Six-minute walk distance predictors, including CT scan measures, in the COPDGene cohort

Mehdi Rambod; Janos Porszasz; Barry J. Make; James D. Crapo; Richard Casaburi; Jeffrey Curtis; Ella Kazerooni; Nicola Hanania; Philip Alapat; Venkata Bandi; Kalpalatha Guntupalli; Elizabeth Guy; Antara Mallampalli; Charles Trinh; Hasan Al-Azzawi; Mustafa Atik; Dawn DeMeo; Craig Hersh; George Washko; Francine Jacobson; R. Graham Barr; Byron Thomashow; John Austin; Neil MacIntyre; Lacey Washington; H. Page McAdams; Richard Rosiello; Timothy Bresnahan; Charlene McEvoy; Joseph Tashjian; Robert Wise; Nadia Hansel; Robert Brown; Gregory Diette; Hans Fischer; Matthew J. Budoff; Amir Sharafkhaneh; Hirani Kamal; Roham Darvishi; Dennis Niewoehner; Tadashi Allen; Quentin Anderson; Kathryn Rice; Marilyn Foreman; Gloria Westney; Eugene Berkowitz; Russell Bowler; Adam Friedlander; David Lynch; Joyce Schroeder; John Newell; Gerard Criner; Victor Kim; Nathaniel Marchetti; Aditi Satti; A. James Mamary; Robert Steiner; Chandra Dass; William Bailey; Mark Dransfield; Hrudaya Nath; Joe Ramsdell; Paul Friedman; Dwight Look; Geoffrey McLennan; Edwin J.R. Van Beek; Brad Thompson; Fernando Martinez; Mei Lan Han; Christine Wendt; Frank Sciurba; Joel Weissfeld; Carl Fuhrman; Jessica Bon; Antonio Anzueto; Sandra Adams; Carlos Orozco; Mario Ruiz; Edwin Silverman; Elizabeth Regan; Sarah Moyle; Lori Stepp; Rochelle Lantz; Terri Beaty; Barbara Klanderman; Nan Laird; Christoph Lange; Michael Cho; Stephanie Santorico; John Hokanson; Jacqueline Hetmanski; Tanda Murray; John Reilly; Harvey Coxson; Philip Judy; Eric Hoffman; Raul San Jose Estepar; James Ross; Rebecca Leek; Jordan Zach; Alex Kluiber; Jered Sieren; Heather Baumhauer; Verity McArthur; Demitry Kazlouski; Deanna Richert; Tom Gethin-Jones; Andrew Allen; Tanya Mann; Anastasia Rodionova; Douglas Stinson; Robert Jensen; Homayoon Farzadegan; Stacey Meyerer; Shivam Chandan; Samantha Bragan; James Murphy; Douglas Everett; Carla Wilson; Ruthie Knowles; Amber Powell; Joe Piccoli; Maura Robinson; Margaret Forbes; Martina Wamboldt; Marci Sontag; Jennifer Black-Shinn; Gregory Kinney

doi:10.1378/chest.11-0870

Six-minute walk distance predictors, including CT scan measures, in the COPDGene cohort

Mehdi Rambod, Janos Porszasz, Barry J. Make, James D. Crapo, Richard Casaburi, Jeffrey Curtis, Ella Kazerooni, Nicola Hanania, Philip Alapat, Venkata Bandi, Kalpalatha Guntupalli, Elizabeth Guy, Antara Mallampalli, Charles Trinh, Hasan Al-Azzawi, Mustafa Atik, Dawn DeMeo, Craig Hersh, George Washko, Francine JacobsonR. Graham Barr, Byron Thomashow, John Austin, Neil MacIntyre, Lacey Washington, H. Page McAdams, Richard Rosiello, Timothy Bresnahan, Charlene McEvoy, Joseph Tashjian, Robert Wise, Nadia Hansel, Robert Brown, Gregory Diette, Hans Fischer, Matthew J. Budoff, Amir Sharafkhaneh, Hirani Kamal, Roham Darvishi, Dennis Niewoehner, Tadashi Allen, Quentin Anderson, Kathryn Rice, Marilyn Foreman, Gloria Westney, Eugene Berkowitz, Russell Bowler, Adam Friedlander, David Lynch, Joyce Schroeder, John Newell, Gerard Criner, Victor Kim, Nathaniel Marchetti, Aditi Satti, A. James Mamary, Robert Steiner, Chandra Dass, William Bailey, Mark Dransfield, Hrudaya Nath, Joe Ramsdell, Paul Friedman, Dwight Look, Geoffrey McLennan, Edwin J.R. Van Beek, Brad Thompson, Fernando Martinez, Mei Lan Han, Christine Wendt, Frank Sciurba, Joel Weissfeld, Carl Fuhrman, Jessica Bon, Antonio Anzueto, Sandra Adams, Carlos Orozco, Mario Ruiz, Edwin Silverman, Elizabeth Regan, Sarah Moyle, Lori Stepp, Rochelle Lantz, Terri Beaty, Barbara Klanderman, Nan Laird, Christoph Lange, Michael Cho, Stephanie Santorico, John Hokanson, Jacqueline Hetmanski, Tanda Murray, John Reilly, Harvey Coxson, Philip Judy, Eric Hoffman, Raul San Jose Estepar, James Ross, Rebecca Leek, Jordan Zach, Alex Kluiber, Jered Sieren, Heather Baumhauer, Verity McArthur, Demitry Kazlouski, Deanna Richert, Tom Gethin-Jones, Andrew Allen, Tanya Mann, Anastasia Rodionova, Douglas Stinson, Robert Jensen, Homayoon Farzadegan, Stacey Meyerer, Shivam Chandan, Samantha Bragan, James Murphy, Douglas Everett, Carla Wilson, Ruthie Knowles, Amber Powell, Joe Piccoli, Maura Robinson, Margaret Forbes, Martina Wamboldt, Marci Sontag, Jennifer Black-Shinn, Gregory Kinney

Research output: Contribution to journal › Article › peer-review

29 Scopus citations

Abstract

Background: Exercise tolerance in COPD is only moderately well predicted by airflow obstruction assessed by FEV₁. We determined whether other phenotypic characteristics, including CT scan measures, are independent predictors of 6-min walk distance (6MWD) in the COPDGene cohort. Methods: COPDGene recruits non-Hispanic Caucasian and African American current and ex-smokers. Phenotyping measures include postbronchodilator FEV₁ % predicted and inspiratory and expiratory CT lung scans. We defined % emphysema as the percentage of lung voxels, < -950 Hounsfield units on the inspiratory scan and % gas trapping as the percentage of lung voxels, < -856 Hounsfield units on the expiratory scan. Results: Data of the first 2,500 participants of the COPDGene cohort were analyzed. Participant age was 61 ± 9 years; 51% were men; 76% were non-Hispanic Caucasians, and 24% were African Americans. Fifty-six percent had spirometrically defined COPD, with 9.3%, 23.4%, 15.0%, and 8.3% in GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages I to IV, respectively. Higher % emphysema and % gas trapping predicted lower 6MWD (P <.001). However, in a given spirometric group, after adjustment for age, sex, race, and BMI, neither % emphysema nor % gas trapping, or their interactions with FEV 1% predicted, remained a significant 6MWD predictor. In a given spirometric group, only 16% to 27% of the variance in 6MWD could be explained by age, male sex, Caucasian race, and lower BMI as significant predictors of higher 6MWD. Conclusions: In this large cohort of smokers in a given spirometric stage, phenotypic characteristics were only modestly predictive of 6MWD. CT scan measures of emphysema and gas trapping were not predictive of 6MWD after adjustment for other phenotypic characteristics.

Original language	English (US)
Pages (from-to)	867-875
Number of pages	9
Journal	CHEST
Volume	141
Issue number	4
DOIs	https://doi.org/10.1378/chest.11-0870
State	Published - Apr 2012

ASJC Scopus subject areas

Pulmonary and Respiratory Medicine
Critical Care and Intensive Care Medicine
Cardiology and Cardiovascular Medicine

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10.1378/chest.11-0870

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Rambod, M., Porszasz, J., Make, B. J., Crapo, J. D., Casaburi, R., Curtis, J., Kazerooni, E., Hanania, N., Alapat, P., Bandi, V., Guntupalli, K., Guy, E., Mallampalli, A., Trinh, C., Al-Azzawi, H., Atik, M., DeMeo, D., Hersh, C., Washko, G., ... Kinney, G. (2012). Six-minute walk distance predictors, including CT scan measures, in the COPDGene cohort. CHEST, 141(4), 867-875. https://doi.org/10.1378/chest.11-0870

Rambod, M, Porszasz, J, Make, BJ, Crapo, JD, Casaburi, R, Curtis, J, Kazerooni, E, Hanania, N, Alapat, P, Bandi, V, Guntupalli, K, Guy, E, Mallampalli, A, Trinh, C, Al-Azzawi, H, Atik, M, DeMeo, D, Hersh, C, Washko, G, Jacobson, F, Barr, RG, Thomashow, B, Austin, J, MacIntyre, N, Washington, L, McAdams, HP, Rosiello, R, Bresnahan, T, McEvoy, C, Tashjian, J, Wise, R , Hansel, N , Brown, R , Diette, G, Fischer, H, Budoff, MJ, Sharafkhaneh, A, Kamal, H, Darvishi, R, Niewoehner, D, Allen, T, Anderson, Q, Rice, K, Foreman, M, Westney, G, Berkowitz, E, Bowler, R, Friedlander, A, Lynch, D, Schroeder, J, Newell, J, Criner, G, Kim, V, Marchetti, N, Satti, A, Mamary, AJ, Steiner, R, Dass, C, Bailey, W, Dransfield, M, Nath, H, Ramsdell, J, Friedman, P, Look, D, McLennan, G, Van Beek, EJR, Thompson, B, Martinez, F, Han, ML, Wendt, C, Sciurba, F, Weissfeld, J, Fuhrman, C, Bon, J, Anzueto, A, Adams, S, Orozco, C, Ruiz, M, Silverman, E, Regan, E, Moyle, S, Stepp, L, Lantz, R, Beaty, T, Klanderman, B, Laird, N, Lange, C, Cho, M, Santorico, S, Hokanson, J, Hetmanski, J, Murray, T, Reilly, J, Coxson, H, Judy, P, Hoffman, E, Estepar, RSJ, Ross, J, Leek, R, Zach, J, Kluiber, A, Sieren, J, Baumhauer, H, McArthur, V, Kazlouski, D, Richert, D, Gethin-Jones, T, Allen, A, Mann, T, Rodionova, A, Stinson, D, Jensen, R, Farzadegan, H, Meyerer, S, Chandan, S, Bragan, S, Murphy, J, Everett, D, Wilson, C, Knowles, R, Powell, A, Piccoli, J, Robinson, M, Forbes, M, Wamboldt, M, Sontag, M, Black-Shinn, J & Kinney, G 2012, 'Six-minute walk distance predictors, including CT scan measures, in the COPDGene cohort', CHEST, vol. 141, no. 4, pp. 867-875. https://doi.org/10.1378/chest.11-0870

@article{6c08f263b3e5419aa447ad0e3bf2da79,

title = "Six-minute walk distance predictors, including CT scan measures, in the COPDGene cohort",

abstract = "Background: Exercise tolerance in COPD is only moderately well predicted by airflow obstruction assessed by FEV1. We determined whether other phenotypic characteristics, including CT scan measures, are independent predictors of 6-min walk distance (6MWD) in the COPDGene cohort. Methods: COPDGene recruits non-Hispanic Caucasian and African American current and ex-smokers. Phenotyping measures include postbronchodilator FEV1 % predicted and inspiratory and expiratory CT lung scans. We defined % emphysema as the percentage of lung voxels, < -950 Hounsfield units on the inspiratory scan and % gas trapping as the percentage of lung voxels, < -856 Hounsfield units on the expiratory scan. Results: Data of the first 2,500 participants of the COPDGene cohort were analyzed. Participant age was 61 ± 9 years; 51% were men; 76% were non-Hispanic Caucasians, and 24% were African Americans. Fifty-six percent had spirometrically defined COPD, with 9.3%, 23.4%, 15.0%, and 8.3% in GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages I to IV, respectively. Higher % emphysema and % gas trapping predicted lower 6MWD (P <.001). However, in a given spirometric group, after adjustment for age, sex, race, and BMI, neither % emphysema nor % gas trapping, or their interactions with FEV 1% predicted, remained a significant 6MWD predictor. In a given spirometric group, only 16% to 27% of the variance in 6MWD could be explained by age, male sex, Caucasian race, and lower BMI as significant predictors of higher 6MWD. Conclusions: In this large cohort of smokers in a given spirometric stage, phenotypic characteristics were only modestly predictive of 6MWD. CT scan measures of emphysema and gas trapping were not predictive of 6MWD after adjustment for other phenotypic characteristics.",

author = "Mehdi Rambod and Janos Porszasz and Make, {Barry J.} and Crapo, {James D.} and Richard Casaburi and Jeffrey Curtis and Ella Kazerooni and Nicola Hanania and Philip Alapat and Venkata Bandi and Kalpalatha Guntupalli and Elizabeth Guy and Antara Mallampalli and Charles Trinh and Hasan Al-Azzawi and Mustafa Atik and Dawn DeMeo and Craig Hersh and George Washko and Francine Jacobson and Barr, {R. Graham} and Byron Thomashow and John Austin and Neil MacIntyre and Lacey Washington and McAdams, {H. Page} and Richard Rosiello and Timothy Bresnahan and Charlene McEvoy and Joseph Tashjian and Robert Wise and Nadia Hansel and Robert Brown and Gregory Diette and Hans Fischer and Budoff, {Matthew J.} and Amir Sharafkhaneh and Hirani Kamal and Roham Darvishi and Dennis Niewoehner and Tadashi Allen and Quentin Anderson and Kathryn Rice and Marilyn Foreman and Gloria Westney and Eugene Berkowitz and Russell Bowler and Adam Friedlander and David Lynch and Joyce Schroeder and John Newell and Gerard Criner and Victor Kim and Nathaniel Marchetti and Aditi Satti and Mamary, {A. James} and Robert Steiner and Chandra Dass and William Bailey and Mark Dransfield and Hrudaya Nath and Joe Ramsdell and Paul Friedman and Dwight Look and Geoffrey McLennan and {Van Beek}, {Edwin J.R.} and Brad Thompson and Fernando Martinez and Han, {Mei Lan} and Christine Wendt and Frank Sciurba and Joel Weissfeld and Carl Fuhrman and Jessica Bon and Antonio Anzueto and Sandra Adams and Carlos Orozco and Mario Ruiz and Edwin Silverman and Elizabeth Regan and Sarah Moyle and Lori Stepp and Rochelle Lantz and Terri Beaty and Barbara Klanderman and Nan Laird and Christoph Lange and Michael Cho and Stephanie Santorico and John Hokanson and Jacqueline Hetmanski and Tanda Murray and John Reilly and Harvey Coxson and Philip Judy and Eric Hoffman and Estepar, {Raul San Jose} and James Ross and Rebecca Leek and Jordan Zach and Alex Kluiber and Jered Sieren and Heather Baumhauer and Verity McArthur and Demitry Kazlouski and Deanna Richert and Tom Gethin-Jones and Andrew Allen and Tanya Mann and Anastasia Rodionova and Douglas Stinson and Robert Jensen and Homayoon Farzadegan and Stacey Meyerer and Shivam Chandan and Samantha Bragan and James Murphy and Douglas Everett and Carla Wilson and Ruthie Knowles and Amber Powell and Joe Piccoli and Maura Robinson and Margaret Forbes and Martina Wamboldt and Marci Sontag and Jennifer Black-Shinn and Gregory Kinney",

note = "Funding Information: Financial/nonfinancial disclosures: The authors have reported to CHEST the following conflicts of interest: Dr Porszasz is a consultant with Forest Laboratories, Inc; Novartis Pharmaceuticals Corporation; and Boehringer Ingelheim GmbH. Dr Make has received grant funds (controlled by National Jewish Health) from and participated in advisory boards or has been a speaker for the National Heart, Lung, and Blood Institute; Abbott Laboratories; AstraZeneca; Dey Pharma, LP; Forest Laboratories, Inc; MedImmune, LLC; Merck and Company; Novartis Pharmaceuticals Corporation; NycoMed International Management GmbH; Respironics-Philips Healthcare; GlaxoSmithKline plc; Nabi Biopharmaceuticals; Boehringer Ingelheim GmbH; Pfizer Inc; and Synovian Inc. Dr Casaburi has received grant funds (controlled by Los Angeles Biomedical Research Institute) from and participated in advisory boards or has been a speaker for the National Heart, Lung, and Blood Institute; AstraZeneca; Forest Laboratories, Inc; Novartis Pharmaceuticals Corporation; Respironics-Philips Healthcare; Boehringer Ingelheim GmbH; Pfizer Inc; Breath Technologies, Inc; Theratechnologies Inc; F. Hoffman-La Roche Ltd; Osiris Therapeutics Inc; Actelion Pharmaceuticals Ltd; and Bayer Healthcare Pharmaceuticals. Drs Rambod and Crapo have reported that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article. Funding Information: Funding/Support: The project described was supported by the National Heart, Lung, and Blood Institute [U01HL089897 and U01HL089856] . ",

year = "2012",

month = apr,

doi = "10.1378/chest.11-0870",

language = "English (US)",

volume = "141",

pages = "867--875",

journal = "CHEST",

issn = "0012-3692",

publisher = "American College of Chest Physicians",

number = "4",

}

TY - JOUR

T1 - Six-minute walk distance predictors, including CT scan measures, in the COPDGene cohort

AU - Rambod, Mehdi

AU - Porszasz, Janos

AU - Make, Barry J.

AU - Crapo, James D.

AU - Casaburi, Richard

AU - Curtis, Jeffrey

AU - Kazerooni, Ella

AU - Hanania, Nicola

AU - Alapat, Philip

AU - Bandi, Venkata

AU - Guntupalli, Kalpalatha

AU - Guy, Elizabeth

AU - Mallampalli, Antara

AU - Trinh, Charles

AU - Al-Azzawi, Hasan

AU - Atik, Mustafa

AU - DeMeo, Dawn

AU - Hersh, Craig

AU - Washko, George

AU - Jacobson, Francine

AU - Barr, R. Graham

AU - Thomashow, Byron

AU - Austin, John

AU - MacIntyre, Neil

AU - Washington, Lacey

AU - McAdams, H. Page

AU - Rosiello, Richard

AU - Bresnahan, Timothy

AU - McEvoy, Charlene

AU - Tashjian, Joseph

AU - Wise, Robert

AU - Hansel, Nadia

AU - Brown, Robert

AU - Diette, Gregory

AU - Fischer, Hans

AU - Budoff, Matthew J.

AU - Sharafkhaneh, Amir

AU - Kamal, Hirani

AU - Darvishi, Roham

AU - Niewoehner, Dennis

AU - Allen, Tadashi

AU - Anderson, Quentin

AU - Rice, Kathryn

AU - Foreman, Marilyn

AU - Westney, Gloria

AU - Berkowitz, Eugene

AU - Bowler, Russell

AU - Friedlander, Adam

AU - Lynch, David

AU - Schroeder, Joyce

AU - Newell, John

AU - Criner, Gerard

AU - Kim, Victor

AU - Marchetti, Nathaniel

AU - Satti, Aditi

AU - Mamary, A. James

AU - Steiner, Robert

AU - Dass, Chandra

AU - Bailey, William

AU - Dransfield, Mark

AU - Nath, Hrudaya

AU - Ramsdell, Joe

AU - Friedman, Paul

AU - Look, Dwight

AU - McLennan, Geoffrey

AU - Van Beek, Edwin J.R.

AU - Thompson, Brad

AU - Martinez, Fernando

AU - Han, Mei Lan

AU - Wendt, Christine

AU - Sciurba, Frank

AU - Weissfeld, Joel

AU - Fuhrman, Carl

AU - Bon, Jessica

AU - Anzueto, Antonio

AU - Adams, Sandra

AU - Orozco, Carlos

AU - Ruiz, Mario

AU - Silverman, Edwin

AU - Regan, Elizabeth

AU - Moyle, Sarah

AU - Stepp, Lori

AU - Lantz, Rochelle

AU - Beaty, Terri

AU - Klanderman, Barbara

AU - Laird, Nan

AU - Lange, Christoph

AU - Cho, Michael

AU - Santorico, Stephanie

AU - Hokanson, John

AU - Hetmanski, Jacqueline

AU - Murray, Tanda

AU - Reilly, John

AU - Coxson, Harvey

AU - Judy, Philip

AU - Hoffman, Eric

AU - Estepar, Raul San Jose

AU - Ross, James

AU - Leek, Rebecca

AU - Zach, Jordan

AU - Kluiber, Alex

AU - Sieren, Jered

AU - Baumhauer, Heather

AU - McArthur, Verity

AU - Kazlouski, Demitry

AU - Richert, Deanna

AU - Gethin-Jones, Tom

AU - Allen, Andrew

AU - Mann, Tanya

AU - Rodionova, Anastasia

AU - Stinson, Douglas

AU - Jensen, Robert

AU - Farzadegan, Homayoon

AU - Meyerer, Stacey

AU - Chandan, Shivam

AU - Bragan, Samantha

AU - Murphy, James

AU - Everett, Douglas

AU - Wilson, Carla

AU - Knowles, Ruthie

AU - Powell, Amber

AU - Piccoli, Joe

AU - Robinson, Maura

AU - Forbes, Margaret

AU - Wamboldt, Martina

AU - Sontag, Marci

AU - Black-Shinn, Jennifer

AU - Kinney, Gregory

N1 - Funding Information: Financial/nonfinancial disclosures: The authors have reported to CHEST the following conflicts of interest: Dr Porszasz is a consultant with Forest Laboratories, Inc; Novartis Pharmaceuticals Corporation; and Boehringer Ingelheim GmbH. Dr Make has received grant funds (controlled by National Jewish Health) from and participated in advisory boards or has been a speaker for the National Heart, Lung, and Blood Institute; Abbott Laboratories; AstraZeneca; Dey Pharma, LP; Forest Laboratories, Inc; MedImmune, LLC; Merck and Company; Novartis Pharmaceuticals Corporation; NycoMed International Management GmbH; Respironics-Philips Healthcare; GlaxoSmithKline plc; Nabi Biopharmaceuticals; Boehringer Ingelheim GmbH; Pfizer Inc; and Synovian Inc. Dr Casaburi has received grant funds (controlled by Los Angeles Biomedical Research Institute) from and participated in advisory boards or has been a speaker for the National Heart, Lung, and Blood Institute; AstraZeneca; Forest Laboratories, Inc; Novartis Pharmaceuticals Corporation; Respironics-Philips Healthcare; Boehringer Ingelheim GmbH; Pfizer Inc; Breath Technologies, Inc; Theratechnologies Inc; F. Hoffman-La Roche Ltd; Osiris Therapeutics Inc; Actelion Pharmaceuticals Ltd; and Bayer Healthcare Pharmaceuticals. Drs Rambod and Crapo have reported that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article. Funding Information: Funding/Support: The project described was supported by the National Heart, Lung, and Blood Institute [U01HL089897 and U01HL089856] .

PY - 2012/4

Y1 - 2012/4

N2 - Background: Exercise tolerance in COPD is only moderately well predicted by airflow obstruction assessed by FEV1. We determined whether other phenotypic characteristics, including CT scan measures, are independent predictors of 6-min walk distance (6MWD) in the COPDGene cohort. Methods: COPDGene recruits non-Hispanic Caucasian and African American current and ex-smokers. Phenotyping measures include postbronchodilator FEV1 % predicted and inspiratory and expiratory CT lung scans. We defined % emphysema as the percentage of lung voxels, < -950 Hounsfield units on the inspiratory scan and % gas trapping as the percentage of lung voxels, < -856 Hounsfield units on the expiratory scan. Results: Data of the first 2,500 participants of the COPDGene cohort were analyzed. Participant age was 61 ± 9 years; 51% were men; 76% were non-Hispanic Caucasians, and 24% were African Americans. Fifty-six percent had spirometrically defined COPD, with 9.3%, 23.4%, 15.0%, and 8.3% in GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages I to IV, respectively. Higher % emphysema and % gas trapping predicted lower 6MWD (P <.001). However, in a given spirometric group, after adjustment for age, sex, race, and BMI, neither % emphysema nor % gas trapping, or their interactions with FEV 1% predicted, remained a significant 6MWD predictor. In a given spirometric group, only 16% to 27% of the variance in 6MWD could be explained by age, male sex, Caucasian race, and lower BMI as significant predictors of higher 6MWD. Conclusions: In this large cohort of smokers in a given spirometric stage, phenotypic characteristics were only modestly predictive of 6MWD. CT scan measures of emphysema and gas trapping were not predictive of 6MWD after adjustment for other phenotypic characteristics.

AB - Background: Exercise tolerance in COPD is only moderately well predicted by airflow obstruction assessed by FEV1. We determined whether other phenotypic characteristics, including CT scan measures, are independent predictors of 6-min walk distance (6MWD) in the COPDGene cohort. Methods: COPDGene recruits non-Hispanic Caucasian and African American current and ex-smokers. Phenotyping measures include postbronchodilator FEV1 % predicted and inspiratory and expiratory CT lung scans. We defined % emphysema as the percentage of lung voxels, < -950 Hounsfield units on the inspiratory scan and % gas trapping as the percentage of lung voxels, < -856 Hounsfield units on the expiratory scan. Results: Data of the first 2,500 participants of the COPDGene cohort were analyzed. Participant age was 61 ± 9 years; 51% were men; 76% were non-Hispanic Caucasians, and 24% were African Americans. Fifty-six percent had spirometrically defined COPD, with 9.3%, 23.4%, 15.0%, and 8.3% in GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages I to IV, respectively. Higher % emphysema and % gas trapping predicted lower 6MWD (P <.001). However, in a given spirometric group, after adjustment for age, sex, race, and BMI, neither % emphysema nor % gas trapping, or their interactions with FEV 1% predicted, remained a significant 6MWD predictor. In a given spirometric group, only 16% to 27% of the variance in 6MWD could be explained by age, male sex, Caucasian race, and lower BMI as significant predictors of higher 6MWD. Conclusions: In this large cohort of smokers in a given spirometric stage, phenotypic characteristics were only modestly predictive of 6MWD. CT scan measures of emphysema and gas trapping were not predictive of 6MWD after adjustment for other phenotypic characteristics.

UR - http://www.scopus.com/inward/record.url?scp=84859498901&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84859498901&partnerID=8YFLogxK

U2 - 10.1378/chest.11-0870

DO - 10.1378/chest.11-0870

M3 - Article

C2 - 21960696

AN - SCOPUS:84859498901

SN - 0012-3692

VL - 141

SP - 867

EP - 875

JO - CHEST

JF - CHEST

IS - 4

ER -

Six-minute walk distance predictors, including CT scan measures, in the COPDGene cohort

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