Predictors and reference equations for augmentation index, an arterial stiffness marker, in healthy children and adolescents

Characterization of intracranial compliance in healthy subjects using a noninvasive method - results from a multicenter prospective observational study

PURPOSE

An FDA-approved non-invasive intracranial pressure (ICP) monitoring system enables the assessment of ICP waveforms by revealing and analyzing their morphological variations and parameters associated with intracranial compliance, such as the P2/P1 ratio and time-to-peak (TTP). The aim of this study is to characterize intracranial compliance in healthy volunteers across different age groups.

METHODS

Healthy participants, both sexes, aged from 9 to 74 years old were monitored for 5 min in the supine position at 0º. Age was stratified into 4 groups: children (≤ 7 years); young adults (18 ≤ age ≤ 44 years); middle-aged adults (45 ≤ age ≤ 64 years); older adults (≥ 65 years). The data obtained was the non-invasive ICP waveform, P2/P1 ratio and TTP.

RESULTS

From December 2020 to February 2023, 188 volunteers were assessed, of whom 104 were male, with a median (interquartile range) age of 41 (29-51), and a median (interquartile range) body mass index of 25.09 (22.57-28.04). Men exhibited lower values compared to women for both the P2/P1 ratio and TTP (p < 0.001). There was a relative rise in both P2/P1 and TTP as age increased (p < 0.001).

CONCLUSIONS

The study revealed that the P2/P1 ratio and TTP are influenced by age and sex in healthy individuals, with men displaying lower values than women, and both ratios increasing with age. These findings suggest potential avenues for further research with larger and more diverse samples to establish reference values for comparison in various health conditions.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials (RBR-9nv2h42), retrospectively registered 05/24/2022. UTN: U1111-1266-8006.

Comparison of Acute Effects of E-cigarettes With and Without Nicotine and Tobacco Cigarettes on Hemodynamic and Endothelial Parameters: A Systematic Review and Meta-analysis

INTRODUCTION

Smoke from traditional cigarettes and e-cigarette aerosols have distinct chemical compositions that may impact blood pressure (BP) and heart rate (HR) differently.

AIMS

This study compared the impact of nicotine-containing e-cigarettes (EC+) versus nicotine-free (EC-) on BP, HR and endothelial markers, and assessed if EC+ posed fewer risks than tobacco cigarettes (TC).

METHODS

Electronic databases were searched from inception until November 2023 for studies reporting changes in systolic and diastolic BP (SBP, DBP) and HR and endothelial parameters before and after the use of EC+, EC- and TC. Data were analyzed using weighted mean differences (WMDs) and 95% confidence intervals (CIs).

RESULTS

Fifteen studies (n = 752) were included in our meta-analysis. We demonstrate that EC+ significantly increased systolic BP (WMD = 3.41, 95% CI [0.1,6.73], p = 0.04], diastolic BP (WMD = 3.42, 95% CI [1.75, 5.09]; p < 0.01], and HR (WMD = 5.36 BPM, 95% CI [1.87, 8.85]; p < 0.01) compared to EC-. However, EC+ was observed to cause less detrimental effect on SBP (WMD = - 4.72 mmHg, 95% CI [- 6.58, - 2.86], p < 0.01), and HR (WMD = - 3.11 BPM, 95% CI [- 4.54, - 1.68]; p < 0.01) as compared to TC with no difference on DBP (WMD = - 1.14 mmHg, 95% CI [- 2.38, 0.1]; p = 0.07). EC+ also led to greater deterioration of endothelial parameters as compared to EC- but to a lesser degree as compared to TC.

CONCLUSION

EC+ shows greater impairment in hemodynamic and endothelial parameters than EC- but less than TC. Additional studies are needed to evaluate prolonged effects of EC use.

Impact of social isolation during COVID-19 on anthropometric data, quality of life, baseline physical activity and aortic pulse wave parameters in children and adolescents in two independent samples

BACKGROUND

The social restrictions resulting from the COVID-19 pandemic had a great impact on the routine of children and adolescents, with important consequences such as sleep, eating, and psychological/psychiatric disorders. Even though there are no studies on the subject, it is possible that these changes in habit and routine have also affected arterial stiffness (AS) in this population, which is an important predictor of cardiovascular risk. This study aimed to assess possible changes in AS, anthropometry, and quality of life (QoL) resulting from the COVID-19 pandemic in children and adolescents.

METHODS

A controlled observational cross-sectional study was performed with 193 children and adolescents aged 9 to 19 years, allocated into two groups: before the pandemic (BPG) and one year after the pandemic (APG), matched by age and sex. Cardiovascular parameters were measured non-invasively by brachial artery oscillometry with a portable device. The main AS indices evaluated were the augmentation index (AIx) and pulse wave velocity (PWV) derived from the aortic pulse wave. QoL was assessed using the Paediatric Quality of Life Inventory version 4.0 (PedsQL 4.0).

RESULTS

Regarding QoL, the APG showed a worsening in emotional (p = 0.002) and school-related (p = 0.010) aspects. There was no statistically significant difference for most anthropometric parameters, except for the hip circumference, which was higher in the APG group (p < 0.001). The main predictor of AS in the paediatric population, AIx@75, was shown to be increased in the APG group (p < 0.001). Other cardiovascular parameters were also different, such as peripheral (p = 0.002) and central (p = 0.003) diastolic blood pressure, stroke volume (p = 0.010), and total vascular resistance (p = 0.002), which were shown to be decreased in the APG group, while the heart rate was increased (p < 0.001).

CONCLUSIONS

Our results show that routine changes resulting from the period of social isolation increased cardiovascular risk in children and adolescents, evident by the increase in AIx@75, which is considered to be an important marker of cardiovascular risk in the paediatric population.

Arterial Structure in 18-Year-Old Males Is Dependent on Physical Activity at 12 Years and Cumulative Cardiorespiratory Fitness From Puberty to Late Adolescence

PURPOSE

To evaluate the long-term effect of body composition, physical activity, and cardiorespiratory fitness (CRF) from puberty on arterial health in late adolescent males.

METHODS

The cumulative burden of physical activity (measured with accelerometer), CRF (VO2peak0.82), and body composition (body mass index, fat mass, and fat percentage) from puberty to late adolescence (sum of 4 time points from 12 to 18 y) was assessed in 102 males. Additional analysis on the first (T1) and last (T4) time points was performed. Intima-media thickness (IMT), carotid-femoral pulse wave velocity, and augmentation index adjusted to heart rate of 75 beats per minute (bpm) as dependent variables were measured at T4 and analyzed in multivariable regression models adjusted for known risk factors including maturation, blood pressure, and smoking habits.

RESULTS

T1 and cumulative body composition measures were independently associated with IMT, while cumulative (β = -0.011, P = .036) and T4 (β = -0.0.031, P = .001) CRF revealed independent associations with IMT. Individuals with moderate to vigorous physical activity >60 minutes per day at T1 showed relationship (β = -1.091, P = .026) with IMT independently of late adolescent physical activity. No significant relationship was present for arterial function.

CONCLUSION

Arterial structure in adolescent males is associated with physical activity at 12 years while relationship with CRF can be seen in late adolescence and cumulatively from puberty to late adolescence.

Adverse childhood experiences are associated with vascular changes in adolescents that are risk factors for future cardiovascular disease

BACKGROUND

Adverse childhood experiences (ACEs), such as abuse, neglect, and household dysfunction, are associated with a higher risk of cardiovascular disease (CVD) and indicators of future CVD risk in adulthood, such as greater vascular stiffness. The impact of ACEs in adolescence is unclear, and understanding how ACEs relate to blood pressure (BP) and vascular function during early life is key for the development of prevention strategies to reduce CVD risk. We hypothesized that exposure to ACEs would be associated with changes in central hemodynamics such as increased vascular stiffness and higher BP during adolescence.

METHODS

This pilot study enrolled 86 adolescents recruited from the Children's of Alabama. A validated ACE questionnaire was employed, and ACEs were modeled both as a continuous variable and a categorical variable (ACE ≥ 1 vs. ACE = 0). The primary outcomes used are considered to be indicators of future cardio-renal disease risk: aortic augmentation index normalized to 75 bpm (Alx75, a surrogate for vascular stiffness), carotid-femoral PWV (m/s), and ambulatory BP patterns.

RESULTS

Adolescents with ACE ≥ 1 had significantly higher Alx75 (ACE: 5.2% ± 2.2 compared to no ACE: - 1.4% ± 3.0; p = 0.043). PWV only reflected this trend when adjustments were made for the body mass index. Adolescents with ACEs showed no differences in ambulatory BP patterns during the 24-h, wake, or sleep periods compared to adolescents with no ACEs.

CONCLUSIONS

ACEs were associated with higher AIx75 in adolescence, which is a risk factor for future CVD. Adolescence could present an opportunity for early detections/interventions to mitigate adverse cardiovascular outcomes in adulthood. A higher resolution version of the Graphical abstract is available as Supplementary information.

Eating behaviour, quality of life and cardiovascular risk in obese and overweight children and adolescents: a cross-sectional study

BACKGROUND

Childhood obesity is a major cardiovascular risk factor because it predisposes individuals to comorbidities that are implicated in an increased risk of cardiovascular events. Its origin may be related to poor eating habits, such as the intake of foods of low nutritional value or inadequate eating behaviours related to emotional factors. This work aims to evaluate the relationship between the total body mass of children and adolescents and its association with eating habits, quality of life (QoL), and possible changes in early markers of cardiovascular risk.

METHODS

This was a cross-sectional observational study that evaluated anthropometric and cardiovascular parameters, QoL, and eating behaviour in 181 children and adolescents aged between 5 and 13 years. Participants were stratified according to BMI/age into three groups (Adequate Weight, Overweight, and Obesity). Anthropometry included weight, height, waist and hip circumferences, waist-hip ratio, and waist-height ratio. QoL was assessed using the Peds-QL 4.0 questionnaire, and eating behaviour was assessed using the Children's Eating Behaviour Questionnaire (CEBQ). Cardiovascular parameters were assessed using the Mobil-O-Graph® device, which measures the pulse wave velocity (PWV) and augmentation index (AIx@75) to estimate arterial stiffness (AS), which is considered an early marker of cardiovascular disease.

RESULTS

In addition to the increase in anthropometric measurements (p < 0.001), the Obesity group exhibited behaviour related to food intake (p < 0.05). When analysing QoL, a worsening in the social domain was also observed in the Obesity group (p < 0.05). However, PWV and AIx@75 did not differ between groups.

CONCLUSIONS

Eating behaviour is related to the development of childhood obesity. However, early markers of cardiovascular risk related to AS did not change as a function of total body mass in the children evaluated.

Rapid trabecular bone growth in puberty associated with stiffer arteries in adulthood - longitudinal study on healthy young males

Longitudinal bone content data from puberty to adulthood was assessed in 102 healthy males and associations with arterial health in adulthood was analysed. Bone growth in puberty was related to arterial stiffening and final bone mineral content to decreased arterial stiffness. Relationships with arterial stiffness were dependent on the studied bone regions.

INTRODUCTION

Our aim was to assess the relationships between arterial parameters in adulthood and bone parameters in several locations longitudinally from puberty to 18-years and cross-sectionally at 18-years.

METHODS

102 healthy male data from a 7-year follow-up study was used to analyse total body (TB), femoral neck (FN) and lumbar spine (LS) mineral content and density by DXA, carotid intima-media thickness (cIMT) by ultrasound, carotid-femoral pulse wave velocity (cfPWV) and heart rate adjusted augmentation index (AIxHR75) by applanation tonometry.

RESULTS

Linear regression analysis revealed negative associations between LS bone mineral density (BMD) and cfPWV [ß=-1.861, CI -3.589, -0.132, p=0.035] which remained significant [ß=-2.679, CI -4.837, -0.522, p=0.016] after adjustment to smoking, lean mass, weight category, pubertal stage, physical fitness, and activity. For AIxHR75 similar results were present [ß=-0.286, CI -0.553, -0.020, p=0.035], but were dependent on confounders. Analysis on pubertal bone growth speed showed independent positive associations to AIxHR75 between Δ FN bone mineral apparent density (BMAD) [ß=672.50, CI 348.07, 996.93, p<0.001] and Δ LS BMAD [ß=700.40, CI 57.384, 1343.423, p=0.033]. Further analysis combining pubertal bone growth and adulthood BMC revealed that the relationships of AIxHR75 with LS BMC and ΔFN BMAD were independent of each other.

CONCLUSION

Trabecular bone regions like lumbar spine and femoral neck, showed stronger relationships with arterial stiffness. Rapid bone growth in puberty is related to arterial stiffening, while final bone mineral content relates to decreased arterial stiffness. These results could indicate that bone metabolism is independently associated with arterial stiffness rather than bone and arteries just having common traits of growth and maturation.

Factors associated with arterial stiffness assessed by pulse pressure amplification in healthy children and adolescents: a cross-sectional study

BACKGROUND

Increasing evidence suggests that reducing pulse pressure amplification (PPA) plays an important role in pathogenesis and progression of cardiovascular disease. This is a cross-sectional, observational, and analytical study in which we evaluated the associated factors with a greater chance of reducing PPA in 136 healthy children and adolescents aged 8 to 19 years old stratified by gender and age group.

METHODS

Arterial stiffness and vascular and hemodynamic parameters were non-invasively measured using Mobil-O-Graph® (IEM, Stolberg, Germany), a cuff-based oscillometric device. PPA was expressed as the peripheral-to-central pulse pressure ratio (PPp / PPc). Participants with PPA < 1.49 were considered as part of the arterial stiffness group.

RESULTS

In a univariate model, the increase in total vascular resistance, the reflection coefficient and the augmentation pressure were more likely to have arterial stiffness in all groups. The factors most likely to have arterial stiffness (as assessed by the reduction of the PPA) in the multivariate model were increasing age, the reflection coefficient and cardiac index in the total sample, male group and child and adolescent groups. In addition to age in the female group, cardiac output, stroke volume, and AIx@75 were the factors most likely to present arterial stiffness.

CONCLUSIONS

The results show for the first time in children and adolescents that the factors most likely to reduce PPA are related to the reflection wave, which determines aortic pressures and, therefore, left ventricular afterload.

Arterial stiffness indices, pulse wave velocity and central systolic blood pressure, are able to discriminate between obese and non-obese children

The objectives of this study were to verify, first, if arterial stiffness indices can discriminate between obese and healthy children. Second, to evaluate arterial stiffness index predictors and hemodynamic parameters in obese children. Arterial stiffness indices evaluated were pulse wave velocity (PWV), central systolic blood pressure (SBPc), and central pulse pressure (PPc). A cross-sectional, descriptive, comparative study design was used. The sample consisted of 78 normal-weight children (8.1 ± 1.96 years) and 58 obese children (9.0 ± 1.87 years). PWV, PPc, and SBPc were significantly higher in the group of obese children than in the control group. The ROC curve analysis showed that maximum PWV and SBPc sensitivity and specificity in differentiating obese from non-obese children occurred at 4.09 m/s and 86.17 mmHg, respectively. PPc did not exhibit a discriminatory capacity between the two groups. Peripheral systolic blood pressure (SBPp), peripheral pulse pressure (PPp), and PPc (R² = 0.98) were predictors of increased PWV. Augmentation pressure, PPp, and reflection coefficient (R² = 0.873) were predictors of PPc. Age, augmentation index, total vascular resistance, cardiac index, and mean fat percentage (R² = 0.801) were predictors of SBPc.

CONCLUSION

This study shows for the first time that PWV > 4.09 m/s and SBPc > 86.17 mmHg are cut-off points associated with a higher risk of obesity. These results indicate that the simple, rapid, and noninvasive measurement of arterial stiffness adds prognostic information regarding cardiovascular risk, in addition to increased body mass index.

WHAT IS KNOWN

• Overweight and obesity are strongly associated with comorbidities que contribute to the development of cardiovascular diseases.

WHAT IS NEW

• This is the first study to show that PWV and SBPc can discriminate obese from non-obese children. These results show that, in addition to an increased BMI, a simple, rapid, and noninvasive measurement of arterial stiffness adds prognostic information on cardiovascular risk.

Effects of prolonged sitting and physical activity breaks on measures of arterial stiffness and cortisol in adolescents

AIM

In adults, prolonged periods of sitting have been linked to acute negative effects on vascular structure and function. The aim of this study was to evaluate the acute effects of physical activity (PA) breaks during prolonged sitting on arterial stiffness, cortisol and psychological factors in adolescents.

METHODS

Adolescents underwent different short (3-min) breaks starting every 20 min, during 80 min of sitting on three separate days. Breaks were (A) social seated breaks (SOC), (B) low-intensity simple resistance activity PA breaks (SRA) and (C) moderate-intensity step-up PA breaks (STEP). The arterial stiffness measures were augmentation index (AIx), AIx@75 and pulse wave velocity (PWV). Cortisol was measured from saliva. Psychological factors were self-reported.

RESULTS

Eleven girls and six boys (average age 13.6 ± 0.7 years) participated, with average baseline heart rates of 72 ± 11 bpm, systolic/diastolic blood pressure 111 ± 7/64 ± 6 mmHg and cortisol 10.9 ± 5.8 nmoL/L. PWV, cortisol and psychological factors did not change after any of the conditions. AIx@75 increased significantly (4.9 ± 8.7-9.2 ± 13.2) after the STEP intervention compared with SOC and SRA (time × condition p < 0.05).

CONCLUSION

Arterial stiffness increased after prolonged sitting with frequent, short step-up activity breaks. The results indicate potential important intensity-dependent effects of physical activity on vascular regulation in youth.

Pediatric obstructive sleep-disordered breathing is associated with arterial stiffness

The association between obstructive sleep-disordered breathing (oSDB) and arterial stiffness, an independent predictor of cardiovascular outcomes, is not well established in children. This study compared cardiovascular parameters between healthy and oSDB children and aimed to identify predictors of arterial stiffness indices in children with oSDB. Cross-sectional study realized in a tertiary hospital from June 2018 to January 2020. Forty-eight children (3 to 10 years old) with clinical diagnosis of oSDB and indication for adenotonsillectomy and 24 controls were evaluated. Cardiovascular parameters were measured non-invasively by brachial artery oscillometry with a portable device. The main arterial stiffness indices assessed were augmentation index and pulse wave velocity, both derived from the aortic pulse wave. In the oSDB group, the questionnaires Obstructive Sleep Apnea-18 (OSA-18) and Pediatric Quality of Life Inventory version 4.0 (PedsQL 4.0) were applied. The oSDB group had higher values of reflection coefficient (p = 0.044) and augmentation index (p = 0.003) than the control group. Stepwise multiple regression analysis revealed that age, female sex, reflection coefficient, and systolic volume were independent predictors of augmentation index. Higher pulse wave velocity values were associated with worse quality of life assessed by PedsQL 4.0 questionnaire. There was no association with OSA-18. The vascular and hemodynamic parameters were similar in both groups.Conclusion: Children with oSDB have increased augmentation index, an independent predictor of cardiovascular outcomes. The early identification of subclinical cardiovascular changes reinforces the importance of treating the disease, as well as changing lifestyle habits, to prevent complications in adulthood. What is Known: • The association between oSDB and cardiovascular risk in adults is well described in the literature. • Children with oSDB, regardless of their weight or sex, have higher PWV values when compared to non-snoring children. What is New: • Children with oSDB have augmented arterial stiffness, evidenced by the increase in AIx@75, measured non-invasively by brachial artery oscillometry with a portable device. • Low quality of life and therefore a high disease burden in children with oSDB may be a risk factor for arterial stiffness.