Myocarditis is common in Multisystem Inflammatory Syndrome in Children (MIS-C), and the mechanism may differ from idiopathic/viral myocarditis as MIS-C involves a hyper-inflammatory state weeks after ...COVID-19. We sought to evaluate exercise stress testing (EST) in these patients as EST may help guide return-to-play recommendations. Retrospective cohort study evaluating ESTs (standard Bruce treadmill protocol) from MIS-C patients from 2020 to 2022, compared to myocarditis patients and age, sex, and weight matched controls from 2005 to 2019. ESTs included 22 MIS-C patients (mean age 11.9 years) with 14 cardiopulmonary and 8 cardiovascular tests, 33 myocarditis (15.5 years), and 44 controls (12.0 years). Percent-predicted peak VO
2
was abnormal (< 80% predicted) in 11/14 (79%) MIS-C patients, 13/33 (39%) myocarditis, and 17/44 (39%) controls (p = 0.04). Exercise duration was shorter in MIS-C than myocarditis or control cohorts (p = 0.01). Isolated atrial or ventricular ectopy was seen in 8/22 (36%) MIS-C, 9/33 (27%) myocarditis, and 5/44 (11%) controls (p = 0.049). No arrhythmias/complex ectopy or evidence of ischemia were noted, though non-specific ST/T wave abnormalities occurred in 4/22 (18%) MIS-C, 5/33 (15%) myocarditis, and 3/44 (7%) controls. Exercise duration and percent-predicted peak VO
2
were significantly reduced in MIS-C at mean 6-month follow-up compared to pre-COVID era idiopathic/viral myocarditis and control cohorts. This may be secondary to deconditioning during the pandemic and/or chronic cardiopulmonary or autonomic effects of COVID/MIS-C. Although there were no exercise-induced arrhythmias in our MIS-C patients, larger cohort studies are warranted. EST in MIS-C follow-up may help evaluate safety and timing of return to play and potentially mitigate further deconditioning.
Pediatric patients are often referred to cardiopulmonary exercise testing (CPET) laboratories for assessment of exercise-related symptoms. For clinicians to understand results in the context of ...performance relative to peers, adequate fitness-based prediction equations must be available. However, reference equations for prediction of peak oxygen uptake (VO
) in pediatrics are largely developed from field-based testing, and equations derived from CPET are primarily developed using adult data. Our objective was to develop a pediatric reference equation for VO
. Clinical CPET data from a validation cohort of 1,383 pediatric patients aged 6 to 18 years who achieved a peak respiratory exchange ratio ≥1.00 were analyzed to identify clinical and exercise testing factors that contributed to the prediction of VO
from tests performed using the Bruce protocol. The resultant prediction equation was applied to a cross-validation cohort of 1,367 pediatric patients. Exercise duration, gender, weight, and age contributed to the prediction of VO
, generating the following prediction equation: (R
= 0.645, p <0.001, standard error of the estimate = 6.19 ml/kg/min): VO
(ml/kg/min) =16.411+ 3.423 (exercise duration minutes) - 5.145 (gender 0 = male, 1 = female) - 0.121 (weight kg) + 0.179 (age years). This equation was stable across the age range included in the present study, with differences ≤0.5 ml/kg/min between mean measured and predicted VO
in all age groups. In conclusion, this study represents what we believe is the largest pediatric CPET-derived VO
prediction effort to date, and this VO
prediction equation provides clinicians who perform and interpret exercise tests in pediatric patients with a resource with which to better quantify fitness when CPET is not available.
To develop reference values for cardiorespiratory fitness, as quantified by peak oxygen uptake (VO
) and treadmill time, in patients aged 6 through 18 years referred for cardiopulmonary exercise ...testing (CPET).
We reviewed a clinical pediatric CPET database for fitness data in children aged 6-18 years with no underlying heart disease. CPET was obtained via the Bruce protocol utilizing objectively confirmed maximal effort via respiratory exchange ratio. Fitness data (VO
and treadmill test duration) were analyzed to determine age- and sex-specific reference values for this pediatric cohort.
Data from 2025 pediatric CPETs (53.2% female) were included in the analyses. VO
increased with age in males, but not females. Treadmill test duration increased with age in both males and females. Fitness was generally higher in males when compared with females in the same age groups.
Our study provides extensive reference values for both VO
and total treadmill test time via the Bruce protocol for a pediatric population without known cardiac disease. Furthermore, the inclusion of objectively confirmed maximal exercise effort increases confidence in these findings compared with prior studies in this area. Clinicians performing CPET in pediatric populations can utilize these reference values to characterize test results according to representative peer data.
An artificial pancreas (AP) computes the optimal insulin dose to be infused through an insulin pump in people with Type 1 Diabetes (T1D) based on information received from a continuous glucose ...monitoring (CGM) sensor. It has been recognized that exercise is a major challenge in the development of an AP system. The use of biometric physiological variables in an AP system may be beneficial for prevention of exercise-induced challenges and better glucose regulation. The goal of the present study is to find a correlation between biometric variables such as heart rate (HR), heat flux (HF), skin temperature (ST), near-body temperature (NBT), galvanic skin response (GSR), and energy expenditure (EE), 2D acceleration-mean of absolute difference (MAD) and changes in glucose concentrations during exercise via partial least squares (PLS) regression and variable importance in projection (VIP) in order to determine which variables would be most useful to include in a future artificial pancreas. PLS and VIP analyses were performed on data sets that included seven different types of exercises. Data were collected from 26 clinical experiments. Clinical results indicate ST to be the most consistently important (important for six out of seven tested exercises) variable over all different exercises tested. EE and HR are also found to be important variables over several types of exercise. We also found that the importance of GSR and NBT observed in our experiments might be related to stress and the effect of changes in environmental temperature on glucose concentrations. The use of the biometric measurements in an AP system may provide better control of glucose concentration.
Purpose of Review
Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease ...risk.
Recent Findings
Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk.
Summary
Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.
•Twelve weeks of home-based exercise training improved aerobic fitness modestly.•Reactive hyperemia improved as well, indicating this intervention had a positive effect on arterial health.•Further, ...walking mobility also improved, via the timed 25 foot speed.
Using a 12-week, randomized controlled trial coupled with social cognitive theory behavioral coaching, we aimed to assess the effect of a home-based aerobic training intervention versus an attention-control on aerobic fitness, subclinical atherosclerosis, and mobility in persons with MS.
Persons with MS with an expanded disability status scale score between 0 and 4 were randomized to a 12-week aerobic exercise (EX) (n = 26; 19 females; 49 yrs; 28.8 kg/m2) or attention-control (CON) condition (stretching; n = 22; 16 females; 44 yrs; 29.2 kg/m2). Aerobic capacity was assessed via a graded cycle ergometry test with indirect calorimetry. The co-primary measures of subclinical atherosclerosis assessed included carotid intima media thickness, a test of vasodilatory reactivity, and arterial stiffness. Mobility was assessed via a timed 25-foot walk test (T25FW) and a 6 min walk test. The EX group engaged in cycle ergometry 3d/wk with gradual increases in the intensity and duration of the exercise sessions. CON participated in standardized stretching designed to provide the same contact time as EX 3d/wk. Behavioral coaching took place via weekly phone/video chats to track adherence.
Aerobic capacity, vasodilatory reactivity, and T25FW speed increased only in the EX group, 7%, 16%, and 13% (p<0.05), respectively; whereas the CON group did not change.
The EX group had modest, yet significant, increases in aerobic capacity over the 12-week period, coupled with improvements in T25FW speed and vasodilatory reactivity. A home-based exercise intervention can improve outcomes of a subclinical marker of atherosclerosis, which provides a basis for examining these outcomes in persons prescreened for CVD-related comorbidities and/or mobility issues.
Background
Cardiovascular disease is a leading cause of disease progression and death in multiple sclerosis (MS). Obesity has a negative impact on vascular structure and function, but whether this ...contributes to worse vascular function similarly in individuals with MS and controls is unknown.
Aim
: To investigate the impact of obesity on vascular function and structure in a group with MS.
Methods
In a sample of n = 133 participants (MS: n = 89, control n = 44), height and weight were measured to calculate BMI. After a 10 minute rest in the supine position, resting heart rate (HR) and brachial blood pressure (BP) were collected. Augmentation index (AIX), HR normalized AIX (AIX@HR75) and pulse wave velocity (PWV) and subendocardial viability ratio (SEVR) were measured with applanation tonometry.
Carotid intima-media thickness (IMT) and beta-stiffness (beta) were measured with carotid ultrasound, and Forearm Blood Flow (FBF Baseline, Peak and Area Under the Curve (AUC)) was measured with strain gauge plethysmography. Data were analyzed with multiple linear regression analyses with group, sex, BMI and GroupxBMI as independent variables.
Results
Higher BMI correlated with higher HR and PWV in both groups. In the MS group however, a higher BMI was also correlated with worse outcomes on the SEVR, FBF Baseline, Peak and AUC.
Outcome variables
Standardized beta
1
Adjusted R
2
Group
Sex
BMI
Grp x BMI
HR rest
1.081*
0.005
0.520*
−0.944
0.11
AIX
−0.019
−0.523*
0.040
0.045
0.26
AIX@HR75
0.341
−0.536*
0.235
−0.270
0.32
SEVR
−1.292*
0.175*
−0.565*
1.090*
0.22
PWVc
0.001
−0.003
0.321*
0.120
0.12
PWVc/MAP
0.324
−0.126
0.278
−0.122
0.11
IMT
0.715
0.164
0.385
−0.511
0.12
FBF Baseline
0.432
0.070
0.326*
−1.090*
0.33
FBF Peak
0.580
0.318*
0.152
−1.035*
0.35
FBF AUC
0.746
0.230*
0.316
−1.174*
0.21
1
Group (0 = control, 1 = multiple sclerosis), Sex (1 = Female, 2 = Male).
* (p < 0.05).
Conclusions
Having a higher BMI contributes even more to a worse vascular profile in MS patients than in controls, suggesting that reducing overweight and obesity in the MS population will benefit their vascular structure and function.
Introduction
Individuals with multiple sclerosis (MS) exhibit impaired cerebrovascular function and have poor sleep quality. In the general population, poor sleep contributes to cerebrovascular ...dysfunction and is related to cardiovascular disease (CVD). Improving sleep quality may have beneficial effects in preventing CVD; however, the relationship between sleep quality and cerebrovascular function in MS has not been examined.
Purpose
To examine the effect of sleep quality on cerebrovascular function in individuals with MS.
Methods
Sixteen individuals with MS had sleep quality assessed with the Pittsburgh Sleep Quality Index. Individuals were categorized as having poor sleep quality (n = 6, score >5) or good sleep quality (n = 10, score ≤5). Cerebrovascular function was assessed via transcranial Doppler ultrasound with the following hemodynamic outcomes: mean middle cerebral artery velocity (mMCAv), pulsatility index (PI), and resistance index (RI). An automated blood pressure cuff was used to measure baseline blood pressure (systolic, diastolic, mean (SBP, DBP, MAP)) and heart rate in a seated position. End-tidal CO
2
(EtCO
2
) was measured by gas capnography.
Results
Those with poor sleep quality had greater PI and RI, and lower mMCAv compared to those with good sleep quality (p<0.05, table 1). No group differences were seen for weight, height, BMI, CO
2
, or hemodynamic variables. Conclusion: Our results suggest that individuals with MS with poor sleep quality have worsened indicators of cerebrovascular function. Therefore, sleep quality may be related to the elevated CVD risk in individual with MS, and it should be assessed in future studies evaluating cerebrovascular function in MS, including intervention studies.
High-intensity resistance exercise (RE) acutely increases arterial stiffness and blood pressure (BP), coupled with reduced cerebral blood flow velocity (CBFv) and greater flow pulsatility in the ...cerebral circulation, which may be detrimental to cerebral microvasculature. Because females have different CV control mechanisms, it is important to assess potential sex differences in cerebrovascular responses to acute RE.
Purpose
To examine the effect of sex on hemodynamics and cerebral vasculature following acute RE.
Methods
Men (n = 18, 27 yrs, BMI = 24.2) and women (n = 14, 25 yrs, BMI = 23.8) performed RE (3 × 10, isokinetic knee flexion/extension). Measurements were obtained at baseline and post-exercise (1, 5, 30-minute). Beat-to-beat heart rate (HR), brachial BP, cardiac output (CO), stroke volume and end-tidal CO
2
were collected. CBFv was measured by transcranial Doppler, carotid BP by applanation tonometry and central pulse wave velocity (PWV) by an automated ambulatory BP monitor.
Results
Table 1
. CBFv pulsatility increased following RE at 1-minute post (p < 0.05) in men and was elevated above baseline 5-minute post-exercise (p < 0.05) in both groups (
Figure 1
). Mean CBFv increased 1-min post-exercise and decreased below baseline 5-minute post-exercise (p < 0.05) in both sexes. PWV increased 1-minute post-exercise (p < 0.05) in both groups.
Table 1
All Data are mean ± SD; *Exercise effect, p < 0.05. †Group effect. p < 0.05. ‡Interaction effect. p < 0.05. a Significantly different from 1-minute, b Significantly different from 5-minute. c Significantly different from 30-minute. p < 0.05). Brachial systolic BP (bSBP), brachial diastolic BP (bDBP), brachial mean BP (bMAP), Carotid systolic BP (cSBP),carotid diastolic BP (cDBP), cardiac output (CO), stroke volume (SV) and central pulse wave velocity (PWV), cerebral blood flow velocity (CBFv).
Variables
Baseline
1-minute
5-minute
30-minute
Heart Rate(bpm)*†
Men
63 ± 9
82 ± 9
71 ± 10
70 ± 8
Women
70 ± 7
93 ± 13
79 ± 10
76 ± 9
CO (L/min) *
Men
4.9 ± 0.7
7.9 ± 1.3
6.1 ± 1.3
5.2 ± 0.9
Women
5.4 ±1.0
8.2 ± 1.4
6.3 ± 1.0
5.7± 0.8
SV (ml/min)*‡
Men
77 ± 16
ab
95 ± 17
bc
85 ± 17
c
72 ± 13
Women
80 ± 1
7
a
91 ± 20
bc
81 ± 14
76 ± 16
bSBP (mmHg)*
Men
124 ± 10
140 ± 12
127 ± 10
127 ± 9
Women
124 ± 9
136 ± 15
122 ± 13
123 ± 9
bDBP (mmHg)*
Men
72 ± 8
74 ± 7
72 ± 7
76 ± 6
Women
73 ± 5
76 ± 9
71 ± 7
73 ± 5
bMAP (mmHg)*
Men
92 ± 8
100 ± 8
93 ± 8
96 ± 7
Women
95 ± 6
101 ± 11
93 ± 8
95 ± 6
cSBP (mmHg)*
Men
120 ± 12
129 ± 18
125 ± 13
126 ± 10
Women
1 22 ± 12
124 ± 13
119 ± 18
123 ± 8
cDBP (mmHg)*
Men
75 ± 7
74 ± 7
75 ± 7
79 ± 6
Women
74 ± 6
73 ± 6
75 ± 7
74 ± 5
cMAP (mniHg)*
Men
93 ± 8
94 ± 8
94 ± 7
97 ± 7
Women
94 ± 6
93 ± 8
95 ± 9
96 ± 5
PWV (m/s)*
Men
5.2 ± 0.5
5.6 ± 0.5
5.4 ± 0.5
5.2 ± 0.3
Women
5.0 ± 0.4
5.3 ± 0.5
5.1 ± 0.3
5.0 ± 0.3
CBFv Mean (cm/s)*†
Men
55.8 ± 7.6
63.9 ± 9.6
51.4 ± 6.9
53.7 ± 7.9
Women
69.8 ± 14.4
81.0 ± 23.1
63.7 ± 12.9
65.8 ± 12.0
CBFv Pulsatility Index*†‡
Men
0.91 ± 0.12
ab
1.10 ± 0.16*
1.13 ± 0.17
c
0.89 ± 0.13
Women
0.81 ± 0.09
b
0.90 ± 0.18
0.95 ± 0.13
c
0.81 ± 0.11
End-Tidal CO
2
(%)*
Men
4.86 ± 0.48
5.72 ± 0.66
4.64 ± 0.51
4.51 ± 0.58
Women
4.41 ± 0.60
5.44 ± 0.65
4.26 ± 0.39
4.24 ± 0.50
Figure 1
All Data are mean ± SD, *Exercise effect, p < 0.05. †Group effect, p < 0.05. ‡Interaction effect, p < 0.05. a Significantly different from 1-minute, b Significantly different from 5-minute. c Significantly different from 30-minute, p < 0.05).
Conclusion
Men increased CBFv pulsatility at 1-minute post-RE compared to women, demonstrating a sex difference in cerebral vascular reactivity. RE increased central arterial stiffness, mean CBFv, HR, and BP similarly for both sexes. CO was also elevated at 5-minute, but CBFv dropped below baseline and pulsatility continued to rise above baseline. This temporary disruption in cerebral autoregulation may impact brain health in both sexes.
To evaluate the effect of neighborhood-level characteristics on cardiorespiratory fitness (CRF) via peak oxygen consumption (VO2peak) for healthy pediatric patients.
The institutional cardiopulmonary ...exercise testing (CPET) database was analyzed retrospectively. All patients aged ≤ 18 years without a diagnosis of cardiac disease and with a maximal effort CPET were included. Patients were divided into three self-identified racial categories: White, Black, and Latinx. The Child Opportunity Index (COI) 2.0 was used to analyze social determinants of health. CRF was evaluated based on COI quintiles and race. Assessment of the effect of COI on racial disparities in CRF was performed using ANCOVA.
A total of 1753 CPETs met inclusion criteria. The mean VO2peak was 42.1 ± 9.8 mL/kg/min. The VO2peak increased from 39.1 ± 9.6 mL/kg/min for patients in the very low opportunity cohort to 43.9 ± 9.4 mL/kg/min for patients in the very high opportunity cohort. White patients had higher percent predicted VO2peak compared with both Black and Latinx patients (P < .01 for both comparisons). The racial differences in CRF were no longer significant when adjusting for COI.
In a large pediatric cohort, COI was associated with CRF. Racial disparities in CRF are reduced when accounting for modifiable risk factors.
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