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Chronotropic Incompetence During Exercise Testing in Obese Adolescents

Conditions
Cardiac Disease
Obesity, Childhood
Cardiovascular Risk Factor
Interventions
Diagnostic Test: The prevalence of chronotropic incompetence during maximal cardiopulmonary exercise testing
Registration Number
NCT04185753
Lead Sponsor
Hasselt University
Brief Summary

In adolescents with obesity cardiopulmonary exercise testing (CPET) has become an important clinical examination providing valuable information with regard to the integrative exercise responses, including the pulmonary, cardiovascular and muscular systems.

During CPET, mechanical constraints in ventilation, an elevated risk for hypoxia and chronotropic incompetence (CI) (defined as the inability of the heart to increase its rate with increased activity), or compromised cardiac function (e.g. lowered heart rate (HR) recovery, chronotropic index and stroke volume) are often observed in obese adults. Moreover, several studies regarding exercise capacity and cardiopulmonary responses to maximal endurance exercise testing have been performed in obese adolescents. Despite these previous investigations in obese adolescents it remains controversial whether cardiopulmonary disturbances can be observed consistently during CPET. However, a number of studies have reported a suboptimal response to exercise, in particular a reduced peak heart rate (HRpeak) and peak cycling power output (Wpeak). Adult obesity modifies cardiac behavior, including resting HR and CI, which has a marked effect on exercise capacity. Therefore, chronotropic variables are the most important factors that affect exercise performance. It has been shown that both peak and resting HR account for over forty percent of variability of exercise capacity. Interestingly, resting HR and HR response to exercise, including a blunted HR increase, low chronotropic index and HR recovery, are important predictors of all-cause mortality and cardiovascular death, at least in adults. These changes in HR during and recovery from CPET are mediated by the balance between sympathetic and vagal activity of the autonomic nervous system. Adverse cardiovascular outcomes associated with the metabolic syndrome may be mediated by autonomic dysfunction, whereby obesity is characterized by sympathetic predominance and a decrease in vagal activity in the basal state, where reduced sympathetic responsiveness has been observed during exercise. Therefore, these multiple exercise risk markers could provide valuable clinical information regarding cardiometabolic health. Nonetheless HR behavior during CPET has not been described in obese adolescents. The goal of this study is to examine the HR behavior of obese adolescents during CPET to clarify whether this population suffer from CI.

Detailed Description

Not available

Recruitment & Eligibility

Status
UNKNOWN
Sex
All
Target Recruitment
60
Inclusion Criteria
  • obese or lean (based on extended international (IOTF) body mass index cut-offs for thinness, overweight and obesity)
  • Parental permission
Exclusion Criteria
  • Chronic cardiovascular, renal, pulmonary or orthopaedic disease
  • Medication use that could possibly influence the heart rate

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
Control groupThe prevalence of chronotropic incompetence during maximal cardiopulmonary exercise testingObese adolescents without chronotropic incompetence
Obese adolescents with CIThe prevalence of chronotropic incompetence during maximal cardiopulmonary exercise testingObese adolescents with chronotropic incompetence
Primary Outcome Measures
NameTimeMethod
Peak workload during exercise testingday 1

Cardiopulmonary exercise test on an electronically braked cycle ergometer is performed and the incremental workload is measured

Heart rate (HR) during exercise testingday 1

Assessed using a 12-lead ECG device

Peak oxygen uptake (VO2) during exercise testingday 1

Cardiopulmonary exercise test on an electronically braked cycle ergometer is performed. With the aid of continuous pulmonary gas exchange analysis VO2 is collected breath-by-breath and averaged every ten seconds.

Secondary Outcome Measures
NameTimeMethod
Hip circumferenceday1

Hip circumference will be measured to the nearest 0.1cm using a flexible metric measuring tape with participants barefoot (in underwear) in standing position. Hip circumference is measured at the widest circumference of the hip at the level of the greater trochanter.

Body weightday 1

Body weight (in underwear) is determined using a digital-balanced weighting scale to the nearest 0.1kg

Low-density lipoprotein cholesterolday 1

Blood analyses

Insulinday 1

Blood analyses

Minute ventilation(VE) during exercise testingday 1

Cardiopulmonary exercise test on an electronically braked cycle ergometer is performed. With the aid of continuous pulmonary gas exchange analysis VE is collected breath-by-breath and averaged every ten seconds.

Breathing frequency (BF) during exercise testingday 1

Cardiopulmonary exercise test on an electronically braked cycle ergometer is performed. With the aid of continuous pulmonary gas exchange analysis BF is collected breath-by-breath and averaged every ten seconds.

Body heightday 1

Body height is measured to the nearest 0.1cm using a wall-mounted Harpenden stadiometer, with participants barefoot

Physical activity questionnaire for adolescents (PAQ-A)day 1

physical activity determined using the validated Dutch physical activity questionnaire for adolescents

Waist circumferenceday 1

Waist circumference will be measured to the nearest 0.1cm using a flexible metric measuring tape with participants barefoot (in underwear) in standing position. Waist circumference is measured at the midpoint between the lower rib margin and the top of the iliac crest.

Serum leptin concentrationday 1

Blood analyses

Tanner stageday 1

Puberty stage (ranging from 1 to 5) will be assessed in all participants by the pediatric endocrinologist using Tanner staging criteria.

Plasma glucoseday 1

Blood analyses

Tidal volume (Vt) during exercise testingday 1

Cardiopulmonary exercise test on an electronically braked cycle ergometer is performed. With the aid of continuous pulmonary gas exchange analysis Vt is collected breath-by-breath and averaged every ten seconds.

High-density lipoprotein cholesterolday 1

Blood analyses

Triglyceride concentrationday 1

Blood analyses

Total cholesterolday 1

Blood analyses

C-reactive proteinday 1

Blood analyses

Homeostatic model assessment for insulin resistance (HOMA-IR)day 1

Homeostatic model assessment for insulin resistance calculated from insulin and glucose concentration

Carbon dioxide output (VCO2) during exercise testingday 1

Cardiopulmonary exercise test on an electronically braked cycle ergometer is performed. With the aid of continuous pulmonary gas exchange analysis VCO2 is collected breath-by-breath and averaged every ten seconds.

Trial Locations

Locations (1)

Virga Jesse hospital - Heart centre Hasselt

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Hasselt, Limburg, Belgium

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