Adherence to a healthy sleep pattern and new-onset acute kidney injury

OBJECTIVES

To investigate the prospective association of individual sleep characteristics and a healthy sleep pattern with new-onset acute kidney injury in general population.

METHODS

The UK Biobank enrolled over 500,000 participants, aged 37-73years, across the UK from 2006 to 2010. Of these, 375,216 participants were included in the current study. A healthy sleep score, ranging from 0 to 5 points, was created by combining five major sleep characteristics, including sleep duration, chronotype, insomnia, snoring, and daytime sleepiness. New-onset acute kidney injury was defined by ICD-10 code N17, ascertained by primary care data, hospital inpatient data, death register records, or self-reported medical conditions.

RESULTS

During a median follow-up period of 12.0years, 14,492 (3.9%) participants developed acute kidney injury. Overall, the healthy sleep score was significantly inversely associated with the risk of new-onset acute kidney injury (per 1-point increment; hazards ratio, 0.95; 95%CI, 0.93-0.97), especially in nondiabetes (hazards ratio, 0.94; 95%CI, 0.92-0.96; vs. diabetes, hazards ratio, 1.01; 95%CI, 0.96-1.05; P-interaction=.008). The genetic predisposition of estimated glomerular filtration rate and acute kidney injury did not significantly modify the association between the healthy sleep score and acute kidney injury (both P-interactions >.05). Sleep 7-8 hours per day (vs. <7 hours or ≥9 hours; hazards ratio, 0.92; 95%CI, 0.88-0.96), early chronotype (vs. evening chronotype; hazards ratio, 0.93; 95%CI, 0.89-0.97), never or rarely insomnia (vs. sometimes/usually insomnia; hazards ratio, 0.93; 95%CI, 0.88-0.97) and no frequent daytime sleepiness (vs. often/always daytime sleepiness; hazards ratio, 0.90; 95%CI, 0.81-0.99) were significantly associated with a lower risk of new-onset acute kidney injury.

CONCLUSIONS

A healthy sleep pattern was significantly associated with a lower risk of new-onset acute kidney injury, regardless of the genetic risks.

Short report: relationship between self-reported sleep characteristics and falls-associated fractures in elderly individuals: a population-based study

Currently, the data for effect of sleep on falls-associated fractures in elderly individuals are still limited. This current study was aimed to assess the link between self-reported sleep characteristics and falls-associated fractures in elderly individuals. This study included a total of 20,497 participants from National Health and Nutritional Examination Survey (NHANES) 2005-2008, and 6,174 participants aged 45 years and older were identified. Self-reported sleep characteristics and conditions of falls-associated fractures of individuals were obtained via the method of personal questionnaires. In a total of 610 participants with exact history of fractures, 168 individuals with falls-associated fractures were identified, and the prevalence was 27.5%. The mean age of falls-associated fractures group was (72.1 ± 8.8) years, and the female (P < 0.001) occupied a higher proportion. Factors of living alone (P = 0.003), combined with hypertension (P = 0.003) and osteoporosis (P < 0.001), sleeping less or more (P = 0.009), and frequent snoring (P = 0.007) were linked to falls-associated fractures. Compared with sleep duration of 6 to 8 h/night, sleep duration of ≤4 h/night (odds ratio [OR] 1.858, 95% confidence interval [CI] 1.115-3.094) and of ≥9 h/night (OR 1.932, 95% CI 1.195-3.123) were related to an increased risk of falls-associated fractures. Collectively, our nationwide data noted that sleep characteristics were closely related to falls-associated fractures in elderly individuals, and a longer sleep duration may exhibit a protective effect against the falls-associated fractures, but it should be limited within 9 h/night.

Effect of antihypertensive medications on sleep status in hypertensive patients

Purpose

Antihypertensive medication is an effective way to control blood pressure. However, some studies reported that it may affect patients' sleep quality during the treatment. Due to the inconsistency of present results, a comprehensive systematic review and network meta-analysis are needed.

Methods

Electronic databases (MEDLINE, EMBASE, WEB OF SCIENCE, PUBMED) were searched up to April 10th, 2021 including no restriction of publication status. Randomized controlled trials (RCTs) or quasi-experimental studies or cohort studies were eligible. The network meta-analysis was used within a Bayesian framework.

Results

Finally, 16 publications (including 12 RCTs and 4 quasi-experimental studies) with 404 subjects were included in this study. Compared to placebo, the results of the network meta-analysis showed that diuretics were effective in improving sleep apnea with a mean difference (MD) of - 15.47 (95% confidence interval [CI]: - 23.56, - 6.59) which was consistent with the direct comparison result (MD: - 17.91; 95% CI - 21.60, - 14.23). In addition, diuretics were effective in increasing nocturnal oxygen saturation with an MD of 3.64 (95% CI 0.07, 7.46). However, the effects of β-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, and the others on sleep apnea were not statistically significant. Additionally, the effects of antihypertensive medication on the total sleep time (min), rapid eye movement (%), and sleep efficiency (%) were not statistically significant.

Conclusion

Our study found that diuretics could effectively reduce the severity of sleep apnea in hypertensive patients. However, the effects of antihypertensive drugs on sleep characteristics were not found.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-022-00391-8.

The relationship between preterm birth and sleep in children at school age: A systematic review

Premature birth (before 37 weeks of gestation) has been linked to a variety of adverse neurological outcomes. Sleep problems are associated with decreased neurocognitive functioning, which is especially common in children born preterm. The exact relationship between prematurity and sleep at school age is unknown. A systematic review is performed with the aim to assess the relationship between prematurity and sleep at school age (5th to 18th year of life), in comparison to sleep of their peers born full-term. Of 347 possibly eligible studies, nine were included. The overall conclusion is that prematurity is associated with earlier bedtimes and a lower sleep quality, in particular more nocturnal awakenings and more non-rapid eye movement stage 2 sleep. Interpretations and limitations of the review are discussed. Moreover, suggestions for future research are brought forward, including the need for a systematic approach with consistent outcome measures in this field of research. A better understanding of the mechanisms that influence sleep in the vulnerable group of children born preterm could help optimize these children's behavioral and intellectual development.

Using relaxation techniques to improve sleep during naps

Insufficient sleep is a common occurrence in occupational settings (e.g. doctors, drivers, soldiers). The resulting sleep debt can lead to daytime sleepiness, fatigue, mood disorder, and cognitive deficits as well as altered vascular, immune and inflammatory responses. Short daytime naps have been shown to be effective at counteracting negative outcomes related to sleep debt with positive effects on daytime sleepiness and performance after a normal or restricted night of sleep in laboratory settings. However, the environmental settings in the workplace and the emotional state of workers are generally not conducive to beneficial effects. Here, we tested whether relaxation techniques (RT) involving hypnosis might increase total sleep time (TST) and/or deepen sleep. In this study, eleven volunteers (aged 37-52) took six early-afternoon naps (30 min) in their occupational workplace, under two different conditions: control 'Naps' or 'Naps + RT' with a within-subjects design. Our results demonstrate that adding RT to naps changes sleep architecture, with a significant increase in the TST, mostly due to N2 sleep stage (and N3, to a lesser extent). Therefore, the deepening of short naps with RT involving hypnosis might be a successful non-pharmacological way to extend sleep duration and to deepen sleep in occupational settings.

Children born extremely preterm had different sleeping habits at 11 years of age and more childhood sleep problems than term-born children

AIM

This study explored whether extremely preterm (EPT) children had different sleep characteristics in childhood than children born at term and how neurodevelopmental disabilities (NDD) affected sleep in children born EPT.

METHODS

A Norwegian national cohort of 231 children born EPT from 1999 to 2000 and separate study data on 556 children born at term in 2001 were compared. Parental questionnaires mapped the children's current sleep habits at 11 years of age, namely the prevalence of sleep problems throughout childhood until this age and five categories of sleep problems. In addition, the EPT children were clinically assessed at five years of age.

RESULTS

The EPT children had different sleep habits than the controls, for example they went to bed earlier. EPT children had a higher prevalence of sleep problems than the controls throughout childhood (26% versus 14%, p < 0.001) and this was also higher for the 93 EPT children with no NDD (20%) than for the controls (14%) and increased with increasing NDD to 67% (p = 0.015) for the six children with severe NDD.

CONCLUSION

EPT children had different sleep habits to term-born controls at 11 years of age, including those with no NDD. The prevalence of sleep problems increased with increasing NDD.

Association Between Sleep Characteristics and Incident Dementia Accounting for Baseline Cognitive Status: A Prospective Population-Based Study

BACKGROUND

Although research has shown that sleep disorders are prevalent among people with dementia, the temporal relationship is unclear. We investigated whether atypical sleep characteristics were associated with incident dementia while accounting for baseline cognitive functioning.

METHODS

Screening Across the Lifespan Twin (SALT) study participants were 11,247 individuals from the Swedish Twin Registry who were at least 65 years at baseline (1998-2002). Sleep and baseline cognitive functioning were assessed via the SALT telephone screening interview. Data on dementia diagnoses came from national health registers. Cox regression was performed to estimate hazard ratios for dementia.

RESULTS

After 17 years of follow-up, 1,850 dementia cases were identified. Short (≤6 hours) and extended (>9 hours) time in bed (TIB) compared to the middle reference group (hazard ratio = 1.40, 95% confidence interval = 1.06-1.85; hazard ratio = 1.11, 95% confidence interval = 1.00-1.24, respectively) and rising at 8:00 AM or later compared to earlier rising (hazard ratio = 1.12, 95% confidence interval = 1.01-1.24) were associated with higher dementia incidence. Bedtime, sleep quality, restorative sleep, and heavy snoring were not significant predictors. Findings stratified by baseline cognitive status indicated that the association between short TIB and dementia remained in those cognitively intact at the start.

CONCLUSIONS

Short and extended TIB and delayed rising among older adults predicted increased dementia incidence in the following 17 years. The pattern of findings suggests that extended TIB and late rising represent prodromal features whereas short TIB appeared to be a risk factor for dementia.