Effect of moderate to high intensity aerobic exercise on blood pressure in young adults: The TEPHRA open, two-arm, parallel superiority randomized clinical trial

Accelerometer-based sedentary time, light physical activity, and moderate-to-vigorous physical activity from childhood with arterial stiffness and carotid IMT progression: A 13-year longitudinal study of 1339 children

AIMS

We examined the longitudinal associations of sedentary time (ST), light physical activity (LPA), and moderate-to-vigorous PA (MVPA) from childhood with carotid-femoral pulse wave velocity (cfPWV), a measure of arterial stiffness and carotid intima-media thickness (cIMT).

METHODS

We studied 1339 children, aged 11 years from Avon Longitudinal Study of Parents and Children, UK, followed up for 13 years. Accelerometer-based ST, LPA, and MVPA were assessed at ages 11, 15, and 24 years clinic visits. cfPWV and cIMT were measured with Vicorder and ultrasound, respectively, at ages 17 and 24 years.

RESULTS

Among 1339 [56.4% female] participants, mean ST increased from ages 11 through 24 years, while mean LPA and MVPA decreased. Persistently high ST tertile from childhood was associated with increased cfPWV progression, effect estimate 0.047 m/s; [(95% CI 0.005 to 0.090); p = 0.030], but not cIMT progression. Persistently high LPA tertile category was associated with decreased cfPWV progression in males -0.022 m/s; [(-0.028 to -0.017); p < 0.001] and females -0.027 m/s; [(-0.044 to -0.010); p < 0.001]. Cumulative LPA exposure decreased the odds of progressively worsening cfPWV [Odds ratio 0.994 (0.994-0.995); p < 0.0001] and cIMT. Persistent exposure to ≥60 min/day of MVPA was paradoxically associated with increased cfPWV progression in males 0.053 m/s; [(0.030 to 0.077); p < 0.001] and females 0.012 m/s; [(0.002 to 0.022); p = 0.016]. Persistent exposure to ≥60 min/day of MVPA was inversely associated with cIMT progression in females -0.017 mm; [(-0.026 to -0.009); p < 0.001].

CONCLUSION

LPA >3 h/day from childhood may attenuate progressively worsening vascular damage associated with increased ST in youth.

Mediating effect of fat mass, lean mass, blood pressure and insulin resistance on the associations of accelerometer-based sedentary time and physical activity with arterial stiffness, carotid IMT and carotid elasticity in 1574 adolescents

This study examined the mediating effect of total body fat mass, lean mass, blood pressure (BP) and insulin resistance on the associations of sedentary time (ST), light physical activity (LPA) and moderate-to-vigorous PA (MVPA) with carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT) and carotid elasticity in 1574 adolescents from the Avon Longitudinal Study of Parents and Children birth cohort, UK. ST, LPA and MVPA were assessed with ActiGraph accelerometer. ST and LPA were sex-categorised in tertiles as low (reference), moderate and high, while MVPA was categorised as <40 min/day (reference), 40-<60 min/day and ≥60 min/day. cfPWV, cIMT and carotid elasticity were measured with Vicorder and ultrasound. Fat mass and lean mass were assessed with dual-energy X-ray absorptiometry and homeostatic model assessment of insulin resistance (HOMA-IR) was computed. Mediation analyses structural equation models and linear mixed-effect models adjusted for cardiometabolic and lifestyle factors were conducted. Among 1574 adolescents [56.2% female; mean (SD) age 15.4 (0.24) years], 41% males and 17% females accumulated ≥60 min/day of MVPA. Higher ST was associated with lower cIMT partly mediated by lean mass. Higher LPA (standardized β = -0.057; [95% CI -0.101 to -0.013; p = 0.014]) and the highest LPA tertile were associated with lower cfPWV. BP had no significant mediating effect movement behaviour relations with vascular indices. Lean mass partially mediated associations of higher MVPA with higher cIMT (0.012; [0.007-0.002; p = 0.001], 25.5% mediation) and higher carotid elasticity (0.025; [0.014-0.039; p = 0.001], 28.1% mediation). HOMA-IR mediated the associations of higher MVPA with higher carotid elasticity (7.7% mediation). Engaging in ≥60 min/day of MVPA was associated with higher carotid elasticity. In conclusion, higher LPA was associated with lower arterial stiffness, but higher MVPA was associated with thicker carotid wall explained by higher lean mass.

HAPI Fit: An Exercise Intervention to Improve Peak Aerobic Capacity in Young Adults Born Very Preterm

INTRODUCTION

Individuals born preterm have reduced aerobic capacity, which could be related to impaired organ development. Their capacity to improve aerobic capacity with exercise training could therefore be limited, but this remains unknown. We aimed to test an exercise intervention to improve cardiorespiratory fitness in adults born preterm.

METHODS

Twenty-one very preterm and 37 full-term individuals aged 18-33 yr took part in a 14-wk supervised exercise intervention of cardiovascular, resistance, and flexibility training (two group and one individual sessions per week). Adherence and compliance to intervention were recorded. Primary outcome was change in peak oxygen consumption (peak V̇O 2 ) measured before and after the intervention. Within- and between-group differences were estimated using nonparametric tests.

RESULTS

Of 219 eligible individuals, 58 were enrolled and 14 participants dropped out over the course of the intervention. Among the 44 who completed the intervention, mean adherence was 82% and 66% for group and individual sessions, respectively. Compliance with training requirement varied between 71% and 100%. There was no difference in adherence between the preterm and full-term groups. Because only one preterm male met the adherence criteria, subsequent analyses were done exclusively on females. Both the term and preterm groups achieved higher peak V̇O 2 after the intervention [term = +4.2 (SD 4.3) mL·min -1 ·kg -1 , P < 0.01; preterm = +4.7 (2.9) mL·min -1 ·kg -1 , P < 0.01]. There was no between-group difference in the response to the intervention ( P = 0.729).

CONCLUSIONS

Recruitment and adherence to an exercise intervention are challenging. Results could indicate improvements in cardiorespiratory fitness in young women born preterm after current exercise program. Adaptation of this intervention is needed for wider uptake.

A machine learning-based score for precise echocardiographic assessment of cardiac remodelling in hypertensive young adults

Aims

Accurate staging of hypertension-related cardiac changes, before the development of significant left ventricular hypertrophy, could help guide early prevention advice. We evaluated whether a novel semi-supervised machine learning approach could generate a clinically meaningful summary score of cardiac remodelling in hypertension.

Methods and results

A contrastive trajectories inference approach was applied to data collected from three UK studies of young adults. Low-dimensional variance was identified in 66 echocardiography variables from participants with hypertension (systolic ≥160 mmHg) relative to a normotensive group (systolic < 120 mmHg) using a contrasted principal component analysis. A minimum spanning tree was constructed to derive a normalized score for each individual reflecting extent of cardiac remodelling between zero (health) and one (disease). Model stability and clinical interpretability were evaluated as well as modifiability in response to a 16-week exercise intervention. A total of 411 young adults (29 ± 6 years) were included in the analysis, and, after contrastive dimensionality reduction, 21 variables characterized >80% of data variance. Repeated scores for an individual in cross-validation were stable (root mean squared deviation = 0.1 ± 0.002) with good differentiation of normotensive and hypertensive individuals (area under the receiver operating characteristics 0.98). The derived score followed expected hypertension-related patterns in individual cardiac parameters at baseline and reduced after exercise, proportional to intervention compliance (P = 0.04) and improvement in ventilatory threshold (P = 0.01).

Conclusion

A quantitative score that summarizes hypertension-related cardiac remodelling in young adults can be generated from a computational model. This score might allow more personalized early prevention advice, but further evaluation of clinical applicability is required.

Associations of accelerometer-based sedentary time, light physical activity and moderate-to-vigorous physical activity with resting cardiac structure and function in adolescents according to sex, fat mass, lean mass, BMI, and hypertensive status

BACKGROUND

This study examined the independent relationships of device-based measured sedentary time (ST) and physical activity (PA) in relation to cardiac structural and functional geometry among adolescents.

METHODS

From the Avon Longitudinal Study of Parents and Children, UK birth cohort, 530 (50% female) adolescents aged 17 years had complete ST, PA, cardiac, and covariate measures. Echocardiography cardiac measures were left ventricular mass indexed for height2.7 (LVMI2.7 ), relative wall thickness, LV diastolic function (LVDF), and LV filling pressure (LVFP). Overweight/obesity and elevated systolic/BP hypertension were categorized as body mass index >24.99 kg/m2 and ≥130 mmHg, respectively. Data were analyzed with linear regression models adjusting for cardiometabolic factors and lifestyle factors.

RESULTS

The prevalence of overweight/obesity in males and females was 17.9% and 24.5%, respectively. The prevalence of elevated systolic BP/hypertension was 11.6% in males and 1.1% among females. The average ST was 484 ± 78 min/day, light PA was 274 ± 62 min/day, and moderate-to-vigorous PA (MVPA) was 41 ± 24 min/day, among females. Average ST, LPA, and MVPA were 468 ± 87 min/day, 293 ± 70 min/day, and 56 ± 30 min/day, respectively, among males. Higher ST was associated with higher LVMI2.7 (standardized β = 0.16; p = 0.01) among females, but higher ST was associated with lower LVDF in males (β = -0.14; p = 0.04). Higher ST and MVPA were associated with higher LVMI2.7 in the total cohort, normal weight, and overweight/obese adolescents. Light PA was associated with higher LVDF in the total cohort and normotensives and lower LVFP among adolescents with high lean mass.

CONCLUSIONS

Higher ST and MVPA were associated with higher LVMI; however, ST-associated LVMI increase was threefold higher than MVPA-associated LVMI increase. Higher LPA was associated with better cardiac function. Reducing ST and increasing LPA may attenuate the risk of altered cardiac structure and function in adolescents.

Aerobic Exercise Training Response in Preterm-Born Young Adults with Elevated Blood Pressure and Stage 1 Hypertension: A Randomized Clinical Trial

Rationale: Premature birth is an independent predictor of long-term cardiovascular risk. Individuals affected are reported to have a lower rate of [Formula: see text]o2 at peak exercise intensity ([Formula: see text]o2PEAK) and at the ventilatory anaerobic threshold ([Formula: see text]o2VAT), but little is known about their response to exercise training. Objectives: The primary objective was to determine whether the [Formula: see text]o2PEAK response to exercise training differed between preterm-born and term-born individuals; the secondary objective was to quantify group differences in [Formula: see text]o2VAT response. Methods: Fifty-two preterm-born and 151 term-born participants were randomly assigned (1:1) to 16 weeks of aerobic exercise training (n = 102) or a control group (n = 101). Cardiopulmonary exercise tests were conducted before and after the intervention to measure [Formula: see text]o2PEAK and the [Formula: see text]o2VAT. A prespecified subgroup analysis was conducted by fitting an interaction term for preterm and term birth histories and exercise group allocation. Measurements and Main Results: For term-born participants, [Formula: see text]o2PEAK increased by 3.1 ml/kg/min (95% confidence interval [CI], 1.7 to 4.4), and the [Formula: see text]o2VAT increased by 2.3 ml/kg/min (95% CI, 0.7 to 3.8) in the intervention group versus controls. For preterm-born participants, [Formula: see text]o2PEAK increased by 1.8 ml/kg/min (95% CI, -0.4 to 3.9), and the [Formula: see text]o2VAT increased by 4.6 ml/kg/min (95% CI, 2.1 to 7.0) in the intervention group versus controls. No significant interaction was observed with birth history for [Formula: see text]o2PEAK (P = 0.32) or the [Formula: see text]o2VAT (P = 0.12). Conclusions: The training intervention led to significant improvements in [Formula: see text]o2PEAK and [Formula: see text]o2VAT, with no evidence of a statistically different response based on birth history. Clinical trial registered with www.clinicaltrials.gov (NCT02723552).

Aerobic exercise increases brain vessel lumen size and blood flow in young adults with elevated blood pressure. Secondary analysis of the TEPHRA randomized clinical trial

IMPORTANCE

Cerebrovascular changes are already evident in young adults with hypertension and exercise is recommended to reduce cardiovascular risk. To what extent exercise benefits the cerebrovasculature at an early stage of the disease remains unclear.

OBJECTIVE

To investigate whether structured aerobic exercise increases brain vessel lumen diameter or cerebral blood flow (CBF) and whether lumen diameter is associated with CBF.

DESIGN

Open, parallel, two-arm superiority randomized controlled (1:1) trial in the TEPHRA study on an intention-to-treat basis. The MRI sub-study was an optional part of the protocol. The outcome assessors remained blinded until the data lock.

SETTING

Single-centre trial in Oxford, UK.

PARTICIPANTS

Participants were physically inactive (<150 min/week moderate to vigorous physical activity), 18 to 35 years old, 24-hour ambulatory blood pressure 115/75 mmHg-159/99 mmHg, body mass index below 35 kg/m² and never been on prescribed hypertension medications. Out of 203 randomized participants, 135 participated in the MRI sub-study. Randomisation was stratified for sex, age (<24, 24-29, 30-35 years) and gestational age at birth (<32, 32-37, >37 weeks).

INTERVENTION

Study participants were randomised to a 16 week aerobic exercise intervention targeting 3×60 min sessions per week at 60 to 80 % peak heart rate.

MAIN OUTCOMES AND MEASURES

cerebral blood flow (CBF) maps from ASL MRI scans, internal carotid artery (ICA), middle cerebral artery (MCA) M1 and M2 segments, anterior cerebral artery (ACA), basilar artery (BA), and posterior cerebral artery (PCA) diameters extracted from TOF MRI scans.

RESULTS

Of the 135 randomized participants (median age 28 years, 58 % women) who had high quality baseline MRI data available, 93 participants also had high quality follow-up data available. The exercise group showed an increase in ICA (0.1 cm, 95 % CI 0.01 to 0.18, p =.03) and MCA M1 (0.05 cm, 95 % CI 0.01 to 0.10, p =.03) vessel diameter compared to the control group. Differences in the MCA M2 (0.03 cm, 95 % CI 0.0 to 0.06, p =.08), ACA (0.04 cm, 95 % CI 0.0 to 0.08, p =.06), BA (0.02 cm, 95 % CI -0.04 to 0.09, p =.48), and PCA (0.03 cm, 95 % CI -0.01 to 0.06, p =.17) diameters or CBF were not statistically significant. The increase in ICA vessel diameter in the exercise group was associated with local increases in CBF.

CONCLUSIONS AND RELEVANCE

Aerobic exercise induces positive cerebrovascular remodelling in young people with early hypertension, independent of blood pressure. The long-term benefit of these changes requires further study.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02723552, 30 March 2016.

Physical Activity and Hypertension

Hypertension and physical inactivity are leading causes of premature mortality. While both are modifiable risk factors for cardiovascular disease, their prevalence remains high. As populations grow older, they are more likely to develop hypertension and to become less physically active. Scientific advances have contributed to understanding of how physical activity improves blood pressure and the clinically relevant ambulatory blood pressure, but this is not reflected in hypertension guidelines for clinical management of hypertension. The aim of this paper is to clearly present up to date knowledge from scientific studies that underpin the role of physical activity in hypertension management. Longitudinal studies in this review demonstrate a protective effect of higher physical activity levels as well as higher levels of cardiorespiratory fitness. Interventional studies report improvements in blood pressure associated with aerobic, resistance and concurrent exercise; the improvements in some studies were greatest among participant groups with established hypertensions; the effect was observed for groups with treatment-resistant hypertension also, a clinically important subgroup. The most recent research provides evidence for the synergy between physical activity and pharmacotherapy for the treatment of hypertension, providing an opportunity for clinicians to promote physical activity as an adjunctive treatment for hypertension as well as a preventative strategy. This review critiques the evidence and summarises the most up to date literature in the field of physical activity and hypertension.