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Background. Mechanical efficiency (ME) might be an important parameter evaluating cardiometabolic health and the effectiveness of physical activity interventions in individuals with obesity. However, whether these cardiometabolic risk factors may relate to ME in adolescents with obesity is not known yet. Therefore, this study aims to compare the mechanical efficiency during maximal exercise testing between adolescents with obesity and lean adolescents, and to examine associations with exercise tolerance and metabolic health. Methods. Twenty-nine adolescents with obesity (BMI SDS: 2.11 ± 0.32, age: 13.4 ± 1.1 years, male/female: 15/14) and 29 lean (BMI SDS: −0.16 ± 0.84, age: 14.0 ± 1.5 years, male/female: 16/13) adolescents performed a maximal cardiopulmonary exercise test from which the net mechanical efficiency (MEnet) and substrate oxidation (carbohydrates and lipids) were calculated. Indicators for peak performance were collected. Biochemistry (lipid profile, glycaemic control, inflammation, leptin) was studied in fasted blood samples. Regression analyses were applied to examine relations between MEnet and exercise tolerance or blood variables in the total group. Results. Peak work rate (WRpeak), oxygen uptake (V˙O2peak)/WRpeak, ME, and MEnet were significantly lower (p &lt, 0.05) in adolescents with obesity compared to their lean counterparts (p &lt, 0.05). Furthermore, a reduced MEnet was independently related to a lower WRpeak (SC β = 2.447, p &lt, 0.001) and elevated carbohydrate oxidation during exercise (SC β = −0.497, 0.001), as well as to elevated blood low-density lipoprotein cholesterol (SC β = −0.275, p = 0.034) and fasting glucose (SC β = −0.256, p = 0.049) concentration. Conclusion. In adolescents with obesity, the mechanical efficiency is lowered during exercise and this relates to exercise intolerance and a worse metabolic health.

BACKGROUND: Adults with obesity may display disturbed cardiac chronotropic responses during cardiopulmonary exercise testing, which relates to poor cardiometabolic health and an increased risk for adverse cardiovascular events. It is unknown whether cardiac chronotropic incompetence (CI) during maximal exercise is already present in obese adolescents and, if so, how that relates to cardiometabolic health. METHODS: Sixty-nine obese adolescents (body mass index standard deviation score = 2.23 ± 0.32, age = 14.1 ± 1.2 years; mean ± SD) and 29 lean adolescents (body mass index standard deviation score = –0.16 ± 0.84, age = 14.0 ± 1.5 years) performed a maximal cardiopulmonary exercise testing from which indicators for peak performance were determined. The resting heart rate and peak heart rate were used to calculate the maximal chronotropic response index. Biochemistry (lipid profile, glycemic control, inflammation, and leptin) was studied in fasted blood samples and during an oral glucose tolerance test within obese adolescents. Regression analyses were applied to examine associations between the presence of CI and blood or exercise capacity parameters, respectively, within obese adolescents. RESULTS: CI was prevalent in 32 out of 69 obese adolescents (46%) and 3 out of 29 lean adolescents (10%). C-reactive protein was significantly higher in obese adolescents with CI compared to obese adolescents without CI (p = 0.012). Furthermore, peak oxygen uptake and peak cycling power output were significantly reduced (p < 0.05) in obese adolescents with CI vs. obese adolescents without CI. The chronotropic index was independently related to blood total cholesterol (standardized coefficient β = –0.332; p = 0.012) and C-reactive protein concentration (standardized coefficient β = –0.269; p = 0.039). CONCLUSION: CI is more common in the current cohort of obese adolescents, and is related to systemic inflammation and exercise intolerance.

Background To date, it is unclear if consumer wearable activity trackers (CWATs), with or without behaviour multi-component strategies, effectively improve adherence to physical activity and health outcomes under free living conditions in populations with chronic diseases. Therefore, we systematically evaluated the efficacy of CWAT-based interventions to promote physical activity levels and cardiometabolic health in populations with chronic diseases. Methods Randomised controlled trials were collected from five bibliographic databases (PubMed, Embase, Web of Science, The Cochrane Central Register of Controlled Trials and CINAHL). Studies were eligible for inclusion if they evaluated a CWAT-based counselling intervention versus control intervention among patients with chronic respiratory diseases, type 2 diabetes mellitus, cardiovascular diseases, overweight/obesity, cognitive disorders, or sedentary older adults. Data were pooled using a random-effects model. Results After deduplication 8147 were identified of which 35 studies met inclusion criteria (chronic respiratory diseases: 7, type 2 diabetes mellitus: 12, cardiovascular diseases: 6, overweight/obesity: 3, cognitive disorders: 1, sedentary older adults: 6). Compared to control groups, CWAT-based interventions significantly increased physical activity by 2123 steps per day (95% confidence interval [CI], [1605–2641]; p p p = 0.002). Conclusion CWAT-based interventions increase physical activity and have beneficial effects on important health-related outcomes such as systolic blood pressure, waist circumference and LDL cholesterol concentration in patients with chronic diseases.

Objectives Cardiovascular diseases and exercise intolerance elevate mortality in type 1 diabetes (T1D). Left ventricular systolic and diastolic function are already affected in T1DM adolescents, displaying poor glycemic control (glycated hemoglobin [A1C]>7.5%) and exercise intolerance. We investigated to the extent to which left ventricular function is affected by disease severity/duration and whether this is related to exercise capacity. Methods Transthoracic echocardiography was performed in 19 T1DM adolescents (14.8±1.9 years old, A1C 7.4±0.9%) and 19 controls (14.4±1.3 years old, A1C 5.3±0.2%), matched for age and Tanner stage. Diastolic and systolic (ejection fraction [EF]) function were assessed. Cardiopulmonary exercise testing was used to evaluate exercise capacity, as measured by peak oxygen uptake (VO2peak). Results VO2peak and left ventricular systolic and diastolic function were similar in both groups. Within the T1D group, EF was negatively associated with disease duration (r=−0.79 corrected for age, standardized body mass index, glucose variability and VO2peak; p=0.011). Regression analyses revealed that 37.6% of the variance in EF could be attributed to disease duration. Conclusions Although left ventricular systolic and diastolic function are preserved in T1D with adequate exercise capacity, disease duration negatively affects EF. The detrimental effects of T1D seem to be driven by disease duration, rather than by disease severity, at least during adolescence. Young T1D patients may, therefore, benefit from cardiovascular evaluation in order to detect cardiovascular abnormalities early in the disease course, and therefore, improve long-term cardiovascular health.

Objective To gain greater insights in the etiology and clinical consequences of altered cardiac function in obese adolescents. Therefore, we aimed to examine cardiac structure and function in obese adolescents, and to examine associations between altered cardiac function/structure and cardiometabolic disease risk factors or cardiopulmonary exercise capacity. Methods In 29 obese (BMI 31.6 ± 4.2 kg/m², age 13.4 ± 1.1 years) and 29 lean (BMI 19.5 ± 2.4 kg/m², age 14.0 ± 1.5 years) adolescents, fasted blood samples were collected to study hematology, biochemistry, liver function, glycemic control, lipid profile, and hormones, followed by a transthoracic echocardiography to assess cardiac structure/function, and a cardiopulmonary exercise test (CPET) to assess cardiopulmonary exercise parameters. Regression analyses were applied to examine relations between altered echocardiographic parameters and blood parameters or CPET parameters in the entire group. Results In obese adolescents, left ventricular septum thickness, left atrial diameter, mitral A-wave velocity, E/e’ ratio were significantly elevated (p