Ventilatory Responses During Submaximal Exercise in Children With Prader–Willi Syndrome

2018 ◽  
Vol 30 (3) ◽  
pp. 411-417 ◽  
Author(s):  
Adam M. Hyde ◽  
Robert G. McMurray ◽  
Frank A. Chavoya ◽  
Daniela A. Rubin
Keyword(s):  
Carbon Dioxide ◽  
Body Mass Index ◽  
Oxygen Uptake ◽  
Tidal Volume ◽  
Body Mass ◽  
Metabolic Cost ◽  
Prader Willi Syndrome ◽  
Breathing Frequency ◽  
Ventilatory Responses ◽  
Carbon Dioxide Output

Purpose: Prader–Willi syndrome (PWS) is a genetic neurobehavioral disorder presenting hypothalamic dysfunction and adiposity. At rest, PWS exhibits hypoventilation with hypercapnia. We characterized ventilatory responses in children with PWS during exercise. Methods: Participants were children aged 7–12 years with PWS (n = 8) and without PWS with normal weight (NW; n = 9, body mass index ≤ 85th percentile) or obesity (n = 9, body mass index ≥ 95th percentile). Participants completed three 5-minute ambulatory bouts at 3.2, 4.0, and 4.8 km/h. Oxygen uptake, carbon dioxide output, ventilation, breathing frequency, and tidal volume were recorded. Results: PWS had slightly higher oxygen uptake (L/min) at 3.2 km/h [0.65 (0.46–1.01) vs 0.49 (0.34–0.83)] and at 4.8 km/h [0.89 (0.62–1.20) vs 0.63 (0.45–0.97)] than NW. PWS had higher ventilation (L/min) at 3.2 km/h [16.2 (13.0–26.5) vs 11.5 (8.4–17.5)], at 4.0 km/h [16.4 (13.9–27.9) vs 12.7 (10.3–19.5)], and at 4.8 km/h [19.7 (17.4–31.8) vs 15.2 (9.5–21.6)] than NW. PWS had greater breathing frequency (breaths/min) at 3.2 km/h [38 (29–53) vs 29 (22–35)], at 4.0 km/h [39 (29–58) vs 29 (23–39)], and at 4.8 km/h [39 (33–58) vs 32 (23–42)], but similar tidal volume and ventilation/carbon dioxide output to NW. Conclusion: PWS did not show impaired ventilatory responses to exercise. Hyperventilation in PWS may relate to excessive neural stimulation and metabolic cost.

Breathing in brief exercise

1960 ◽  
Vol 15 (4) ◽  
pp. 583-588 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Respiratory Exchange Ratio ◽  
Metabolic Cost ◽  
Carbon Dioxide Tension ◽  
Minute Volume ◽  
Carbon Dioxide Output ◽  
Respiratory Minute Volume ◽  
Before And After

Two men ran for 20 or 60 seconds while inhaling air, oxygen or 4% carbon dioxide. Inspired respiratory minute volume was determined for each breath. Ventilation increased suddenly in the first breath with minimal changes in end-expiratory carbon dioxide tension and respiratory exchange ratio to a rate that remained constant for 20 seconds before increasing further. The rate of carbon dioxide output was uniform during the first 20 seconds. A 12% grade did not increase ventilation or oxygen uptake during runs of 20 seconds, but in the first minute of recovery, ventilation was 64% greater than after level runs. Inhalation of oxygen inhibited ventilation by 24% in the 20-second periods before and after the end of a 60-second run. Inhalation of carbon dioxide begun at rest produced increments in ventilation and end-expiratory carbon dioxide tension that varied little during running and recovery. In the 20-second runs ventilation varied with speed but appeared independent of ultimate metabolic cost. Submitted on January 21, 1960

Absent peripheral chemosensitivity in Prader-Willi syndrome

1994 ◽  
Vol 77 (5) ◽  
pp. 2231-2236 ◽  
Author(s):  
D. Gozal ◽  
R. Arens ◽  
K. J. Omlin ◽  
S. L. Ward ◽  
T. G. Keens
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Vital Capacity ◽  
Minute Ventilation ◽  
Prader Willi Syndrome ◽  
Peripheral Chemoreceptor ◽  
Afferent Pathways ◽  
Ventilatory Responses ◽  
Control Subjects ◽  
And Control

Abnormalities in ventilatory control during wakefulness and sleep have been observed in patients with Prader-Willi syndrome (PWS). The role of peripheral chemoreceptors in the pathophysiology of abnormal ventilatory responses in PWS is unknown. We studied peripheral chemoreceptor function during wakefulness in 17 genetically confirmed PWS patients [age 27.0 +/- 2.5 (SE) yr; 7 males, 10 females; body mass index 31.1 +/- 1.4 kg/m2] and compared their responses with 17 control subjects matched for age, sex, and body mass index. All PWS and control subjects had normal resting end-tidal PCO2 and arterial O2 saturation while awake. Peripheral chemoreceptor function was assessed by the ventilatory responses to 100% O2 breathing, five tidal breaths of 100% N2, and vital capacity breaths of 15% CO2 in O2. Control subjects decreased minute ventilation (VE) by 15.5 +/- 3.6% during hyperoxia. However, PWS patients increased VE by 17.6 +/- 3.3%, indicating a paradoxical response to hyperoxia (P < 0.00001). After CO2 vital capacity breaths, PWS patients showed no significant change and control subjects showed a marked increase (P < 0.0001) in VE. During N2 breathing, again PWS patients showed no change and control subjects exhibited a marked increase (P < 0.00005) in VE. We conclude that PWS patients have absent peripheral chemoreceptor ventilatory responses. We speculate that the lack of ventilatory responses is due to primary peripheral chemoreceptor dysfunction and/or defective afferent pathways to central controllers.

Effectiveness of Deep Brain Stimulation in Reducing Body Mass Index and Weight: A Systematic Review

2021 ◽  
pp. 1-11
Author(s):  
William Omar Contreras López ◽  
Paula Alejandra Navarro ◽  
Santiago Crispín
Keyword(s):  
Systematic Review ◽  
Body Mass Index ◽  
Deep Brain Stimulation ◽  
Body Mass ◽  
Brain Stimulation ◽  
The Body ◽  
Health Concern ◽  
Prader Willi Syndrome ◽  
Falling Asleep ◽  
Deep Brain

<b><i>Background:</i></b> Obesity has become a major public health concern worldwide, with current behavioral, pharmacological, and surgical treatments offering varying rates of success and adverse effects. Neurosurgical approaches to treatment of refractory obesity include deep brain stimulation (DBS) on either specific hypothalamic or reward circuitry nuclei, which might contribute to weight reduction through different mechanisms. We aimed to determine the safety and clinical effect of DBS in medical refractory obesity. <b><i>Summary:</i></b> Adhering to PRISMA guidelines, we performed a systematic review to identify all original studies – observational and experimental – in which DBS was performed to treat refractory obesity. From database inception to April 2021, we conducted our search in PubMed, Scopus, and LILACS databases using the following MeSH terms: “Obesity” OR “Prader-Willi Syndrome” AND “Deep Brain Stimulation.” The main outcomes were safety and weight loss measured with the body mass index (BMI). The Grading of Recommendations Assessment, Development, and Evaluation methods were applied to evaluate the quality of evidence. This study protocol was registered with PROSPERO ID: CRD42019132929. Seven studies involving 12 patients met the inclusion criteria; the DBS target was the nucleus accumbens in four (57.1%), the lateral hypothalamic area in two (29.6%), and the ventral hypothalamus in one (14.3%). Further, 33% of participants had obesity secondary to Prader-Willi syndrome (PWS) and 66.6% had primary obesity. The global BMI average at baseline was 46.7 (SD: 9.6, range: 32.2–59.1), and after DBS, 42.8 (SD: 8.8, range: 25–53.9), with a mean difference of 3.9; however, the delta in PWS patients was −2.3 and 10 in those with primary obesity. The incidence of moderate side effects was 33% and included manic symptoms (<i>N</i> = 2), electrode fracture (<i>N</i> = 1), and seizure (<i>N</i> = 1); mild complications (41.6%) included skin infection (<i>N</i> = 2), difficulties falling asleep (<i>N</i> = 1), nausea (<i>N</i> = 1), and anxiety (<i>N</i> = 1). <b><i>Key Messages:</i></b> Despite available small case series and case reports reporting a benefit in the treatment of refractory obesity with DBS, this study emphasizes the need for prospective studies with longer follow-ups in order to further address the efficacy and indications.

Use of respiratory quotients in assessment of aerobic work capacity

1962 ◽  
Vol 17 (1) ◽  
pp. 47-50 ◽  
Author(s):  
B. Issekutz ◽  
N. C. Birkhead ◽  
K. Rodahl
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Work Load ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Carbon Dioxide Output ◽  
Ergometer Test ◽  
Aerobic Work Capacity ◽  
Bicycle Ergometer Test ◽  
Better Than

Oxygen uptake and carbon dioxide output were measured in 32 untrained subjects during exercise on the bicycle ergometer. It was shown that the work respiratory quotient (RQ) under standardized conditions can be used as a measure of physical fitness. ΔRQ (work RQ minus 0.75) increases logarithmically with the work load and maximal O2 uptake is reached at a ΔRQ value of 0.40. This observation offered the possibility of predicting the maximal O2 uptake of a person, based on the measurement of RQ during a single bicycle ergometer test at a submaximal load. For each work RQ between 0.95 and 1.15 a factor was presented, together with the aid of a simple equation, which gave a good approximation (generally better than ±10%) of the maximal O2 uptake.

scholarly journals The Metabolic Phenotype of Prader-Willi Syndrome (PWS) in Childhood: Heightened Insulin Sensitivity Relative to Body Mass Index

2011 ◽  
Vol 96 (1) ◽  
pp. E225-E232 ◽  
Author(s):  
Andrea M. Haqq ◽  
Michael J. Muehlbauer ◽  
Christopher B. Newgard ◽  
Steven Grambow ◽  
Michael Freemark
Keyword(s):  
Body Mass Index ◽  
Insulin Sensitivity ◽  
Body Mass ◽  
Density Lipoprotein ◽  
High Sensitivity ◽  
Metabolic Phenotype ◽  
Prader Willi Syndrome ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Total Adiponectin

Context: Insulin sensitivity is higher in patients with Prader-Willi syndrome (PWS) than in body mass index-matched obese controls (OCs). Factors contributing to the heightened insulin sensitivity of PWS remain obscure. We compared the fasting levels of various hormones, cytokines, lipids, and liver function tests in 14 PWS patients and 14 OCs with those in 14 age- and gender-matched lean children (LC). We hypothesized that metabolic profiles of children with PWS are comparable with those of LC, but different from those of OCs. Results: Leptin levels were comparable in PWS patients and OCs, suggesting comparable degrees of adiposity. Glucose levels were comparable among groups. However, fasting insulin concentrations and homeostasis model assessment insulin resistance index were lower in PWS patients than in OCs (P &lt; 0.05) and similar to LC. Moreover, high-density lipoprotein levels were lower and triglycerides higher in OCs (P &lt; 0.05) but not PWS patients. Total adiponectin, high-molecular-weight (HMW) adiponectin and the HMW to total adiponectin ratio were higher in PWS patients (P &lt; 0.05) than in OCs and similar to LC. High-sensitivity C-reactive protein and IL-6 levels were higher in OCs than in PWS patients or LC (P &lt; 0.05). Nevertheless, PAI-1 levels were elevated in both OC and PWS patients. There were no group differences in glucagon-like peptide-1, macrophage chemoattractant protein-1, TNFα, IL-2, IL-8, IL-10, IL-12p40, IL-18, resistin, total or low-density lipoprotein cholesterol, aspartate aminotransferase, or alanine aminotransferase. Conclusions: The heightened insulin sensitivity of PWS patients relative to OCs is associated with higher levels of adiponectin and lower levels of high-sensitivity C-reactive protein and IL-6. Future studies will determine whether PWS children are protected from obesity comorbidities such as type 2 diabetes, hyperlipidemia, and nonalcoholic fatty liver disease.

scholarly journals Prediction of Maximal Oxygen Uptake by Six-Minute Walk Test and Body Mass Index in Healthy Boys

2018 ◽  
Vol 200 ◽  
pp. 155-159 ◽  
Author(s):  
Majid Jalili ◽  
Farzad Nazem ◽  
Akbar Sazvar ◽  
Kamal Ranjbar
Keyword(s):  
Body Mass Index ◽  
Oxygen Uptake ◽  
Body Mass ◽  
Maximal Oxygen Uptake ◽  
Walk Test ◽  
Six Minute Walk Test ◽  
Minute Walk

scholarly journals Influence of sex-specific concurrent changes in age, maturity status, and morphological covariates on the development of peak ventilatory variables in 10–17-year-olds

2020 ◽  
Author(s):  
Neil Armstrong ◽  
Jo Welsman
Keyword(s):  
Oxygen Uptake ◽  
Tidal Volume ◽  
Body Mass ◽  
Explanatory Variable ◽  
Multilevel Modelling ◽  
Peak Oxygen Uptake ◽  
Anthropometric Measures ◽  
Allometric Models ◽  
Explanatory Variables ◽  
Temporal Spacing

Abstract Purposes (i) To investigate the influence of concurrent changes in age, maturity status, stature, body mass, and skinfold thicknesses on the development of peak ventilatory variables in 10–17-year-olds; and, (ii) to evaluate the interpretation of paediatric norm tables of peak ventilatory variables. Methods Multiplicative multilevel modelling which allows both the number of observations per individual and the temporal spacing of the observations to vary was used to analyze the expired ventilation (peak $${\dot{\mathrm{V}}}_{\mathrm{E}}$$ V ˙ E ) and tidal volume (peak VT) at peak oxygen uptake of 420 (217 boys) 10–17-year-olds. Models were founded on 1053 (550 from boys) determinations of peak ventilatory variables supported by anthropometric measures and maturity status. Results In sex-specific, multiplicative allometric models, concurrent changes in body mass and skinfold thicknesses (as a surrogate of FFM) and age were significant (p < 0.05) explanatory variables of the development of peak $${\dot{\mathrm{V}}}_{\mathrm{E}}$$ V ˙ E , once these covariates had been controlled for stature had no additional, significant (p > 0.05) effect on peak $${\dot{\mathrm{V}}}_{\mathrm{E}}$$ V ˙ E . Concurrent changes in age, stature, body mass, and skinfold thicknesses were significant (p < 0.05) explanatory variables of the development of peak VT. Maturity status had no additional, significant (p > 0.05) effect on either peak $${\dot{\mathrm{V}}}_{\mathrm{E}}$$ V ˙ E or peak VT once age and morphological covariates had been controlled for. Conclusions Elucidation of the sex-specific development of peak $${\dot{\mathrm{V}}}_{\mathrm{E}}$$ V ˙ E requires studies which address concurrent changes in body mass, skinfold thicknesses, and age. Stature is an additional explanatory variable in the development of peak VT, in both sexes. Paediatric norms based solely on age or stature or body mass are untenable.

scholarly journals Growth hormone treatment in Prader-Willi syndrome patients: systematic review and meta-analysis

2020 ◽  
Vol 4 (1) ◽  
pp. e000630 ◽  
Author(s):  
Caroline de Gouveia Buff Passone ◽  
Ruth Rocha Franco ◽  
Simone Sakura Ito ◽  
Evelinda Trindade ◽  
Michel Polak ◽  
...  
Keyword(s):  
Systematic Review ◽  
Body Mass Index ◽  
Body Mass ◽  
Motor Development ◽  
Randomised Controlled Trials ◽  
Meta Analysis ◽  
Controlled Trials ◽  
Prader Willi Syndrome ◽  
Randomised Controlled ◽  
Rhgh Treatment

BackgroundGrowth hormone (GH) treatment is currently recommended in Prader-Willi syndrome (PWS) patients.ObjectivesTo evaluate the impact (efficacy and safety) of the use of recombinant human GH (rhGH) as a treatment for PWS.MethodWe performed a systematic review and, where possible, meta-analysis for the following outcomes: growth, body mass index, body composition, cognitive function, quality of life, head circumference, motor development/strength, behaviour and adverse effects. We included all PWS patients, with all types of genetic defects and with or without GH deficiency, who participated in rhGH studies performed in infancy, childhood and adolescence, that were either randomised controlled trials (RCTs) (double-blinded or not) or non-randomised controlled trials (NRCTs) (cohort and before and after studies). The databases used were MEDLINE, Embase and Cochrane Central.ResultsIn 16 RCTs and 20 NRCTs selected, the treated group had an improvement in height (1.67 SD scores (SDS); 1.54 to 1.81); body mass index z-scores (−0.67 SDS; −0.87 to −0.47) and fat mass proportion (−6.5% SDS; −8.46 to −4.54) compared with the control group. Data about cognition could not be aggregated.ConclusionBased on high quality evidence, rhGH treatment favoured an improvement of stature, body composition and body mass index, modifying the disease’s natural history; rhGH treatment may also be implicated in improved cognition and motor development in PWS patients at a young age.Ethics and disseminationThe current review was approved by the ethical committee of our institution. The results will be disseminated through conference presentations and publications in peer-reviewed journals.PROSPERO registration numberCRD42019140295

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