Sleep biology updates: Hemodynamic and autonomic control in sleep disorders

The Clinical Implication of Nocturia in Predicting Hypertension Among Working-Aged Koreans

BACKGROUND

Evidence has indicated that nocturia is a clinical manifestation of adverse health conditions, including cardiovascular diseases and metabolic disorders. However, previous studies are less available for the clinical implication of nocturia on the development of hypertension.

METHODS

Study participants were 32,420 working-aged Koreans (21,355 men and 11,065 women) who periodically received health checkups. They were categorized into 4 groups by the frequency of nocturia (never, <1, 1-2, and ≥3/week). We used Cox proportional hazards models to analyze the multivariable-adjusted hazard ratio (HR) and 95% confidence intervals (CIs) for incident hypertension (multivariable-adjusted HR [95% CI]) in relation to the frequency of nocturia. Subgroup analysis was conducted by gender and sleep quality (good and poor sleep quality).

RESULTS

In women, nocturia was associated with an increased risk of hypertension, compared with never nocturia (HR [95% CI]; never: reference, <1/week: 1.33 [1.10-1.60], 1-2/week: 1.26 [1.00-1.58], and ≥3/week: 1.34 [1.05-1.72]). This association was not observed in men (HR [95% CI]; never: reference, <1/week: 1.00 [0.93-1.08], 1-2/week: 1.00 [0.88-1.12], and ≥3/week: 1.06 [0.94-1.23]). In subgroup analysis by sleep quality, only women with good sleep quality showed an association between nocturia and the risk of hypertension. However, women with poor sleep quality and men did not show an association between the frequency of nocturia and the risk of hypertension.

CONCLUSIONS

Nocturia is a potential risk factor for incident hypertension in working-aged women with good sleep quality.

Moderating role of functional/ mobility limitations in the association between sleep problems and hypertension among middle-aged and older adults in India

Hypertension has become a global health concern and is recognized as an important modifiable risk factor for cardiovascular diseases (CVDs). There are very limited studies in India and worldwide focused on sleep problems, activities of daily living (ADL), instrumental ADL (IADL) and mobility limitations, and their discrete and combined effects on hypertension. Therefore, this study examined whether sleep problems are associated with hypertension, and whether the association is more pronounced among middle-aged and older adults with functional/mobility limitations. This study used data from the Longitudinal Ageing Study in India (LASI) wave 1, 2017-18, with a total sample of 59,951 adults aged 45 years and above. Log-binomial regression, and interaction terms were used to assess the relationship between sleep problems and hypertension, and the moderating effect of functional/mobility limitations. Respondents with sleep problems had a 29 % higher prevalence of hypertension [PR (prevalence ratio): 1.29; CI (confidence interval): 1.20-1.39]. Those with ADL and IADL limitations had 20 % [PR: 1.20; CI: 1.09-1.32] and 9 % [PR: 1.09; CI: 1.00-1.18] greater prevalence of hypertension. Interaction analysis revealed that individuals with ADL, IADL, and mobility limitations had 58 %, 52 %, and 45 % higher prevalence of hypertension, respectively, and was especially pronounced among women. Our findings highlight that improved sleep can reduce the prevalence of hypertension in middle-aged and older adults. Individuals with functional/mobility limitations may need additional care and support from their family members or the community, which could lower the prevalence of elevated blood pressure due to their sleep problems.

The Impact of Sleep Disorders on Cardiovascular Health: Mechanisms and Interventions

This comprehensive review article explores the intricate mechanisms at work and possible remedies for the connection between sleep issues and cardiovascular health. Sleep disorders, which include conditions like insomnia and sleep apnea, are drawing increasing amounts of attention due to their serious detrimental consequences on cardiovascular health. This article carefully examines the body of existing evidence to explain the intricate mechanisms that connect sleep disruptions to cardiovascular issues. Mechanisms include inflammation, disruption of the autonomic nervous system, endothelial dysfunction, and aberrant metabolic processes all have an impact on these pathways. The study also looks at a variety of existing and novel therapeutic modalities that aim to minimize the detrimental effects of sleep disruptions on cardiovascular health. This includes evaluating the effectiveness of lifestyle changes, pharmaceutical interventions, and behavioural therapy for enhancing sleep quality and hence preserving cardiovascular health. By synthesising and presenting the most recent study data, this article offers valuable insights into the complex relationships between sleep patterns, cardiovascular function, and potential therapeutics. These results provide a solid foundation for guiding future research endeavours and clinical judgements. Pharmacotherapy is a possibility for momentary relief. Cardiovascular illness has been linked to the sensorimotor problem known as restless legs syndrome (RLS), which causes a strong impulse to move the legs. Sleep disruption caused by RLS-related leg movements leads to sympathetic activation, elevated blood pressure, impaired vascular function, and potential iron deficiency. Treating the underlying iron deficiency, when present, and medications targeting dopamine receptors or regulating calcium channels are the primary interventions for RLS. In conclusion, sleep disorders significantly impact cardiovascular health through multiple mechanisms. Early detection, accurate diagnosis, and appropriate interventions are crucial for mitigating associated cardiovascular risks. Multidisciplinary approaches including lifestyle modifications, behavioral interventions, and targeted pharmacotherapy have shown promise in improving sleep quality and cardiovascular outcomes. Further research is needed to enhance our understanding of the complex interplay between sleep disorders and cardiovascular health, leading to the development of more effective interventions and improved patient outcomes.

Higher frequency of fish intake and healthy lifestyle behaviors may be associated with a lower platelet count in Japan: Implication for the anti-atherosclerotic effect of fish intake

BACKGROUND

Habitual fish intake and healthier lifestyles are associated with a lower risk of atherosclerotic cardiovascular disease (ASCVD). Higher platelet counts (PLCs) are reportedly associated with higher ASCVD events. We aimed to investigate the association between fish intake and lifestyle with PLCs.

METHODS

We conducted a cross-sectional study in a cohort of 9329 participants (average age: 46.9 ± 12.9 years; 58.9% men) with no history of ASCVD registered at the Health Planning Center of Nihon University Hospital in 2019.

RESULTS

The average fish intake frequency was 2.15 ± 1.28 days/week. As fish intake frequency increased (0, 1, 2, 3, 4, 5, 6, and 7 days), PLC decreased significantly (p < 0.0001). Multivariable logistic regression analysis showed that higher fish intake frequency tended to be a determinant of lower PLC. Aerobic exercise habits and sleep duration were independent negative determinants of PLC. Cigarette smoking habits were a positive independent determinant of PLC. Furthermore, with increasing fish intake frequency, the proportion of participants with habitual aerobic exercise, non-smoking habits, and longer sleep duration increased (p < 0.0001 for all). Higher n-3 polyunsaturated fatty acid (n-3 PUFA), calculated based on data from the Japanese National Health and Nutrition Survey, intake was associated with a lower PLC.

CONCLUSION

Higher fish intake and healthier lifestyle behaviors may be comprehensively associated with lower PLCs. The intake of N-3 PUFA with anti-inflammatory effects, rich in fish, may also be related to the lower PLC. This association may explain the preventive effects of fish intake on ASCVD risk.

Inadequate sleep duration may attenuate the anti-inflammatory effects of fish consumption in a healthy Japanese population: a cross-sectional study

High fish consumption may be associated with lower inflammation, suppressing atherosclerotic CVD (ASCVD). Long sleep duration, as well as short sleep, may contribute to inflammation, thus facilitating ASCVD. This study investigated the overall association between fish consumption, sleep duration and leucocytes count. We conducted a cross-sectional study between April 2019 and March 2020 with a cohort of 8947 apparently healthy participants with no history of ASCVD (average age, 46·9 ± 12·3 years and 59 % males). The average frequency of fish consumption and sleep duration were 2·13 ± 1·26 d/week and 6·0 ± 0·97 h/d. Multivariate linear regression analysis revealed that increased fish consumption was an independent determinant of sleep duration (β = 0·084, P < 0·0001). Additionally, habitual aerobic exercise (β = 0·059, P < 0·0001) or cigarette smoking (β = −0·051, P < 0·0001) and homoeostasis model assessment-insulin resistance (HOMA-IR) (β = −0·039, P = 0·01) were independent determinants of sleep duration. Furthermore, multivariate linear regression analysis identified fish consumption as an independent determinant of leucocytes count (β = −0·091, P < 0·0001). However, a significant U-shaped curve was found between leucocytes count and sleep duration, with 6–7 h of sleep as the low value (P = 0·015). Higher fish consumption may be associated with a lower leucocytes count in the presence of adequate sleep duration and healthy lifestyle behaviors. However, long sleep duration was also related to increased inflammation, even in populations with high fish consumption. Further studies are needed to clarify the causality between these factors.

Nonlinear associations between sleep duration and the risks of all-cause and cardiovascular mortality among the general adult population: a long-term cohort study

Objective

This study aims to investigate the correlation between sleep duration and all-cause and cardiovascular mortality in the general population.

Methods

A total of 26,977 participants aged ≥18 years were included in the analysis from the National Health and Nutrition Examination Survey (NHANES) database covering the period from 2005 to 2014. Data on cardiovascular and all-cause deaths were collected until December 2019. Sleep duration was assessed using a structured questionnaire, and participants were categorized into five groups based on their reported sleep duration (≤5, 6, 7, 8, or ≥9 h). Kaplan-Meier survival curves were employed to examine the mortality rates across different sleep duration groups. Multivariate Cox regression models were utilized to explore the association between sleep duration and mortality. Additionally, a restricted cubic spline regression model was employed to identify the non-linear relationship between sleep duration and all-cause and cardiovascular mortality.

Results

The average age of participants was 46.23 ± 18.48 years, with 49.9% of the subjects being male. Over a median follow-up period of 9.42 years, 3,153 (11.7%) participants died from all-cause mortality, among which 819 (3.0%) were attributed to cardiovascular causes. The groups with sleep durations of ≥9 and ≤5 h exhibited the lowest cumulative survival rates for all-cause mortality and cardiovascular mortality, respectively. When using a sleep duration of 7 h as the reference, the hazard ratios (with 95% confidence intervals) for all-cause mortality were 1.28 (1.14-1.44) for ≤5 h, 1.10 (0.98-1.23) for 6 h, 1.21 (1.10-1.34) for 8 h, and 1.53 (1.35-1.73) for ≥9 h. The hazard ratios (with 95% confidence intervals) for cardiovascular mortality were 1.32 (1.04-1.67) for ≤5 h, 1.22 (0.97-1.53) for 6 h, 1.29 (1.05-1.59) for 8 h, and 1.74 (1.37-2.21) for ≥9 h. A U-shaped non-linear relationship between sleep duration and all-cause and cardiovascular mortality was observed, with inflection point thresholds at 7.32 and 7.04 h, respectively.

Conclusion

The findings suggest that the risk of all-cause and cardiovascular mortality is minimized when sleep duration is approximately 7 h.

The past, present, and future of sleep quality assessment and monitoring

Sleep quality is considered to be an individual's self-satisfaction with all aspects of the sleep experience. Good sleep not only improves a person's physical, mental and daily functional health, but also improves the quality-of-life level to some extent. In contrast, chronic sleep deprivation can increase the risk of diseases such as cardiovascular diseases, metabolic dysfunction and cognitive and emotional dysfunction, and can even lead to increased mortality. The scientific evaluation and monitoring of sleep quality is an important prerequisite for safeguarding and promoting the physiological health of the body. Therefore, we have compiled and reviewed the existing methods and emerging technologies commonly used for subjective and objective evaluation and monitoring of sleep quality, and found that subjective sleep evaluation is suitable for clinical screening and large-scale studies, while objective evaluation results are more intuitive and scientific, and in the comprehensive evaluation of sleep, if we want to get more scientific monitoring results, we should combine subjective and objective monitoring and dynamic monitoring.

Progress of autonomic disturbances in narcolepsy type 1

Narcolepsy type 1 is a kind of sleep disorder characterized by a specific loss of hypocretin neurons in the lateral hypothalamus and reduced levels of hypocretin-1 in the cerebrospinal fluid. Hypocretin deficiency is associated with autonomic disorders. This article summarizes the autonomic disorders and possible mechanisms associated with narcolepsy type 1. Patients with narcolepsy type 1 often have various systemic autonomic symptoms, including non-dipping blood pressure, reduced heart rate variability, dynamic cerebral autoregulation impairment, reduced gastric motility and emptying, sleep-related erectile dysfunction, skin temperature abnormalities, and blunted pupillary light reflex. Similar findings should strengthen the recognition and intervention of these disturbances in clinical practice. In addition to hypocretin deficiency, current evidence also indicates that pharmacological therapy (including psychostimulants and anti-cataplectic drugs) and comorbidities may contribute to the alterations of autonomic system observed in narcolepsy type 1.

Sleep and risk of hypertension in general American adults: the National Health and Nutrition Examination Surveys (2015-2018)

OBJECTIVE

The purpose of research is to investigate the associations of sleep factors separately and jointly with risk of hypertension.

METHODS

The National Health and Nutrition Examination Surveys (NHANES) is a nationally representative survey. Participants aged over 20 years with complete and credible data from the NHANES 2015-2016 and 2017-2018 waves were included. Hypertension was assessed based on self-report medical diagnoses, or antihypertensive medication use, or systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg. Sleep information (sleep duration, trouble sleeping, daytime sleepiness, self-reported snoring and sleep-related breathing issue) was obtained from household interview.

RESULTS

Of 7426 participants, the mean (standard deviation) age was 48.0 (17.3) years, 3845 (51.8%) were females. The prevalence of hypertension was 32.8%, and lower in those with 7-9 h sleep, no trouble sleeping, no excessive daytime sleepiness, no snoring or sleep apnea symptoms, decreased as the quantity of healthy sleep factors increased. The self-reported short sleep (odds ratio [OR]: 1.25, 95% confidence interval [CI]: 1.02-1.54, P  = 0.032), trouble sleeping (OR: 1.53, 95% CI: 1.20 to 1.95, P  = 0.001), excessive daytime sleepiness (OR: 1.17, 95% CI: 1.01-1.35, P  = 0.041) and sleep apnea symptoms (OR: 1.33, 95% CI: 1.10-1.61, P  = 0.004) were associated with 25%, 53%, 17% and 33% increased risk of hypertension, respectively. Participants with a poor sleep pattern was associated with higher hypertension risk (OR: 2.47, 95% CI: 1.90-3.22, P  < 0.001).

CONCLUSION

Sleep behaviors were cross-sectionally associated with a considerably higher hypertension risk.

Altered regional cerebral blood flow in obstructive sleep apnea is associated with sleep fragmentation and oxygen desaturation

Altered cerebral perfusion has been reported in obstructive sleep apnea (OSA). Using dynamic susceptibility contrast MRI, we compared cerebral perfusion between male OSA patients and male healthy reference subjects and assessed correlations of perfusion abnormalities of OSA patients with sleep parameters and neuropsychological deficits at 3 T MRI, polysomnography and neuropsychological tests in 68 patients with OSA and 21 reference subjects. We found lower global and regional cerebral blood flow and cerebral blood volume, localized mainly in bilateral parietal and prefrontal cortices, as well as multiple focal cortical and deep structures related to the default mode network and attention network. In the correlation analysis between regional hypoperfusion and parameters of polysomnography, different patterns of regional hypoperfusion were distinctively associated with parameters of intermittent hypoxia and sleep fragmentation, which involved mainly parietal and orbitofrontal cortices, respectively. There was no association between brain perfusion and cognition in OSA patients in areas where significant association was observed in reference subjects, largely overlapping with nodes of the default mode network and attention network. Our results suggest that impaired cerebral perfusion in important areas of functional networks could be an important pathomechanism of neurocognitive deficits in OSA.

Relationship between Sleep and Hypertension: Findings from the NHANES (2007-2014)

Background: To evaluate the association of sleep factors (sleep duration, self-reported trouble sleeping, diagnosed sleep disorder) and combined sleep behaviors with the risk of hypertension. Methods: We analyzed 12,166 adults aged 30–79 years who participated in the 2007–2014 National Health and Nutrition Examination Survey. Sleep duration, self-reported trouble sleeping and sleep disorders were collected using a standardized questionnaire. We included three sleep factors (sleep duration, self-reported trouble sleeping and sleep disorder) to generate an overall sleep score, ranging from 0 to 3. We then defined the sleep pattern as “healthy sleep pattern” (overall sleep score = 3), “intermediate sleep pattern” (overall sleep score = 2), and “poor sleep pattern” (0 ≤ overall sleep score ≤ 1) based on the overall sleep score. The definition of hypertension was based on self-reported antihypertensive medication use or biological measurement (systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg). We used weighted logistic regression models to investigate the associations between sleep and hypertension. Results: The overall prevalence of hypertension was 37.8%. A short sleep duration (OR = 1.20, 95% CI: 1.08 to 1.33, p = 0.001), self-reported trouble sleeping (OR = 1.45, 95% CI: 1.28 to 1.65, p < 0.001) and sleep disorder (OR = 1.33, 95% CI: 1.07 to 1.66, p = 0.012) were related to the risk of hypertension. Poor sleep patterns were closely correlated with the risk of hypertension (OR = 1.90, 95% CI: 1.62 to 2.24). Conclusions: Participants with poor sleep patterns were associated with an increased risk for hypertension.

Hemodynamics Changes in the Phase Before, During, and After Sleep Based on Patients’ Sleep Quality in High Care Unit

BACKGROUND: Sleep is a human physiological need that must be fulfilled. Sleep disturbance is generally experienced by hospitalized patients and measured by sleep quality. Sleep disturbance can adversely affect hemodynamic parameters, physiological, and psychological outcome that contribute to the healing of patients. However, few literatures discussing the hemodynamic changes based on the patients’ sleep quality. AIM: The study aimed to describe the hemodynamic changes before, during, and after sleeping phases METHODS: This is an observational analytic quantitative study conducted between February and March 2019 and involved 45 patients. The samples were the conscious patients, aged between 18 and 60 years old (adult) and had been hospitalized for more than 2 days. The Richards-Campbell Sleep Questionnaire was utilized to measure the patients sleep quality, while hemodynamic values were observed by patients’ bedside monitor before, during and after sleep. Data analysis used the Friedman test to determine hemodynamic changes. RESULTS: The results showed that most respondents were female (75.6%), used oxygen (46.7%), sleep in supine position (55.6%), and average age of 35.47 (standard deviation [SD] = 9.581) years old. Patients’ sleep quality score was 44.27 (SD = 22.809), with the average days of treatment were 2.47 days (SD = 694). The average score of Hemodynamic Mean Arterial Pressure (MAP), Heart Rate (HR), and Oxygen saturation (SpO2) before sleeping was 97.64, 94.04, and 94.09, during sleeping was 89.87, 85.00, and 91.22 while after sleeping was 98.27, 97.56, and 97.89, respectively. There was a significant change in HR with p = 0.019, and there was no significant change in the MAP (p = 0.152) and SpO2 (p = 0.149) CONCLUSION: There were variations in hemodynamic score changes before, during, and after sleep, changes in MAP, HR, and SpO2 score within normal ranges. The high hemodynamic changes in the early phase, decrease during sleep, and rise again after sleep. HR is a hemodynamic parameter that significantly changes in those three phases. Monitoring of hemodynamic values in patients could be carried out in the before, during, and after sleep phases to determine the patients’ physiological and psychological condition so as to contribute the healing process.

Respiratory activity extracted from wrist-worn reflective photoplethysmography in a sleep-disordered population

OBJECTIVE

Respiratory activity is an essential parameter to monitor healthy and disordered sleep, and unobtrusive measurement methods have important clinical applications in diagnostics of sleep-related breathing disorders. We propose a respiratory activity surrogate extracted from wrist-worn reflective photoplethysmography validated on a heterogeneous dataset of 389 sleep recordings.

APPROACH

The surrogate was extracted by interpolating the amplitude of the PPG pulses after evaluation of pulse morphological quality. Subsequent multistep post-processing was applied to remove parts of the surrogate with low quality and high motion levels. In addition to standard respiration rate performance, we evaluated the similarity between surrogate respiratory activity and reference inductance plethysmography of the thorax, using Spearman's correlations and spectral coherence, and assessed the influence of PPG signal quality, motion levels, sleep stages and obstructive sleep apnea.

MAIN RESULTS

Prior to post-processing, the surrogate already had a strong similarity with the reference (correlation = 0.54, coherence = 0.81), and reached respiration rate estimation performance in line with the literature (estimation error = 0.76± 2.11 breaths/min). Detrimental effects of low PPG quality, high motion levels and sleep-dependent physiological phenomena were significantly mitigated by the proposed post-processing steps (correlation = 0.62, coherence = 0.88, estimation error = 0.53± 1.85 breaths/min).

SIGNIFICANCE

Wrist-worn PPG can be used to extract respiratory activity, thus allowing respiration monitoring in real-world sleep medicine applications using (consumer) wearable devices.

Haemodynamic effects of hyperventilation on healthy men with different levels of autonomic tone

The topicality of the research is stipulated by insufficient study of the correlation between the functional state of the cardiorespiratory system and autonomic tone. The goal of the research was to analyze the changes of central haemodynamics with 10-minute regulated breathing at the rate of 30 cycles per minute and within 40 minutes of recovery after the test in healthy young men with different levels of autonomic tone. Records of the chest rheoplethysmogram were recorded on a rheograph KhAI-medica standard (KhAI-medica, Kharkiv, Ukraine), a capnogram - in a lateral flow on a infrared capnograph (Datex, Finland), and the duration of R-R intervals was determined by a Polar WIND Link in the program of Polar Protrainer 5.0 (Polar Electro OY, Finland). Systolic and diastolic blood pressure were measured by Korotkov’s auscultatory method by mercury tonometer (Riester, Germany). The indicator of the normalized power of the spectrum in the range of 0.15–0.40 Hz was evaluated by 5-minute records; three groups of persons were distinguished according to its distribution at rest by the method of signal deviation, namely, sympathicotonic, normotonic and parasympathicotonic. The initial level of autonomic tone was found to impact the dynamics of СО2 level in alveolar air during hyperventilation and during recovery thereafter. Thus, PetCО2 was higher (41.3 mm Hg) in parasympathicotonic than in sympathicotonic (39.3 mm Hg) and normotonic (39.5 mm Hg) persons. During the test, R-R interval duration decreased being more expressed in normotonic persons. At the same time, the heart index was found to increase in three groups, and general peripheral resistance – to decrease mostly in normo- and parasympathicotonic persons. In addition, the reliable increase of stroke index and heart index was found in these groups. In the recovery period after hyperventilation, the decrease of tension index and ejection speed was found in normo- and, particularly, parasympathicotonic compared with sympathicotonic men and the increase of tension phase and ejection phase duration.

Changes in heart rate and blood pressure during nocturnal hot flashes associated with and without awakenings

Hot flashes (HFs) are a hallmark of menopause in midlife women. They are beyond bothersome symptoms, having a profound impact on quality of life and wellbeing, and are a potential marker of cardiovascular (CV) disease risk. Here, we investigated the impact on CV functioning of single nocturnal HFs, considering whether or not they were accompanied by arousals or awakenings. We investigated changes in heart rate (HR, 542 HFs), blood pressure (BP, 261 HFs), and pre-ejection period (PEP, 168 HFs) across individual nocturnal physiological HF events in women in the menopausal transition or post-menopause (age: 50.7 ± 3.6 years) (n = 86 for HR, 45 for BP, 27 for PEP). HFs associated with arousals/awakenings (51.1%), were accompanied by an increase in systolic (SBP; ~6 mmHg) and diastolic (DBP; ~5 mmHg) BP and HR (~20% increase), sustained for several minutes. In contrast, HFs occurring in undisturbed sleep (28.6%) were accompanied by a drop in SBP and a marginal increase in HR, likely components of the heat dissipation response. All HFs were accompanied by decreased PEP, suggesting increased cardiac sympathetic activity, with a prolonged increase for HFs associated with sleep disruption. Older age predicted greater likelihood of HF-related sleep disturbance. HFs were less likely to wake a woman in rapid-eye-movement and slow-wave sleep. Findings show that HFs associated with sleep disruption, which are in the majority and more likely in older women, lead to increases in HR and BP, which could have long-term impact on nocturnal CV restoration in women with multiple HFs.

Neurological Sleep Disorders and Blood Pressure: Current Evidence

Hypertension is a major determinant of cardiovascular morbidity and mortality and is highly prevalent in the general population. While the relationship between sleep apnea and increased blood pressure has been well documented, less recognized is emerging evidence linking sleep-related movement disorders such as restless legs syndrome/periodic limb movements of sleep and sleep-related bruxism with blood pressure (BP) dysregulation and hypertension. There is also recent literature linking narcolepsy-cataplexy with elevated BP and altered pressor responses, and there are data suggesting abnormal BP control in rapid eye movement sleep behavior disorder. It is thought that neural circulatory mechanisms, sympathetic activation in particular, comprise the predominant mediator underlying elevated BP in these neurological sleep disorders. There is very limited evidence that treating these sleep disorders may be beneficial in lowering BP primarily because this question has received very little attention. In this review, we discuss the potential pathophysiologic mechanisms underlying elevated BP in restless legs syndrome/periodic limb movements of sleep, sleep-related bruxism, narcolepsy-cataplexy, and rapid eye movement sleep behavior disorder. We also examine the relationship between these sleep disorders and elevated BP and the impact of treatment of these conditions on BP control. Last, we discuss gaps in the literature evaluating the associations between these sleep disorders and elevated BP and identify areas for further research.

Longitudinal effect of nocturnal R-R intervals changes on cardiovascular outcome in a community-based cohort

RATIONALE

Sleep-disordered breathing (SDB) is strongly linked to adverse cardiovascular outcomes (cardiovascular diseases (CVD)). Whether heart rate changes measured by nocturnal R-R interval (RRI) dips (RRI dip index (RRDI)) adversely affect the CVD outcomes is unknown.

OBJECTIVES

To test whether nocturnal RRDI predicts CVD incidence and mortality in the Wisconsin Sleep Cohort study (WSCS), independent of the known effects of SDB on beat-to-beat variability.

METHODS

The study analysed electrocardiograph obtained from polysomnography study to assess the nocturnal total RRDI (the number of RRI dips divided by the total recording time) and sleep RRDI (the number of RRI dips divided by total sleep time). A composite CVD risk as a function of total and sleep RRDI was estimated by Cox proportional hazards in the WSCS.

RESULTS

The study sample consisted of 569 participants from the WSCS with no prior CVD at baseline were followed up for up to 15 years. Nocturnal total RRDI (10-unit change) was associated with composite CVD event(s) (HR, 1.24 per 10-unit increment in RRDI (95% CI 1.10 to 1.39), p<0.001). After adjusting for demographic factors (age 58±8 years old; 53% male; and body mass index 31±7 kg/m²), and apnoea-hypopnoea index (AHI 4%), individuals with highest total nocturnal RRDI category (≥28 vs<15 dips/hour) had a significant HR for increased incidence of CVD and mortality of 7.4(95% CI 1.97 to 27.7), p=0.003). Sleep RRDI was significantly associated with new-onset CVD event(s) (HR, 1.21 per 10-unit increment in RRDI (95% CI 1.09 to 1.35), p<0.001) which remained significant after adjusting for demographic factors, AHI 4%, hypoxemia and other comorbidities.

CONCLUSION

Increased nocturnal RRDI predicts cardiovascular mortality and morbidity, independent of the known effects of SDB on beat-to-beat variability. The frequency of RRDI is higher in men than in women, and is significantly associated with new-onset CVD event(s) in men but not in women.

The interplay between neuroendocrine and sleep alterations following traumatic brain injury

BACKGROUND

Sleep and endocrine disruptions are prevalent after traumatic brain injury (TBI) and are likely to contribute to morbidity.

OBJECTIVE

To describe the interaction between sleep and hormonal regulation following TBI and elucidate the impact that alterations of these systems have on cognitive responses during the posttraumatic chronic period.

METHODS

Review of preclinical and clinical literature describing long-lasting endocrine dysregulation and sleep alterations following TBI. The bidirectional relationship between sleep and hormones is described. Literature describing co-occurrence between sleep-wake disturbances and hormonal dysregulation will be presented. Review of literature describing cognitive effects of seep and hormones. The cognitive and functional impact of sleep disturbances and hormonal dysregulation is discussed within the context of TBI.

RESULTS/CONCLUSIONS

Sleep and hormonal alterations impact cognitive and functional outcome after TBI. Diagnosis and treatment of these disturbances will impact recovery following TBI and should be considered in the post-acute rehabilitative setting.

Controversies in the 2017 ACC/AHA Hypertension Guidelines: Who Can Be Eligible for Treatments Under the New Guidelines? - An Asian Perspective

Until the 2017 ACC/AHA Hypertension Guidelines were released, the target blood pressure (BP) for adults with hypertension (HTN) was 140/90 mmHg in most of the guidelines. The new 2018 ESC/ESH, Canadian, Korean, Japan, and Latin American hypertension guidelines have maintained the <140/90 mmHg for the primary target in the general population and encourage reduction to <130/80 if higher risk. This is more in keeping with the 2018 American Diabetes Association guidelines. However, the 2017 ACC/AHA guidelines classify HTN as BP ≥130/80 mmHg and generally recommend target BP levels below 130/80 mmHg for hypertensive patients independently of comorbid disease or age. Although the new guidelines mean that more people (nearly 50% of adults) will be diagnosed with HTN, the cornerstone of therapy is still lifestyle management unless BP cannot be lowered to this level; thus, more people will require BP-lowering medications. To date, there have been many controversies about the definition of HTN and the target BP. Targeting an intensive systolic BP goal can increase the adverse effects of multiple medications and the cardiovascular disease risk by excessively lowering diastolic BP, especially in patients with high risk, including those with diabetes, chronic kidney disease, heart failure, and coronary artery disease, and the elderly. In this review, we discuss these issues, particularly regarding the optimal target BP.