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Bhammar DM, Nusekabel CW, Wilhite DP, Daulat S, Liu Y, Glover RIS, Babb TG. Effects of Obesity and Sex on Ventilatory Constraints during a Cardiopulmonary Exercise Test in Children. Med Sci Sports Exerc 2024; 56:2039-2048. [PMID: 38768025 PMCID: PMC11402596 DOI: 10.1249/mss.0000000000003481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
PURPOSE Ventilatory constraints are common during exercise in children, but the effects of obesity and sex are unclear. The purpose of this study was to investigate the effects of obesity and sex on ventilatory constraints (i.e., expiratory flow limitation (EFL) and dynamic hyperinflation) during a maximal exercise test in children. METHODS Thirty-four 8- to 12-yr-old children without obesity (18 females) and 54 with obesity (23 females) completed pulmonary function testing and maximal cardiopulmonary exercise tests. EFL was calculated as the overlap between tidal flow-volume loops during exercise and maximal expiratory flow-volume loops. Dynamic hyperinflation was calculated as the change in inspiratory capacity from rest to exercise. RESULTS Maximal minute ventilation was not different between children with and without obesity. Average end-inspiratory lung volumes (EILV) and end-expiratory lung volumes (EELV) were significantly lower during exercise in children with obesity (EILV: 68.8% ± 0.7% TLC; EELV: 41.2% ± 0.5% TLC) compared with children without obesity (EILV: 73.7% ± 0.8% TLC; EELV: 44.8% ± 0.6% TLC; P < 0.001). Throughout exercise, children with obesity experienced more EFL and dynamic hyperinflation compared with those without obesity ( P < 0.001). Also, males experienced more EFL and dynamic hyperinflation throughout exercise compared with females ( P < 0.001). At maximal exercise, the prevalence of EFL was similar in males with and without obesity; however, the prevalence of EFL in females was significantly different, with 57% of females with obesity experiencing EFL compared with 17% of females without obesity ( P < 0.05). At maximal exercise, 44% of children with obesity experienced dynamic hyperinflation compared with 12% of children without obesity ( P = 0.002). CONCLUSIONS Obesity in children increases the risk of developing mechanical ventilatory constraints such as dynamic hyperinflation and EFL. Sex differences were apparent with males experiencing more ventilatory constraints compared with females.
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Affiliation(s)
- Dharini M Bhammar
- Center for Tobacco Research, Division of Medical Oncology, Department of Internal Medicine, The Ohio State University, Columbus, OH
| | - Celia W Nusekabel
- Center for Tobacco Research, Division of Medical Oncology, Department of Internal Medicine, The Ohio State University, Columbus, OH
| | | | - Shilpa Daulat
- Department of Internal Medicine, Rush University, Chicago, IL
| | - Yulun Liu
- School of Public Health, UT Southwestern Medical Center and Simmons Comprehensive Cancer Center, Dallas, TX
| | - Rae I S Glover
- Center for Tobacco Research, Division of Medical Oncology, Department of Internal Medicine, The Ohio State University, Columbus, OH
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital and UT Southwestern Medical Center, Dallas, TX
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Watso JC, Cuba JN, Boutwell SL, Moss JE, Bowerfind AK, Fernandez IM, Cassette JM, May AM, Kirk KF. Acute nasal breathing lowers diastolic blood pressure and increases parasympathetic contributions to heart rate variability in young adults. Am J Physiol Regul Integr Comp Physiol 2023; 325:R797-R808. [PMID: 37867476 PMCID: PMC11178300 DOI: 10.1152/ajpregu.00148.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/24/2023]
Abstract
There is growing interest in how breathing pace, pattern, and training (e.g., device-guided or -resisted breathing) affect cardiovascular health. It is unknown whether the route of breathing (nasal vs. oral) affects prognostic cardiovascular variables. Because nasal breathing can improve other physiological variables (e.g., airway dilation), we hypothesized that nasal compared with oral breathing would acutely lower blood pressure (BP) and improve heart rate variability (HRV) metrics. We tested 20 adults in this study [13 females/7 males; age: 18(1) years, median (IQR); body mass index: 23 ± 2 kg·m-2, means ± SD]. We compared variables between nasal- and oral-only breathing (random order, five min each) using paired, two-tailed t tests or Wilcoxon signed-rank paired tests with significance set to P < 0.05. We report the median (interquartile range) for diastolic BP and means ± SD for all other variables. We found that nasal breathing was associated with a lower mean BP (nasal: 84 ± 7 vs. oral: 86 ± 5 mmHg, P = 0.006, Cohen's d = 0.70) and diastolic BP [nasal: 68(8) vs. oral: 72(5) mmHg, P < 0.001, Rank-biserial correlation = 0.89] but not systolic BP (nasal: 116 ± 11 vs. oral: 117 ± 9 mmHg, P = 0.48, Cohen's d = 0.16) or heart rate (HR; nasal: 74 ± 10 vs. oral: 75 ± 8 beats·min-1, P = 0.90, Cohen's d = 0.03). We also found that nasal breathing was associated with a higher high-frequency (HF) contribution to HRV (nasal: 59 ± 19 vs. oral: 52 ± 21%, P = 0.04, Cohen's d = 0.50) and a lower low frequency-to-HF ratio at rest (nasal: 0.9 ± 0.8 vs. oral: 1.2 ± 0.9, P = 0.04, Cohen's d = 0.49). These data suggest that nasal compared with oral breathing acutely 1) lowers mean and diastolic BP, 2) does not affect systolic BP or heart rate, and 3) increases parasympathetic contributions to HRV.NEW & NOTEWORTHY There is growing interest in how breathing pace, pattern, and training (e.g., device-guided or -resisted breathing) affect prognostic cardiovascular variables. However, the potential effects of the breathing route on prognostic cardiovascular variables are unclear. These data suggest that nasal compared with oral breathing 1) lowers mean and diastolic blood pressure (BP), 2) does not affect systolic BP or heart rate (HR), and 3) increases parasympathetic contributions to heart rate variability (HRV). These data suggest that acute nasal breathing improves several prognostic cardiovascular variables.
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Affiliation(s)
- Joseph C Watso
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Jens N Cuba
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Savannah L Boutwell
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Justine E Moss
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Allison K Bowerfind
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Isabela M Fernandez
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Jessica M Cassette
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Allyson M May
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Katherine F Kirk
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
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Stickford JL, Bhammar DM, Balmain BN, Babb TG. Static respiratory mechanics are unaltered in males and females with obesity. J Appl Physiol (1985) 2023; 135:1255-1262. [PMID: 37881847 PMCID: PMC10979829 DOI: 10.1152/japplphysiol.00519.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 10/19/2023] [Accepted: 10/20/2023] [Indexed: 10/27/2023] Open
Abstract
We tested the hypothesis that independent of the obesity-related shift in lung volume subdivisions, obesity would not reduce the interrelationships of expiratory flow, lung volume, and static lung elastic recoil pressure in males and females. Simultaneous measurements of expiratory flow, volume, and transpulmonary pressure were continuously recorded while flow-volume loops of varying expiratory efforts were performed in a pressure-corrected, volume-displacement body plethysmograph in males and females with obesity. Static compliance curves were collected using the occlusion technique. Flow-volume, static pressure-volume, and static pressure-flow relationships were examined. Isovolume pressure-flow curves were constructed for the determination of the critical pressure for maximal flow. Data were compared with that collected in lean males and females. Individuals with obesity displayed a notable decrease in functional residual capacity. The interrelationships of flow, lung volume, static elastic recoil pressure, and the minimum pressure required for maximal expiratory flow in males and females with obesity were not different from that in lean males and females (all P > 0.05). Obesity does not alter the interrelationships of flow-volume-pressure of the lung in adult males and females (all P > 0.05). We further explored potential sex differences in static mechanics independent of obesity and observed that females have lower maximal expiratory flow due to a combination of smaller lungs and greater upstream flow resistance compared with males (all P ≤ 0.05).NEW & NOTEWORTHY The potential influence of obesity on the interrelationships between maximal expiratory flow, lung volume, and static lung elastic recoil pressure is unclear. These data show that the presence of obesity does not alter the relationship of flow and pressure across the mid-expiratory range in males and females. In addition, independent of obesity, females have smaller lungs and greater upstream flow resistance, which contributes to reduced maximal flow, when compared with males.
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Affiliation(s)
- Jonathon L Stickford
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, Dallas, Texas, United States
| | - Dharini M Bhammar
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, Dallas, Texas, United States
- Center for Tobacco Research, Division of Medical Oncology, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Bryce N Balmain
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, Dallas, Texas, United States
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, Dallas, Texas, United States
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Balmain BN, Tomlinson AR, MacNamara JP, Hynan LS, Wakeham DJ, Levine BD, Sarma S, Babb TG. Reducing Pulmonary Capillary Wedge Pressure During Exercise Exacerbates Exertional Dyspnea in Patients With Heart Failure With Preserved Ejection Fraction: Implications for V˙/Q˙ Mismatch. Chest 2023; 164:686-699. [PMID: 37030529 PMCID: PMC10548458 DOI: 10.1016/j.chest.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/29/2023] [Accepted: 04/01/2023] [Indexed: 04/09/2023] Open
Abstract
BACKGROUND The primary cause of dyspnea on exertion in heart failure with preserved ejection fraction (HFpEF) is presumed to be the marked rise in pulmonary capillary wedge pressure during exercise; however, this hypothesis has never been tested directly. Therefore, we evaluated invasive exercise hemodynamics and dyspnea on exertion in patients with HFpEF before and after acute nitroglycerin (NTG) treatment to lower pulmonary capillary wedge pressure. RESEARCH QUESTION Does reducing pulmonary capillary wedge pressure during exercise with NTG improve dyspnea on exertion in HFpEF? STUDY DESIGN AND METHODS Thirty patients with HFpEF performed two invasive 6-min constant-load cycling tests (20 W): one with placebo (PLC) and one with NTG. Ratings of perceived breathlessness (0-10 scale), pulmonary capillary wedge pressure (right side of heart catheter), and arterial blood gases (radial artery catheter) were measured. Measurements of V˙/Q˙ matching, including alveolar dead space (Vdalv; Enghoff modification of the Bohr equation) and the alveolar-arterial Po2 difference (A-aDO2; alveolar gas equation), were also derived. The ventilation (V˙e)/CO2 elimination (V˙co2) slope was also calculated as the slope of the V˙e and V˙co2 relationship, which reflects ventilatory efficiency. RESULTS Ratings of perceived breathlessness increased (PLC: 3.43 ± 1.94 vs NTG: 4.03 ± 2.18; P = .009) despite a clear decrease in pulmonary capillary wedge pressure at 20 W (PLC: 19.7 ± 8.2 vs NTG: 15.9 ± 7.4 mm Hg; P < .001). Moreover, Vdalv (PLC: 0.28 ± 0.07 vs NTG: 0.31 ± 0.08 L/breath; P = .01), A-aDO2 (PLC: 19.6 ± 6.7 vs NTG: 21.1 ± 6.7; P = .04), and V˙e/V˙co2 slope (PLC: 37.6 ± 5.7 vs NTG: 40.2 ± 6.5; P < .001) all increased at 20 W after a decrease in pulmonary capillary wedge pressure. INTERPRETATION These findings have important clinical implications and indicate that lowering pulmonary capillary wedge pressure does not decrease dyspnea on exertion in patients with HFpEF; rather, lowering pulmonary capillary wedge pressure exacerbates dyspnea on exertion, increases V˙/Q˙ mismatch, and worsens ventilatory efficiency during exercise in these patients. This study provides compelling evidence that high pulmonary capillary wedge pressure is likely a secondary phenomenon rather than a primary cause of dyspnea on exertion in patients with HFpEF, and a new therapeutic paradigm is needed to improve symptoms of dyspnea on exertion in these patients.
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Affiliation(s)
- Bryce N Balmain
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, University of Texas Southwestern Medical Center, Dallas, TX; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Andrew R Tomlinson
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, University of Texas Southwestern Medical Center, Dallas, TX; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - James P MacNamara
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, University of Texas Southwestern Medical Center, Dallas, TX; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Linda S Hynan
- The O'Donnell School of Public Health and Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Denis J Wakeham
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, University of Texas Southwestern Medical Center, Dallas, TX; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, University of Texas Southwestern Medical Center, Dallas, TX; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Satyam Sarma
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, University of Texas Southwestern Medical Center, Dallas, TX; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, University of Texas Southwestern Medical Center, Dallas, TX; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX.
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Foster J, Balmain BN, Wilhite DP, Watso JC, Babb TG, Cramer MN, BelvaL LN, Crandall CG. Inhibiting regional sweat evaporation modifies the ventilatory response to exercise: interactions between core and skin temperature. J Appl Physiol (1985) 2023; 134:1011-1021. [PMID: 36892886 PMCID: PMC10110718 DOI: 10.1152/japplphysiol.00597.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 02/27/2023] [Accepted: 03/03/2023] [Indexed: 03/10/2023] Open
Abstract
In humans, elevated body temperatures can markedly increase the ventilatory response to exercise. However, the impact of changing the effective body surface area (BSA) for sweat evaporation (BSAeff) on such responses is unclear. Ten healthy adults (9 males, 1 female) performed eight exercise trials cycling at 6 W/kg of metabolic heat production for 60 min. Four conditions were used where BSAeff corresponded to 100%, 80%, 60%, and 40% of BSA using vapor-impermeable material. Four trials (one at each BSAeff) were performed at 25°C air temperature, and four trials (one at each BSAeff) at 40°C air temperature, each with 20% humidity. The slope of the relation between minute ventilation and carbon dioxide elimination (V̇E/V̇co2 slope) assessed the ventilatory response. At 25°C, the V̇E/V̇co2 slope was elevated by 1.9 and 2.6 units when decreasing BSAeff from 100 to 80 and to 40% (P = 0.033 and 0.004, respectively). At 40°C, V̇E/V̇co2 slope was elevated by 3.3 and 4.7 units, when decreasing BSAeff from 100 to 60 and to 40% (P = 0.016 and P < 0.001, respectively). Linear regression analyses using group average data from each condition demonstrated that end-exercise mean body temperature (integration of core and mean skin temperature) was better associated with the end-exercise ventilatory response, compared with core temperature alone. Overall, we show that impeding regional sweat evaporation increases the ventilatory response to exercise in temperate and hot environmental conditions, and the effect is mediated primarily by increases in mean body temperature.NEW & NOTEWORTHY Exercise in the heat increases the slope of the relation between minute ventilation and carbon dioxide elimination (V̇E/V̇co2 slope) in young healthy adults. An indispensable role for skin temperature in modulating the ventilatory response to exercise is noted, contradicting common belief that internal/core temperature acts independently as a controller of ventilation during hyperthermia.
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Affiliation(s)
- Josh Foster
- Thermal and Vascular Physiology Laboratory, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Bryce N Balmain
- Pulmonary Physiology Laboratory, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Daniel P Wilhite
- Pulmonary Physiology Laboratory, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Joseph C Watso
- Thermal and Vascular Physiology Laboratory, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Cardiovascular and Applied Physiology Laboratory, Department of Nutrition & Integrative Physiology, Florida State University, Tallahassee, Florida, United States
| | - Tony G Babb
- Pulmonary Physiology Laboratory, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Matthew N Cramer
- Thermal and Vascular Physiology Laboratory, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Luke N BelvaL
- Thermal and Vascular Physiology Laboratory, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Craig G Crandall
- Thermal and Vascular Physiology Laboratory, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and University of Texas Southwestern Medical Center, Dallas, Texas, United States
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Bernhardt V, Stickford JL, Bhammar DM, Balmain BN, Babb TG. Repeatability of dyspnea measurements during exercise in women with obesity. Respir Physiol Neurobiol 2022; 297:103831. [PMID: 34922000 PMCID: PMC11463220 DOI: 10.1016/j.resp.2021.103831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 11/10/2021] [Accepted: 12/13/2021] [Indexed: 11/24/2022]
Abstract
While the 0-10 Borg scale to rate perceived breathlessness (RPB) is widely used to assess dyspnea on exertion, the repeatability of RPB in women with obesity is unknown. We examined the repeatability of RPB in women with obesity during submaximal constant-load cycling following at least 10 weeks of normal daily life. Seventeen women (37 ± 7 yr; 34.6 ± 4.5 kg/m2) who rated their breathlessness as 3 on the Borg scale (i.e., "moderate") during 60 W submaximal cycling repeated the same test following 19 ± 9 weeks of normal living. Mean body weight (93.8 ± 16.1 vs. 93.6 ± 116.8 kg, p = 0.94) and RPB (3.0 ± 0.0 vs. 3.1 ± 1.4, p = 0.80) did not differ between pre- and post-normal living periods. We demonstrate that subjective ratings of breathlessness are repeatable for the majority of subjects and can be used to accurately assess DOE during submaximal constant-load cycling in women with obesity.
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Affiliation(s)
| | | | | | - Bryce N Balmain
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Herkenrath SD, Treml M, Hagmeyer L, Matthes S, Randerath WJ. Severity stages of obesity-related breathing disorders - a cross-sectional cohort study. Sleep Med 2022; 90:9-16. [PMID: 35051737 DOI: 10.1016/j.sleep.2021.12.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 11/16/2022]
Abstract
INTRODUCTION There is a general underappreciation of the spectrum of obesity-related breathing disorders and their consequences. We therefore compared characteristics of obese patients with eucapnic obstructive sleep apnea (OSA), OSA with obesity-related sleep hypoventilation (ORSH) or obesity hypoventilation syndrome (OHS) to identify the major determinants of hypoventilation. PATIENTS AND METHODS In this prospective, diagnostic study (NCT04570540), obese patients with OSA, ORSH or OHS were characterized applying polysomnography with transcutaneous capnometry, blood gas analyses, bodyplethysmography and measurement of hypercapnic ventilatory response (HCVR). Pathophysiological variables known to contribute to hypoventilation and differing significantly between the groups were specified as potential independent variables in a multivariable logistic regression to identify major determinants of hypoventilation. RESULTS Twenty, 43 and 19 patients were in the OSA, ORSH and OHS group, respectively. BMI was significantly lower in OSA as compared to OHS. The extent of SRBD was significantly higher in OHS as compared to OSA or ORSH. Patients with ORSH or OHS showed a significantly decreased forced expiratory volume in 1 s and forced vital capacity compared to OSA. HCVR was significantly lower in OHS and identified as the major determinant of hypoventilation in a multivariable logistic regression (Nagelkerke R2 = 0.346, p = 0.050, odds ratio (95%-confidence interval) 0.129 (0.017-1.004)). CONCLUSION Although there were differences in BMI, respiratory mechanics and severity of upper airway obstruction between groups, our data support HCVR as the major determinant of obesity-associated hypoventilation.
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Affiliation(s)
- Simon D Herkenrath
- Bethanien Hospital, Clinic for Pneumology and Allergology, Center for Sleep Medicine and Respiratory Care, Solingen, Germany; Institute for Pneumology at the University of Cologne, Germany
| | - Marcel Treml
- Institute for Pneumology at the University of Cologne, Germany
| | - Lars Hagmeyer
- Bethanien Hospital, Clinic for Pneumology and Allergology, Center for Sleep Medicine and Respiratory Care, Solingen, Germany; Institute for Pneumology at the University of Cologne, Germany
| | - Sandhya Matthes
- Bethanien Hospital, Clinic for Pneumology and Allergology, Center for Sleep Medicine and Respiratory Care, Solingen, Germany
| | - Winfried J Randerath
- Bethanien Hospital, Clinic for Pneumology and Allergology, Center for Sleep Medicine and Respiratory Care, Solingen, Germany; Institute for Pneumology at the University of Cologne, Germany.
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Kumar A, Mitra V, Oliver C, Ullal A, Biddulph M, Mance I. Estimating Respiratory Rate From Breath Audio Obtained Through Wearable Microphones. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:7310-7315. [PMID: 34892786 DOI: 10.1109/embc46164.2021.9629661] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Respiratory rate (RR) is a clinical metric used to assess overall health and physical fitness. An individual's RR can change from their baseline due to chronic illness symptoms (e.g., asthma, congestive heart failure), acute illness (e.g., breathlessness due to infection), and over the course of the day due to physical exhaustion during heightened exertion. Remote estimation of RR can offer a cost-effective method to track disease progression and cardio-respiratory fitness over time. This work investigates a model-driven approach to estimate RR from short audio segments obtained after physical exertion in healthy adults. Data was collected from 21 individuals using microphone-enabled, near-field headphones before, during, and after strenuous exercise. RR was manually annotated by counting perceived inhalations and exhalations. A multi-task Long-Short Term Memory (LSTM) network with convolutional layers was implemented to process mel-filterbank energies, estimate RR in varying background noise conditions, and predict heavy breathing, indicated by an RR of more than 25 breaths per minute. The multi-task model performs both classification and regression tasks and leverages a mixture of loss functions. It was observed that RR can be estimated with a concordance correlation coefficient (CCC) of 0.76 and a mean squared error (MSE) of 0.2, demonstrating that audio can be a viable signal for approximating RR.Clinical relevance-The subject technology facilitates the use of accessible, aesthetically acceptable wearable headphones to provide a technologically efficient and cost-effective method to estimate respiratory rate and track cardio-respiratory fitness over time.
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Spencer MD, Balmain BN, Bernhardt V, Wilhite DP, Babb TG. Dyspnea during exercise and voluntary hyperpnea in women with obesity. Respir Physiol Neurobiol 2021; 287:103638. [PMID: 33581294 DOI: 10.1016/j.resp.2021.103638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/23/2020] [Accepted: 02/01/2021] [Indexed: 10/22/2022]
Abstract
Temporal responses of ratings of perceived breathlessness (RBP) during constant-load and incremental exercise, and during voluntary hyperpnea (EVH) were examined in women with obesity. Following 6 min of constant-load (60W) cycling, 34 women rated RPB≥4 (+DOE) and 22 women rated RPB≤2 (-DOE). Both groups completed an incremental cycling test and an EVH test at 40 and 60L/min; RPB was assessed each minute of incremental cycling and at the end of each EVH trial. RPB increased with ventilation during constant-load (+DOE: R2=0.86; -DOE: R2=0.82) and incremental (+DOE: R2=0.91; -DOE: R2=0.92) exercise, but + DOE had a greater y-intercept than -DOE (60W: -0.16±1.53 vs. -0.73±0.55; incremental: -0.50±1.40 vs. -1.71±0.84). Despite matching ventilation, RPB was greater in + DOE at baseline (0.97±1.14 vs. 0.14±0.28), 40L/min (2.50±1.43 vs. 0.98±0.91), and 60L/min (3.94±2.19 vs. 2.07±1.32) during EVH. These findings show that despite linear associations between RPB and ventilation during exercise and voluntary hyperpnea, breathlessness perception at a given ventilatory demand is heightened in +DOE compared with -DOE.
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Affiliation(s)
- Matthew D Spencer
- Centre for Research in Occupational Safety and Health, Laurentian University, ON, Canada
| | - Bryce N Balmain
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vipa Bernhardt
- Texas A&M University Commerce, Department of Health and Human Performance, Commerce, TX, USA
| | - Daniel P Wilhite
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Multidimensional aspects of dyspnea in obese patients referred for cardiopulmonary exercise testing. Respir Physiol Neurobiol 2019; 274:103365. [PMID: 31899350 DOI: 10.1016/j.resp.2019.103365] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/26/2019] [Accepted: 12/29/2019] [Indexed: 11/23/2022]
Abstract
We investigated the contributions of obesity on multidimensional aspects of dyspnea on exertion (DOE) in patients referred for clinical cardiopulmonary exercise testing (CPET). Ratings of perceived breathlessness (RPB, Borg scale 0-10) were collected in obese (BMI ≥ 30; n = 47) and nonobese (BMI ≤ 25; n = 27) patients during two (one lower: ∼30 W; and one higher: ∼50 W) 4-6 min constant load cycling bouts. Multidimensional dyspnea profiles (MDP) were collected in the final 26 obese and 14 nonobese patients of the sample. RPB was greater (p = 0.05) in obese (3.3 ± 2.2 vs 2.4 ± 1.4) at lower work rates, but similar at higher work rates (4.9 ± 2.2 vs 4.4 ± 1.8). MDP sensory score including unpleasantness was 4.3 ± 2.2 in obese vs 2.5 ± 1.9 in nonobese (p < 0.001). The affective score was 1.9 ± 2.2 vs 0.7 ± 0.7, respectively (p < 0.01). Breathing sensations including 'air hunger', 'effort', and 'breathing at lot' were greater (p < 0.05) in obese, making these patients more frustrated/angry (p < 0.05). Obesity should be considered as a potential independent influencing factor that provokes DOE and unpleasantness when assessing breathlessness during CPET.
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Ramalho SHR, Santos M, Claggett B, Matsushita K, Kitzman DW, Loehr L, Solomon SD, Skali H, Shah AM. Association of Undifferentiated Dyspnea in Late Life With Cardiovascular and Noncardiovascular Dysfunction: A Cross-sectional Analysis From the ARIC Study. JAMA Netw Open 2019; 2:e195321. [PMID: 31199443 PMCID: PMC6575149 DOI: 10.1001/jamanetworkopen.2019.5321] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/23/2019] [Indexed: 12/12/2022] Open
Abstract
Importance Undifferentiated dyspnea is common in late life, but the relative contribution of subclinical cardiac dysfunction is unknown. Impairments in cardiac structure and function may be characteristics of undifferentiated dyspnea in elderly people, providing potential insights into occult heart failure (HF). Objective To quantify the association of undifferentiated dyspnea with cardiac dysfunction after accounting for other potential contributors. Design, Setting, and Participants This cross-sectional study used data from Atherosclerosis Risk in Communities study participants 65 years and older who attended the fifth study visit (from 2011 to 2013) and had not been diagnosed with HF, chronic obstructive pulmonary disease, morbid obesity, or severe kidney disease. Analyses were conducted from October 2017 to June 2018. Exposures Dyspnea measured using the modified Medical Research Council scale, with a score less than 2 classified as none to mild and a score of 2 or more classified as moderate to severe. Main Outcomes and Measures Using multivariable logistic regression, the association of undifferentiated dyspnea was defined using cardiac structure, systolic and diastolic function, pulmonary pressure (echocardiography), pulmonary function (spirometry), glomerular filtration rate, hemoglobin, body mass index, depression, and physical performance. The population-attributable risk was calculated for each dysfunction metric. Results Among 4342 participants (mean [SD] age, 75.9 [5.0] years; 2533 [58.3%] women), 1173 (27.0%) had undifferentiated dyspnea. Moderate to severe dyspnea was present in 574 participants (13.2%) and was associated with left ventricular (LV) hypertrophy (odds ratio [OR], 1.53; 95% CI, 1.25-1.87; P < .001) and LV diastolic (OR, 1.46; 95% CI, 1.20-1.78; P < .001) and systolic (OR, 1.28; 95% CI, 1.05-1.56; P = .02) dysfunction. Moderate to severe dyspnea was also associated with obstructive (OR, 1.59; 95% CI, 1.28-1.99; P < .001) and restrictive (OR, 2.56; 95% CI, 1.99-3.27; P < .001) findings on spirometry, renal impairment (OR, 1.32; 95% CI, 1.08-1.61; P = .01), anemia (OR, 1.72; 95% CI, 1.39-2.12; P < .001), lower (OR, 2.77; 95% CI, 2.18-3.51; P < .001) and upper (OR, 1.82; 95% CI, 1.49-2.23; P < .001) extremity weakness, depression (OR, 3.01; 95% CI, 2.24-4.25; P < .001), and obesity (OR, 2.35; 95% CI, 1.95-2.83; P < .001). After accounting for these, moderate to severe dyspnea was associated with LV hypertrophy (OR, 1.30; 95% CI, 1.01-1.67; P = .04) and was not associated with systolic or diastolic function. In contrast, in the fully adjusted model, other organ system measures were associated with dyspnea, except for glomerular filtration rate and grip strength. The population-attributable risk of dyspnea associated with obesity alone was 22.6% compared with 5.8% for LV hypertrophy. Conclusions and Relevance Undifferentiated dyspnea is multifactorial in older adults, and this study showed an association with obesity. When accounting for other relevant organ systems, cardiovascular function poorly discriminated those with vs those without dyspnea. Therefore, dyspnea should not be assumed to represent occult HF in this population.
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Affiliation(s)
- Sergio H. R. Ramalho
- Health Sciences and Technologies Post-Graduation Program, University of Brasília, Brasília, Brazil
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Mario Santos
- Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Brian Claggett
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Kunihiro Matsushita
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | | | - Laura Loehr
- Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill
| | - Scott D. Solomon
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Hicham Skali
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Amil M. Shah
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts
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Bernhardt V, Bhammar DM, Marines-Price R, Babb TG. Weight loss reduces dyspnea on exertion and unpleasantness of dyspnea in obese men. Respir Physiol Neurobiol 2019; 261:55-61. [PMID: 30658095 PMCID: PMC6368458 DOI: 10.1016/j.resp.2019.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/12/2019] [Accepted: 01/14/2019] [Indexed: 01/11/2023]
Abstract
We hypothesized that weight loss would ameliorate dyspnea on exertion (DOE) and feelings of unpleasantness related to the DOE in obese men. Eighteen men (34 ± 7yr, 35 ± 4 kg/m2 BMI, mean ± SD) participated in a 12-week weight loss program. Body composition, pulmonary function, cardiorespiratory measures, DOE, and unpleasantness (visual analog scale) were assessed before and after weight loss. Subjects were grouped by Ratings of Perceived Breathlessness (RPB, Borg 0-10 scale) during submaximal cycling: Ten men rated RPB ≥ 4 (+DOE), eight rated RPB ≤ 2 (-DOE). Subjects lost 10.3 ± 5.6 kg (9.2 ± 4.5%) of body weight (n = 18). RPB during submaximal cycling was significantly improved in both groups (+DOE: 4.1 ± 0.3-2.8 ± 1.1; -DOE: 1.3 ± 0.7 to 0.8 ± 0.6, p < 0.001). Several submaximal exercise variables (e.g., V˙O2, V˙E) were decreased similarly in both groups (p < 0.01). Unpleasantness associated with the DOE was reduced (p < 0.05). The improved RPB was not significantly correlated with changes in body weight or cardiopulmonary exercise responses (p > 0.05). Moderate weight loss appears to be an effective option to ameliorate DOE and unpleasantness related to DOE in obese men.
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Affiliation(s)
- Vipa Bernhardt
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center in Dallas, TX, USA; Department of Health and Human Performance, Texas A&M University-Commerce in Commerce, TX, USA.
| | - Dharini M Bhammar
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center in Dallas, TX, USA; Department of Kinesiology and Nutrition Sciences, University of Nevada, Las Vegas in Las Vegas, NV, USA.
| | - Rubria Marines-Price
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center in Dallas, TX, USA; Parkland Health and Hospital System, Dallas, TX, USA.
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center in Dallas, TX, USA.
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Marines-Price R, Bernhardt V, Bhammar DM, Babb TG. Dyspnea on exertion provokes unpleasantness and negative emotions in women with obesity. Respir Physiol Neurobiol 2018; 260:131-136. [PMID: 30471435 DOI: 10.1016/j.resp.2018.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/18/2018] [Accepted: 11/20/2018] [Indexed: 11/19/2022]
Abstract
PURPOSE While dyspnea on exertion (DOE) is a common complaint in otherwise healthy obese women, less is known about feelings of unpleasantness and/or negative emotions provoked by DOE. We examined whether ratings of perceived breathlessness (RPB) during exercise were associated with ratings of unpleasantness and negative emotions (depression, anxiety, frustration, anger, and fear) in obese women. METHODS Seventy-four women (34 ± 7 yrs, 36 ± 4 kg/m2, 46 ± 5% body fat) performed 6 min of constant-load cycling (60 W); RPB (0-10 scale), and unpleasantness and negative emotions (visual analog scales, 10 cm) were assessed at the end. RESULTS RPB were significantly correlated with unpleasantness and negative emotions (p < 0.05). The strongest correlations were between RPB and unpleasantness (r = 0.61, p < 0.001), and RPB and anxiety (r = 0.50, p < 0.001). CONCLUSIONS DOE can significantly provoke unpleasantness and negative emotions during exercise in obese women. This may affect their willingness to engage in regular physical activity.
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Affiliation(s)
- Rubria Marines-Price
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, United States; Parkland Health and Hospital System, United States
| | - Vipa Bernhardt
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, United States; Department of Health and Human Performance, Texas A&M University-Commerce, United States
| | - Dharini M Bhammar
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, United States; Department of Kinesiology and Nutrition Sciences, University of Nevada, Las Vegas, United States
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, United States.
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Bernhardt V, Babb TG. Exertional dyspnoea in obesity. Eur Respir Rev 2016; 25:487-495. [PMID: 27903669 PMCID: PMC9487557 DOI: 10.1183/16000617.0081-2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/12/2016] [Indexed: 01/22/2023] Open
Abstract
The purpose of cardiopulmonary exercise testing (CPET) in the obese person, as in any cardiopulmonary exercise test, is to determine the patient's exercise tolerance, and to help identify and/or distinguish between the various physiological factors that could contribute to exercise intolerance. Unexplained dyspnoea on exertion is a common reason for CPET, but it is an extremely complex symptom to explain. Sometimes obesity is the simple answer by elimination of other possibilities. Thus, distinguishing among multiple clinical causes for exertional dyspnoea depends on the ability to eliminate possibilities while recognising response patterns that are unique to the obese patient. This includes the otherwise healthy obese patient, as well as the obese patient with potentially multiple cardiopulmonary limitations. Despite obvious limitations in lung function, metabolic disease and/or cardiovascular dysfunction, obesity may be the most likely reason for exertional dyspnoea. In this article, we will review the more common cardiopulmonary responses to exercise in the otherwise healthy obese adult with special emphasis on dyspnoea on exertion.
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Affiliation(s)
- Vipa Bernhardt
- Dept of Health and Human Performance, Texas A&M University-Commerce, Commerce, TX, USA
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, Dallas, TX, USA
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Bernhardt V, Stickford JL, Bhammar DM, Babb TG. Aerobic exercise training without weight loss reduces dyspnea on exertion in obese women. Respir Physiol Neurobiol 2015; 221:64-70. [PMID: 26593640 DOI: 10.1016/j.resp.2015.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/07/2015] [Accepted: 11/09/2015] [Indexed: 10/22/2022]
Abstract
Dyspnea on exertion (DOE) is a common symptom in obesity. We investigated whether aerobic exercise training without weight loss could reduce DOE. Twenty-two otherwise healthy obese women participated in a 12-week supervised aerobic exercise training program, exercising 30 min/day at 70-80% heart rate reserve, 4 days/week. Subjects were grouped based on their Ratings of Perceived Breathlessness (RPB) during constant load 60 W cycling: +DOE (n=12, RPB≥4, 37±7 years, 34±4 kg/m(2)) and -DOE (n=10, RPB≤2, 32±6 years, 33±3 kg/m(2)). No significant differences between the groups in body composition, pulmonary function, or cardiorespiratory fitness were observed pre-training. Post-training,peak was improved significantly in both groups (+DOE: 12±7, -DOE: 14±8%). RPB was significantly decreased in the +DOE (4.7±1.0-2.5±1.0) and remained low in the -DOE group (1.2±0.6-1.3±1.0) (interaction p<0.001). The reduction in RPB was not significantly correlated with the improvement in cardiorespiratory fitness. Aerobic exercise training improved cardiorespiratory fitness and DOE and thus appears to be an effective treatment for DOE in obese women.
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Affiliation(s)
- Vipa Bernhardt
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Southwestern Medical Center, Dallas, TX, USA; Texas A&M University Commerce, Department of Health and Human Performance, Commerce, TX, USA.
| | - Jonathon L Stickford
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Southwestern Medical Center, Dallas, TX, USA.
| | - Dharini M Bhammar
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Southwestern Medical Center, Dallas, TX, USA.
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Southwestern Medical Center, Dallas, TX, USA.
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Bernhardt V, Babb TG. Weight loss reduces dyspnea on exertion in obese women. Respir Physiol Neurobiol 2014; 204:86-92. [PMID: 25220695 DOI: 10.1016/j.resp.2014.09.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 09/04/2014] [Accepted: 09/05/2014] [Indexed: 12/23/2022]
Abstract
During submaximal exercise, some otherwise healthy obese women experience breathlessness, or dyspnea on exertion (+DOE), while others have mild or no DOE (-DOE). We investigated whether weight loss could reduce DOE. Twenty nine obese women were grouped based on their Ratings of Perceived Breathlessness (RPB) during constant load 60 W cycling: +DOE (n = 14, RPB ≥ 4, 34 ± 8 years, and 36 ± 3 kg/m(2)) and -DOE ( n= 15, RPB ≤ 2, 32 ± 8 years, and 36 ± 4 kg/m(2)) and then completed a 12-week weight loss program. Both groups lost a moderate amount of weight (+DOE: 6.6 ± 2.4 kg, -DOE: 8.4 ± 3.5 kg, and p < 0.001). RPB decreased significantly in the +DOE group (from 4.7 ± 1.1 to 3.1 ± 1.6) and remained low in the -DOE (from 1.5 ± 0.7 to 1.6 ± 1.1) (interaction p < 0.002). Most physiological variables measured (i.e. body composition, fat distribution, pulmonary function, oxygen cost of breathing, and cardiorespiratory measures) improved with weight loss; however, the decrease in RPB was not correlated with any of these variables (p > 0.05). In conclusion, moderate weight loss was effective in reducing breathlessness on exertion in obese women who experienced DOE at baseline.
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Affiliation(s)
- Vipa Bernhardt
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, 7232 Greenville Ave., Ste 435, Dallas 75231, TX, United States.
| | - Tony G Babb
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, 7232 Greenville Ave., Ste 435, Dallas 75231, TX, United States.
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