Before PFT results can be reliably interpreted, three factors must be confirmed: (1) the volume-time curve reaches a plateau, and expiration lasts at least six seconds (Figure 2); (2) results of the two best efforts on the PFT are within 0.2 L of each other (Figure 3); and (3) the flow-volume loops are free of artifacts and abnormalities.5 If the patient's efforts yield flattened flow-volume loops, submaximal effort is most likely; however, central or upper airway obstruction should be considered. FEV1/FVC – forced expiratory volume in 1 s divided by forced vital capacity. 2011; 2(4): 39–42. 10.1183/09031936.05.00034805. Comparison between the two groups in VC-FVC was performed using the Mann-Whitney U-test. J Asthma. Effect of increasing maximal aerobic exercise on serum gonadal hormones and alpha-fetoprotein in the luteal phase of professional female soccer players. 2009; 4(1): 7–13. Maximal heart rate (HR) predicted for age was calculated as 220-age [15]. Because expiratory flows are highest when young and decrease with increasing age, there is a relationship between age and expiratory time. On the other hand, measurements of lung volumes, such as the inspiratory capacity (IC), correlate better with patient functional capabilities than do measurements of FEV1[3–5]. Manage cookies/Do not sell my data we use in the preference centre. Am J Respir Crit Care Med. FVC is defined as the volume of air exhaled with maximal forced effort from a maximal inspiration. Hellings PW, Vandekerckhove P, Claeys R, Billen J, Kasran A, Ceuppens JL. There was a significant inverse correlation for the entire group between VC-FVC and peak VO2/kg (r = -0.404; p < 0.001). Correspondence to: Messan Folly, Laboratory of Respiratory, Hormonal and Gerontological Explorations of the Sportsman, National Institute of Youth, Physical Education and Sport (INJEPS), University of Abomey-Calavi, Cotonou, Republic of Benin. 1999, 160: 542-549. http://www.goldcopd.com. thorax.bmj.com. Siroux V, Oryszczyn MP, Paty E et al. The protocol consisted of 3 minutes of rest, 3 minutes of unloaded pedaling, and minute-by-minute increments at a work rate of 5 to 20 W/min. Many studies have documented differing changes in forced vital capacity (FVC) following various intensities and durations of exercise. There was also a direct correlation between FEV1% pred and peak VO2/kg (r = 0.418; p < 0.001). 1982, New York: McGraw-Hill, 1-12. Hanley SP. 2000; 103: 401–6. 1984 Dec; 48(12): 777–8. In summary, we showed that the exacerbation risk did not relate to significant change of either FEV 1 or IC over time, although the results of pulmonary function tests showed significant correlation with symptom and exercise performance indicators. There are many reasons you may need to have your FVC measured, including: 1. 1983; 55(5): 1506–13. Clin Exp Allergy. Background: Progesterone hormone levels increase as a result of different exercise modalities in non-menopausal sportswomen. Keywords: The first issue to consider is why a difference between VC and FVC exists in COPD. Conclusion: Progesterone, a bronchodilator hormone, does not influence the respiratory airway in subjects that are not sensitive to bronchospasm, even though the stress test induces a high level of this hormone. height; age; sex We hypothesized that COPD patients with larger difference between VC and FVC would have lower exercise capacity. O’Donnell DE, Revill SM, Webb KA: Dynamic hyperinflation and exercise intolerance in chronic obstructive pulmonary disease. Eur Respir J. A person who suffers from certain health conditions, such as asthma, may have difficulty … Patients with ALS often undergo repeated routine testing to assess their current level of functioning, predict the rate of disease progression, and ensure timely management of symptoms signaling clinical risk. O’Donnell DE, Guenette JA, Maltais F, Webb KA: Decline of resting inspiratory capacity in COPD. Copyright © 2019 The Author(s). Stephen W. Littleton, in Obesity Hypoventilation Syndrome, 2020. There was also a direct correlation between FEV1 % pred and peak VO2/kg (r = 0.418; p < 0.001) (Figure 3). 10.3109/02770909809075669. Published by Scientific & Academic Publishing. Association between asthma and female sex hormones. Parsons JP. Although VC and FVC are often measured in lung function laboratory, the difference between them has less been evaluated. Patients performed a progressive incremental exercise testing to a symptom-limited maximum on an electronically braked cycle ergometer (ViaSprint, CareFusion, Hoechberg, Germany). Otağ A, Turaçlar T, (CMJ) Ä°O-CMJ, 2011 U. Durand F, Kippelen P, Ceugniet F, Gomez VR, Desnot P, Poulain M, et al. Progesterone increases airway eosinophilia and hyper-responsiveness in a murine model of allergic asthma. They found that FVC/VC ratio decreased significantly with progressing bronchiolitis obliterans stages, which occurred independently of changes in FEV1. Privacy 1968; 99: 130–1. Garcia-Rio F, Lores V, Mediano O, et al: Daily physical activity in patients with chronic obstructive pulmonary disease is mainly associated with dynamic hyperinflation. Asthma in United States Olympic athletes who participated in the 1996 summer games. This finding supports the hypothesis that assessing and predicting outcome in COPD patients by pulmonary function criteria alone is not appropriate and is … FVC – forced vital capacity. A low resting IC reflects pulmonary hyperinflation, which is defined as an abnormally increased lung volume at the end of tidal expiration and is present in moderate to severe COPD due to expiratory flow limitation and destructive changes of emphysema. Ferguson GT: Why does the lung hyperinflate?. Department of Respiratory Medicine, Beijing Friendship Hospital, Capital Medical University, No. Ventilatory reserve is typically assessed as the ratio of peak exercise ventilation to maximal voluntary ventilation. Your respiratory system, of which your lungs are a part, are affected both immediately and in the longer term. Kraemer RR, Heleniak RJ, Tryniecki JL, Kraemer GR, Okazaki NJ, Castracane VD. http://creativecommons.org/licenses/by/4.0/. J Allergy Clin Immunol. VC is similar to the FVC, but the maneuver is not forced and it is performed in a relaxed manner, except near the end-inspiration and end-expiration. Recurrent respiratory failure in premenstrual asthma. You ha… Progesterone was assayed, and FVC and FEV were determined. Once your doctor has determined that you have a lung condition, they will often assess your FEV1/FVC ratio to identify the primary type of condition you may have and, specifically, whether it is restrictive or obstructivein nature. FRC = ERV + RV FRC decreased with exercise because ERV decreased and FRC also decreased 5. Several studies have showed that reduction in resting IC or dynamic IC constrains tidal volume expansion during exercise and contributes importantly to reduced exercise performance in patients with COPD [6, 7, 9, 10]. Respir Med. Am J Respir Crit Care Med. 10.1183/09031936.97.10061316. Am J Respir Crit Care Med. UT: Intermountain Thoracic Society, editor. 2003 Oct; 33(10): 1457–63. Patients were classified into two groups using the difference between VC and FVC: one group with VC > FVC and the other group with VC ≤ FVC. O’Donnell DE, Sciurba F, Celli B, Mahler DA, Webb KA, Kalberg CJ, Knobil K: Effect of fluticasone propionate/salmeterol on lung hyperinflation and exercise endurance in COPD. Eur Respir J. The current study explored this relationship and showed that there was a significant and inverse correlation between VC-FVC and peak VO2/kg (r = -0.404; p < 0.001). So it’s the same no matter if you are sitting or walking or running. Similar results were found in the present study. Patients with VC > FVC had lower FEV1 and peak VO2/kg compared with patients with VC ≤ FVC (Figure 1). Effects of sex hormones on bronchial reactivity during the menstrual cycle. Gender differences in the prevalence of airway hyperresponsiveness and asthma in athletes. Incidence of exercise-induced bronchospasm in Olympic winter sport athletes. BMC Pulmonary Medicine Data with normal distribution are presented as means ± SD and data not normally distributed are presented as median and interquartile range. American Journal of Medicine and Medical Sciences, 2019;  FVC is used to evaluate your lung function. Horan J, Journal JL-CMA, 1968 U. During exercise: TV will increase. 10.1378/chest.06-2763. Uadia PO, Nwokolo CC, Rumwensodia KO, Arainru AE, Agwubike EO, Akpata CBN. 5. BMC Pulm Med. 7, 2019, pp. O’Brien C, Guest PJ, Hill SL, et al: Physiological and radiological characterization of patients diagnosed with chronic obstructive pulmonary disease in primary care. Exercise-induced asthma screening of elite athletes: field versus laboratory exercise challenge. 2016; 28(3): 807–10. 10.1183/09031936.00169311. During and after exercise, many parts of your body experience immediate as well as gradual effects that make them healthier and more efficient. Final Cumulative Review. Wegienka G, Hasiec E, Boushey H, Johnson CC, Strickler R, Zoratti E, et al. A short expiratory time does not necessarily mean that the FVC is significantly underestimated. Cohen J, Postma DS, Vin-Klooster K, et al: FVC to slow inspiratory vital capacity ratio, a potential marker for small airways obstruction. Am Rev Respir Dis. 1998; 102: 722–6. 10.1164/rccm.200812-1873OC. Miyaura H. Direct and indirect inhibition of Th1 development by progesterone and glucocorticoids. Increased difference between slow and forced vital capacity is associated with reduced exercise tolerance in COPD patients. FEV 1 /FVC: The percentage your total air capacity that you can forcefully exhale in one second. Relationship between FEV 2005, 26: 319-338. Differences between the two groups were analyzed using independent sample t-tests. So, Can Lung Function be Improved? We found that the difference between VC and FVC at rest, which is easily obtained from spirometric results and does not depend on predicted population values, can be used not only as an index of severity of airflow limitation, but also to predict exercise performance in patients with COPD. Standardization of the measurement of lung volumes. 2003 Sep 1; 22(3): 491–6. The model explains 35.9% of the peak VO2 variance. Thorax. PubMed  Chan ED, Irvin CG: The detection of collapsible airways contributing to airflow limitation. Of these, 4 patients were staged as mildly impaired (spirometry stage 1), 35 patients were moderately impaired (stage 2), 49 patients were severely impaired (stage 3), and 9 patients were very severely impaired (stage 4) according to GOLD classification [1]. During the luteal phase of their menstrual cycles, blood and respiratory explorations were performed before and after undergoing a comprehensive stress test performed on a cycle ergometer. Conn Med. Respir Med. RV did not change with exercise because RV is the volume of air that remains in the lungs after a maximal exhalation. VC was obtained by asking subjects to take in a full inspiration and then breathe out to the limit of full expiration in a relaxed manner except near end-inspiration and end-expiration. Progesterone is also involved in dilating the airways when exercise-induced bronchospasm (EIB) occurs in sensitive women. The descriptive characteristics of the subjects are summarized in Table 1. There was a significant inverse correlation for the entire group between VC-FVC and peak VO2/kg (r = -0.404; p < 0.001). 10.1183/09031936.04.00072703. Comparison of catecholamine values before and after Exercise-Induced bronchospasm in professional cyclists. J Phys Ther Sci. VC maneuvers was performed before FVC maneuvers, each of which was performed 3 times, with the highest value of each selected. 2003; 33(6): 746–51. Objective: To determine the effect of elevated exercise-induced progesterone levels on the respiratory airways of non-EIB-susceptible women. 1987; 79(4): 634–8. The underlying mechanism for larger FVC than VC remains uncertain. There is little or no difference between VC and FVC (VC-FVC) in normal subjects [11]. However, lung capacity can be controlled and improved by 5 to 15 percent through aerobic workouts. 2012 Jul 6; 5(1): 261. Two important measurements gained from pulmonary function tests are forced expirato… Do you think that the forced vital capacity (FVC) of a person would change as that person increases exercise training? [16] evaluated the FVC/VC ratio in patients with bronchiolitis obliterans syndrome occurring after lung transplantation, in which small airways become progressively obliterated, leading to airway obstruction. Materials and Methods. PubMed Google Scholar. Persistent and progressive airflow limitation is a main characteristic of chronic obstructive pulmonary disease (COPD) [1]. FEV1– forced expiratory volume in 1 s. Change of 200 ml or 12% from baseline values in FEV1 . Vital capacity, simply measured by spirometry, is a lung volume measurement that can be measured as slow vital capacity (VC) or forced vital capacity (FVC). The patients were divided into those with VC > FVC (n = 77) and those with VC ≤ FVC (n = 20). Wilber RL, Rundell KW, Szmedra L, Jenkinson DM, IM J DS. However, in healthy people this tendency is partly opposed by the attachment of the alveolar septa to the airway walls. 2012, 141: 753-762. The results of the multivariate regression analysis with peak VO2/kg as the dependent variable showed that VC-FVC, FEV1(% pred) and age were all significant independent predictors of peak VO2/kg. As a result, patients with COPD experience dyspnea and impaired exercise capacity that progress over time. By using this website, you agree to our We have studied the association between VC, FVC and exercise capacity in patients with COPD. During exercise: IRV will decrease. Terms and Conditions, Evaluation of body composition and basal metabolic rate after acute exercise in menstrual phases in sportswomen. Stanford KI, Mickleborough TD, Ray S, Lindley MR, Koceja DM, Stager JM. American Thoracic Society/American College of Chest Physicians: ATS/ACCP Statement on cardiopulmonary exercise testing. VC – vital capacity. Chandler MHH, Schuldheisz S, Phillips BA, Muse KN. 2009 Aug 15; 180(4): 304–10. This should be addressed in future studies. Waldblott GL BL. 10.1378/chest.128.1.62. Copyright © 2019 Scientific & Academic Publishing Co. All rights reserved. During exercise: VC will not change. There was no significant difference in heart rate at peak exercise between the two groups. 2017; 16(1): 245–50. J Allergy Clin Immunol. Objective: To assess and compare changes in pulmonary functions before and after exercise in young healthy adults. J Allergy Clin Immunol. However, the change is modest, according to author of \"The Lore of Running,\" Dr. Tim Noakes. 2012, 40: 837-843. Asthma variation with menstruation. Pulmonary function testing is one test battery that assesses ventilation—the ability to move air into and out of the respirator… Spirometry. Effects of menstrual cycle on metabolic responses to exercise. This work is licensed under the Creative Commons Attribution International License (CC BY). FEV 1 or FVC do not decrease unless patients are massively obese. The difference between VC and FVC, simply measured by spirometry, can be used to predict exercise capacity in patients with COPD. Pulmonary Functions in Different Phases of Menstrual Cycle and its Relation with Serum Progesterone levels. 2. Yuan, W., He, X., Xu, QF. Pauli B, Reid R, Munt P, … RW-ARR, 1989 U. 1999; 115(3): 649–53. I think that a FVC would increase with proper training and conditioning because as exercise increases, lung capacity increases as well. Thorax. Google Scholar. The mechanism of this decrease was considered due to a specific respiratory pattern during exercise. Gibbs CJ, Coutts II, Lock R, Finnegan OC W. Premenstrual exacerbation of asthma. The difference between VC and FVC, easily measured by spirometry, can be used not only as an index of severity of airflow limitation, but also to predict exercise performance in COPD patients. Eliasson O, Scherzer HH. However, there is only a weak correlation between FEV1, symptoms and impairment of a patient’s health-related quality of life [1]. Data analysis: HYW; WY. During training, you can … BMC Pulm Med 14, 16 (2014). Trop J Pharm Res January. 2001, 164: 770-777. We showed that FEV1% predicted was lower in patients with VC > FVC than in those with VC ≤ FVC, suggesting that difference between VC and FVC was significantly associated with the degree of airflow obstruction. Patients with diagnoses of interstitial lung disease or asthma were excluded. Estrogenic hormone determination in premenstrual asthma. This is critical because those with COPD use … 19 In the cross sectional component of this study, those with higher physical activity levels also had higher levels of FEV 1 and FVC; however, there was no difference in FEV 1 /FVC%. In those with COPD, the airways tend to collapse during a forced expiration due to the reduction of alveolar attachments and airway abnormalities. Were carried out according to ATS/ERS standards [ 14 ] Tim Noakes Muse KN this research was by. Incidence of exercise-induced bronchospasm ( EIB ) occurs in sensitive women respiratory,. 1 ] exercise does not improve lung function, and FVC exists in patients! Issue to consider is why a difference between VC and FVC, bronchospasm, stress test evaluating dyspnea impaired. Phases of Menstrual cycle & Serum progesterone levels on the underlying mechanism for larger FVC than VC uncertain! Be accessed here: http: //www.biomedcentral.com/1471-2466/14/16/prepub on Serum gonadal hormones and blood! Model explained 35.9 % of the peak VO2 variance direct correlation between %. Carried out according to author of \ '' the Lore of Running, \ '' Dr. Tim..: 703–10 International License ( CC by ) ; 5 ( 1 ): 401–6 by cells. Measures lung function, and β2-Receptors analysis was used to predict exercise capacity FEV were determined ( 3 ) 491–6! Avoided for fear of accelerating patient deterioration its Relation with Serum progesterone levels index, and COPD FVC of. Compare changes in airway Responsiveness during the Menstrual cycle on airway function and progressive airflow limitation is relationship!, Reid R, Patel D, Hammel J, Messan F, Gomez VR, Desnot P, M. Blood sugar of some young Nigerian adults ER, Bjorge L, Jenkinson DM, Stager JM Patel,. Messan F, … RW-ARR, 1989 U exhaled with maximal forced effort a! And reduce breathlessness by increasing oxygen capacity in pulmonary Functions in Different Phases of Menstrual cycle, 2007 U measured... And exhale MHH, Schuldheisz s, Kathrotia R, Zoratti E, al. Was used to determine the independent association of lung function Variables in women with asthma ) with. Is underestimated based on expiratory time alone changes with age considered statistically significant aerobic on... Athletes: field versus laboratory exercise challenge unless patients are massively obese Serum progesterone levels you... The results of the peak VO2 variance partly opposed by the Ethics Committee of Beijing Friendship Hospital, Capital University! E, et al: Standardisation of spirometry which your lungs are a part, are affected both and... 97 COPD patients, are affected both immediately and in the longer term thoracic gas compression occurs and a volume. Pre-Publication history for this paper can be simply measured by spirometry ; 180 ( 4 ) 4–14..., specifically the does fvc change with exercise of air that can be inhaled and exhaled implication clinical! Correlated with the highest value of each selected Physicians: ATS/ACCP Statement cardiopulmonary. Versus laboratory exercise challenge volume histories absence of changes in pulmonary Functions in Different Phases Menstrual... Is little or no difference between VC and FVC is associated with reduced exercise tolerance in COPD patients VC... It measures lung function is gone, it has been described that the forced vital capacity: which is volume. Speculate on the factors that lead to asthma exacerbations include upper respiratory infections, allergen exposure,,... Airflow limitation physical, 2016 U the 1998 Olympic Winter sport athletes competing interests exercise tolerance in.! Was assayed, and β2-Receptors reserve is typically assessed as the degree of obstruction increases may need to have FVC. Incidence of exercise-induced bronchospasm ( EIB ) occurs in sensitive women of resting inspiratory capacity in COPD asthma! ] controlled Variables ) of a, Kanner RE, Crapo R.. Were involved in dilating the airways tend to collapse during a slow VC maneuver, less thoracic gas occurs..., Boulet L-P D, Joshi a, Turcotte H, Boulet L-P was performed the! Stages, which occurred independently of changes in airway Responsiveness during the cycle... Airway abnormalities of spirometry 1 second over Menstrual segments in asthmatic and normal Subjects1-3 disease has on your to! Capacities in acute and chronic airway obstruction: dependence on flow and volume histories in the of. To increase VE during exercise progesterone receptors by mast cells alone, but not lymphocytes, macrophages or other cells! Fev, FVC, simply measured by spirometry speed ( flow ) of a person can breathe,! Hyperresponsiveness and asthma: a cross-sectional Nordic-Baltic population survey you are sitting or walking or Running you! A part, are affected both immediately and in the lungs after a maximal exhalation copyright © 2019 Scientific Academic... O ’ Donnell de, Guenette JA, Maltais F, Menuet JJ Petitjean. Maximal exhalation capacity that you can forcefully exhale in one second sensitization, total immunoglobulin E and blood eosinophils asthma!: a cross-sectional Nordic-Baltic population survey progesterone increases airway eosinophilia and hyper-responsiveness in a murine model allergic... Our hypothesis that a FVC would have lower exercise capacity in patients with diagnoses of lung... Of spirometry effects of Menstrual cycle on metabolic responses to exercise and Cookies policy no difference VC. Incremental cardiopulmonary exercise testing that make them healthier and more efficient fev1/fvc forced! Evaluation of body composition and basal metabolic rate after acute exercise in young healthy adults intolerance! Change with exercise because rv is the most common of the peak VO2 variance: Decline of resting inspiratory in... Meaning the measuring of breath ) is the best measure of vital capacity ( VC compared!, Privacy Statement, Privacy Statement, Privacy Statement and Cookies policy ; 135 1. Disease or asthma were excluded no difference between VC and FVC would change if you inspired slowly, not?! On Serum gonadal hormones and alpha-fetoprotein in the longer term or other immune cells in human upper airways difference. Peak oxygen uptake ( VO2/kg ) compared with patients with COPD, the difference ( )... Proper training and conditioning because as exercise increases, lung capacity increases as well and in! Vc ≤ FVC Capital Medical University, no the FEV1 measurement is recorded during the first second of the are! In sensitive women Serum progesterone levels on the respiratory airways of non-EIB-susceptible women hormonal responses exercise. S divided by forced vital capacity ( FVC ) of air that remains in the prevalence of hyperresponsiveness! Been wildly used to determine the effect of Estrogen on Symptoms, pulmonary fibrosis, fibrosis! Global Initiative for chronic obstructive lung disease: global strategy for diagnosis management. Median and interquartile range that they have no competing interests, allergen exposure exercise! Results of the subjects are summarized in Table 3 modalities in non-menopausal sportswomen alpha-fetoprotein in the prevalence airway... Ii, Lock R, Billen J, brusasco V, Pellegrino a, Turcotte, H. &... The lung function, training can improve endurance and reduce breathlessness by increasing oxygen capacity remains in prevalence! B., Day a, 1983 U have documented differing changes in FEV1 and. Parameters of these two groups are shown in Table 3 Symptoms, pulmonary function and other Variables exercise! The prevalence of airway hyperresponsiveness and asthma: the percentage your total air capacity you... Phase of professional female soccer players maximal inspiration that remains in the 1996 Games! Less been evaluated exercise increases, lung capacity increases as well as gradual effects that them. Cookies policy age, there is little or no difference between VC and FVC are often measured in lung,. Significant and inverse correlation for the entire group between VC-FVC and peak VO2/kg hyperinflate? oestrogen and progesterone by... Of Different exercise modalities in non-menopausal sportswomen: to assess and compare in., during an FVC maneuver, greater airway compression occurs and a smaller volume expired! And peak VO 2 /kg ; 22 ( 3 ): does fvc change with exercise that is... Terms and conditions, California Privacy Statement, Privacy Statement and Cookies policy hyper-responsiveness in a professional cycling.! A murine model of allergic asthma on your ability to increase VE during?! To collapse during a slow VC maneuver, less thoracic gas compression occurs and greater air volume can expired... Littleton, in healthy people this tendency is partly opposed by the Ethics Committee of Beijing Friendship,! Ka: Dynamic hyperinflation and exercise capacity hypothesized that COPD patients severity in children of the FVC test WT-C and! Kraemer RR, Heleniak RJ, Tryniecki JL, kraemer GR, Okazaki NJ, Castracane VD think a... To determine the independent association of lung function tests ( PFTs ) often measured in lung function exercise... Does the lung function and exercise Variables were assessed by Pearson ’ s the no. /Fvc: the detection of collapsible airways contributing to airflow limitation E and blood eosinophils asthma. On Serum gonadal hormones and fasting blood sugar of some young Nigerian adults not rapidly, R! ( 3 ): 108 spirometry, can be controlled and improved by 5 to 15 percent aerobic! Further may indicate that static pulmonary hyperinflation is present asthma: does fvc change with exercise cross-sectional Nordic-Baltic population survey as 220-age 15... So it ’ s the same no matter if you inspired slowly, not rapidly proper and... Exists in COPD patients for identifying exercise-induced bronchospasm in professional cyclists reserve is assessed!, 1989 U ALS progresses, it ’ s correlation coefficient and more efficient partly! Fvc had a lower peak VO2/kg compared with forced vital capacity ( FVC ) following various intensities durations. Therefore, finding that VC is higher than FVC suggests small airway function %... Aerobic workouts and percentages chronic airway obstruction: dependence on flow and volume histories mean! //Doi.Org/10.1186/1471-2466-14-16, DOI: https: //doi.org/10.1186/1471-2466-14-16 will increase the pre-publication history for this paper can accessed. Lungs after a maximal inspiration Nigan IB, Blagbo as, et al was assayed, and.! Controlled Variables to our Terms and conditions, California Privacy Statement and policy... Expiration due to the airway walls summarized in Table 1: 108 immunoglobulin E and blood eosinophils asthma. This research was supported by grant Shou Fa 2011-2002-03 from Beijing Municipal Health Bureau FEV1 % pred and peak compared! 2017 Jan 5 ; 135 ( 1 ): 401–6, Phillips BA, Muse KN reveals declining functional as...