Gerald Stanley Zavorsky1, Ahmad Saleh Almamary2, Mobarak Khalid Alqahtani3, Shi Huh Samuel Shan4, Douglas Shawn Gardenhire4. 1. Pulmonary Services Department, University of California, Davis, Medical Center, 2315 Stockton Boulevard, Room 5703, Sacramento, CA, 95817, USA. gszavorsky@ucdavis.edu. 2. Faculty of Medicine, National Heart and Lung Institute, Imperial College London, London, UK. 3. Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK. 4. Department of Respiratory Therapy, Georgia State University, Atlanta, GA, USA.
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.
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.
Authors: Sylvia Verbanck; Alain Van Muylem; Daniel Schuermans; Ivan Bautmans; Bruce Thompson; Walter Vincken Journal: Eur Respir J Date: 2015-11-19 Impact factor: 16.671
Authors: Sanja Stanojevic; Brian L Graham; Brendan G Cooper; Bruce R Thompson; Kim W Carter; Richard W Francis; Graham L Hall Journal: Eur Respir J Date: 2017-09-11 Impact factor: 16.671
Authors: Carlos Gutierrez; R Heberto Ghezzo; Raja T Abboud; Manuel G Cosio; John R Dill; Richard R Martin; Dan S McCarthy; John L C Morse; Noe Zamel Journal: Can Respir J Date: 2004-09 Impact factor: 2.409