Inverse Relationship between Sleep Duration and Cardio-Ankle Vascular Index in Children

The impact of dietary and sleep rhythms on blood pressure in children and adolescents: a cross-sectional study

Evidence about the relationship between meal and sleep time and CVD in children is scarce. The aims of this study were to describe the association between life rhythm patterns and blood pressure in children. This research was conducted among 5,608 children aged 6 to 15 years old in Chongqing and Sichuan provinces in 2021 and 2022. Dietary and sleep rhythms information was collected. The time of the first meal and last meal, and sleep time, were obtained. The mean age was 10.48 ± 2.24 years old, with 2958 (52.75%) male participants. The mean feeding window on weekdays was 11.69 h, 12.42 h, and 13.23 h for participants aged 6-7 years old, 8-12 years old and 13-15 years old, respectively. Weekday feeding window and last mealtime were positively correlated with blood pressure levels. And the changes in the feeding window between weekdays and weekends were significantly correlated with BP. Sleep duration and change in wake time were significantly correlated with SBP. Based on these results, this study identified the optimal combination of dietary and sleep rhythm interventions for children younger than 12 years of age and aged 12 and older, respectively. Disorder dietary and sleep rhythms disorders may correlate with elevated blood pressure levels, suggesting developing optimal dietary and sleep rhythm patterns could prevent the incidence of CVDs in children. The optimal dietary rhythm was defined by the indexes of breakfast time, dinner time and daily feeding window. As good meal patterns are defined as satisfied the following three items: for children younger than 12 years should have breakfast after 7:30 am; aged 12 years and over should have breakfast after 7 am; having dinner before 6 pm; daily feeding window less than 12.5 h. And less optimal dietary rhythm should satisfy any condition or eat dinner between 6 pm and 8 pm; and poor dietary rhythm should not satisfy any of the three criteria and eat dinner after 8 pm. Children with optimal dietary rhythm (in group A) had lower SBP (P < 0.001), DBP (P = 0.002) and MAP (P < 0.001) than those in group C.

Non-linear relationship between sleep duration and blood pressure in children with short stature

Background

Evidence regarding the relationship between sleep duration and blood pressure is controversial. Therefore, the aim of this study was to investigate the relationship between sleep duration and blood pressure in children with short stature.

Methods

A total of 1,085 participants with short stature were enrolled from the Affiliated Hospital of Jining Medical University in China. The variables involved in this study included sleep duration, anthropometric indicators and biochemical parameters. Sleep duration was evaluated in a face-to-face interview.

Results

The average age of the 1,085 selected participants was 10.2 ± 3.5 years old, and approximately 763 (70.32%) of them were male. The results of adjusted linear regression showed that sleep duration was negatively associated with systolic blood pressure z scores (SBP-Z) and diastolic blood pressure z scores (DBP-Z) after adjusting for confounders (β -0.07, 95% CI -0.13, -0.01 P = 0.038; β -0.05, 95% CI -0.10, -0.01 P = 0.035, respectively). A nonlinear relationship was detected between sleep duration and blood pressure, including SBP-Z, DBP-Z and mean arterial pressure z scores (MAP-Z). The inflection point of the nonlinear relationship between sleep duration and SBP-Z is 10 h, and the inflection point of DBP-Z and MAP-Z is 8 h.

Conclusion

This study revealed a nonlinear relationship between sleep duration and blood pressure in children with short stature. The findings suggest that the optimal sleep duration in children with short stature was 8-10 h, and sleep durations either too short or too long were associated with increased blood pressure levels.

Association of Sleep Duration and Cardio-Ankle Vascular Index in Community-Dwelling Older Adults

AIM

This study aims to investigate the association of the Cardio-Ankle Vascular Index (CAVI) with self-reported sleep duration and sleep quality in community-dwelling older adults aged ≥ 65 years.

METHODS

The Tarumizu Study was a cohort of community-based health checkups conducted in the Tarumizu City, Japan, in 2018 and 2019. In total, 997 participants aged ≥ 65 years (median age, 74 years) were examined. We obtained the average sleep duration and sleep quality using self-reported questionnaires and classified them into three separate groups according to sleep duration (＜6 h, 6-8 h, and ≥ 8 h) and sleep quality (good, medium, and poor). The arterial stiffness was measured using the CAVI.

RESULTS

As per our findings, the CAVI was significantly higher in the ≥ 8 h sleep group (CAVI=9.6±1.3) than in the ＜6 h (CAVI=9.1±1.1) or 6-8 h (CAVI=9.1±1.2) groups (p＜0.001). After adjustment for age, sex, systolic blood pressure, current smoking status, body mass index, frequency of exercise, educational background, frailty, sleep medication, sleep quality, and nap duration, multivariable regression analysis demonstrated that the CAVI was significantly higher in the ≥ 8 h group than in the 6-8 h group (p=0.016). In contrast, multivariable regression analysis showed that there was no significant association between sleep quality and CAVI.

CONCLUSIONS

A significant association was noted between long sleep duration (≥ 8 h) and elevated CAVI in community-dwelling older adults aged ≥ 65 years. We, therefore, suggest that long sleep duration, not sleep quality, is correlated with arterial stiffness in older adults.

Hypertension and Associated Risk Factors among Children with Intellectual Disability: A Cross-Sectional Study

To investigate the prevalence of hypertension and associated risk factors in Chinese children with intellectual disability, a cross-sectional study was conducted in a sample of 558 children with intellectual disability aged 6–18 years in Hong Kong, and 452 (81.0%) with valid data were included in the data analysis. Blood pressure was measured according to a standard protocol. Hypertension was defined using the age-, gender-, and height-specific classification criteria recommended by the 2018 Chinese Guidelines for Children. Multivariate and hierarchical logistic regression was fitted to examine the associations of hypertension with potential risk factors. Overall, 31.4% of the participants were classified as having hypertension. Obese children were more likely to develop hypertension than non-obese children (adjusted OR = 2.77, 95% CI: 1.28, 5.99, p = 0.010). A paternal education of college or above and a paternal occupation of clerks, sales representatives, and workers were also associated with an increased risk of hypertension. The prevalence of hypertension is high among Chinese children with intellectual disability. Obesity was the strongest risk factor. Further longitudinal studies are warranted to confirm our findings. Nevertheless, preventions against obesity are promising to receive doubled benefits in reducing both obesity and hypertension, given its strong relationship with hypertension in this special population.

Predictive ability of arterial stiffness parameters for renal function decline: a retrospective cohort study comparing cardio-ankle vascular index, pulse wave velocity and cardio-ankle vascular index 0

OBJECTIVE

The relative usefulness of arterial stiffness parameters on renal function remains controversial. This study aimed to compare the predictive ability of three arterial stiffness parameters at baseline; cardio-ankle vascular index (CAVI), heart-ankle pulse wave velocity (haPWV) and CAVI 0 , a variant of CAVI that theoretically excludes dependence on blood pressure, for renal function decline in Japanese general population.

METHODS

A total of 27 864 Japanese urban residents without renal impairment at baseline who participated in two to eight consecutive (mean 3.5 ± 1.7 times) annual health examinations were studied.

RESULTS

During the study period, 6.6% of participants developed renal function decline (estimated glomerular filtration rate <60 ml/min per 1.73 m 2 ), all of whom had relatively high values in all arterial stiffness parameters. In receiver-operating characteristic curve analysis, the discriminatory power for renal function decline showed a decreasing trend of CAVI to haPWV to CAVI 0 (C-statistic: 0.740 vs. 0.734 vs. 0.726). The cut-offs were CAVI 8.0, haPWV 7.23 and CAVI 0 11.6. In Cox-proportional hazards analysis for increase of each parameter above cut-off or by 1 standard deviation (SD) adjusted for two models of confounders, only CAVI always contributed significantly to renal function decline. Restricted cubic spline regression analysis suggested that CAVI most accurately reflected the risk of renal function decline.

CONCLUSION

Increase in arterial stiffness parameters, especially CAVI, may represent a major modifiable risk factor for renal function decline in the general population. Further research is needed to examine whether CAVI-lowering interventions contribute to the prevention of chronic kidney disease.

The Role of Cardio-Ankle Vascular Index as a Predictor of Mortality in Patients on Maintenance Hemodialysis

Aim

Mortality rate of maintenance hemodialysis patients is known to be high. Cardio-ankle vascular index (CAVI) is an index reflecting the proper stiffness of the arterial tree from the origin of the aorta to the ankle. We aimed to clarify the utility of CAVI as a predictor of mortality in hemodialysis patients. The roles of age and nutritional conditions on survival were also examined.

Methods

We followed 242 patients undergoing hemodialysis for 6 consecutive years. Data from 209 patients (mean age was 60 ± 11 years) excluding those with ankle-brachial index <0.90 were then analyzed. CAVI and heart to ankle pulse wave velocity (haPWV) were measured using Vasera 1500.

Results

Thirty-eight hemodialysis patients who died during the 6-year period had higher age, cardiothoracic ratio (CTR), CAVI, and haPWV, and lower diastolic blood pressure, albumin, phosphate, and calcium phosphate product. The Kaplan–Meier curves for cumulative survival among the tertile groups showed that the mortality rate was higher in the highest tertile (T3) compared to T1/T2 for both CAVI and haPWV. Receiver operating characteristic (ROC) analysis revealed that CAVI had better discriminatory power for all-cause mortality compared to haPWV. In the Cox-proportional hazards analyses, 1 SD increase in both parameters contributed independently to all-cause mortality [CAVI: HR 1.595 (95% CI 1.108–2.297), haPWV: HR 1.695 (95% CI 1.185–2.425)], as well as age and CTR. Both parameters above the cut-offs estimated in the ROC analysis (CAVI ≥ 9.2, haPWV ≥ 8.9) also had independent contributions to mortality.

Conclusion

Through the 6 consecutive years of follow-up in 209 HD patients, increased CAVI might represent a major modifiable risk factor for all-cause mortality. Further research is needed to examine whether CAVI-lowering interventions contribute to improved prognosis.

Evaluation of body mass index and related lifestyle factors among 14-17-year-old Turkish adolescents

OBJECTIVE:

During adolescence, unhealthy body weight status is considered as a global concern as it may lead to adverse health consequences in adulthood, therefore evaluation of the risk factors is crucial. The aim of the study was to determine the prevalence of adolescents under the risk of being underweight, overweight, and obese among 14–17-year-old Turkish adolescents. In addition, we examined the association between unhealthy body weight categories and lifestyle factors.

METHODS:

This study was designed as cross-sectional study which included body weight status and associated parameters of 1561 adolescents aged between 14 and 17 who were registered 25 different high schools in Istanbul, Uskudar. Height and body weight of participants were measured and related factors were obtained through a questionnaire. Differences in distributions were analyzed using the Chi-square test and to control confounding factors, multivariate logistic regression analysis was performed. As statistical significance limit of p<0.05 was determined.

RESULTS:

Body mass index (BMI) percentile analyses indicated that 3.6% of participants were underweight, 14.3% were overweight, and 13.8% were obese. We demonstrated that age, gender, and school types were statistically very significantly associated with BMI (p<0.001) and daily meal frequency, eating speed, and mealtime regularity were significantly related with BMI (p<0.05). In addition, according to multivariate analysis results, gender and school types were closely related with obesity among 14–17-year old Turkish adolescents.

CONCLUSION:

This study has been demonstrated that frequency of adolescent obesity in Istanbul, Turkey, has increased and obesity closely related to gender and type of school. Further educational and interventional studies should be organized in this region with consideration of relevant risk factors.

Effects of sleep deprivation on endothelial function in adult humans: a systematic review

Sleep deprivation is highly prevalent and is associated with increased cardiovascular disease (CVD) morbidity and mortality. Age-related alterations in sleep and chronobiology may exaggerate CVD susceptibility in older individuals. The mechanisms responsible for the association between sleep deprivation and CVD are not fully understood, but endothelial dysfunction may play a central role. Our objective was to conduct a systematic literature review to evaluate the evidence on the effects of sleep deprivation on endothelial function (EF). This review adhered to the PRISMA guidelines and was pre-registered with PROSPERO (#CRD42020192485, 07/24/2020). We searched PubMed, Web of Science, Embase, and Cochrane Library for articles published through May 1, 2020. Eligibility criteria included publication in English and use of well-established EF methodologies in adult humans. Two investigators independently performed the literature search, study selection, data extraction, risk-of-bias assessment, and qualitative data synthesis. Out of 3571 articles identified, 24 articles were included in the systematic review. Main findings include the following: (1) shorter sleep duration is associated with lower macrovascular EF; (2) not sleeping 7-9 h/night is linked with impaired microvascular EF; (3) sleep restriction impairs micro- and macrovascular EF; (4) acute total sleep deprivation impairs micro- and macrovascular EF but data on macrovascular EF are less consistent; and (5) shift work impairs macrovascular EF. In conclusion, sleep deprivation impairs EF, which may explain the link between insufficient sleep and CVD. Future investigations should fully elucidate the underlying mechanisms and develop strategies to combat the adverse endothelial effects of sleep deprivation across the lifespan.

New Horizons of Arterial Stiffness Developed Using Cardio-Ankle Vascular Index (CAVI)

Arterial stiffness is recognized mainly as an indicator of arteriosclerosis and a predictor of cardiovascular events. Cardio-ankle vascular index (CAVI), which reflects arterial stiffness from the origin of the aorta to the ankle, was developed in 2004. An important feature of this index is the independency from blood pressure at the time of measurement. A large volume of clinical evidence obtained using CAVI has been reported. CAVI is high in patients with various atherosclerotic diseases including coronary artery disease and chronic kidney disease. Most coronary risk factors increase CAVI and their improvement reduces CAVI. Many prospective studies have investigated the association between CAVI and future cardiovascular disease (CVD), and proposed CAVI of 9 as the optimal cut-off value for predicting CVD. Research also shows that CAVI reflects afterload and left ventricular diastolic dysfunction in patients with heart failure. Furthermore, relatively acute changes in CAVI are observed under various pathophysiological conditions including mental stress, septic shock and congestive heart failure, and in pharmacological studies. CAVI seems to reflect not only structural stiffness but also functional stiffness involved in acute vascular functions. In 2016, Spronck and colleagues proposed a variant index CAVI₀, and claimed that CAVI₀ was truly independent of blood pressure while CAVI was not. This argument was settled, and the independence of CAVI from blood pressure was reaffirmed. In this review, we summarize the recently accumulated evidence of CAVI, focusing on the proposed cut-off values for CVD events, and suggest the development of new horizons of vascular function index using CAVI.

Pediatric reference values for arterial stiffness parameters cardio-ankle vascular index and CAVI0

The process of arteriosclerosis begins early in life, and cardiovascular risk factors identified in childhood tend to persist into adulthood. Cardio-ankle vascular index (CAVI), a recent parameter of arterial stiffness, is considered an independent predictor of cardiovascular risk. However, there are no studies reporting sex- and age-specific physiological values of CAVI in childhood. We aimed to establish reference values for CAVI and its blood pressure-corrected variant (CAVI₀) in 500 healthy children and adolescents aged 7 to 19 years and to study potential relationships with anthropometric indices. Sex- and age-specific distributions of CAVI and CAVI₀ values in healthy children and adolescents are presented. Boys aged 15-19 years had lower CAVI than girls, which could result from CAVI's slight blood pressure dependence. CAVI₀ did not show such sex difference. Body roundness index-a novel parameter to quantify abdominal fat-was a strong anthropometric predictor of both CAVI and CAVI₀. This is the first study providing pediatric age- and sex-specific reference values for arterial stiffness parameters CAVI and CAVI₀. The presented data can contribute to the understanding of the evolution of these indices during childhood and adolescence. Under specific conditions, CAVI₀ may offer more robust information about arterial stiffness than standard CAVI.

Actigraphy-based sleep characteristics and aortic stiffness: the Multi-Ethnic Study of Atherosclerosis

The study aimed to examine the association between objective estimates of sleep duration and quality and aortic stiffness while accounting for the potential confounding effect of sleep-disordered breathing. Participants were part of the Multi-Ethnic Study of Atherosclerosis Sleep study. Sleep duration and quality were assessed by 7-day wrist actigraphy, sleep-disordered breathing by home polysomnography, and aortic stiffness by magnetic resonance imaging-based aortic pulse wave velocity (aPWV), ascending and descending aorta distensibility. Aortic stiffness of participants with "normal" sleep duration (6-8 hours) were compared with those of "short" (<6 hours) and "long" sleep duration (>8 hours) adjusting for common cardiovascular risk factors and apnea-hypopnea index. The sample consisted of 908 participants (mean age 68.4 ± 9.1 years, 55.3% female). There was a significant linear trend of increased aPWV across short (n = 252), normal (n = 552), and long sleep durations (n = 104) (P for trend = .008). Multivariable analysis showed that people with short sleep duration had 0.94 m/s lower aPWV (95% CI: -1.54, -0.35), compared with those with normal sleep duration. In this ethnically diverse community cohort, habitual short sleep duration as estimated by actigraphy was associated with lower aortic stiffness.

A Systematic Review of Sleep, Hypertension, and Cardiovascular Risk in Children and Adolescents

PURPOSE OF REVIEW

Many of the risk factors for heart disease have recently been shown to develop during childhood such as left ventricular hypertrophy and fibrous plaque lesions. As risk for cardiovascular disease in children and adolescents has risen, sleep duration has decreased, and inadequate sleep in children and adolescents has been found to be associated with cardiovascular disease risk. The aims of this manuscript are to provide an updated systematic review of the literature assessing sleep, hypertension, and cardiovascular risk and evaluate the strength of the evidence based on the available research.

RECENT FINDINGS

A systematic review was conducted using six databases from January 1, 2015 through March 9, 2018. We sought studies which looked at the relationship between sleep duration, sleep timing, or sleep quality and outcome variables of hypertension, inflammation, obesity, glucose or insulin, and lipids in children and adolescents. We found 24 studies which met our criteria. Nine studies included hypertension as an outcome variable; fifteen included obesity; thirteen included glucose or insulin; eight included lipids; and three included measures of inflammation. The existing literature on sleep and cardiovascular disease in children and adolescents is limited and relatively weak. Only one RCT was identified, and the overwhelming majority of studies had a high risk of bias. The strongest evidence of an association with sleep is with obesity, hypertension, and insulin sensitivity. Further research using more standardized methods and objective measures is needed to determine if a causal relationship truly exists between sleep and cardiovascular risk.

Arterial stiffness in junior high school students: Longitudinal observations

BACKGROUND

Early atherosclerotic change is found even in childhood, and there is an urgent need to clarify the factors causing childhood atherosclerosis and take preventive measures. Early detection of the contributing risk factors is crucial to facilitate preventive measures. Pulse wave velocity (PWV) is a widely used technique for the assessment of atherosclerosis in children.

METHODS

Lifestyle questionnaire, brachio-ankle PWV (baPWV) and anthropometric data were obtained from junior high school students in an urban area of Japan between 2006 and 2008, from seventh to ninth grades.

RESULTS

Mean baPWV increased from 867.4 ± 99.5 m/s to 944.5 ± 117.5 m/s in boys, and from 864.0 ± 99.5 m/s to 923.0 ± 101.3 m/s in girls. Obese students had higher baPWV than non-obese students in both genders across each grade. On logistic regression analysis of ninth grade student data, high baPWV was dependent on systolic blood pressure (SBP), time watching television (TV) and symptoms of depression and anxiety, whereas low baPWV was dependent on time playing video games, light exercise, sleep and indoor play, as well as good friendship and motivation.

CONCLUSION

Systolic blood pressure, time watching TV, and symptoms of depression and anxiety may contribute to arterial stiffness and be related to obesity in junior high school students.