Dysanapsis in men and women with obesity

2021 ◽  
Author(s):  
Jonathon Lee Stickford ◽  
Daniel P. Wilhite ◽  
Dharini M. Bhammar ◽  
Bryce N. Balmain ◽  
Tony G. Babb
Keyword(s):  
Transpulmonary Pressure ◽  
Pulmonary Mechanics ◽  
Significant Group ◽  
Men And Women ◽  
Luminal Area ◽  
Occlusion Technique ◽  
Expiratory Flow ◽  
Reported Data ◽  
Conducting Airways ◽  
Function Testing

Obesity alters chest wall mechanics, reduces lung volumes, and increases airway resistance. In addition, the luminal area of the larger conducting airways is smaller in women than in men when matched for lung size. We examined whether differences in pulmonary mechanics with obesity and sex were associated with the dysanapsis ratio (DR), an estimate of airway size when expiratory flow is maximal, in men and women with and without obesity. Additionally, we examined the ability to estimate DR using predicted versus measured static recoil pressure at 50%FVC (Pst50FVC). Participants completed pulmonary function testing and measurements of pulmonary mechanics. Flow, volume, and transpulmonary pressure were recorded while completing forced vital capacity (FVC) maneuvers in a body plethysmograph. Static compliance curves were collected using the occlusion technique. DR was calculated using measured values of forced mid-expiratory flow and Pst50FVC. DR was also calculated using Pst predicted from previously reported data. There was no significant group (lean vs. obese) by sex interaction or main effect of group on DR. However, women displayed significantly larger DR compared with men. Predicted Pst50FVC was significantly greater than measured Pst50FVC. DR calculated from measured Pst was significantly greater than when using predicted Pst. In conclusion, while obesity does not appear to alter airway size, women may have larger airways compared with men when mid-expiratory flow is maximal. Additionally, DR estimated using predicted Pst should be used with caution.

scholarly journals Sex differences in large conducting airway anatomy

2018 ◽  
Vol 125 (3) ◽  
pp. 960-965 ◽  
Author(s):  
Paolo B. Dominelli ◽  
Juan G. Ripoll ◽  
Troy J. Cross ◽  
Sarah E. Baker ◽  
Chad C. Wiggins ◽  
...  
Keyword(s):  
Sex Differences ◽  
Main Bronchus ◽  
Lower Lobe ◽  
Left Lower Lobe ◽  
Smoking History ◽  
Men And Women ◽  
Previous Evidence ◽  
Healthy Women ◽  
Luminal Area ◽  
Conducting Airways

Airway luminal area is the major determinant of resistance to airflow in the tracheobronchial tree. Women may have smaller central conducting airways than men; however, previous evidence is confounded by an indirect assessment of airway geometry and by subjects with prior smoking history. The purpose of this study was to examine the effect of sex on airway size in healthy nonsmokers. Using low-dose high-resolution computed tomography, we retrospectively assessed airway luminal area in healthy men ( n = 51) and women ( n = 73) of varying ages (19–86 yr). Subjects with a positive smoking history, cardiopulmonary disease, or a body mass index > 40 kg/m2 were excluded. Luminal areas of the trachea, right and left main bronchus, bronchus intermediate, left and right upper lobes, and the left lower lobe were analyzed at three discrete points. The luminal areas of the conducting airways were ~26%–35% smaller in women. The trachea had the largest differences in luminal area between men and women (298 ± 47 vs. 195 ± 28 mm2 or 35% smaller for men and women, respectively), whereas the left lower lobe had the smallest differences (57 ± 15 vs. 42 ± 9 mm2 or 26% smaller for men and women, respectively). When a subset of subjects was matched for height, the sex differences in airway luminal area persisted, with women being ~20%–30% smaller. With all subjects, there were modest relationships between height and airway luminal area ( r = 0.73–0.53, P < 0.05). Although there was considerable overlap between sexes, the luminal areas of the large conducting airways were smaller in healthy women than in men. NEW & NOTEWORTHY Previous evidence for sex differences in airway size has been confounded by indirect measures and/or cohorts with significant smoking histories or pathologies. We found that central airways in healthy women were significantly smaller (~26%–35%) than men. The significant sex-difference in airway size was attenuated (20%–30% smaller) but preserved in a subset of subjects matched for height. Over a range of ages, healthy women have smaller central airways than men.

Pulmonary mechanics during exercise in subjects with chronic airflow obstruction

1980 ◽  
Vol 49 (3) ◽  
pp. 511-515 ◽  
Author(s):  
D. G. Stubbing ◽  
L. D. Pengelly ◽  
J. L. Morse ◽  
N. L. Jones
Keyword(s):  
Tidal Flow ◽  
Airflow Obstruction ◽  
Maximum Flow ◽  
Transpulmonary Pressure ◽  
Pulmonary Mechanics ◽  
Flow Volume ◽  
Tidal Breathing ◽  
Flow Rates ◽  
Control Value ◽  
Expiratory Flow

A body plethysmograph was used to measure pulmonary mechanics in six subjects with chronic airflow obstruction during steady states at rest and during exercise at 200 and 400 kpm . min-1. The mean forced expired volume in 1 s was 1.32 liters (39.2% predicted). The flow rates during tidal breathing reached the maximum expiratory flow-volume (MEFV) curve in all but one subject, and on exercise they all reached the MEFV curve. Total lung capacity did not change significantly, but functional residual capacity increased to 104% of the control value (P less than 0.05) and residual volume increased to 113.3% of the control value (P less than 0.02). The MEFV curves did not change and tidal flow rates in excess of th MEFV curve were not seen. Dynamic compliance fell with increasing exercise to 52.8% (P less than 0.01) and static expiratory pulmonary compliance to 90.2% of the control value. Transpulmonary pressures during tidal breathing when expiratory flow reached the MEFV curve increased to progressively higher values as the work load increased. At low work loads there were several subjects with negative transpulmonary pressure when maximum flow rates were present. In patients with chronic airflow obstruction, little change occurs during exercise in pulmonary mechanics; the tidal flow patterns are dominated by the expired flow-volume curve, which is not changed by exercise; maximum flow occurs in some patients when transpulmonary pressure is still negative.

scholarly journals Reference Values and Related Factors for Peak Expiratory Flow in Middle-aged and Elderly Chinese

2020 ◽  
Author(s):  
Chao Ji ◽  
Huixu Dai ◽  
Zhiying Zhao ◽  
Tiancong Liu ◽  
Shuhui Tong ◽  
...  
Keyword(s):  
Peak Expiratory Flow ◽  
Reference Values ◽  
Chinese Population ◽  
Linear Regression Analysis ◽  
Middle Aged ◽  
Value Analysis ◽  
Men And Women ◽  
Expiratory Flow ◽  
Older Chinese ◽  
Age And Sex

Abstract Background: Peak expiratory flow (PEF), as an essential index used for screening and monitoring asthma, chronic obstructive pulmonary disease, and respiratory mortality especially in elderly, is recommended especially for low resource settings in low- and middle-income countries. However, few reports have focused on the reference of PEF in China, especially in the middle-aged and elderly. Thus, the aim of this study was to determine age- and sex-specific reference values of PEF in the middle-aged and older Chinese population.Methods: There were 11,717 participants included for reference value analysis and 11,340 participants were included for risk factor analysis. The PEF was measured using a peak flow meter in L/min. The distribution of PEF terciles stratified by sex and age were reported. Multiple linear regression analysis was used to determine the associations between risk factors and PEF.Results: The PEF was higher in men than women across all age subgroups. The value of PEF decreased with age in both men and women. Height, weight, handgrip strength, and household air pollution were positively associated with PEF, and age, waist circumference smoking status were negatively associated with PEF significantly in both men and women (all P <0.05). The mean values were 9.38 L/min and 64.12 L/min for men and women. Meanwhile, the prevalence of low PEF was 1.62% and 2.16% for men and women, respectively.Conclusions: Age- and sex-specific centiles of PEF for the middle-aged and older Chinese population were estimated. The reference values for low PEF were provided for epidemiological studies and clinical practice in the future. Interventions on lung function or respiratory disease should be pay more attention on factors associated with PEF.

Evidence for increased intrathoracic fluid volume in man at high altitude

1979 ◽  
Vol 47 (4) ◽  
pp. 670-676 ◽  
Author(s):  
J. J. Jaeger ◽  
J. T. Sylvester ◽  
A. Cymerman ◽  
J. J. Berberich ◽  
J. C. Denniston ◽  
...  
Keyword(s):  
Pulmonary Edema ◽  
High Altitude ◽  
Transpulmonary Pressure ◽  
Fluid Volume ◽  
Pulmonary Mechanics ◽  
Volume Curve ◽  
Extravascular Fluid ◽  
Pressure Volume Curve ◽  
Transthoracic Electrical Impedance ◽  
Extravascular Fluid Volume

To determine if subclinical pulmonary edema occurs commonly at high altitude, 25 soldiers participated in two consecutive 72-h field exercises, the first at low altitude (200–875 m) and the second at high altitude (3,000–4,300 m). Various aspects of ventilatory function and pulmonary mechanics were measured at 0, 36, and 72 h of each exercise. Based on physical examination and chest radiographs there was no evidence of pulmonary edema at high altitude. There was, however, an immediate and sustained decrease in vital capacity and transthoracic electrical impedance as well as a clockwise rotation of the transpulmonary pressure-volume curve. In contrast, closing capacity and residual volume did not change immediately upon arrival at high altitude but did increase later during the exposure. These observations are consistent with an abrupt increase in thoracic intravascular fluid volume upon arrival at high altitude followed by a more gradual increase in extravascular fluid volume in the peribronchial spaces of dependent lung regions.

scholarly journals Simultaneous measurement of nitric oxide production by conducting and alveolar airways of humans

1999 ◽  
Vol 87 (4) ◽  
pp. 1532-1542 ◽  
Author(s):  
Anthony P. Pietropaoli ◽  
Irene B. Perillo ◽  
Alfonso Torres ◽  
Peter T. Perkins ◽  
Lauren M. Frasier ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Normal Subjects ◽  
Breath Holding ◽  
No Production ◽  
Large Contribution ◽  
Flow Rates ◽  
Expiratory Flow ◽  
Human Airways ◽  
Conducting Airways ◽  
Expiratory Flow Rates

Human airways produce nitric oxide (NO), and exhaled NO increases as expiratory flow rates fall. We show that mixing during exhalation between the NO produced by the lower, alveolar airways (V˙l NO) and the upper conducting airways (V˙u NO) explains this phenomenon and permits measurement ofV˙l NO,V˙u NO, and the NO diffusing capacity of the conducting airways (Du NO). After breath holding for 10–15 s the partial pressure of alveolar NO (Pa) becomes constant, and during a subsequent exhalation at a constant expiratory flow rate the alveoli will deliver a stable amount of NO to the conducting airways. The conducting airways secrete NO into the lumen (V˙u NO), which mixes with Pa during exhalation, resulting in the observed expiratory concentration of NO (Pe). At fast exhalations, Pa makes a large contribution to Pe, and, at slow exhalations, NO from the conducting airways predominates. Simple equations describing this mixing, combined with measurements of Pe at several different expiratory flow rates, permit calculation of Pa,V˙u NO, and Du NO.V˙l NOis the product of Pa and the alveolar airway diffusion capacity for NO. In seven normal subjects, Pa = 1.6 ± 0.7 × 10−6 (SD) Torr,V˙l NO= 0.19 ± 0.07 μl/min,V˙u NO= 0.08 ± 0.05 μl/min, and Du NO = 0.4 ± 0.4 ml ⋅ min−1 ⋅ Torr−1. These quantitative measurements ofV˙l NOandV˙u NOare suitable for exploring alterations in NO production at these sites by diseases and physiological stresses.

scholarly journals Evidence for dysanapsis using computed tomographic imaging of the airways in older ex-smokers

2009 ◽  
Vol 107 (5) ◽  
pp. 1622-1628 ◽  
Author(s):  
A. William Sheel ◽  
Jordan A. Guenette ◽  
Ren Yuan ◽  
Lukas Holy ◽  
John R. Mayo ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Tomographic Imaging ◽  
Smoking History ◽  
Men And Women ◽  
Male And Female ◽  
Computed Tomographic ◽  
Males And Females ◽  
Airway Tree ◽  
Conducting Airways ◽  
The Relationship

We sought to determine the relationship between lung size and airway size in men and women of varying stature. We also asked if men and women matched for lung size would still have differences in airway size and if so where along the pulmonary airway tree would these differences exist. We used computed tomography to measure airway luminal areas of the large and central airways. We determined airway luminal areas in men ( n = 25) and women ( n = 25) who were matched for age, body mass index, smoking history, and pulmonary function and in a separate set of men ( n = 10) and women ( n = 11) who were matched for lung size. Men had greater values for the larger airways and many of the central airways. When male and female subjects were pooled there were significant associations between lung size and airway size. Within the male and female groups the magnitudes of these associations were decreased or nonsignificant. In males and females matched for lung size women had significantly smaller airway luminal areas. The larger conducting airways in females are significantly smaller than those of males even after controlling for lung size.

Pulmonary mechanics during rapid mechanical ventilation in rabbits with saline-lavaged lungs

1986 ◽  
Vol 61 (4) ◽  
pp. 1431-1437 ◽  
Author(s):  
J. J. Perez Fontan ◽  
B. S. Turner ◽  
G. P. Heldt ◽  
G. A. Gregory
Keyword(s):  
Tidal Volume ◽  
Gas Flow ◽  
Transpulmonary Pressure ◽  
Inspiratory Flow ◽  
Pulmonary Mechanics ◽  
Mechanically Ventilated ◽  
Ventilatory Rate ◽  
Residual Capacity ◽  
Pressure Volume Relationship ◽  
Linear Ramp

Infants with respiratory failure are frequently mechanically ventilated at rates exceeding 60 breaths/min. We analyzed the effect of ventilatory rates of 30, 60, and 90 breaths/min (inspiratory times of 0.6, 0.3, and 0.2 s, respectively) on the pressure-flow relationships of the lungs of anesthetized paralyzed rabbits after saline lavage. Tidal volume and functional residual capacity were maintained constant. We computed effective inspiratory and expiratory resistance and compliance of the lungs by dividing changes in transpulmonary pressure into resistive and elastic components with a multiple linear regression. We found that mean pulmonary resistance was lower at higher ventilatory rates, while pulmonary compliance was independent of ventilatory rate. The transpulmonary pressure developed by the ventilator during inspiration approximated a linear ramp. Gas flow became constant and the pressure-volume relationship linear during the last portion of inspiration. Even at a ventilatory rate of 90 breaths/min, 28–56% of the tidal volume was delivered with a constant inspiratory flow. Our findings are consistent with the model of Bates et al. (J. Appl. Physiol. 58: 1840–1848, 1985), wherein the distribution of gas flow within the lungs depends predominantly on resistive factors while inspiratory flow is increasing, and on elastic factors while inspiratory flow is constant. This dynamic behavior of the surfactant-depleted lungs suggests that, even with very short inspiratory times, distribution of gas flow within the lungs is in large part determined by elastic factors. Unless the inspiratory time is further shortened, gas flow may be directed to areas of increased resistance, resulting in hyperinflation and barotrauma.

scholarly journals Yoga Practice Has Minor Influence on Respiratory Function at Rest in Men and Women

2018 ◽  
Vol 1 (88) ◽  
Author(s):  
Kristina Zaičenkovienė ◽  
Arvydas Stasiulis ◽  
Roma Aleksandravičienė ◽  
Loreta Stasiulevičienė
Keyword(s):  
Pulmonary Function ◽  
Respiratory Function ◽  
Vital Capacity ◽  
Inspiratory Flow ◽  
Hatha Yoga ◽  
Forced Expiration ◽  
Yoga Practice ◽  
Men And Women ◽  
Minor Influence ◽  
Expiratory Flow

Research background and hypothesis. Hatha yoga breathing has the potential of training the respiratory system in such a way that it helps an individual to cope with the respiratory demand (Ray et al., 2011).Research aim was to compare pulmonary function variables between physically inactive subjects and the ones practicing hatha yoga and to evaluate changes after 6 months of yoga practice in the latter group. Research methods. Pulmonary function was measured by means of the gas analyser “Oxycon Mobile” (Germany) before and after 6 months of yoga training in men (n = 11) (age – 30.8 (7.06), BMI – 25.6 (2.6)) and women (n = 11) (age – 28.9 (6.86), BMI – 22.5 (2.3)) practicing yoga and control subjects (n = 22) of similar age. Measurements included forced vital capacity (FVC), forced expiration volume in one second (FEV(1)), forced inspiratory volume in one second FIV1, vital capacity (VC), peak expiratory flow (PEF), forced expiratory flow rate (FEF (25–75)%), forced inspiratory flow at 50% of the vital capacity (FIF50%), maximum voluntary ventilation (MVV), vital capacity (VC MAX), peak inspiratory flow (PIF), etc.Research results. Pulmonary function measures FEF 75/85 (L/s) (p = 0.036), total volume inspired FVC IN (L) (p = 0.014), FIV1 (L) (p = 0.045) were significantly higher in the group practicing yoga than in the control group of women, and VC MAX (%) (p = 0.018), FEV 1 (%) (p = 0.041), FEF 25 (L/s) (p = 0.017), FVC IN (L) (p = 0.002) in men practicing yoga, than in men not practicing yoga. They also demonstrated higher values of MVV (L/min)  (p = 0.068) and FVC (L) (p = 0.050). After 6 months of practicing yoga we found higher FEF 50 (L/s) (p = 0.003), FEF 50% (L/s) (p = 0.003) in women’s group and VCMAX (%) (p = 0.028) in men’s group. We also found a tendency of the increase of VCMAX (L) (p = 0.053), PIF (L/s) (p = 0.051), FVC IN (L) (p = 0.061), FIVI (L)  (p = 0.064) indexes in men and PIF (L/s) (p = 0.072), FVC IN (L) (p =  0.076) in women.Discussion and conclusions. Yoga practice appeared to have minor influence on respiratory function at rest in men and women of middle age. Additional studies examining various yoga practices are warranted to gain a more comprehensive understanding of the effects of yoga techniques on pulmonary functions.Keywords: pulmonary function at rest, yoga training, yoga breathing.

Positive effort dependence of maximal expiratory flow

1987 ◽  
Vol 62 (2) ◽  
pp. 718-724 ◽  
Author(s):  
J. L. Allen ◽  
R. G. Castile ◽  
J. Mead
Keyword(s):  
Chest Wall ◽  
Conformational Changes ◽  
Vital Capacity ◽  
Transpulmonary Pressure ◽  
Normal Subjects ◽  
Forced Expiration ◽  
Respiratory Inductive Plethysmography ◽  
Maximal Expiratory Flow ◽  
Expiratory Flow ◽  
Normal Males

The maximal expiratory-flow volume (MEFV) curve in normal subjects is thought to be relatively effort independent over most of the vital capacity (VC). We studied seven normal males and found positive effort dependence of maximal expiratory flow between 50 and 80% VC in five of them, as demonstrated by standard isovolume pressure-flow (IVPF) curves. We then attempted to distinguish the effects of chest wall conformational changes from possible mechanisms intrinsic to the lungs as an explanation for positive effort dependence. IVPF curves were repeated in four of the subjects who had demonstrated positive effort dependence. Transpulmonary pressure was varied by introducing varied resistances at the mouth but effort, as defined by pleural pressure, was maintained constant. By this method, chest wall conformation at a given volume would be expected to remain the same despite changing transpulmonary pressures. When these four subjects were retested in this way, no increases in flow with increasing transpulmonary pressure were found. In further studies, voluntarily altering the chest wall pattern of emptying (as defined by respiratory inductive plethysmography) did however alter maximal expiratory flows, with transpulmonary pressure maintained constant. We conclude that maximal expiratory flow can increase with effort over a larger portion of the vital capacity than is commonly recognized, and this effort dependence may be the result of changes in central airway mechanical properties that occur in relation to changes in chest wall shape during forced expiration.

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