{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,29]],"date-time":"2026-08-29T03:06:44Z","timestamp":1787972804452,"version":"build-2784847793"},"reference-count":42,"publisher":"BMJ","issue":"1","license":[{"start":{"date-parts":[[2024,10,14]],"date-time":"2024-10-14T00:00:00Z","timestamp":1728864000000},"content-version":"unspecified","delay-in-days":13,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open Resp Res"],"accepted":{"date-parts":[[2024,9,11]]},"published-print":{"date-parts":[[2024,10]]},"abstract":"<jats:sec>\n                  <jats:title>Objectives<\/jats:title>\n                  <jats:p>This study aimed to evaluate pulmonary diffusing capacity for nitric oxide (DLNO) and pulmonary diffusing capacity for carbon monoxide (DLCO) in Mexican Hispanics born and raised at 2240 m altitude (midlanders) compared with those born and raised at sea level (lowlanders). It also aimed to assess the effectiveness of race-specific reference equations for pulmonary diffusing capacity (white people vs Mexican Hispanics) in minimising root mean square errors (RMSE) compared with race-neutral equations.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>DLNO, DLCO, alveolar volume (VA) and gas transfer coefficients (KNO and KCO) were measured in 392 Mexican Hispanics (5 to 78 years) and compared with 1056 white subjects (5 to 95 years). Reference equations were developed using segmented linear regression (DLNO, DLCO and VA) and multiple linear regression (KNO and KCO) and validated with Least Absolute Shrinkage and Selection Operator. RMSE comparisons between race-specific and race-neutral models were conducted using repeated k-fold cross-validation and random forests.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Midlanders exhibited higher DLCO (mean difference: +4 mL\/min\/mm Hg), DLNO (mean difference: +7 mL\/min\/mm Hg) and VA (mean difference: +0.17 L) compared with lowlanders. The Bayesian information criterion favoured race-specific models and excluding race as a covariate increased RMSE by 61% (DLNO), 18% (DLCO) and 4% (KNO). RMSE values for VA and KCO were comparable between race-specific and race-neutral models. For DLCO and DLNO, race-neutral equations resulted in 3% to 6% false positive rates (FPRs) in Mexican Hispanics and 20% to 49% false negative rates (FNRs) in white subjects compared with race-specific equations.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Mexican Hispanics born and raised at 2240 m exhibit higher DLCO and DLNO compared with lowlanders. Including race as a covariate in reference equations lowers the RMSE for DLNO, DLCO and KNO and reduces FPR and FNR compared with race-neutral models. This study highlights the need for altitude-specific and race-specific reference equations to improve pulmonary function assessments across diverse populations.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjresp-2024-002341","type":"journal-article","created":{"date-parts":[[2024,10,14]],"date-time":"2024-10-14T22:50:28Z","timestamp":1728946228000},"page":"e002341","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":10,"title":["Reference equations for DLNO and DLCO in Mexican Hispanics: influence of altitude and race"],"prefix":"10.1136","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3009-5867","authenticated-orcid":false,"given":"Laura","family":"Gochicoa-Rangel","sequence":"first","affiliation":[{"name":"Instituto Nacional de Enfermedades Respiratorias Ismael Cos\u00edo Villegas, Mexico City, Mexico"},{"name":"Instituto de Desarrollo e Innovaci\u00f3n en Fisiolog\u00eda Respiratoria, Mexico City, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-5553-7330","authenticated-orcid":false,"given":"Ada","family":"De-Los-Santos-Mart\u00ednez","sequence":"additional","affiliation":[{"name":"Instituto Nacional de Enfermedades Respiratorias Ismael Cos\u00edo Villegas, Mexico City, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-0044-9978","authenticated-orcid":false,"given":"Alejandro","family":"Reyes-Garc\u00eda","sequence":"additional","affiliation":[{"name":"Instituto Nacional de Enfermedades Respiratorias Ismael Cos\u00edo Villegas, Mexico City, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8613-2658","authenticated-orcid":false,"given":"David","family":"Mart\u00ednez-Brise\u00f1o","sequence":"additional","affiliation":[{"name":"Instituto Nacional de Enfermedades Respiratorias Ismael Cos\u00edo Villegas, Mexico City, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8420-980X","authenticated-orcid":false,"given":"Mario H","family":"Vargas","sequence":"additional","affiliation":[{"name":"Instituto Nacional de Enfermedades Respiratorias Ismael Cos\u00edo Villegas, Mexico City, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1296-6115","authenticated-orcid":false,"given":"Irma","family":"Lechuga-Trejo","sequence":"additional","affiliation":[{"name":"Instituto Nacional de Enfermedades Respiratorias Ismael Cos\u00edo Villegas, Mexico City, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlos","family":"Guzm\u00e1n-Valderr\u00e1bano","sequence":"additional","affiliation":[{"name":"Instituto Nacional de Enfermedades Respiratorias Ismael Cos\u00edo Villegas, Mexico City, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2183-7662","authenticated-orcid":false,"given":"Luis","family":"Torre-Bouscoulet","sequence":"additional","affiliation":[{"name":"Instituto de Desarrollo e Innovaci\u00f3n en Fisiolog\u00eda Respiratoria, Mexico City, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4473-1601","authenticated-orcid":false,"given":"Gerald Stanley","family":"Zavorsky","sequence":"additional","affiliation":[{"name":"Department of Physiology and Membrane Biology, University of California-Davis, Davis, California, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2024,10,14]]},"reference":[{"key":"2025083110444223000_11.1.e002341.1","doi-asserted-by":"crossref","DOI":"10.1001\/jamanetworkopen.2023.16174","article-title":"Global, Race-Neutral Reference Equations and Pulmonary Function Test Interpretation","volume":"6","author":"Moffett","year":"2023","journal-title":"JAMA Netw Open"},{"key":"2025083110444223000_11.1.e002341.2","doi-asserted-by":"publisher","DOI":"10.1164\/rccm.202302-0310ST"},{"key":"2025083110444223000_11.1.e002341.3","doi-asserted-by":"crossref","first-page":"768","DOI":"10.1164\/rccm.202205-0963OC","article-title":"A Race-neutral Approach to the Interpretation of Lung Function Measurements","volume":"207","author":"Bowerman","year":"2023","journal-title":"Am J Respir Crit Care Med"},{"key":"2025083110444223000_11.1.e002341.4","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kwq417"},{"key":"2025083110444223000_11.1.e002341.5","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.00080312"},{"key":"2025083110444223000_11.1.e002341.6","doi-asserted-by":"publisher","DOI":"10.1164\/ajrccm.153.2.8564114"},{"key":"2025083110444223000_11.1.e002341.7","doi-asserted-by":"crossref","DOI":"10.1186\/s12890-021-01591-7","article-title":"The need for race-specific reference equations for pulmonary diffusing capacity for nitric oxide","volume":"21","author":"Zavorsky","year":"2021","journal-title":"BMC Pulm Med"},{"key":"2025083110444223000_11.1.e002341.8","doi-asserted-by":"publisher","DOI":"10.1159\/000080633"},{"key":"2025083110444223000_11.1.e002341.9","doi-asserted-by":"crossref","DOI":"10.1183\/13993003.00962-2016","article-title":"Standardisation and application of the single-breath determination of nitric oxide uptake in the lung","volume":"49","author":"Zavorsky","year":"2017","journal-title":"Eur Respir J"},{"key":"2025083110444223000_11.1.e002341.10","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.resp.2016.11.008","article-title":"Can the measurement of pulmonary diffusing capacity for nitric oxide replace the measurement of pulmonary diffusing capacity for carbon monoxide?","volume":"241","author":"Zavorsky","year":"2017","journal-title":"Respir Physiol Neurobiol"},{"key":"2025083110444223000_11.1.e002341.11","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1152\/jappl.1957.11.2.290","article-title":"Relative importance of diffusion and chemical reaction rates in determining rate of exchange of gases in the human lung, with special reference to true diffusing capacity of pulmonary membrane and volume of blood in the lung capillaries","volume":"11","author":"Roughton","year":"1957","journal-title":"J Appl Physiol"},{"key":"2025083110444223000_11.1.e002341.12","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.resp.2016.03.003","article-title":"In vivo estimates of NO and CO conductance for haemoglobin and for lung transfer in humans","volume":"228","author":"Gu\u00e9nard","year":"2016","journal-title":"Respir Physiol Neurobiol"},{"key":"2025083110444223000_11.1.e002341.13","doi-asserted-by":"crossref","DOI":"10.1183\/09031936.93.04060766a","article-title":"NO and CO transfer","volume":"4","author":"Borland","year":"1991","journal-title":"Eur Respir J"},{"key":"2025083110444223000_11.1.e002341.14","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.93.01060573"},{"key":"2025083110444223000_11.1.e002341.15","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1042\/cs0810759","article-title":"Effect of varying alveolar oxygen partial pressure on diffusing capacity for nitric oxide and carbon monoxide, membrane diffusing capacity and lung capillary blood volume","volume":"81","author":"Borland","year":"1991","journal-title":"Clin Sci (Lond)"},{"key":"2025083110444223000_11.1.e002341.16","first-page":"29","article-title":"Arterial Blood Gases in Normal Subjects at 2240 Meters Above Sea Level: Impact of Age, Gender, and Body Mass Index","volume":"75","author":"Cid-Ju\u00e1rez","year":"2023","journal-title":"Rev Invest Clin"},{"key":"2025083110444223000_11.1.e002341.17","unstructured":"CONEVAL . Share of population living in poverty in Mexico in 2020, by state. In: Anexo estad\u00edstico de pobreza en M\u00e9xico\/INEGI. 2021. Available: https:\/\/www.coneval.org.mx\/Medicion\/MP\/Paginas\/AE_pobreza_2020.aspx"},{"key":"2025083110444223000_11.1.e002341.18","doi-asserted-by":"publisher","DOI":"10.1016\/j.niox.2007.10.002"},{"key":"2025083110444223000_11.1.e002341.19","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.00063207"},{"key":"2025083110444223000_11.1.e002341.20","doi-asserted-by":"publisher","DOI":"10.1016\/j.rmed.2006.12.001"},{"key":"2025083110444223000_11.1.e002341.21","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0113177","article-title":"The single-breath diffusing capacity of CO and NO in healthy children of European descent","volume":"9","author":"Thomas","year":"2014","journal-title":"PLoS One"},{"key":"2025083110444223000_11.1.e002341.22","doi-asserted-by":"crossref","DOI":"10.1183\/13993003.00677-2015","article-title":"Reference equations for pulmonary diffusing capacity of carbon monoxide and nitric oxide in adult Caucasians","volume":"52","author":"Munkholm","year":"2018","journal-title":"Eur Respir J"},{"key":"2025083110444223000_11.1.e002341.23","doi-asserted-by":"crossref","DOI":"10.1136\/bmjresp-2021-001087","article-title":"Reference equations for pulmonary diffusing capacity using segmented regression show similar predictive accuracy as GAMLSS models","volume":"9","author":"Zavorsky","year":"2022","journal-title":"BMJ Open Respir Res"},{"key":"2025083110444223000_11.1.e002341.24","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.05.00034805"},{"key":"2025083110444223000_11.1.e002341.25","doi-asserted-by":"crossref","DOI":"10.1183\/23120541.00193-2021","article-title":"Lung diffusing capacity for nitric oxide measured by two commercial devices: a randomised crossover comparison in healthy adults","volume":"7","author":"Radtke","year":"2021","journal-title":"ERJ Open Res"},{"key":"2025083110444223000_11.1.e002341.26","doi-asserted-by":"publisher","DOI":"10.1183\/09031936.06.00146805"},{"key":"2025083110444223000_11.1.e002341.27","doi-asserted-by":"publisher","DOI":"10.1002\/sim.1545"},{"key":"2025083110444223000_11.1.e002341.28","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1214\/aos\/1176344136","article-title":"Estimating the dimension of a model","volume":"6","author":"Schwarz","year":"1978","journal-title":"Ann Statist"},{"key":"2025083110444223000_11.1.e002341.29","doi-asserted-by":"publisher","DOI":"10.2307\/271063"},{"key":"2025083110444223000_11.1.e002341.30","doi-asserted-by":"crossref","first-page":"276","DOI":"10.11613\/BM.2012.031","article-title":"Interrater reliability: the kappa statistic","volume":"22","author":"McHugh","year":"2012","journal-title":"Biochem Med (Zagreb)"},{"key":"2025083110444223000_11.1.e002341.31","doi-asserted-by":"crossref","DOI":"10.1186\/s13040-023-00322-4","article-title":"The Matthews correlation coefficient (MCC) should replace the ROC AUC as the standard metric for assessing binary classification","volume":"16","author":"Chicco","year":"2023","journal-title":"BioData Min"},{"key":"2025083110444223000_11.1.e002341.32","doi-asserted-by":"publisher","DOI":"10.1177\/0748730414553029"},{"key":"2025083110444223000_11.1.e002341.33","unstructured":"Fryar CD , Carroll MD , Gu Q , et al . Anthropometric reference data for children and adults: United States, 2015-2018. Analytical and epidemiological studies. Washington, D.C: National Center for Health Statistics, 2021."},{"key":"2025083110444223000_11.1.e002341.34","doi-asserted-by":"crossref","DOI":"10.1183\/13993003.00010-2017","article-title":"Official ERS technical standards: Global Lung Function Initiative reference values for the carbon monoxide transfer factor for Caucasians","volume":"50","author":"Stanojevic","year":"2017","journal-title":"Eur Respir J"},{"key":"2025083110444223000_11.1.e002341.35","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1513\/AnnalsATS.201712-922OC","article-title":"Diffusing Capacity of the Lung for Carbon Monoxide in Mexican\/Latino Children. Quality Control and Reference Values","volume":"16","author":"Gochicoa-Rangel","year":"2019","journal-title":"Ann Am Thorac Soc"},{"key":"2025083110444223000_11.1.e002341.36","doi-asserted-by":"publisher","DOI":"10.4187\/respcare.04590"},{"key":"2025083110444223000_11.1.e002341.37","first-page":"768","article-title":"Differential ethnic standards for lung functions, or one standard for all?","volume":"65","author":"Myers","year":"1984","journal-title":"S Afr Med J"},{"key":"2025083110444223000_11.1.e002341.38","doi-asserted-by":"publisher","DOI":"10.1164\/ajrccm.164.9.2106075"},{"key":"2025083110444223000_11.1.e002341.39","doi-asserted-by":"crossref","DOI":"10.1016\/S0012-3692(15)31573-7","article-title":"Influence of environmental P-O2 on the growth of the pulmonary gas exchange apparatus","volume":"59","author":"Burri","year":"1971","journal-title":"Chest"},{"key":"2025083110444223000_11.1.e002341.40","doi-asserted-by":"publisher","DOI":"10.1016\/j.resp.2005.02.001"},{"key":"2025083110444223000_11.1.e002341.41","doi-asserted-by":"publisher","DOI":"10.1016\/0034-5687(80)90112-7"},{"key":"2025083110444223000_11.1.e002341.42","doi-asserted-by":"crossref","DOI":"10.1183\/23120541.00644-2023","article-title":"Two is better than one: the double diffusion technique in classifying heart failure","volume":"10","author":"Zavorsky","year":"2024","journal-title":"ERJ Open Res"}],"container-title":["BMJ Open Respiratory Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjresp-2024-002341","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,31]],"date-time":"2025-08-31T17:44:51Z","timestamp":1756662291000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopenrespres.bmj.com\/lookup\/doi\/10.1136\/bmjresp-2024-002341"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10]]},"references-count":42,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2024,10,14]]},"published-print":{"date-parts":[[2024,10]]}},"alternative-id":["10.1136\/bmjresp-2024-002341"],"URL":"https:\/\/doi.org\/10.1136\/bmjresp-2024-002341","relation":{},"ISSN":["2052-4439"],"issn-type":[{"value":"2052-4439","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,10]]}}}