scholarly journals The need for race-specific reference equations for pulmonary diffusing capacity for nitric oxide

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gerald Stanley Zavorsky ◽  
Ahmad Saleh Almamary ◽  
Mobarak Khalid Alqahtani ◽  
Shi Huh Samuel Shan ◽  
Douglas Shawn Gardenhire

Abstract Background Few reference equations exist for healthy adults of various races for pulmonary diffusing capacity for nitric oxide (DLNO). The purpose of this study was to collect pilot data to demonstrate that race-specific reference equations are needed for DLNO. Methods African Americans (blacks) were chosen as the comparative racial group. In 2016, a total of 59 healthy black subjects (27 males and 32 females) were recruited to perform a full battery of pulmonary function tests. In the development of DLNO reference equations, a white reference sample (randomly drawn from a population) matched to the black sample for sex, age, and height was used. Multiple linear regression equations for DLNO, alveolar volume (VA), and pulmonary diffusing capacity for carbon monoxide (DLCO) using a 5–6 s breath-hold were developed. Results Our models demonstrated that sex, age2, race, and height explained 71% of the variance in DLNO and DLCO, with race accounting for approximately 5–10% of the total variance. After normalizing for sex, age2, and height, blacks had a 12.4 and 3.9 mL/min/mmHg lower DLNO and DLCO, respectively, compared to whites. The lower diffusing capacity values in blacks are due, in part, to their 0.6 L lower VA (controlling for sex and height). Conclusion The results of this pilot data reveal small but important and statistically significant racial differences in DLNO and DLCO in adults. Future reference equations should account for racial differences. If these differences are not accounted for, then the risk of falsely diagnosing lung disease increase in blacks when using reference equations for whites.

2018 ◽  
Vol 52 (1) ◽  
pp. 1500677 ◽  
Author(s):  
Mathias Munkholm ◽  
Jacob Louis Marott ◽  
Lars Bjerre-Kristensen ◽  
Flemming Madsen ◽  
Ole Find Pedersen ◽  
...  

The aim of this study was to determine reference equations for the combined measurement of diffusing capacity of the lung for carbon monoxide (CO) and nitric oxide (NO) (DLCONO). In addition, we wanted to appeal for consensus regarding methodology of the measurement including calculation of diffusing capacity of the alveolo-capillary membrane (Dm) and pulmonary capillary volume (Vc).DLCONO was measured in 282 healthy individuals aged 18–97 years using the single-breath technique and a breath-hold time of 5 s (true apnoea period). The following values were used: 1) specific conductance of nitric oxide (θNO)=4.5 mLNO·mLblood−1·min−1·mmHg−1; 2) ratio of diffusing capacity of the membrane for NO and CO (DmNO/DmCO)=1.97; and 3) 1/red cell CO conductance (1/θCO)=(1.30+0.0041·mean capillary oxygen pressure)·(14.6/Hb concentration in g·dL−1).Reference equations were established for the outcomes of DLCONO, including DLCO and DLNO and the calculated values Dm and Vc. Independent variables were age, sex, height and age squared.By providing new reference equations and by appealing for consensus regarding the methodology, we hope to provide a basis for future studies and clinical use of this novel and interesting method.


1962 ◽  
Vol 17 (2) ◽  
pp. 259-262 ◽  
Author(s):  
Joseph C. Ross ◽  
Glen D. Ley ◽  
Ronald F. Coburn ◽  
J. L. Eller ◽  
Robert E. Forster

Previous investigations of the effect of inflation of a pressure suit on pulmonary diffusing capacity (DL) have been reported from our two laboratories, one (Indianapolis) finding an increase and the other (Philadelphia) finding no change. The present investigation was carried out in Philadelphia, using some of the same subjects and pressure suits in order to reconcile the contradictory results. The earlier contradictory results were confirmed. The pressure suit used in the investigations at Philadelphia ( suit P)covered the entire body below the nipples, whereas the suit used in the investigations at Indianapolis( suit I) extended cephalad only as far as the costal margin. When suit P was inflated in the present study, DL again did not increase significantly in two subjects. However, when the upper part of the suit was folded down so that the thoracic cage was not covered, inflation of the suit did produce a significant increase in DL. Inflation of suit P when it covered the chest made it difficult for a subject not to perform a Valsalva maneuver during breath holding and caused more decrease in alveolar volume (Va) than when it was inflated in the folded-down position. In two subjects studied, we found no difference in air trapping with inflation of suit P in the two positions. The discrepancy between the results of the two earlier studies appears to have resulted from the different construction of the two pressure suits used. We conclude that pressure suit inflation in man will produce an increase in DL, presumably by means of pulmonary congestion. Submitted on September 22, 1961


Author(s):  
Mathias Munkholm ◽  
Jacob Louis Marott ◽  
Lars Bjerre-Kristensen ◽  
Flemming Madsen ◽  
Ole Find Pedersen ◽  
...  

Obesity ◽  
2008 ◽  
Vol 16 (11) ◽  
pp. 2431-2438 ◽  
Author(s):  
Gerald S. Zavorsky ◽  
Do J. Kim ◽  
Elspeth R. McGregor ◽  
Jennifer M. Starling ◽  
Jeffrey A. Gavard

1998 ◽  
Vol 84 (2) ◽  
pp. 606-611 ◽  
Author(s):  
Hartmut Heller ◽  
Gabi Fuchs ◽  
Klaus-Dieter Schuster

Heller, Hartmut, Gabi Fuchs, and Klaus-Dieter Schuster. Pulmonary diffusing capacities for oxygen-labeled CO2 and nitric oxide in rabbits. J. Appl. Physiol. 84(2): 606–611, 1998.—We determined the pulmonary diffusing capacity (Dl) for18O-labeled CO2(C18O2) and nitric oxide (NO) to estimate the membrane component of the respective gas conductances. Six anesthetized paralyzed rabbits were ventilated by a computerized ventilatory servo system. Single-breath maneuvers were automatically performed by inflating the lungs with gas mixtures containing 0.9% C18O2or 0.05% NO in nitrogen, with breath-holding periods ranging from 0 to 1 s for C18O2and from 2 to 8 s for NO. The alveolar partial pressures of C18O2and NO were determined by using respiratory mass spectrometry. Dl was calculated from gas exchange during inflation, breath hold, and deflation. We obtained values of 14.0 ± 1.1 and 2.2 ± 0.1 (mean value ± SD) ml ⋅ mmHg−1 ⋅ min−1for[Formula: see text]and Dl NO, respectively. The measured[Formula: see text]/Dl NOratio was one-half that of the theoretically predicted value according to Graham’s law (6.3 ± 0.5 vs. 12, respectively). Analyses of the several mechanisms influencing the determination of[Formula: see text]and Dl NOand their ratio are discussed. An underestimation of the membrane diffusing component for CO2 is considered the likely reason for the low[Formula: see text]/Dl NOratio obtained.


1997 ◽  
Vol 82 (4) ◽  
pp. 1091-1097 ◽  
Author(s):  
Pierre Vaïda ◽  
Christian Kays ◽  
Daniel Rivière ◽  
Pierre Téchoueyres ◽  
Jean-Luc Lachaud

Vaı̈da, Pierre, Christian Kays, Daniel Rivière, Pierre Téchoueyres, and Jean-Luc Lachaud.Pulmonary diffusing capacity and pulmonary capillary blood volume during parabolic flights. J. Appl. Physiol. 82(4): 1091–1097, 1997.—Data from the Spacelab Life Sciences-1 (SLS-1) mission have shown sustained but moderate increase in pulmonary diffusing capacity (Dl). Because of the occupational constraints of the mission, data were only obtained after 24 h of exposure to microgravity. Parabolic flights are often used to study some effects of microgravity, and we measured changes in Dl occurring at the very onset of weightlessness. Measurements of Dl, membrane diffusing capacity, and pulmonary capillary blood volume were made in 10 male subjects during the 20-s 0-G phases of parabolic flights performed by the “zero-G” Caravelle aircraft. Using the standardized single-breath technique, we measured Dl for CO and nitric oxide simultaneously. We found significant increases indl for CO (62%), in membrane diffusing capacity for CO (47%), in Dl for nitric oxide (47%), and in pulmonary capillary blood volume (71%). We conclude that major changes in the alveolar membrane gas transfers and in the pulmonary capillary bed occur at the very onset of microgravity. Because these changes are much greater than those reported during sustained microgravity, the effects of rapid transition from hypergravity to microgravity during parabolic flights remain questionable.


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