Validity of A-STEP as a surrogate VO2Max using CPET Cycle Ergometry in Adults with Cystic Fibrosis

Validity of A-STEP as a surrogate VO2Max using CPET Cycle Ergometry in Adults with Cystic Fibrosis | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 18 June 2025 V1 Latest version Share on Validity of A-STEP as a surrogate VO2Max using CPET Cycle Ergometry in Adults with Cystic Fibrosis Authors : Brenda Button 0000-0002-3044-8872 [email protected] , Mahesh Dharmakumara , Lisa Wilson 0000-0003-2663-1049 , Nic Parry , Brigitte Borg , and Dominic Keating T Authors Info & Affiliations https://doi.org/10.22541/au.175025000.07269627/v1 182 views 68 downloads Contents Abstract Supplementary Material Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract not-yet-known not-yet-known not-yet-known unknown Background The Alfred Step Test Protocol (A-STEP) and feasibly study were previously published. The aim here was to determine the validity of the A-STEP compared to cycle ergometry (CPET) in adults with CF. Methods The A-STEP and CPET were carried out in random order two weeks apart. A wearable, portable metabolic system was used to measure breath-by-breath and minute-by-minute sampling of O 2, CO 2, heart rate and measurement of VO 2. The main outcome measures were VO 2max and HRmax. Results Seven stable state adults (3 male) on CFTR modulator therapy with a mean(SD) and range of : age 38.2(13.4) 26–64 years; height 169.9 (10.9) 149.7-185.3 cm; BMI 22.8 (2.10) 19.5-28 kg/m 2; FEV 1 79.4 (18.9) 38.0-106.0; and FVC 95.1 (16.7) 63.0-114.0 percent predicted (pp) completed both A-STEP and CPET. The VO 2Max had high correlation and good agreement between the A-STEP 31.3 (5.9) and CPET 29.8 (6.2) mL/min/kg, r=0.88. The HR MAX was strongly correlated with the A-STEP 174 (17) bpm and 95.7 (7.4)pp versus 168 (15) bpm and 92.4 (5.3)pp with r=0.92 and 0.86 respectively. The SpO 2Nadir for A-STEP was 91.0 (4.0) and CPET 92.0 (3.3), r=0.82. The VO 2@AT occurred significantly earlier for the CPET at 1021 (260) versus A-STEP 1361 (234) minutes, p<0.05. The VE Max for CPET was 84.1 (18.8) and A-STEP 73.5 (15.8) L/minute, p<0.05. The AWESCORE also ensured baseline stability. The number of levels completed during the A-STEP was 10.7 (12.9) range 9–15. Conclusion The A-STEP is a portable valid surrogate incremental maximal step test to CPET using cycle ergometry. Supplementary Material File (a_step_validity_cpet_manuscript_tables_figs.docx) Download 100.05 KB Information & Authors Information Version history V1 Version 1 18 June 2025 Copyright This work is licensed under a Non Exclusive No Reuse License. Keyword vo2max step-ergometry cycle-ergometry cystic fibrosis incremental Authors Affiliations Brenda Button 0000-0002-3044-8872 [email protected] Alfred Health View all articles by this author Mahesh Dharmakumara Alfred Health View all articles by this author Lisa Wilson 0000-0003-2663-1049 Alfred Health View all articles by this author Nic Parry Alfred Health View all articles by this author Brigitte Borg Alfred Health View all articles by this author Dominic Keating T Alfred Health View all articles by this author Metrics & Citations Metrics Article Usage 182 views 68 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Brenda Button, Mahesh Dharmakumara, Lisa Wilson, et al. Validity of A-STEP as a surrogate VO2Max using CPET Cycle Ergometry in Adults with Cystic Fibrosis. Authorea . 18 June 2025. 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