The Relationship Between Blood Pressure and Sleep Duration in Turkish Children: A Cross-Sectional Study

Objective and subjective measures of sleep initiation are differentially associated with DNA methylation in adolescents

INTRODUCTION

The onset of puberty is associated with a shift in the circadian timing of sleep, leading to delayed sleep initiation [i.e., later sleep onset time (SOT)] due to later bedtimes and/or longer sleep onset latency (SOL). Several genome-wide association studies (GWAS) have identified genes that may be involved in the etiology of sleep phenotypes. However, circadian rhythms are also epigenetically regulated; therefore, epigenetic biomarkers may provide insight into the physiology of the pubertal sleep onset shift and the pathophysiology of prolonged or delayed sleep initiation.

RESULTS

The gene-wide analysis indicated differential methylation within or around 1818 unique genes across the sleep initiation measurements using self-report, actigraphy (ACT), and polysomnography (PSG), while GWAS-informed analysis yielded 67 genes. Gene hits were identified for bedtime (PSG), SOL (subjective, ACT and PSG) and SOT (subjective and PSG). DNA methylation within 12 genes was associated with both subjective and PSG-measured SOL, 31 with both ACT- and PSG-measured SOL, 19 with both subjective and ACT-measured SOL, and one gene (SMG1P2) had methylation sites associated with subjective, ACT- and PSG-measured SOL.

CONCLUSIONS

Objective and subjective sleep initiation in adolescents is associated with altered DNA methylation in genes previously identified in adult GWAS of sleep and circadian phenotypes. Additionally, our data provide evidence for a potential epigenetic link between habitual (subjective and ACT) SOL and in-lab SOT and DNA methylation in and around genes involved in circadian regulation (i.e., RASD1, RAI1), cardiometabolic disorders (i.e., FADS1, WNK1, SLC5A6), and neuropsychiatric disorders (i.e., PRR7, SDK1, FAM172A). If validated, these sites may provide valuable targets for early detection and prevention of disorders involving prolonged or delayed SOT, such as insomnia, delayed sleep phase, and their comorbidity.

Polymorphisms of Fat Mass and Obesity-Associated Gene in the Pathogenesis of Child and Adolescent Metabolic Syndrome

Childhood metabolic syndrome (MetS) is prevalent around the world and is associated with a high likelihood of suffering from severe diseases such as cardiovascular disease later in adulthood. MetS is associated with genetic susceptibility that involves gene polymorphisms. The fat mass and obesity-associated gene (FTO) encodes an RNA N6-methyladenosine demethylase that regulates RNA stability and molecular functions. Human FTO contains genetic variants that significantly contribute to the early onset of MetS in children and adolescents. Emerging evidence has also uncovered that FTO polymorphisms in intron 1, such as rs9939609 and rs9930506 polymorphisms, are significantly associated with the development of MetS in children and adolescents. Mechanistic studies reported that FTO polymorphisms lead to aberrant expressions of FTO and the adjacent genes that promote adipogenesis and appetite and reduce steatolysis, satiety, and energy expenditure in the carriers. The present review highlights the recent observations on the key FTO polymorphisms that are associated with child and adolescent MetS with an exploration of the molecular mechanisms underlying the development of increased waist circumference, hypertension, and hyperlipidemia in child and adolescent MetS.

Associations between sleep characteristics and risk for high blood pressure among students aged 9-18: A cross-sectional study in China

OBJECTIVE

The aim was to investigate the association of multidimensional sleep indicators with high blood pressure (HBP) of Chinese students.

METHODS

Participants in this cross-sectional study included 11561 students aged 9-18. Sleep was characterized by sleep timing (e.g., bedtime), sleep duration and sleep consistency (e.g., bedtime/wake-up time deviations and social jet lag (SJL)). We used odds ratios (OR) and 95% confidence intervals (95% CI) to assess the relationship between sleep and HBP.

RESULTS

Primary school students who slept 8.00-9.00h had a lower risk of HBP compared with sleeping >10h (OR 0.370, 95%CI 0.208, 0.658), while junior middle school students reporting ≤8.00h on weekday night had a lower risk of HBP compared with sleeping >10h (OR 0.303, 95%CI 0.111, 0.829). Moreover, compared with deviations = 0h, the OR (95%CI) for wake-up time deviations <0h and bedtime deviations >0h in primary school students with HBP were 0.314 (0.125, 0.790) and 2.155 (1.205, 3.853). Furthermore, compared with SJL = 0h, senior high school students reporting SJL = 0.01-0.50h, SJL = 0.51-1.00h and SJL = 1.01-2.00h had greater risk of HBP (OR 1.566, 95%CI 1.039, 2.361; OR 1.760, 95%CI 1.177, 2.631; OR 1.660, 95%CI 1.124, 2.452, respectively). Bedtime at night was associated with HBP for three educational periods students, however, there was no significant association between mid-day nap and HBP.

CONCLUSIONS

Sleep timing, sleep duration and sleep consistency are associated with high blood pressure in children and adolescents.

Sleep duration and risk of high blood pressure in Thai adolescents: the Thai National Health Examination Survey V, 2014 (NHES-V)

Background

Sleep duration has been proposed to be associated with high blood pressure. However, nationwide studies regarding this association in adolescents remain limited. This study aimed to explore the national prevalence of high blood pressure among Thai adolescents and to determine the association between sleep duration and high blood pressure.

Methods

Data from adolescents aged 10–19 years from the Thai National Health and Examination Survey V were included. We collected demographic data (including age and gender), height, weight, waist circumference, blood pressure, fasting blood chemistries and sleep duration data. Sleep durations were categorized as short, normal or long for each age group based on the United States National Sleep Foundation’s recommendations. High blood pressure was diagnosed using the 2017 guidelines of the American Academy of Pediatrics. Factors associated with high blood pressure were analyzed using multivariate logistic regression.

Results

A total of 3505 adolescents (1785 female) were included. The prevalence of high blood pressure was 9.4% (95% CI 8.5–10.4%). The high blood pressure group had higher BMI z-score, LDL-C, triglyceride and lower HDL-C than the normotensive group. In the multivariate analysis, BMI z-score, LDL-C and HDL-C were independently associated with high blood pressure. However, there was no association between sleep duration and high blood pressure.

Conclusions

High blood pressure risk was increased in adolescents with high BMI z-score. Neither short nor long sleep duration was associated with an increased risk of high blood pressure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14430-z.

Subjective sleep score is associated with central and peripheral blood pressure values in children aged 7-12 years

Shortened and poor-quality sleep have emerged as non-traditional risk factors for the development of hypertension in adults, and it is likely these relations extend to paediatric populations when evaluating sleep subjectively. Therefore, we aimed to evaluate subjective sleep metrics and their associations with central and peripheral blood pressure (BP) values in children. We hypothesized that poor-quality sleep and short sleep duration would be associated with elevated pressures in healthy children. Subjective sleep habits and sleep duration were evaluated using the Children's Sleep Habits Questionnaire (CSHQ) in 29 children aged 7-12 years (13 male/16 female). A total sleep score was generated by summing subscale scores: a higher score indicates poorer sleep habits. Peripheral BP was measured, and central pressures were estimated using pulse wave analysis. Pearson's r correlations were used to assess relations between total sleep score, sleep duration, and sleep score subscales with BP values. Sleep score was positively associated with central and peripheral systolic pressure (r = 0.43, p = 0.02 and r = 0.41, p = 0.03, respectively), diastolic pressure (r = 0.42, p = 0.02 and r = 0.36, p = 0.05, respectively) and mean arterial pressure (r = 0.40, p = 0.03 and r = 0.36, p = 0.03, respectively). Sleep duration was negatively associated with central and peripheral diastolic pressure (r = -0.40, p = 0.03 and r = -0.41, p = 0.03, respectively). Regarding the CSHQ subscales, daytime sleepiness and parasomnias were consistently positively associated with BP values. These findings support sleep as a primordial prevention target for hypertension and the maintenance of cardiovascular health during childhood. Consideration of a variety of sleep habits using tools such as the CSHQ may provide important insights into early-life cardiovascular risk.

Alterations in Rev-ERBα/BMAL1 ratio and glycated hemoglobin in rotating shift workers: the EuRhythDia study

OBJECTIVE

To detect premature gluco-metabolic defects among night shift workers with disturbances in circadian rhythms.

DESIGN AND METHODS

We performed a hypothesis-generating, cross-sectional analysis of anthropometric, metabolic, lipid, and inflammation parameters, comparing active (a-NSW, n = 111) and former (f-NSW, n = 98) rotating night shift workers with diurnal workers (controls, n = 69). All participants were hospital nurses. We also evaluated the Pittsburgh Sleep Quality Index (PSQI) and assessed expression of transcription factors REV-ERBα and BMAL1 in peripheral blood mononuclear cells (PBMCs), as indicators of the molecular clock.

RESULTS

Both a-NSW and f-NSW participants had significantly higher glycated hemoglobin (HbA1c) and white blood cell counts (WBC) (p < 0.001 for both), PSQI global score (p = 0.001) and diastolic blood pressure levels (p = 0.024) compared with controls. Expression of REV-ERBα/BMAL1 RNA in PBMC was significantly higher in a-NSW (p = 0.05) than in f-NSW or control participants. Multivariate regression analysis showed that working status and PSQI were independent determinants of higher HbA1c levels (p < 0.001).

CONCLUSIONS

We demonstrated that young, healthy night shift workers show subclinical abnormalities in HbA1c and changes in peripheral clock gene expression.

Blood Pressure in Childhood and Adolescence

Elevated blood pressure (BP) and hypertension commonly occur in children and adolescents and increase the risk of cardiovascular disease in adulthood. The purpose of this review is to summarize recent research in pediatric hypertension including changes in defining hypertension, BP measurement techniques, hypertension epidemiology, risk factors, treatment, and BP-related target organ damage. Defining pediatric hypertension using the 2017 American Academy of Pediatrics' updated Clinical Practice Guideline resulted in a larger proportion of children being classified as having elevated BP or hypertension compared with prior guidelines. Trends in the distribution of BP among US children and adolescents suggest that BP levels and the prevalence of hypertension may have increased from 2011-2014 to 2015-2018. Factors including a family history of hypertension, obesity, minority race/ethnicity, physical inactivity, high dietary intake of sodium, and poor sleep quality are associated with an increased prevalence of elevated BP and hypertension. Evidence of a linear relationship between systolic BP and target organ damage indicates that BP levels currently considered normal could increase the risk of target organ damage in childhood. Lifestyle changes, such as adhering to the Dietary Approaches to Stop Hypertension diet, are a central component of effectively reducing BP and have been shown to reduce target organ damage. Pharmacologic treatment using angiotensin-converting enzyme inhibitors and angiotensin receptor blockers is an effective and safe method for reducing BP among children with uncontrolled BP after implementing lifestyle changes. Research gaps in the prevention, detection, classification, and treatment of hypertension in children demonstrate opportunities for future study.

Effect of Sleep Disorders on Blood Pressure and Hypertension in Children

PURPOSE OF REVIEW

In this review, we aim to discuss the pathophysiologic basis of hypertension in sleep disorders and the current evidence in the medical literature linking sleep disorders and hypertension in children.

RECENT FINDINGS

The medical literature in adults is clear about the contribution of sleep disorders, poor sleep quality, and sleep deprivation to hypertension and increased cardiovascular risk. The literature on cardiovascular consequences of sleep disorders in children is not as robust, but there is some evidence of early cardiovascular changes in children with sleep deprivation and obstructive sleep apnea. Children with obstructive sleep apnea have increased sympathetic activation during sleep, blunted dipping, or elevated systolic or diastolic pressures. Although the literature on other sleep disorders such as narcolepsy and restless legs syndrome is scarce, there is evidence in adults and some recent supportive data in children.

Sleep Duration and Blood Pressure: Recent Advances and Future Directions

PURPOSE OF REVIEW

This review discusses the recent literature on subjectively and objectively assessed sleep duration in relation to hypertension risk and out-of-clinic blood pressure (BP) measures and highlights critical areas for future research.

RECENT FINDINGS

Sleep duration, particularly short sleep, may influence BP through disturbed autonomic balance, hormonal imbalances, increased adiposity and metabolic dysfunction, and disrupted circadian rhythms. Observational studies indicate that short and long sleep are associated with hypertension risk, reduced nocturnal dipping, and elevated morning BP, but evidence is stronger for short sleep. Experimental sleep restriction increases BP, while sleep extension may lower BP in prehypertensive individuals. Women and racial/ethnic minorities are more prone to the detrimental effects of short sleep on BP. Additional studies are warranted to clarify the association of objectively assessed sleep with BP level and diurnal pattern and to determine the sex- and race-specific effects of sleep restriction and extension on BP.

Sleep duration and blood pressure in children: Analysis of the pan-European IDEFICS cohort

The present study aims to examine the cross-sectional and longitudinal association between self-reported nocturnal sleep duration, blood pressure, and hypertension in European children, aged 2-9.9 years, participating in the IDEFICS project. Blood pressure (BP) and the main anthropometric indices were measured according to standardized procedures. Childhood elevated BP and hypertension were defined according to the European Society of Hypertension Guidelines for children and adolescents. Parents reported lifestyle and socio-demographic data. Nocturnal sleep duration was assessed as part of a parental 24-h recall and categorized as follows: (a) ≤9 hours/night; (b) >9 hours to ≤10 hours/night; (c) >10 hours to ≤11 hours/night; and (d) >11 hours/night. A complete set of variables included in the present analysis was provided by 7974 participants (boys/girls = 4049/3925) at the baseline survey (T0). Of them, 5656 were re-examined 2 years later at follow-up (T1). Children reporting shorter sleep duration at T0 had significantly higher BP values (P for trend < 0.001) compared to those who slept more. Prospective analyses showed that shorter sleep duration at baseline predicted, over the 2-year follow-up, higher increases in systolic blood pressure and diastolic blood pressure, after adjustment for age, sex, country of origin, BMI z-score, parental education, physical activity, screen time, and T0 value of the examined outcome variables (P for trend < 0.001). Our findings reveal that shorter sleep duration is associated with higher BP in childhood, suggesting that sleep may be a potential risk factor for hypertension later in life.