Resting energy expenditure in children at risk of hypothalamic dysfunction

OBJECTIVE

Children with suprasellar brain damage are at risk of hypothalamic dysfunction (HD). HD may lead to decreased resting energy expenditure (REE). Decreased REE, however, is not present in all children with HD. Our aim was to assess which children suspect for HD have low REE, and its association with clinical severity of HD or radiological hypothalamic damage.

PATIENTS AND METHODS

A retrospective cohort study was performed. Measured REE (mREE) of children at risk of HD was compared to predicted REE (pREE). Low REE was defined as mREE <90% of predicted. The mREE/pREE quotient was associated to a clinical score for HD symptoms and to radiological hypothalamic damage.

RESULTS

In total, 67 children at risk of HD (96% brain tumor diagnosis) with a mean BMI SDS of +2.3 ± 1.0 were included. Of these, 45 (67.2%) had low mREE. Children with severe HD had a significant lower mean mREE/pREE quotient compared to children with no, mild, or moderate HD. Mean mREE/pREE quotient of children with posterior hypothalamic damage was significantly lower compared to children with no or anterior damage. Tumor progression or tumor recurrence, severe clinical HD, and panhypopituitarism with diabetes insipidus (DI) were significant risk factors for reduced REE.

CONCLUSION

REE may be lowered in children with hypothalamic damage and is associated to the degree of clinical HD. REE is, however, not lowered in all children suspect for HD. For children with mild or moderate clinical HD symptoms, REE measurements may be useful to distinguish between those who may benefit from obesity treatment that increases REE from those who would be better helped using other obesity interventions.

Results from the Netherlands' 2018 Report Card and Report Card+ on physical activity for children and youth with and without chronic medical condition

OBJECTIVE

The objective of this study was to summarize the results of the 2018 the Netherlands' Physical Activity Report Card (PARC) for children and youth as well as for children and youth with a chronic medical condition (CMC; PARC⁺).

STUDY DESIGN

This study is a survey.

METHODS

A total of 12 indicators were graded using the Active Healthy Kids Global Alliance PARC development process, which includes a synthesis of the best available research, surveillance, policy and practice findings and expert consensus. Grades were based on the best available evidence and ranged from grade A (>80% of the children succeed) to grade F (less than 20% succeed) or incomplete (INC). Sources included national surveys, peer-reviewed literature and grey literature such as government and non-government reports and online content.

RESULTS

Grades assigned for PARC/PARC⁺ were as follows: Overall Physical Activity: C-/D+; Organized Sports Participation: B/B-; Active Play: D/D; Active Transportation: A-/B+; Sedentary Behaviour: D/D; Physical Fitness: INC /INC; Family and Peers: C/INC; School: C+/A-; Community and Environment: INC /INC; Government: INC /INC; Sleep: A-/B+ and Weight Status: A-/A-, respectively.

CONCLUSIONS

The report shows that the Netherlands' youth scores well on (organized) participation in sports and active transport to and from school. However, they do not participate enough in overall physical activity. Despite the fact that outdoor play is the most important exercise activity for children, outdoor play scores an insufficient score for both healthy children and children with a CMC. Sports participation also contributed significantly to daily physical activity. However, sports participation alone is not enough to comply with the national activity guidelines.

Extended steep ramp test normative values for 19-24-year-old healthy active young adults

Purpose

To extend currently available sex and age-specific normative values in children and adolescents for the peak work rate (WR_peak) attained at the steep ramp test (SRT) to healthy active young adults.

Methods

Healthy male and female participants aged between 19 and 24 years were recruited. After screening and anthropometric measurements, participants performed a SRT on a cycle ergometer (increments of 25 W/10 s), monitoring and recording SRT-WR_peak, heart rate (HR), and blood pressure (BP) at rest and directly after peak exercise.

Results

Fifty-seven participants (31 males and 26 females; median age of 21.3 years) volunteered and were tested. Anthropometrics, resting BP and lung function were all within normal ranges. Ninety-three percent of the participants attained a peak HR (HR_peak) > 80% of predicted (mean HR_peak 87 ± 5% of predicted). No differences were found in resting and peak exercise variables between females and males, except for absolute SRT-WR_peak (350 W [Q1: 306; Q3: 371] and 487 W [Q1: 450; Q3: 517], respectively) and SRT-WR_peak normalized for body mass (relative SRT-WR_peak; 5.4 ± 0.5 and 6.2 ± 0.6 W/kg, respectively). Low-to-moderate correlations (ρ [0.02–0.71]) were observed between SRT-WR_peak and anthropometric variables for females and males separately. Extended reference curves (8–24-year-old subjects) for SRT performance show different trends between male and female subjects when modelled against age, body height, and body mass.

Conclusions

The present study provides sex-, age-, body height-, and body mass-related normative values (presented as reference centiles) for absolute and relative SRT performance throughout childhood and early adulthood.

Electronic supplementary material

The online version of this article (10.1007/s00421-019-04255-x) contains supplementary material, which is available to authorized users.

Reference values for maximum work rate in apparently healthy Dutch/Flemish adults: data from the LowLands fitness registry

Background: The peak oxygen uptake (VO₂peak) test is the gold standard for cardiorespiratory fitness. However, the test is demanding, requiring sophisticated apparatus for measuring the oxygen uptake. Peak work rate (WRpeak) testing is a promising substitute for peak VO₂peak testing. However, there is a paucity of research conducted to determine reference values (RVs) for WRpeak. Methods: The database from the LowLands fitness registry was used, containing data from health checks from apparently healthy subjects among various professions. Exercise tests were performed using a cycle ergometer and a calibrated metabolic cart. Analysis was executed on 3463 subjects, 2868 male and 595 female. Reference values with corresponding centiles were developed using the LMS method. Results: VO₂peak and WRpeak where highly associated with Pearson's correlation of 0.9 (p = .001). Weight, height, maximum heart rate, and the respiratory exchange ratio had a positive significant effect (p < .001) on WRpeak, and age a negative significant effect, in both males and females. The following formulas were computed for RVs: WRpeak=-102+(1.5 * weight[kg])+(1.9 * height[cm])-(2.0 * age)-(sex * 60[M:0;V:1]) WRpeak/kg=2.45-(0.026 * weight[kg])+(0.024 * height[cm])-(0.024 * age)-(sex * 0.84 [M:0;V:1]) Conclusions: WRpeak can be used as a substitute for VO₂peak when a respiratory gas-analysis system is not available. This study provides RVs for WRpeak and WRpeak/kg in a healthy Dutch/Flemish adult population using cycle ergometry. Further research is needed to obtain RVs for elderly subjects, specific diseases, ethnicities and ergometers.

Evaluation of Left Ventricular Function Long Term After Arterial Switch Operation for Transposition of the Great Arteries

Long-term after arterial switch operation for transposition of the great arteries, abnormal coronary anatomy and altered loading conditions could compromise ventricular function. The current study investigates whether left ventricular function, measured with echocardiographic bi-plane ejection fraction and deformation imaging, in patients long term after arterial switch operation for transposition of the great arteries differs from healthy peers. A cross-sectional cohort study of patients at least 12 years after arterial switch operation was analyzed with bi-plane Simpson's left ventricular ejection fraction (LVEF) and deformation (speckle tracking) echocardiography. 81 patients, median age 20.6 (interquartile range 13.5-28.4) years, were included. LVEF was normal on average at 55.5 ± 6.1%. Global longitudinal strain (GLS) was lower in patients compared to healthy peers throughout all age groups and on pooled average (- 15.4 ± 1.1% vs. - 23.2 ± 0.9%). Although LVEF is normal on average in patients after arterial switch operation for transposition of the great arteries, GLS is impaired compared to healthy peers. The reduced GLS could indicate sub-clinical myocardial dysfunction.

[An activity-friendly environment: that's also the doctor's business]

Achieving and maintaining sufficient levels of physical activity is important for the health of the Dutch population. However, the vast majority of the Dutch population - including children - does not comply with the current physical activity guideline. This is the case despite excellent infrastructure which allows safe movement and facilitates walking or cycling to school or work. Perhaps the layout of our living environment is unattractive for movement. It may possibly be unchallenging for young people or too much concrete for adults. In this article we discuss the role of the physical environment on physical activity and ultimately our health. Ways in which the environment could influence the levels of physical activity of the population are also considered.

Relationship between lung function and Modified Shuttle Test performance in adult patients with cystic fibrosis: a cross-sectional, retrospective study

OBJECTIVES

To investigate the relationship between lung function and exercise capacity in adults with cystic fibrosis (CF), and to develop a CF-specific equation to predict Modified Shuttle Test (MST) performance from baseline data.

DESIGN

Cross-sectional, retrospective study.

SETTING

Adult CF centre.

PARTICIPANTS

One hundred and twenty-seven patients with CF [61 male; mean age 25 years (range 17 to 52 years), mean forced expiratory volume in 1second (FEV1) 56% predicted (range 15 to 124%)].

MAIN OUTCOME MEASURES

MST and FEV1.

RESULTS

Overall, a moderate-to-good relationship was found between lung function and MST performance (walking distance vs FEV1% predicted: r=0.64, P=0.01). This relationship between FEV1 and MST shows an obvious threshold at an FEV1 of 67% predicted. Above this threshold, no significant association was observed between FEV1 and MST performance. However, a strong relationship (MST vs FEV1% predicted: r≥0.74, P<0.01 for men and r=0.79, P<0.01 for women) was found below an FEV1 of 67% predicted.

CONCLUSIONS

This study suggests that a strong association exists between lung function (FEV1% predicted) and MST (walking distance) in adult patients with moderate-to-severe CF (FEV1<67% predicted). A reference equation for MST performance was developed for those patients with FEV1 ≤67% predicted, providing a tool to make an a-priori prediction of MST walking distance.

Application of the steep ramp test for aerobic fitness testing in children with cancer

BACKGROUND

Children with and after cancer are found to have a decreased physical fitness, frequently resulting in decreased physical functioning. The gold standard test for assessing aerobic fitness, a component of physical fitness, is the respiratory gas analyses-based cardiopulmonary exercise test (CPET). However, equipment for gas analysis is often unavailable in local physical therapy centres and non-university hospitals. The steep ramp test (SRT), is a cycle ergometer test with a fast increase in workload, a short duration, and does not require respiratory gas analysis equipment.

AIM

The aim of this study was to compare the results of the CPET and the SRT, in children with cancer, and to assess whether the SRT can be used for aerobic fitness assessment in clinical practice in this population.

DESIGN

This study is a cross-sectional assessment using baseline data of a randomized controlled trial.

SETTING

The study was performed in a hospital setting.

POPULATION

Sixty-one children (mean age 12.9 years; 33 boys) with cancer were included in the analysis; 16 children were on non-intensive chemotherapy treatment, 45 were in the first year thereafter.

METHODS

Participants performed both the SRT and the CPET on a cycle ergometer with respiratory gas analysis. Data of the two tests were compared and regression analyses were performed.

RESULTS

CPET test results revealed a higher impact on the cardiovascular system, as shown by higher peak ventilation (47.8 versus 52.0 Litres per min) and peak heart rates (173 versus 191 beats per min), compared to the SRT. In addition, the test time was significantly longer (90 s versus 390 s). Yet, the primary outcome of the SRT (peak work rate) was able to reliably estimate the peak oxygen uptake of the CPET.

CONCLUSION

The peak oxygen uptake was comparable between the SRT and the CPET, although the peak work rate was significantly higher during the SRT. This study showed that the SRT is a valid instrument to assess aerobic fitness in children with cancer.

CLINICAL REHABILITATION IMPACT

The SRT is less time consuming and can be performed without gas analysis in a non-clinical setting, making it less demanding for children.

Exercise tolerance in obese vs. lean adolescents: a systematic review and meta-analysis

To prescribe feasible and medically safe exercise interventions for obese adolescents, it remains to be determined whether exercise tolerance is altered and whether anomalous cardiopulmonary responses during maximal exercise testing are present. Studies that examined cardiopulmonary responses to maximal exercise testing in obese adolescents were searched: cardiopulmonary exercise tests with respiratory gas exchange measurements of peak oxygen uptake (VO2peak) were performed and comparisons between obese and lean adolescents were made. Study quality was assessed using a standardized item list. By meta-analyses VO2peak, peak cycling power output (Wpeak) and peak heart rate (HRpeak) were compared between groups. Nine articles were selected (333 obese vs. 145 lean adolescents). VO2peak (L min(-1)), HRpeak and Wpeak were not different between groups (P ≥ 0.10), while a trend was found for a reduced VO2peak (mL min(-1) kg(-1) lean tissue mass) (P=0.07) in obese vs. lean adolescents. It remained uncertain whether anomalous cardiopulmonary responses occur during maximal exercise testing in obese adolescents. In conclusion, a trend was found for lowered VO2peak (mL min(-1)kg(-1) lean tissue mass) in obese vs. lean adolescents. Whether cardiopulmonary anomalies during maximal exercise testing would occur in obese adolescents remains uncertain. Studies are therefore warranted to examine the cardiopulmonary response during maximal exercise testing in obese adolescents.

Exercise training programs to improve hand rim wheelchair propulsion capacity: a systematic review

Objective:

An adequate wheelchair propulsion capacity is required to perform daily life activities. Exercise training may be effective to gain or improve wheelchair propulsion capacity. This review investigates whether different types of exercise training programs are effective in improving wheelchair propulsion capacity.

Data sources:

PubMed and EMBASE databases were searched from their respective inceptions in October 2013.

Review methods:

Exercise training studies with at least one outcome measure regarding wheelchair propulsion capacity were included. In this study wheelchair propulsion capacity includes four parameters to reflect functional wheelchair propulsion: cardio-respiratory fitness (aerobic capacity), anaerobic capacity, muscular fitness and mechanical efficiency. Articles were not selected on diagnosis, training type or mode. Studies were divided into four training types: interval, endurance, strength, and mixed training. Methodological quality was rated with the PEDro scale, and the level of evidence was determined.

Results:

The 21 included studies represented 249 individuals with spinal-cord injury (50%), various diagnoses like spina bifida (4%), cerebral palsy (2%), traumatic injury, (3%) and able-bodied participants (38%). All interval training studies found a significant improvement of 18-64% in wheelchair propulsion capacity. Three out of five endurance training studies reported significant effectiveness. Methodological quality was generally poor and there were only two randomised controlled trials.

Conclusion:

Exercise training programs seem to be effective in improving wheelchair propulsion capacity. However, there is remarkably little research, particularly for individuals who do not have spinal-cord injury.

Exercise therapy improves mental and physical health in schizophrenia: a randomised controlled trial

OBJECTIVE

The objective of this multicenter randomised clinical trial was to examine the effect of exercise versus occupational therapy on mental and physical health in schizophrenia patients.

METHOD

Sixty-three patients with schizophrenia were randomly assigned to 2 h of structured exercise (n = 31) or occupational therapy (n = 32) weekly for 6 months. Symptoms (Positive and Negative Syndrome Scale) and cardiovascular fitness levels (Wpeak and VO2peak ), as assessed with a cardiopulmonary exercise test, were the primary outcome measures. Secondary outcome measures were the Montgomery and Åsberg Depression Rating Scale, Camberwell Assessment of Needs, body mass index, body fat percentage, and metabolic syndrome (MetS).

RESULTS

Intention-to-treat analyses showed exercise therapy had a trend-level effect on depressive symptoms (P = 0.07) and a significant effect on cardiovascular fitness, measured by Wpeak (P < 0.01), compared with occupational therapy. Per protocol analyses showed that exercise therapy reduced symptoms of schizophrenia (P = 0.001), depression (P = 0.012), need of care (P = 0.050), and increased cardiovascular fitness (P < 0.001) compared with occupational therapy. No effect for MetS (factors) was found except a trend reduction in triglycerides (P = 0.08).

CONCLUSION

Exercise therapy, when performed once to twice a week, improved mental health and cardiovascular fitness and reduced need of care in patients with schizophrenia.

Validation of the Actical and Actiheart monitor in ambulatory children with spina bifida

BACKGROUND

Ambulatory children with Spina Bifida (SB) often show a decline in physical activity leading to deconditioning and functional decline. Therefore, assessment and promotion of physical activity is important. Because energy expenditure during activities is higher in these children, the use of existing pediatric equations to predict physical activity energy expenditure (PAEE) may not be valid.

AIMS

(1) To evaluate criterion validity of existing predictions converting accelerocounts into PAEE in ambulatory children with SB and (2) to establish new disease-specific equations for PAEE.

METHODS

Simultaneous measurements using the Actical, the Actiheart, and indirect calorimetry took place to determine PAEE in 26 ambulatory children with SB.

DATA ANALYSIS

Paired T-tests, Intra-class correlations limits of agreement (LoA), and explained variance (R(2)) were used to analyze validity of the prediction equations using true PAEE as criterion. New equations were derived using regression techniques.

RESULTS

While T-tests showed no significant differences for some models, the predictions developed in healthy children showed moderate ICC's and large LoA with true PAEE. The best regression models to predict PAEE were: PAEE=174.049+3.861 × HRAR - 60.285 × ambulatory status (R(2) =0.720) and PAEE=220.484+0.67 × Actical counts - 60.717 × ambulatory status (R(2) =0.681).

CONCLUSIONS

Existing equations to predict PAEE are not valid for use in children with SB for the individual evaluation of PAEE. The best regression model was based on HRAR in combination with ambulatory status, followed by a new model for the Actical monitor. A benefit of HRAR is that it does not require the use of expensive accelerometry equipment. Further cross-validation of these models is still needed.

Different anthropometric adiposity measures and their association with cardiovascular disease risk factors: a meta-analysis

Objectives

To investigate which anthropometric adiposity measure has the strongest association with cardiovascular disease (CVD) risk factors in Caucasian men and women without a history of CVD.

Design

Systematic review and meta-analysis.

Methods

We searched databases for studies reporting correlations between anthropometric adiposity measures and CVD risk factors in Caucasian subjects without a history of CVD. Body mass index (BMI), waist circumference, waist-to-hip ratio, waist-to-height ratio and body fat percentage were considered the anthropometric adiposity measures. Primary CVD risk factors were: systolic blood pressure, diastolic blood pressure, high density lipoprotein (HDL) cholesterol, triglycerides and fasting glucose. Two independent reviewers performed abstract, full text and data selection.

Results

Twenty articles were included describing 21,618 males and 24,139 females. Waist circumference had the strongest correlation with all CVD risk factors for both men and women, except for HDL and LDL in men. When comparing BMI with waist circumference, the latter showed significantly better correlations to CVD risk factors, except for diastolic blood pressure in women and HDL and total cholesterol in men.

Conclusions

We recommend the use of waist circumference in clinical and research studies above other anthropometric adiposity measures, especially compared with BMI, when evaluating CVD risk factors.

Towards an individualized protocol for workload increments in cardiopulmonary exercise testing in children and adolescents with cystic fibrosis

BACKGROUND

There is no single optimal exercise testing protocol for children and adolescents with cystic fibrosis (CF) that differs widely in age and disease status. The aim of this study was to develop a CF-specific, individualized approach to determine workload increments for a cycle ergometry testing protocol.

METHODS

A total of 409 assessments consisting of maximal exercise data, anthropometric parameters, and lung function measures from 160 children and adolescents with CF were examined. 90% of the database was analyzed with backward linear regression with peak workload (W(peak)) as the dependent variable. Afterwards, we [1] used the remaining 10% of the database (model validation group) to validate the model's capacity to predict W(peak) and [2] validated the protocol's ability to provide a maximal effort within a 10±2 minute time frame in 14 adolescents with CF who were tested using this new protocol (protocol validation group).

RESULTS

No significant differences were seen in W(peak) and predicted W(peak) in the model validation group or in the protocol validation group. Eight of 14 adolescents with CF in the protocol validation group performed a maximal effort, and seven of them terminated the test within the 10±2 minute time frame. Backward linear regression analysis resulted in the following equation: W(peak) (W)=-142.865+2.998×Age (years)-19.206×Sex (0=male; 1=female)+1.328×Height (cm)+23.362×FEV(1) (L) (R=.89; R(2)=.79; SEE=21). Bland-Altman analysis showed no systematic bias between the actual and predicted W(peak).

CONCLUSION

We developed a CF-specific linear regression model to predict peak workload based on standard measures of anthropometry and FEV(1), which could be used to calculate individualized workload increments for a cycle ergometry testing protocol.

Exercise and inflammation in pediatric Crohn's disease

We examined inflammatory cells, cytokines and growth factors in response to acute bouts of moderate intensity continuous exercise and high intensity intermittent exercise in youth with Crohn's disease and in healthy matched-controls. 15 patients and 15 controls performed 30 min of cycling at 50% of peak mechanical power (PMP) and 6 bouts of 4×15-s of cycling at 100% PMP. Blood was collected at rest, at the mid-point, at the end of exercise and at 30 and 60 min into recovery. In patients with CD, both types of exercise increased immune cells and GH and decreased IGF-I. Moderate intensity exercise induced a greater increase in leukocytes (p<0.05), neutrophils (p<0.05), lymphocytes (p<0.001), monocytes (p<0.05), IL-6 (p<0.05), IL-17 (p<0.05) and GH (p<0.05) and a similar decrease in IGF-I, compared with high intensity exercise. TNF-α did not change significantly with either exercise. Responses in patients were similar compared with controls; however, in patients monocytes remained elevated significantly longer in response to MICE. Youth with Crohn's disease can engage in distinctly different types of exercise without a significant acute exacerbation of inflammation.

Factors associated with physical activity in patients with osteoarthritis of the hip or knee: a systematic review

OBJECTIVE

To give an overview of factors related to the level of physical activity in patients with hip or knee osteoarthritis (OA).

METHODS

An extensive systematic literature search was conducted in PubMed, CINAHL and Embase. Inclusion criteria were: studies on patients with a diagnosis of OA of hip and/or knee, studies describing factors related to physical activity (objective or subjective), full length articles that were published in Dutch, German or English language. Two reviewers independently assessed the methodological quality. A best-evidence synthesis was performed for factors which were investigated in two or more studies.

RESULTS

Eight studies were included, all with a cross-sectional design (five high quality and three low quality studies), resulting in, at most, limited evidence in the best-evidence synthesis. For patients with knee OA there is limited evidence that a lower level of physical function is associated with a lower level of physical activity. There is also limited evidence that depression is not associated with the level of physical activity. For patients with hip OA there is limited evidence that higher age, higher body mass index (BMI) and a low level of physical function is associated with a low level of physical activity.

CONCLUSION

A high age (hip OA), a high BMI (hip OA) and a low level of physical function (both hip and knee OA) are related to a low level of physical activity. However, the level of evidence was only limited. Before new strategies and interventions to increase physical activity in patients with OA can be developed, high quality longitudinal studies are needed to get more insight in the causality between factors and low levels of physical activity.

Cardiopulmonary exercise testing in congenital heart disease: equipment and test protocols

Cardiopulmonary exercise testing (CPET) in paediatric cardiology differs in many aspects from the tests as performed in adult cardiology. Children's cardiovascular responses during exercise testing present different characteristics, particularly oxygen uptake, heart rate and blood pressure response, which are essential in interpreting haemodynamic data. Diseases that are associated with myocardial ischaemia are very rare in children. The main indications for CPET in children are evaluation of exercise capacity and the identification of exercise-induced arrhythmias. In this article we will review exercise equipment and test protocols for CPET in children with congenital heart disease. (Neth Heart J 2009;17:339-44.).

Habitual physical activity in Dutch children and adolescents with haemophilia

For patients with haemophilia, a physically active lifestyle is important to maintain musculoskeletal health and to prevent chronic diseases, such as cardiovascular disease. Therefore, we studied physical activity levels, in Dutch children and adolescents with haemophilia as well as its association with aerobic fitness and joint health. Forty-seven boys with haemophilia (aged 8-18) participated. Physical activity was measured using the Modifiable Activity Questionnaire (MAQ) and was compared with the general population. Aerobic fitness was determined using peak oxygen uptake (VO(₂peak)). Joint health was measured using the Haemophilia Joint Health Score (HJHS). Associations between physical activity, joint health and aerobic fitness were evaluated by correlation analysis. Subjects were 12.5 (SD 2.9) years old, had a Body Mass Index (BMI) of 19.5 (SD 3.1; z-score 0.5) and a median HJHS score of 0 (range 0-6). Cycling, physical education and swimming were most frequently reported (86%, 69% and 50% respectively). Children with severe haemophilia participated significantly less in competitive soccer and more in swimming than children with non-severe haemophilia. Physical activity levels were similar across haemophilia severities and comparable to the general population. VO(₂peak) kg⁻¹ was slightly lower than healthy boys (42.9 ± 8.6 vs. 46.9 ± 1.9 mL kg⁻¹ min⁻¹; P = 0.03). Joint health, aerobic fitness and physical activity showed no correlation. Dutch children with haemophilia engaged in a wide range of activities of different intensities and showed comparable levels of physical activity to the general population. Aerobic fitness was well preserved and showed no associations with physical activity levels or joint health.

The oxygen uptake efficiency slope in children with congenital heart disease: construct and group validity

OBJECTIVE

The oxygen uptake efficiency slope (OUES) has been proposed as an independent and objective alternative to the peak oxygen uptake (VO(2peak)), which does not require maximal exercise. The aim of this study was to investigate the construct and group validity of the OUES in children with congenital heart disease (CHD).

METHODS

Thirty-one patients with CHD, of which 16 patients (mean age ± SD 11.2 ± 2.7 years) with a Fontan repair and 15 patients (mean age ± SD 13.2 ± 3.6 years) with surgical repair of tetralogy of Fallot (ToF) completed a symptom-limited cardiopulmonary exercise test. The OUES was calculated and normalized for body surface area at three different exercise intensities: (1) using 100% of the exercise data; (2) using the first 75% of the exercise data; and (3) using exercise data up to the ventilatory threshold (VT). Furthermore, peak oxygen uptake (VO(2peak)), VT, ventilatory efficiency (V(E)/VO(2)-slope), and ventilatory drive (V(E)/VCO(2)-slope) were calculated and compared with values of 46 healthy children (mean age ± SD 12.2 ± 2.4 years).

RESULTS

In all three groups, the OUES values determined at the three different exercise intensities were not significantly different from each other. Moreover, the OUES was significantly reduced in the children with CHD, with significantly lower values in the Fontan patients compared to ToF. Strong correlations were found between the OUES and both the VO(2peak) and VT in Fontan and ToF patients.

DISCUSSION

The OUES provides a valid measure of cardiopulmonary fitness in children with CHD, which is independent of exercise intensity and strongly correlated with VO(2peak) and VT (construct validity). Furthermore, the OUES is capable of differentiating between healthy children and children with CHD and between Fontan and ToF patients (group validity). Therefore, the OUES may be a valid, effort-independent parameter of cardiopulmonary fitness in children with CHD.

Is static hyperinflation a limiting factor during exercise in adolescents with cystic fibrosis?

Increased work of breathing is considered to be a limiting factor in patients with cystic fibrosis (CF) performing aerobic exercise. We hypothesized that adolescents with CF and with static hyperinflation are more prone to a ventilatorily limited exercise capacity than non-static hyperinflated adolescents with CF. Exercise data of 119 adolescents with CF [range 12-18 years], stratified for static hyperinflation, defined as ratio of residual volume to total lung capacity (RV/TLC) > 30%, were obtained during a progressive bicycle ergometer test with gas analysis and analyzed for ventilatory limitation. Static hyperinflation showed a significant, though weak association (Φ 0.38; P < 0.001) with a ventilatorily limited exercise capacity (breathing reserve index at maximal effort >0.70; FEV(1)  < 80% predicted and reduced exercise capacity, defined as VO(2peak)  < 85% predicted). Analysis of association for increasing degrees of hyperinflation showed an increase to Φ 0.49 (P < 0.001) for RV/TLC > 50%. In adolescents with static hyperinflation, peak work rate (W(peak) ; 3.1 ± 0.7 W/kg (75.1 ± 17.3% of predicted), peak oxygen uptake (VO(2peak) /kg (ml/min/kg); 39.2 ± 9.2 ml/min/kg (91.0 ± 20.3% of predicted), peak heart rate (HR(peak) ; 176 ± 19 beats/min) were significantly (P < 0.05) decreased when compared with non-static hyperinflated adolescents (W(peak) 3.5 ± 0.5 W/kg (81.4 ± 10.0% of predicted)); VO(2peak) /kg (ml/min/kg); 43.1 ± 7.5 ml/min/kg (98.0 ± 15.1% of predicted); and HR(peak) 185 ± 14 beats/min). Additionally, no difference was found in the degree of association of FEV(1) (%) and RV/TLC (%) with VO(2peak) /kg(pred) and W(peak) /kg(Pred) , but we found the RV/TLC (%) to be a slightly stronger predictor of VO(2peak) /kg(pred) and W(peak) /kg(Pred) than FEV(1) (%). These results indicate that the presence of static hyperinflation in adolescents with CF by itself does not strongly influence ventilatory constraints during exercise and that static hyperinflation is only a slightly stronger predictor of W(peak) /kg(Pred) and VO(2peak) /kg(Pred) than airflow obstruction (FEV(1) (%)).

High-intensity interval training in an adolescent with cystic fibrosis: a physiological perspective

Nutritional, musculoskeletal, and/or ventilatory status can lead to a decreased exercise capacity in children with cystic fibrosis (CF). Exercise training is already part of the usual care; however, the "optimal" intensity and volume of exercise training to improve exercise capacity is still unknown. Six weeks of high-intensity interval training (HIT) for a patient with CF with a ventilatory limitation was evaluated by a cardiopulmonary exercise test (CPET). Peak oxygen uptake and peak workload increased 19% and 16%, respectively, and there was a rise in peak ventilation from 50 L/min to 75 L/min, with an increase in both breathing depth and respiratory rate. A relative short period of HIT resulted in a significant increase in exercise capacity. In patients with CF, HIT might be an effective and efficient training regimen, especially in CF patients with a ventilatory limitation. Further research is necessary to investigate whether HIT is a better alternative than traditional aerobic training programs especially in ventilatory limited patients with CF.

Aerobic capacity and muscle strength in juvenile-onset mixed connective tissue disease (MCTD)

OBJECTIVES

To study the aerobic capacity and muscle strength in children and adolescents with mixed connective tissue disease (MCTD). Frequently reported clinical symptoms include joint swelling, muscle weakness, fatigue, decreased stamina/exercise tolerance, and shortness of breath. The exercise capacity of patients with MCTD has not been studied systematically in this detail before.

METHODS

Eleven children and adolescents diagnosed with MCTD (mean age 15.7 years, range 11.3–19.9 years) were studied. Maximal exercise testing on a cycle ergometer was used to determine the peak oxygen uptake (VO2peak) and a hand-held dynamometer was used to measure muscle strength. Cardiac and pulmonary function tests (ultrasonography, electrocardiography, spirometry) were used to measure cardiac function and obstructive or restrictive respiratory impairment. Complementary data (e.g. disease duration and concurrent symptoms) were collected from a medical chart review.

RESULTS

VO2peak was significantly lower in patients with MCTD compared to the VO2peak of healthy subjects (Z-score –1.9, p = 0.008). The strength of the proximal muscles (hip flexors, shoulder abductors, knee extensors) of the patients was significantly lower than in the controls, whereas the strength of the distal muscles (dorsal flexors of the foot and handgrip strength) showed no differences. In eight children, arthritis was observed. No clinically relevant impairment in cardiac or pulmonary function was observed.

CONCLUSIONS

Aerobic capacity and also proximal muscle strength were significantly impaired in our sample of children and adolescents with MCTD. Because respiratory problems were non-dominant in our patient group, the decreased aerobic capacity and muscle strength were probably caused by musculoskeletal impairments. Further studies in larger multicentre samples are warranted to confirm our findings.

The Dutch translation of the revised Childhood Health Assessment Questionnaire: a preliminary study of score distribution

BACKGROUND

The Childhood Health Assessment Questionnaire (CHAQ30) is the most commonly used physical functioning questionnaire for children with Juvenile Idiopathic Arthritis (JIA). By revising the CHAQ30 Lam et al. succeeded in decreasing the ceiling effect of this questionnaire in a North American population of children with diverse musculoskeletal diseases.

OBJECTIVES

To examine the score distribution of the revised CHAQ in a population of children with JIA.

METHODS

In this Dutch multicentre study 72 children with JIA participated (55 girls), with a mean age of 11.0 (+/- 3.1) and a mean disease duration of 4.6 year (+/- 3.7). The score distribution of the original CHAQ30 and four versions of the revised CHAQ was analysed with the median, range and interquartile range (IQR) and visualised with box-and-whisker plots. The normality of the score distribution was tested by the Kolmogorov-Smirnov one-sample test of normality.

RESULTS

Although the addition of 8 more challenging items improved the spread of the scores of the revised CHAQ versions, the original CHAQ30 showed a better distribution of the scores.

CONCLUSIONS

The revised CHAQ38 with the distribution characteristics, found in this study, might be especially relevant in interventions for patients with JIA at the mild end of the disability spectrum.

Reproducibility of energy cost of locomotion in ambulatory children with spina bifida

OBJECTIVES

Many ambulatory children with Spina Bifida (SB) experience functional decline in ambulation despite stable or even improving motor exams. Improving or maintaining low energy cost of locomotion during childhood and throughout the teenage years, could be an important goal for children and adolescents with SB. Purpose of this study was to determine reproducibility of energy expenditure measures during gait in ambulatory children with SB.

DESIGN

Reproducibility study.

SETTING

Child Development and Exercise Center of the University Children's Hospital in Utrecht, the Netherlands.

PARTICIPANTS

Fourteen ambulatory children (6 boys/8 girls) with SB. Mean age was 10.8 years (+ or - 3.4).

INTERVENTIONS

Net and gross energy expenditure measures during locomotion were determined during a six-minute walking test. These measures consisted of energy consumption (ECS), expressed in J/kg/min, and energy cost (EC), expressed in J/kg/m. For reliability, the intra-class coefficient (ICC) was determined. For agreement, the smallest detectable difference (SDD) was calculated.

RESULTS

ICCs vary from 0.86 to 0.96 for both EC and ECS. The SDD ranges from 18-24% for gross measures, up to over 30% for net values.

CONCLUSION

Reproducibility of energy expenditure during ambulation in children with SB should be considered carefully when using these measures in the evaluation of gait. High reliability of energy expenditure measurements makes these measurements appropriate to use as discriminative tools in children with SB, while agreement of only gross EC seems acceptable to use as a evaluative tool in children with SB. Overall, measures of reliability and agreement seem higher in young children when compared to adolescents. Further research is recommended to determine clinically relevant changes in energy expenditure in children with SB.

Workload demand in police officers during mountain bike patrols

To the authors' knowledge this is the first paper that has used the training impulse (TRIMP) 'methodology' to calculate workload demand. It is believed that this is a promising method to calculate workload in a range of professions in order to understand the relationship between work demands and aerobic fitness. The aim of this study was to assess workload demand in police officers from the Utrecht police department in the Netherlands, during patrol by mountain bike. Maximum oxygen intake, maximum heart rate (HRmax), ventilatory threshold (VT)1 and VT2 were determined with a maximal exercise test on a bicycle ergometer. Heart rates were registered throughout three shifts in 20 subjects using a heart rate monitor. Exercise intensity was divided into three phases: phase I (between 40% of HRmax and VT1); phase II (between VT and the respiratory compensation point (RCP)); and phase III (>RCP). The total TRIMP score was obtained by summating the results of the three phases. Average daily workload demands of 355 TRIMPs per day and 1777 TRIMPs per week were measured. Workload demand approached and in some cases exceeded the upper limit of 2000 TRIMPs per week threshold level for physiological stress demands in professional male cyclists.

Exercise therapy in juvenile idiopathic arthritis: a Cochrane Review

BACKGROUND

Exercise therapy is considered an important component of the treatment of arthritis. The efficacy of exercise therapy has been reviewed in adults with rheumatoid arthritis but not in children with juvenile idiopathic arthritis (JIA).

OBJECTIVES

To assess the effects of exercise therapy on functional ability, quality of life and aerobic capacity in children with JIA.

METHODS

Several electronic databases were searched up to October 2007 and references were tracked. The selection criteria were randomized controlled trials (RCTs) of exercise treatment in JIA. As for data collection and analysis, potentially relevant references were evaluated and all data were extracted by two review authors working independently.

RESULTS

Three out of 16 identified studies met the inclusion criteria, with a total of 212 participants. All the included studies fulfilled at least seven of 10 methodological criteria. The outcome data of the following measures were homogenous and were pooled in a meta-analysis: functional ability (N=198; weighted mean difference [WMD] -0.07, 95% CI -0.22 to 0.08), quality of life (CHQ-PhS: N=115; WMD -3.96, 95% CI -8.91 to 1.00) and aerobic capacity (N=124; WMD 0.04, 95% CI -0.11 to 0.19). The results suggest that the outcome measures all favoured the exercise therapy but none were statistically significant. None of the studies reported negative effects of the exercise therapy.

CONCLUSIONS

Overall, based on ''silver-level'' evidence there was no clinically important or statistically significant evidence that exercise therapy can improve functional ability, quality of life, aerobic capacity or pain. The included and excluded studies were all consistent about the adverse effects of exercise therapy; no short-term detrimental effects of exercise therapy were found in any study. Both included and excluded studies showed that exercise does not exacerbate arthritis. Although the short-term effects look promising, the long-term effect of exercise therapy remains unclear.