Characterization of sleep efficiency transitions in family caregivers.

Family caregivers are at high risk of psychological distress and low sleep efficiency resulting from their caregiving responsibilities. Although psychological symptoms are associated with sleep efficiency, there is limited knowledge about the association of psychological distress with variations in sleep efficiency. We aimed to characterize the short- and long-term patterns of caregivers' sleep efficiency using Markov chain models and compare these patterns between groups with high and low psychological symptoms (i.e., depression, anxiety, and caregiving stress). Based on 7-day actigraphy data from 33 caregivers, we categorized sleep efficiency into three states, < 75% (S1), 75-84% (S2), and ≥ 85% (S3), and developed Markov chain models. Caregivers were likely to maintain a consistent sleep efficiency state from one night to the next without returning efficiently to a normal state. On average, it took 3.6-5.1 days to return to a night of normal sleep efficiency (S3) from lower states, and the long-term probability of achieving normal sleep was 42%. We observed lower probabilities of transitioning to or remaining in a normal sleep efficiency state (S3) in the high depression and anxiety groups compared to the low symptom groups. The differences in the time required to return to a normal state were inconsistent by symptom levels. The long-term probability of achieving normal sleep efficiency was significantly lower for caregivers with high depression and anxiety compared to the low symptom groups. Caregivers' sleep efficiency appears to remain relatively consistent over time and does not show rapid recovery. Caregivers with higher levels of depression and anxiety may be more vulnerable to sustained suboptimal sleep efficiency.

Cardiovascular Disease Incidence and Risk in Family Caregivers of Adults With Chronic Conditions: A Systematic Review.

BACKGROUND: Family caregivers experience psychological distress or physical strain that may lead to an increased risk of cardiovascular disease (CVD) morbidity and mortality. OBJECTIVE: This systematic review aimed to describe the current evidence and gaps in the literature on measures used to assess CVD outcomes in family caregivers, the association of caregiving with CVD incidence/risk outcomes, and associated factors in family caregivers of patients with chronic disease. METHODS: Medline, PubMed, CINAHL, Web of Science, and Google Scholar were searched for English-language, peer-reviewed studies published from 2008 to 2020 that examined CVD incidence and risk among family caregivers of adults with chronic conditions. RESULTS: Forty-one studies were included in this review. The measures used to assess CVD risk were categorized into biochemical, subclinical markers, components of metabolic syndrome, and global risk scores. Compared with noncaregivers, caregivers were more likely to have higher CVD incidence rates and objectively measured risk. Cardiovascular disease risks were also increased by their caregiving experience, including hours/duration of caregiving, caregivers' poor sleep status, psychological symptoms, poor engagement in physical/leisure activities, and care recipient's disease severity. CONCLUSIONS: Although there were limited longitudinal studies in caregivers of patients with diverse health conditions, we found evidence that caregivers are at high risk of CVD. Further research for various caregiver groups using robust methods of measuring CVD risk is needed. Caregiver factors should be considered in developing interventions aimed at reducing CVD risk for caregivers.

Perceived role overload and physical symptom experience among caregivers of older adults: The moderating effect of social support.

We investigated the association between perceived role overload and physical symptom experience, and the potential moderating effect of social support among caregivers of older adults. We analyzed data of 1,471 caregivers obtained from the 2017 National Study of Caregiving. In the survey, participants were assessed for physical symptoms (pain, limited leg strength, and low energy), symptom-related activity limitations, perceived role overload, and informal/formal support sources. We performed multiple logistic regression analyses with interaction terms. Caregivers who perceived higher role overload were more likely to experience the physical symptoms and frequent limited activities due to the symptoms. The associations of perceived role overload with pain and low energy, respectively, were attenuated among caregivers with high informal support. The moderating effect of formal support appeared to be the opposite in relation to pain. Caregivers who perceived high burden may benefit from their informal support to prevent detrimental effects of caregiving on physical health.

Association of obesity with arterial stiffness: The Multi-Ethnic Study of Atherosclerosis (MESA).

Arterial stiffness (AS) and obesity are recognized as important risk factors of cardiovascular disease (CVD). The purpose of this study was to investigate the relationship between AS and obesity. AS was defined as high augmentation index (AIx) and low elasticity (C1, large artery elasticity; C2, small artery elasticity) in participants enrolled in the Multi-Ethnic Study of Atherosclerosis at baseline. We compared AIx, C1, and C2 by body mass index (BMI) (< 25, 25-29.9, 30-39.9, ⩾ 40 kg/m2) and waist-hip ratio (WHR) (< 0.85, 0.85-0.99, ⩾ 1). The obesity-AS association was tested across 10-year age intervals. Among 6177 participants (62 ± 10 years old, 52% female), a significant inverse relationship was observed between obesity and AS. After adjustments for CVD risk factors, participants with a BMI > 40 kg/m2 had 5.4% lower AIx (mean difference [Δ] = -0.82%; 95% CI: -1.10, -0.53), 15.4% higher C1 (Δ = 1.66 mL/mmHg ×10; 95% CI: 1.00, 2.33), and 40.2% higher C2 (Δ = 1.49 mL/mmHg ×100; 95% CI: 1.15, 1.83) compared to those with a BMI < 25 kg/m2 (all p for trend < 0.001). Participants with a WHR ⩾ 1 had 5.6% higher C1 (∆ = 0.92 mL/mmHg ×10; 95% CI: 0.47, 1.37) compared to those with a WHR < 0.85. The WHR had a significant interaction with age on AIx and C2, but not with BMI; the inverse relationships of the WHR with AIx and C2 were observed only in participants < 55 years between the normal (WHR < 0.85) and the overweight (0.85 ⩽ WHR < 0.99) groups. Different associations of WHR and BMI with arterial stiffness among older adults should be further investigated.

RNA-sequencing analysis of differential gene expression associated with arterial stiffness.

OBJECTIVES: Arterial stiffness is recognized as an important predictor of cardiovascular disease morbidity and mortality, independent of traditional cardiovascular disease risk factors. Given that arterial tissue is not easily accessible, most gene expression studies on arterial stiffness have been conducted on animals or on patients who have undergone by-pass surgeries. In order to obtain a deeper understanding of early changes of arterial stiffness, this study compared transcriptome profiles between healthy adults with higher and lower arterial stiffness. METHODS: The sample included 20 healthy female adults without cardiovascular disease. Arterial stiffness was measured by carotid-femoral pulse wave velocity, the "gold-standard" measure of central arterial stiffness. Peripheral blood samples collected to PAXgene™ RNA tubes were used for RNA sequencing (RNA-seq). The potential confounding effects of age, body mass index, and mean arterial pressure were controlled for in RNA-seq analysis. To validate RNA-seq results, quantitative real-time PCR (qRT-PCR) was performed for six selected genes. RESULTS: The findings demonstrated that genes including CAPN9, IL32, ERAP2, RAB6B, MYBPH, and miRNA626 were down-regulated, and that MOCS1 gene was up-regulated among the people with higher arterial stiffness. Real-time PCR showed that the changes of CAPN9, IL32, ERAP2, and RAB6B were in concordance with RNA-seq data, and confirmed the validity of the gene expression profiles obtained by RNA-seq analysis. CONCLUSIONS: Previous studies have suggested the potential roles of CAPN9, IL32, and ERAP2 in structural changes of the arterial wall through up-regulation of metalloproteinases. However, the current study showed that CAPN9, IL32, and ERAP2 were down-regulated in the individuals with higher arterial stiffness, compared with those with lower arterial stiffness. The unexpected directions of expression of these genes may indicate an effort to maintain vascular homeostasis during increased arterial stiffness among healthy individuals. Further studies are guaranteed to investigate the roles of CAPN9, IL32, and ERAP2 in regulating arterial stiffness in people with and without cardiovascular disease.

Effects of Static Stretching Exercise on Lumbar Flexibility and Central Arterial Stiffness.

BACKGROUND: Previous studies have demonstrated that arterial stiffness is associated with lumbar flexibility (LF). Stretching exercise targeted to improve LF may have a beneficial effect on reducing arterial stiffness. OBJECTIVES: We examined the effects of a single bout of a structured, static stretching exercise on arterial stiffness, LF, peripheral and central blood pressure (BP), and heart rate (HR) and tested the association between LF and central arterial stiffness. METHOD: The study had a pretest-posttest design without a control group. Thirty healthy women followed a video demonstration of a 30-minute whole-body stretching exercise. Carotid-femoral pulse wave velocity (cf-PWV), augmentation index, LF, peripheral and central BP, and HR were measured before and after the stretching exercise. RESULTS: One bout of a static stretching exercise significantly reduced cf-PWV (t29 = 2.708, P = .011) and HR (t29 = 7.160, P = .000) and increased LF (t29 = 12.248, P < .000). Augmentation index and peripheral and central BP also decreased but did not reach statistical significance. Despite no association found between cf-PWV and LF, the larger increase in LF the subjects had, the larger decrease in cf-PWV they had after exercise (r = 0.500, P = .005). CONCLUSIONS: Study findings highlight the potential benefit of a static stretching exercise on central arterial stiffness, an independent predictor of cardiovascular morbidity. Static stretching exercise conducted in the sitting position may be used as an effective intervention to reduce cardiovascular risk after a cardiac event or for patients whose sympathetic function should not be overly activated or whose gaits are not stable.

Effects of Stretching Exercise on Heart Rate Variability During Pregnancy.

BACKGROUND: Little evidence exists for effects of low-intensity exercises such as stretching on cardiovascular health in pregnant women. AIM: Our aim was to evaluate the effect of a 20-minute stretching exercise on heart rate variability (HRV), blood pressure (BP), and heart rate (HR) in healthy pregnant women. METHODS: In 15 pregnant women with a mean (SD) age of 29.47 (4.07) years and mean (SD) gestational weeks of 26.53 (8.35), HRV, and BP were measured before and after the 20-minute stretching exercise. RESULTS: Compared with before the stretching exercise, standard deviation of the normal-to-normal intervals, total variability of heart rate, increased by 7.40 milliseconds (t = -2.31, P = .04) and root mean square of successive differences, a surrogate measure of parasympathetic outflow, also increased by 11.68 milliseconds (Z = -2.04, P = .04) after the stretching exercise. Diastolic BP and HR decreased by 2.13 mm Hg (t = 1.93, P = .07) and 3.31 bpm (t = 2.17, P = .05), respectively, but they did not reach statistical significance. DISCUSSION: These preliminary data suggest that 20 minutes of stretching exercise may promote cardiovascular health by attenuating the loss of parasympathetic tone associated with pregnancy.

Morning blood pressure surge and nighttime blood pressure in relation to nocturnal sleep pattern and arterial stiffness.

OBJECTIVE: The phenomenon of morning blood pressure (BP) surge (MBPS) is known to increase the risk for cardiovascular events and stroke. The purposes of this study were to explore associations between MBPS and nighttime BP and to examine arterial stiffness and sleep pattern in association with MBPS. METHODS: This study included 30 healthy Korean American women aged 25 to 60 years. Ambulatory BP was monitored for 24 hours. To evaluate MBPS, maximum morning BP(power) was calculated. Arterial stiffness was measured by carotid-femoral pulse wave velocity, and sleep pattern was evaluated using an actigraphy. RESULTS: The participants (n = 8) in the upper quartile of MBPS had higher morning systolic BPs (SBPs; P = 0.015) and lower nighttime diastolic BPs (P = 0.031). The MBPS in SBP was significantly increased in the participants who had a more wakeful night (P = 0.038) and who slept longer at night (P = 0.041). Although MBPS was not significantly related to arterial stiffness, higher morning SBP (P = 0.005), morning diastolic BP (P = 0.048), and prewake SBP (P = 0.005) were associated with arterial stiffness. CONCLUSIONS: Our findings imply a possible link between disturbed sleep and MBPS. Clinicians should understand the importance of the modification of altered sleep pattern for reducing MBPS in nonhypertensive participants.

Preventing obesity: exercise and daily activities of low-income pregnant women.

Low-income women are at risk for excessive gestational weight gain. Inactive lifestyle and lack of regular moderate exercise may contribute to the risk of weight gain. This study was conducted to (1) determine the rate and characteristics of low-income pregnant women who exercised regularly and met the American College of Obstetricians and Gynecologists recommendation and (2) describe how these women spent time for other physical activities compared with those who did not exercise regularly. Medicaid-recipient or uninsured pregnant women (n = 816) were asked to complete a physical activity questionnaire at rural and urban county health departments located in North Carolina. Twenty percent of low-income women met the American College of Obstetricians and Gynecologists recommendation for moderate exercise (≥10 METs-h/wk [metabolic equivalent task-hours per week]). The women who met the recommendation spent 3 hours 45 minutes per week walking as exercise, whereas those who did not meet the recommendation spent 1 hour per week (P < .0001). Women who exercised regularly spent longer hours at work (4.25 vs. 1.75 hours per day; P = .019) and on household tasks (5.25 vs. 4.0 hours per day; P = .002) than women who did not exercise regularly. Time spent on domestic and occupation activities does not seem to prohibit low-income women from engaging in moderate exercise on a regular basis.

Pulse wave velocity in Korean American men and women.

Arterial stiffness is an important clinical marker of cardiovascular diseases. Although many studies have been conducted on different racial groups, less is known about arterial stiffness in Asian Americans. Korean Americans constitute the fifth largest subgroup in the Asian American population and reportedly have a noticeably high prevalence of hypertension. The aims of this study were to assess arterial stiffness and blood pressure and to examine the effect of age and gender on arterial stiffness and blood pressure in 102 Korean American men and women aged 21 to 60 years. The values of arterial stiffness for Korean Americans in this study were compared to published reference values for other racial and ethnic groups. Arterial stiffness was measured by carotid-femoral pulse wave velocity, which is the gold standard for determining arterial stiffness. Findings indicated that aging was an important determinant of arterial stiffness, which increased linearly with age. Although there was no gender difference observed in arterial stiffness, the effect of age on arterial stiffness was greater in women than in men. After adjusting for covariates including age, body mass index, and smoking, multiple regression models showed that arterial stiffness and gender were significant predictors of systolic and diastolic blood pressure. The comparisons of these findings to those from several other studies that used the same method to measure arterial stiffness showed that Korean Americans may have levels of arterial stiffness that are similar to or slightly higher than those of other racial groups. Considering that arterial stiffness is an independent predictor of future development of hypertension, more studies are required to examine cardiovascular risk of this understudied group.

Examining factors affecting self-care-self-regulation among registered nurses using path analysis.

BACKGROUND: Practicing self-care is a requisite for nurses as they face the extreme physical, mental, and emotional challenges presented by the pandemic era. This study aimed to examine factors that contribute to self-care-self-regulation (SCSR) and investigate the mediation effect of psychological and physical health in the relationship between work stress and SCSR among registered nurses in the United States. MATERIALS AND METHODS: This cross-sectional study was conducted on the data collected from 386 registered nurses who completed an online survey over a 3-week period during the COVID-19 pandemic (April 19 to May 6, 2020). The survey assessed demographic and work-related characteristics, work stress, depressive mood, self-rated health, and SCSR. The model was tested with depressive mood as the first mediator and self-rated health as the second mediator. The potential serial mediation effect was analyzed using PROCESS macros adjusting for covariates. RESULTS: The sequential indirect effect of work stress on SCSR through depressive mood and self-rated health in series was significant, while its direct effect was not. CONCLUSION: The findings of the path analysis demonstrate that psychological and physical health status is important to promote self-care behaviors when nurses experience high work stress.

Sleep Deficiency by Caregiving Status: Findings From Nationally Representative Data.

OBJECTIVE: Caregiving demands may influence caregivers' sleep duration and quality, which are essential for optimal health. We aimed to examine the association between caregiving status and sleep deficiency (i.e., short sleep duration and/or poor quality) and identify factors associated with sleep deficiency among caregivers. METHODS: This secondary analysis used data from 3870 adults living in the United States, obtained from the 2019 Health Information National Trends Survey. Multinomial logistic regressions were performed to examine the association between caregiving status (i.e., caregivers vs. non-caregivers) and sleep status (i.e., normal duration-good quality [optimal sleep, reference], short duration-good quality, normal duration-poor quality, and short duration-poor quality), and to identify caregiving-related factors associated with sleep deficiency in the caregiver group. RESULTS: Compared to non-caregivers, caregivers were more likely to report short sleep duration (<7 hours) with good quality sleep (relative risk ratio [RRR] = 1.566, 95% CI [1.238, 1.980]) or poor quality sleep (RRR = 1.376, 95% CI [1.034, 1.832]) than the optimal sleep status. Caregivers providing care for ≥20 hours per week (vs. <20 hours) and providing care to individuals with dementia (vs. no dementia caregiving) were 2.8 times more likely to report normal sleep duration with poor sleep quality than optimal sleep (RRR = 2.796, 95% CI [1.125, 6.950]; RRR = 2.776, 95% CI [1.154, 6.675], respectively). CONCLUSION: The findings of a higher risk of sleep deficiency among caregivers suggest that health care providers need to assess both caregivers' sleep duration and quality status. Interventions tailored to the caregiving context are also warranted.

An Examination of Psychological Stress, Fatigue, Sleep, and Physical Activity in Chinese Americans.

Chinese Americans comprise the largest Asian subgroup in the U.S. Yet, little research has focused on the well-being of this population. This study aimed to (1) examine psycho-physiological health (psychological stress and fatigue) and lifestyle behaviors (sleep and physical activity) between Chinese Americans and whites, and (2) investigate whether race and lifestyle behaviors were independent predictors of psycho-physiological health. This study included 87 middle-aged healthy adults (41 Chinese Americans, 46 whites). Each participant underwent a two-night actigraphy-based sleep assessment. Chinese Americans reported higher psychological stress and fatigue, had poorer objective sleep outcomes (shorter sleep duration, lower sleep efficiency, and longer sleep onset), and engaged in lower physical activity levels than whites. Race and poor perceived sleep quality were independently associated with high psychological stress and fatigue. The findings warrant further exploration of social and cultural determinants of health in this minority group to reduce health disparities.

Exploring Experiences of Pain Management Among Family Caregivers of Community-Dwelling Older Adults With Dementia.

BACKGROUND: Pain is often underreported and under-treated in older adults with dementia. The role of family caregivers (FCGs) in managing pain for their loved ones with dementia living in community has been significantly burdensome. Surprisingly, research has not delved into the experiences of FCGs' concerning pain management in this context. METHODS: A qualitative descriptive study was conducted to gain a deep understanding of FCGs' experiences in managing pain for their loved ones. Family caregivers participated in semi-structured face-to-face or telephone interviews. Inclusion criterion included being an adult providing care to community-dwelling older adults with dementia. Recruitment stopped upon reaching thematic saturation. Basic demographic characteristics was also collected. Constant comparison analytic method was employed. RESULTS: The study included 25 FCGs in central Virginia, spanning ages from 29 to 95. Participants were predominantly white, female, married, and had a minimum high school education. Most of them were adult children (52%) or the spouses (28%) of the care recipients. Four thematic categories emerged around exploring FCGs' pain management experiences: (1) Values; (2) Barriers; (3) Support; and (4) Adaptation. Each theme included sub-themes. CONCLUSION: Family caregivers follow their values to make decisions in pain management. Barriers existed for effective pain management. Adaptation and support from professional or formal caregivers greatly improved FCGs' perception of their competence in pain management. The finding underscores the need for further research and the development of interventions aimed at enhancing FCGs' perception of self-efficacy in this crucial aspect of caregiving.

Determinants of Daytime Sleepiness Among Middle-Aged Adults.

Daytime sleepiness is highly prevalent in middle-aged adults and has a detrimental impact on their quality of life. Our study examined the psychological and behavioral determinants of daytime sleepiness among adults aged 35 to 64 years. The main variables of interest were psychological factors (perceived stress and anxiety), physical activity factors (moderate-to-vigorous physical activity and sedentary behaviors), and dietary factors (fat, sugar, fruit, and vegetable intake). Partial correlation and multiple linear regression were conducted to determine their associations with daytime sleepiness, with adjustment for covariates. Our sample included 87 adults with a mean age of 47 ± 9 years. About 21% met the criterion for excessive daytime sleepiness. Greater anxiety, longer time spent in sedentary behaviors, and higher consumption of foods rich in trans fat, sugar, and calories were independently associated with higher daytime sleepiness levels. Targeted interventions or treatments are warranted to address the identified risk factors for middle-aged adults.

Association of disrupted sleep with 24-hour blood pressure variability in caregivers.

BACKGROUND: A growing body of research highlights the negative impact of caregiving on cardiovascular disease (CVD) risk. OBJECTIVES: This study aimed to examine associations of psychological symptoms and sleep quality with 24-hour blood pressure variability (BPV), which is an independent predictor of CVD, among family caregivers of community-dwelling individuals with chronic illness. METHODS: For this cross-sectional study, we assessed caregiving burden and depressive symptoms using questionnaires and 7-day sleep quality (i.e., number of awakenings, wake after sleep onset, sleep efficiency) using an actigraph. The participants carried out a 24-hour ambulatory BP monitoring for systolic and diastolic BPV over 24 h and during awake/sleep times. We performed Pearson's correlations and multiple linear regression. RESULTS: The analytic sample consisted of 30 caregivers (25 female; mean age 62 years). The number of awakenings during sleep was positively correlated with systolic BPV-awake (r = 0.426, p = 0.019) and diastolic BPV-awake (r = 0.422, p = 0.020). Sleep efficiency was negatively correlated with diastolic BPV-awake (r = -0.368, p = 0.045). Caregiving burden and depressive symptoms were not correlated with BPV. After controlling for age and mean arterial pressure, the number of awakenings was significantly associated with increased systolic BPV-24 h (ß = 0.194, p = 0.018) and systolic BPV-awake (ß = 0.280, p = 0.002), respectively. CONCLUSIONS: Caregivers' disrupted sleep may play a role in increased CVD risk. While these findings should be confirmed in large clinical studies, improving sleep quality would need to be considered in CVD prevention for caregivers.

Multi-ancestry epigenome-wide analyses identify methylated sites associated with aortic augmentation index in TOPMed MESA.

Despite the prognostic value of arterial stiffness (AS) and pulsatile hemodynamics (PH) for cardiovascular morbidity and mortality, epigenetic modifications that contribute to AS/PH remain unknown. To gain a better understanding of the link between epigenetics (DNA methylation) and AS/PH, we examined the relationship of eight measures of AS/PH with CpG sites and co-methylated regions using multi-ancestry participants from Trans-Omics for Precision Medicine (TOPMed) Multi-Ethnic Study of Atherosclerosis (MESA) with sample sizes ranging from 438 to 874. Epigenome-wide association analysis identified one genome-wide significant CpG (cg20711926-CYP1B1) associated with aortic augmentation index (AIx). Follow-up analyses, including gene set enrichment analysis, expression quantitative trait methylation analysis, and functional enrichment analysis on differentially methylated positions and regions, further prioritized three CpGs and their annotated genes (cg23800023-ETS1, cg08426368-TGFB3, and cg17350632-HLA-DPB1) for AIx. Among these, ETS1 and TGFB3 have been previously prioritized as candidate genes. Furthermore, both ETS1 and HLA-DPB1 have significant tissue correlations between Whole Blood and Aorta in GTEx, which suggests ETS1 and HLA-DPB1 could be potential biomarkers in understanding pathophysiology of AS/PH. Overall, our findings support the possible role of epigenetic regulation via DNA methylation of specific genes associated with AIx as well as identifying potential targets for regulation of AS/PH.

Genome-Wide mRNA Expression Analysis of Acute Psychological Stress Responses.

INTRODUCTION: Most previous studies have examined the effects of acute psychological stress in humans based on select gene panels. The genomic approach may help identify novel genes that underline biological mechanisms of acute psychological stress responses. OBJECTIVE: This exploratory study aimed to investigate genome-wide transcriptional activity changes in response to acute psychological stress. METHODS: The sample included 40 healthy women (mean age 31.4 ± 11.6 years). Twenty-two participants had a stress experience induced by the Trier Social Stress Test (experimental group) and 18 did not (control group). Psychological stress levels and hemodynamic changes were assessed before and after the Trier Social Stress Test. Peripheral blood samples obtained before and after the Trier Social Stress Test were processed for mRNA sequencing. RESULTS: Psychological and hemodynamic stress parameters indicated that the Trier Social Stress Test induced moderate levels of stress in the experimental group. Six genes (HCG26, HCP5, HLA-F, HLA-F-AS1, LOC1019287, and SLC22A16) were up-regulated, and fi ve genes (CA1, FBXO9, SNCA, STRADB, and TRMT12) were down-regulated among those who experienced stress induction, compared with the control group. Nine genes of eleven were linked to endocrine system disorders, neurological disease, and organismal injury and abnormalities. CONCLUSIONS: Of the genes identifi ed in this study, HCP5, SLC22A16, and SNCA genes have previously been proposed as therapeutic targets for cancer and Parkinson disease. Further studies are needed to examine pathological mechanisms through which these genes mediate eff ects of psychological stress on adverse health outcomes. Such studies may ultimately identify therapeutic targets that enhance biological resilience to adverse eff ects of psychological stress.

Elucidation of obstructive sleep apnoea related blood pressure surge using a novel continuous beat-to-beat blood pressure monitoring system.

BACKGROUND: Obstructive sleep apnoea (OSA) episode related blood pressure (BP) surge may mediate the association of OSA with cardiovascular disease. However, BP is not measured during a clinical sleep study. METHOD: We tested the feasibility of incorporating the Caretaker physiological monitor, which utilizes a novel continuous beat-to-beat (b-b) BP monitoring technology, into polysomnography (PSG) and aimed to characterize BP surges related to obstructive respiratory events. B-b BP was concurrently collected and merged with PSG data on a posthoc basis. We compared BP surge between mean respiratory (apnoea, hypopnea and desaturation-alone events) and nonrespiratory events (spontaneous or leg movement-related arousals). We examined the association of the degree of oxygen desaturation with BP surge in a given respiratory event combining all events. A total of 17 consecutive patients (12 men, mean 52 years old, nine diagnostic and eight split-night PSGs) undergoing clinically indicated PSG were included after excluding one patient with poor signal quality due to excessive movement. RESULTS: Caretaker was well tolerated. Mean respiratory BP surge ranged from 5 to 19 mmHg [Median (IQR) = 13.9 (9.5--16.2)]. Mean BP surge between the respiratory and nonrespiratory events was similar [13.8 (4.5) vs. 14.9 (5.3) mmHg, P = 0.13]. Accounting for the count distribution of desaturation/BP surge data pair events, there was a linear correlation between the degree of oxygen desaturation and BP surge (R = 0.57, P < 0.001). In eight patients undergoing split-night sleep studies, the number of BP surge events (≥10 mmHg/h) decreased during continuous positive airway pressure in all but one patient. CONCLUSION: We demonstrated highly variable OSA-related BP surge patterns using the Caretaker's b-b BP monitoring technology that has the potential to be integrated into sleep studies.

Sleep moderates the association between arterial stiffness and 24-hour blood pressure variability.

BACKGROUND: Arterial stiffness and increased blood pressure variability (BPV) are important subclinical cardiovascular diseases (CVDs). Evidence is accumulating that poor sleep is associated with subclinical CVDs. The purpose of our study was to investigate how sleep was related to arterial stiffness and BPV. We also explored whether sleep moderated the association between arterial stiffness and BPV. METHODS: We conducted a cross-sectional study including 78 healthy adults aged between 35 and 64 years. Variables of interest were: 1) objective seep characteristics, assessed with a wrist actigraphy for two consecutive nights; 2) arterial stiffness, measured by carotid-femoral pulse wave velocity (cfPWV); and 3) BPV, measured using an ambulatory blood pressure monitor over 24 h and estimated by average real variability. RESULTS: Lower sleep efficiency was an independent predictor of higher cfPWV and higher systolic BPV, while longer wake after sleep onset (WASO) was an independent predictor of higher cfPWV only. In addition, cfPWV showed a positive relationship with systolic BPV, and this relationship was moderated by sleep efficiency and WASO, respectively. The relationship between cfPWV and systolic BPV became stronger among individuals who had a level of sleep efficiency lower than 84% and who had WASO higher than 67 min, respectively. CONCLUSION: Our study showed that poor sleep not only directly linked with arterial stiffness and BPV but also moderated the relationship between these two subclinical CVDs. These findings suggest that improving sleep quality could be a target intervention to promote cardiovascular health in clinical practice.