationship between sleep timing and congestive heart failure (CHF). We aimed to examine this relationship in this study. Methods and Results We recruited 4765 participants (2207 men; mean age, 63.6±11.0 years) from the SHHS (Sleep Heart Health Study) database in this multicenter prospective cohort study. Follow-up was conducted until the first CHF diagnosis between baseline and the final censoring date. Sleep timing (bedtimes and wake-up times on weekdays and weekends) was based on a self-reported questionnaire. Cox proportional hazard models were constructed to investigate the association between sleep timing and CHF. During the mean follow-up period of 11 years, 519 cases of CHF (10.9%) were reported. The multivariable Cox proportional hazards models revealed that participants with weekday bedtimes >12:00 am (hazard ratio [HR], 1.56; 95% CI, 1.15-2.11; <i>P</i>=0.004) and from 11:01 pm to 12:00 am (HR, 1.25; 95% CI, 1.00-1.56; <i>P</i>=0.047) had an increased risk of CHF compared with those with bedtimes from 10:01 pm to 11:00 pm. After stratified analysis, the association was intensified in participants with a self-reported sleep duration of 6 to 8 hours. Furthermore, wake-up times >8:00 am on weekdays (HR, 1.53; 95% CI, 1.07-2.17; <i>P</i>=0.018) were associated with a higher risk of incident CHF than wake-up times ≤6:00 am. Conclusions Delayed bedtimes (>11:00 pm) and wake-up times (>8:00 am) on weekdays were associated with an increased risk of CHF.
Project description:BACKGROUND AND OBJECTIVE:Early pubertal timing is associated with sleep among Western adolescents, but little is known about this association in Chinese adolescents, especially with regard to the association between bedtimes and early pubertal timing. This paper aimed to identify the association between sleep duration, bedtimes, and early pubertal timing in Chinese adolescents. METHODS:An anonymous cross-sectional survey was conducted among primary and junior middle students (grades 3 to 9) from QiJiang District, ChongQing, China. Participants were recruited by applying stratified cluster sampling. Pubertal timing, sleep duration, and bedtimes were assessed using the Pubertal Development Scale and a self-designed sleep questionnaire. We utilized multivariable logistic linear regression (MLLR) to test the association between sleep duration, bedtimes, and pubertal timing. RESULTS:A total of 5461 adolescents were evaluated, with mean age and BMI values of 11.41 ± 2.05 and 18.03 ± 3.03, respectively, of whom 1257 (23.02%) were in early pubertal timing. In MLLR controlling for age, BMI, family economic status, and other covariates, sufficient sleep (b = - 0.214, P = 0.032, OR = 0.808, 95% CI 0.664-0.982) was negatively related to early pubertal timing, and later bedtime (b = 0.195, P < 0.001, OR = 1.215, 95% CI 1.104-1.338) was positively associated with early pubertal timing. CONCLUSION:Students with early pubertal timing had less sleep duration and later bedtimes, which may be the result of increased stress caused by physical and psychological changes. Therefore, more attention should be paid to pubertal health education for adolescents during puberty. Further longitudinal studies are needed to confirm the causality between sleep and early pubertal timing in Chinese adolescents.
Project description:<h4>Background</h4>Inadequate sleep duration, sleep patterns, and sleep quality have been associated with metabolic, circadian, and behavioral changes that promote obesity. Adolescence is a period during which sleep habits change to include less sleep, later bedtimes, and greater bedtime shift (e.g., difference between weekend and weekday bedtime). Thus, sleep may play a role in adolescent obesity and weight-related behaviors. This study assesses sleep duration, quality, and schedules and their relationships to relative weight and body fat percentage as well as diet, physical activity, and screen time in adolescents with overweight/obesity.<h4>Methods</h4>Adolescents between 12 and 17 years old (n?=?186) were weighed and measured, reported typical sleep and wake times on weekdays and weekends, and responded to questionnaires assessing diet, physical activity, and screen time habits.<h4>Results</h4>Controlling for sleep duration, later weekend bedtime and greater bedtime shift were associated with greater severity of overweight (??=?0.20; ??=?0.16) and greater screen time use (??=?0.22; ??=?0.2). Later bedtimes on the weekdays and weekends were associated with fewer healthy diet practices (??=?-0.26; ??=?-0.27). In addition, poorer sleep quality was associated with fewer healthy diet habits (??=?-0.21), greater unhealthy diet habits (??=?0.15), and less physical activity (??=?-0.22). Sleep duration was not associated with any weight or weight-related behavior.<h4>Conclusions</h4>Sleep patterns and quality are associated with severity of overweight/obesity and various weight-related behaviors. Promoting a consistent sleep schedule throughout the week may be a worthwhile treatment target to optimize behavioral and weight outcomes in adolescent obesity treatment.
Project description:<h4>Study objectives</h4>To investigate the association between sleep duration and semen parameters as well as reproductive hormone levels.<h4>Methods</h4>We designed a cohort of male college students in Chongqing, China. A total of 796 subjects were recruited in 2013 and 656 (82.4%) were followed up in 2014. Each time, semen and peripheral blood samples were collected for semen quality and reproductive hormone measurement. Sleep duration was estimated by revised Munich Chronotype Questionnaire. In 2014, sleep quality was also measured by Pittsburgh Sleep Quality Index (PSQI).<h4>Results</h4>There was a substantial inverse U-shaped association between sleep duration and two semen parameters (semen volume and total sperm number), with 7.0-7.5 h/day of sleep showing highest parameters. Either longer or shorter sleep was associated with decreased semen parameters in a dose-response manner (P = 0.002 and 0.001, respectively). Sleeping > 9.0 h was associated with a 21.5% (95% confidence interval 9.2, 32.2) reduction in semen volume and 39.4% (23.3, 52.1) reduction in total sperm number; sleeping ? 6.5 h was associated with 4.6% (-10.5, 22.3) and 25.7% (-1.2, 60.1) reduction. Increase of the two parameters was found in those who changed sleep duration toward 7.0-7.5 h/day from 2013 to 2014. The U-shaped association was independent from PSQI and was replicated in another dataset of 1,346 males. No association found between sleep duration and reproductive hormone.<h4>Conclusions</h4>Either restricted or excessive sleep may impair semen quality. Further research is needed to validate this finding.
Project description:Racially and ethnically diverse young children who live with socioeconomic adversity are at high risk for sleep deficiency, but few behavioral sleep interventions (BSIs) are tailored to their needs. To support the future development of a feasible, acceptable, and culturally relevant sleep intervention, we conducted a community-engaged, mixed-methods study with 40 low-income, racially, and ethnically diverse parents to describe sleep characteristics, sleep habits, and parental sleep knowledge of their 6-36-month-old children and to examine the associations between children's sleep characteristics and sleep habits. This report presents quantitative data from this mixed-methods study. We measured objective (actigraphy) and parent-reported sleep (Brief Infant Sleep Questionnaire) characteristics, sleep habits at bedtime, sleep onset, and during night awakenings, parental sleep knowledge, psychological function (Brief Symptom Inventory), and parenting stress (Parenting Stress Index). Children had low sleep duration (537.2 ± 54.7 nighttime and 111.2 ± 29.8 nap minutes), late bedtimes (22:36 ± 1.5 hr), and high bedtime variability (mean squared successive difference = 3.68 ± 4.31 hr) based on actigraphy. Parental knowledge about sleep recommendations was limited. Sleep habits before bedtime, at sleep onset, and during night awakenings were varied. Sixty-five percent of parents reported co-sleeping. Feeding near bedtime or during the night was associated with later bedtimes, more fragmented sleep, and increased bedtime variability. These findings suggest the need for BSIs to support earlier bedtimes and improve sleep duration and continuity by addressing modifiable behaviors. Tailored BSIs that consider socioecological influences on the development of sleep habits are needed.