Validity of the Supramaximal Test to Verify Maximal Oxygen Uptake in Children and Adolescents

This is the author accepted manuscript. The final version is available from Human Kinetics via the DOI in this record.Purpose: This study had 2 objectives: (1) to examine whether the validity of the supramaximal verification test for maximal oxygen uptake ( formula presented ) differs in children and adolescents when stratified for sex, body mass, and cardiorespiratory fitness and (2) to assess sensitivity and specificity of primary and secondary objective criteria from the incremental test to verify formula presented . Methods: In total, 128 children and adolescents (76 male and 52 females; age: 9.3-17.4 y) performed a ramp-incremental test to exhaustion on a cycle ergometer followed by a supramaximal test to verify formula presented . Results: Supramaximal tests verified formula presented in 88% of participants. Group incremental test peak formula presented was greater than the supramaximal test (2.27 [0.65] L·min-1 and 2.17 [0.63] L·min-1; P  .18). Supramaximal test time to exhaustion predicted supramaximal test formula presented verification (P = .04). Primary and secondary objective criteria had insufficient sensitivity (7.1%-24.1%) and specificity (50%-100%) to verify formula presented . Conclusion: The utility of supramaximal testing to verify formula presented is not affected by sex, body mass, or cardiorespiratory fitness status. Supramaximal testing should replace secondary objective criteria to verify formula presented

The reliability of a breath‐hold protocol to determine cerebrovascular reactivity in adolescents

This is the published version. Available on open access from Wiley via the DOI in this recordPurpose Cerebrovascular reactivity (CVR) is impaired in adolescents with cardiovascular disease risk factors. A breath‐hold test is a noninvasive method of assessing CVR, yet there are no reliability data of this outcome in youth. This study aimed to assess the reliability of a breath‐hold protocol to measure CVR in adolescents. Methods Twenty‐one 13 to 15 year old adolescents visited the laboratory on two separate occasions, to assess the within‐test, within‐day and between‐day reliability of a breath‐hold protocol, consisting of three breath‐hold attempts. CVR was defined as the relative increase from baseline in middle cerebral artery mean blood velocity following a maximal breath‐hold of up to 30 seconds, quantified via transcranial Doppler ultrasonography. Results Mean breath‐hold duration and CVR were never significantly correlated (r  .08). The within‐test coefficient of variation for CVR was 15.2%, with no significant differences across breath‐holds (P = .88), so the three breath‐hold attempts were averaged for subsequent analyses. The within‐ and between‐day coefficients of variation for CVR were 10.8% and 15.3%, respectively. Conclusions CVR assessed via a three breath‐hold protocol can be reliably measured in adolescents, yielding similar within‐ and between‐day reliability. Analyses revealed that breath‐hold length and CVR were unrelated, indicating the commonly reported normalization of CVR to breath‐hold duration (breath‐hold index) may be unnecessary in youth

The acute and postprandial effects of sugar moiety on vascular and metabolic health outcomes in adolescents

This is the author accepted manuscript. The final version is available from Canadian Science Publishing via the DOI in this recordThis study explored the cardiometabolic responses to sugar moieties acutely, and following a subsequent mixed meal tolerance test (MMTT). Twenty-one healthy adolescents (N=10 female, 14.3±0.4 years) completed three experimental and one control condition, in a counterbalanced order. These consisted of different drinks to compare the effect of 300 mL of water (control), or 300 mL of water mixed with 60 g of glucose, fructose or sucrose, on vascular function (flow-mediated dilation; FMD, microvascular reactivity (total hyperaemic response; TRH); and cerebrovascular reactivity; CVR), and blood samples for [uric acid], [glucose], [triglycerides] and [lactate]. FMD increased 1 hour after glucose and sucrose (P<0.001, ES≥0.92) but was unchanged following fructose and water (P>0.19, ES>0.09). CVR and TRH were unchanged 1 hour following all conditions (P>0.57, ES>0.02). Following the MMTT, FMD was impaired in all conditions (P0.40) with no differences between conditions (P>0.13, ES<0.39). Microvascular TRH was increased in all conditions (P=0.001, ES=0.88), and CVR was preserved in all conditions post MMTT (P=0.87, ES=0.02). Blood [uric acid] was elevated following fructose consumption and the MMTT (P0.40). Consumption of a sugar sweetened beverage did not result in vascular dysfunction in healthy adolescents, however the vascular and metabolic responses were dependent on sugar moiety

Temporal longitudinal associations of carotid-femoral pulse wave velocity and carotid intima-media thickness with resting heart rate and inflammation in youth.

This is the author accepted manuscriptData Availability Statement: The informed consent obtained from ALSPAC participants does not allow the data to be made freely available through any third party maintained public repository. However, data used for this submission can be made available on request to the ALSPAC Executive. The ALSPAC data management plan describes in detail the policy regarding data sharing, which is through a system of managed open access. Full instructions for applying for data access can be found here: http://www.bristol.ac.uk/alspac/researchers/access/. The ALSPAC study website contains details of all the data that are available (http://www.bristol.ac.uk/alspac/researchers/our-data/).We examined the temporal longitudinal associations of carotid-femoral pulse wave velocity (cfPWV) and carotid intima-media thickness (cIMT) with the risk of elevated resting heart rate (RHR) and high-sensitivity C-reactive protein (hsCRP). We studied 3862 adolescents, aged 17.7 years, followed-up for 7 years, from Avon Longitudinal Study of Parents and Children. RHR, fasting hsCRP, cfPWV and cIMT were repeatedly assessed and analysed using logistic regression, linear mixed-effect, and structural equation models. Among 3862 adolescents (2143 [55.5%] female), 10% and 44% were at moderate-to-high risk of elevated RHR and hsCRP at 24.5 years, respectively. Higher cfPWV at 17.7 years was associated with elevated RHR risk at follow-up [Odds-ratio (OR) 1.58 (CI 1.20-2.08); p=0.001] whilst cIMT at 17.7 years was associated with elevated hsCRP risk [OR 2.30 (1.18-4.46); p=0.014] at follow-up, only among females. In mixed-model, 7-year progression in cfPWV was directly associated with 7-year increase in RHR [effect-estimate 6 beats/min (1-11); p=0.017] and hsCRP. cIMT progression was associated with 7-year increase in RHR and hsCRP. In cross-lagged model, higher cfPWV at 17.7 years was associated with higher RHR [β = 0.06, standard-error = 3.85, p<0.0001] at 24.5 years but RHR at 17.7 years was unassociated with cfPWV at 24.5 years. Baseline cIMT or RHR was unassociated with either outcome at follow-up. Higher hsCRP at 17.7 years was associated with higher cfPWV and cIMT at 24.5 years. In conclusion, adolescent arterial stiffness but not cIMT appears to precede higher RHR in young adulthood, whilst elevated hsCRP in adolescence preceded higher cfPWV and cIMT.Medical Research CouncilWellcome TrustBritish Heart FoundationMedical Research CouncilJenny and Antti Wihuri FoundationNorth Savo regional and central Finnish Cultural FoundationNorth Savo regional and central Finnish Cultural FoundationYrjö Jahnsson FoundationFinnish Foundation for Cardiovascular ResearchOrion Research FoundationAarne Koskelo FoundationAntti and Tyyne Soininen FoundationPaulo FoundationPaavo Nurmi Foundatio