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Selvanathan J, Aaron SD, Sykes JR, Vandemheen KL, FitzGerald JM, Ainslie M, Lemière C, Field SK, McIvor RA, Hernandez P, Mayers I, Mulpuru S, Alvarez GG, Pakhale S, Mallick R, Boulet LP, Gupta S. Performance Characteristics of Spirometry With Negative Bronchodilator Response and Methacholine Challenge Testing and Implications for Asthma Diagnosis. Chest 2020; 158:479-490. [PMID: 32298731 DOI: 10.1016/j.chest.2020.03.052] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/27/2020] [Accepted: 03/21/2020] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND In patients with a history suggestive of asthma, diagnosis is usually confirmed by spirometry with bronchodilator response (BDR) or confirmatory methacholine challenge testing (MCT). RESEARCH QUESTION We examined the proportion of participants with negative BDR testing who had a positive MCT (and its predictors) result and characteristics of MCT, including effects of controller medication tapering and temporal variability (and predictors of MCT result change), and concordance between MCT and pulmonologist asthma diagnosis. STUDY DESIGN AND METHODS Adults with self-reported physician-diagnosed asthma were recruited by random-digit dialing across Canada. Subjects performed spirometry with BDR testing and returned for MCT if testing was nondiagnostic for asthma. Subjects on controllers underwent medication tapering with serial MCTs over 3 to 6 weeks. Subjects with a negative MCT (the provocative concentration of methacholine that results in a 20% drop in FEV1 [PC20] > 8 mg/mL) off medications were examined by a pulmonologist and had serial MCTs after 6 and 12 months. RESULTS Of 500 subjects (50.5 ± 16.6 years old, 68.0% female) with a negative BDR test for asthma, 215 (43.0%) had a positive MCT. Subjects with prebronchodilator airflow limitation were more likely to have a positive MCT (OR, 1.90; 95% CI, 1.17-3.04). MCT converted from negative to positive, with medication tapering in 18 of 94 (19.1%) participants, and spontaneously over time in 25 of 165 (15.2%) participants. Of 231 subjects with negative MCT, 28 (12.1%) subsequently received an asthma diagnosis from a pulmonologist. INTERPRETATION In subjects with a self-reported physician diagnosis of asthma, absence of bronchodilator reversibility had a negative predictive value of only 57% to exclude asthma. A finding of spirometric airflow limitation significantly increased chances of asthma. MCT results varied with medication taper and over time, and pulmonologists were sometimes prepared to give a clinical diagnosis of asthma despite negative MCT. Correspondingly, in patients for whom a high clinical suspicion of asthma exists, repeat testing appears to be warranted.
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Affiliation(s)
- Janannii Selvanathan
- Keenan Research Center in the Li Ka Shing Knowledge Institute of St. Michael's Hospital, University of Toronto, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Shawn D Aaron
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON
| | - Jenna R Sykes
- Department of Medicine, Division of Respirology, St. Michael's Hospital, Toronto, ON
| | | | - J Mark FitzGerald
- Centre for Heart and Lung Health, Vancouver Coastal Health Research Institute, Vancouver, BC
| | - Martha Ainslie
- Department of Medicine, University of Manitoba, Winnipeg, MB
| | | | - Stephen K Field
- Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB
| | - R Andrew McIvor
- Firestone Institute for Respiratory Health, McMaster University, Hamilton, ON
| | - Paul Hernandez
- Department of Medicine, Dalhousie University, QEII Health Sciences Centre, Halifax, NS
| | - Irvin Mayers
- Department of Medicine, University of Alberta, Edmonton, AB
| | - Sunita Mulpuru
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON
| | - Gonzalo G Alvarez
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON
| | - Smita Pakhale
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON
| | - Ranjeeta Mallick
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON
| | | | - Samir Gupta
- Keenan Research Center in the Li Ka Shing Knowledge Institute of St. Michael's Hospital, University of Toronto, Toronto, ON, Canada; Department of Medicine, Division of Respirology, St. Michael's Hospital, Toronto, ON.
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Tikkakoski AP, Tikkakoski A, Kivistö JE, Huhtala H, Sipilä K, Karjalainen J, Kähönen M, Lehtimäki L. Association of air humidity with incidence of exercise-induced bronchoconstriction in children. Pediatr Pulmonol 2019; 54:1830-1836. [PMID: 31393065 DOI: 10.1002/ppul.24471] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 07/24/2019] [Indexed: 01/15/2023]
Abstract
BACKGROUND The effects of humidity and temperature on results of free running test in children are not known. OBJECTIVE Assess the relation of outdoor air temperature, relative humidity (RH), and absolute humidity (AH) to airway obstruction in children after free running exercise test. METHODS We analyzed all exercise challenge tests with impulse oscillometry in children between January 2012 and April 2015 in the Tampere University Hospital. The associations of AH, RH, and temperature of outdoor air with change in airway resistance were studied using regression analysis and by comparing the frequency of exercise-induced bronchoconstriction (increase ≥40% in resistance at 5 Hz) at different levels of temperature and humidity. RESULTS Overall, 868 children with reliable results were included (mean age: 5.4 years; range: 3.0-14.1). In regression analysis, the relative change in resistance at 5 Hz after exercise was related to temperature (regression coefficient = -0.223, P = .020) and AH (regression coefficient = -0.893, P = .002), but not to RH. If absolute air humidity was <5 g/m3 , exercise-induced bronchoconstriction (EIB) occurred in 17.6% of study subjects and at AH levels ≥10 g/m3 , it occurred in 5.9% of study subjects (P = .008). In multiple regression analysis comparing the effects of temperature and humidity and adjusting for covariates, only AH was independently associated with change in airway resistance (P = .009). CONCLUSION High AH of air is associated with lower incidence of EIB after outdoor exercise test in children. A negative test result at AH ≥10 g/m3 should be interpreted with caution.
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Affiliation(s)
- Anna P Tikkakoski
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Antti Tikkakoski
- Department of Clinical Physiology, Tampere University Hospital, Tampere, Finland
| | - Juho E Kivistö
- Allergy Centre, Tampere University Hospital, Tampere, Finland
| | - Heini Huhtala
- Faculty of Social Sciences, Tampere University, Tampere, Finland
| | - Kalle Sipilä
- Department of Clinical Physiology, Tampere University Hospital, Tampere, Finland
| | | | - Mika Kähönen
- Department of Clinical Physiology, Tampere University Hospital, Tampere, Finland
| | - Lauri Lehtimäki
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Allergy Centre, Tampere University Hospital, Tampere, Finland
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Huang SJ, Lin LL, Chen LC, Ou LS, Yao TC, Tsao KC, Yeh KW, Huang JL. Prevalence of airway hyperresponsiveness and its seasonal variation in children with asthma. Pediatr Neonatol 2018; 59:561-566. [PMID: 29398555 DOI: 10.1016/j.pedneo.2018.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Revised: 11/12/2017] [Accepted: 01/02/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Airway hyperresponsiveness (AHR) is a key feature of asthma and can be detected using various bronchoprovocation tests. In pediatric populations, the percentage of a positive methacholine challenge test (MCCTs) in children with asthma varies among studies, and some have reported seasonal variability. However, these studies have mostly been conducted in temperate regions. This study evaluated the prevalence of AHR to methacholine and its seasonal variation in asthmatic children in Taiwan, a subtropical country. METHODS A total of 276 children with asthma and their MCCT results were retrospectively reviewed. All were diagnosed with asthma and received asthma controllers regularly. They were assigned to four season groups depending in which season MCCTs were administered, with seasons categorized by the Central Weather Bureau of Taiwan. Subgroup analyses, including for sex, age, and atopy level, were compared for seasonal difference. RESULTS The prevalence of methacholine hyperresponsiveness was 70.7% (n = 195), and the children who were younger and had higher total serum IgE were more sensitive to methacholine (p = 0.019 and p < 0.005, respectively). No significant difference in AHR prevalence among seasons was observed (p = 0.480). The percentage of borderline, mild, and moderate severity of MCCT results was almost equally distributed among the seasons. In subgroup analysis, the children with a higher IgE level (≥75th percentile of all data) had a higher proportion of positive MCCTs in summer (88.6%, p = 0.016). CONCLUSION In total, 70% of the children with asthma in Taiwan had AHR to methacholine, which varied among seasons. Children with a higher total serum IgE level may be more seasonally dependent, particularly in summer.
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Affiliation(s)
- Shu-Jung Huang
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taiwan
| | - Li-Lun Lin
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taiwan
| | - Li-Chen Chen
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taiwan
| | - Liang-Shiou Ou
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taiwan
| | - Tsung-Chieh Yao
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taiwan
| | - Kuo-Chien Tsao
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taiwan; Department of Biotechnology & Laboratory Science, Chang Gung University, Taoyuan, Taiwan; Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan, Taiwan
| | - Kuo-Wei Yeh
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taiwan
| | - Jing-Long Huang
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taiwan.
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Mendes FAR, França-Pinto A, Martins MA, Cukier A, Stelmach R, Giavina-Bianchi P, Carvalho CRF. Seasonal changes influence the improvement in asthma symptoms by exercise training in subjects with asthma* .. J Asthma 2018; 56:674-679. [PMID: 29972094 DOI: 10.1080/02770903.2018.1484131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To investigate whether patients with moderate-to-severe asthma who commence an exercise training program in winter or summer show differences in exercise capacity, health-related quality of life (HRQoL) and asthma symptoms. METHODS Forty-two consecutive subjects visiting the outpatient clinic were enrolled in the 17-week rehabilitation program. One group of patients received the intervention from summer to winter (SWG, n = 21), and the other group participated from winter to summer (WSG, n = 21). Before and after the exercise training program, all patients were evaluated by cardiopulmonary exercise test, pulmonary function test, quality of life questionnaire and a daily diary that evaluated clinical asthma symptoms. RESULTS After the training period, both groups improved similarly in health-related quality of life (HRQoL) and aerobic capacity. The WSG patients had a greater increase that those in the SWG in asthma symptom-free days (p < 0.05). CONCLUSIONS Our results indicate that seasonal variations affect the improvement in asthma symptoms after an exercise training program but have no effect on health-related quality of life, exercise capacity or pulmonary function.
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Affiliation(s)
- Felipe A R Mendes
- a Department of Physical Therapy , Universidade Ibirapuera , São Paulo , Brazil.,b Department of Physical Therapy, School of Medicine , University of São Paulo , São Paulo , Brazil
| | - Andrezza França-Pinto
- c Department of Clinical Immunology and Allergy, School of Medicine , University of São Paulo , São Paulo , Brazil
| | - Milton A Martins
- d Department of Medicine, School of Medicine , University of São Paulo , São Paulo , Brazil
| | - Alberto Cukier
- e Department of Pulmonary Diseases, Heart Institute (Incor), Clinics Hospital, School of Medicine , University of São Paulo , São Paulo , Brazil
| | - Rafael Stelmach
- e Department of Pulmonary Diseases, Heart Institute (Incor), Clinics Hospital, School of Medicine , University of São Paulo , São Paulo , Brazil
| | - Pedro Giavina-Bianchi
- c Department of Clinical Immunology and Allergy, School of Medicine , University of São Paulo , São Paulo , Brazil
| | - Celso R F Carvalho
- b Department of Physical Therapy, School of Medicine , University of São Paulo , São Paulo , Brazil
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Liu CL, Lin CY, Yang SH. Seasonal Differences in FEV 1 Response to Bronchodilation: A Comparison between Young and Elderly Patients. INT J GERONTOL 2018. [DOI: 10.1016/j.ijge.2018.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Different clinical effect of several types of airborne allergens on the severity of bronchial hyperreactivity. Wien Klin Wochenschr 2017; 129:674-679. [PMID: 28593388 DOI: 10.1007/s00508-017-1220-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 05/19/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Atopic sensitization belongs to the most common risk factors for bronchial asthma. However, in clinical practice, it is not clear whether sensitization against pollen and perennial allergens is differently associated with the severity of bronchial hyperresponsiveness (BHR). AIM To find out whether patients sensitized to perennial allergens differ in severity of bronchial hyperresponsiveness from patients sensitized to pollen allergens. METHODS The study includes 109 patients. Based on the results of skin prick tests, patients were divided into three groups: sensitivity to pollen allergens - group A; sensitivity to perennial allergens - group B; sensitivity to both pollen and perennial allergens - group C. Based on the histamine bronchoprovocation test, we compared the values of histamine provocative concentration causing a 20% drop in FEV1 (PC20) among particular groups of patients. Mild bronchial hyperresponsiveness was determined if the value of PC20 was >4 mg/ml, while if the value of PC20 was <4 mg/ml, the bronchial hyperresponsiveness was considered as moderate/severe. RESULTS A statistically significant difference was found in the degrees of bronchial hyperresponsiveness between the three groups of patients, namely, group A with the patients sensitized only to the pollen allergens, group B comprising patients sensitized to the perennial allergens only, and group C, involving patients sensitized to the combination of both pollen and perennial allergens. The PC20 values were higher among the patients from the group A (7.46 mg/ml) compared to group B (4.25 mg/ml) and C (4.52 mg/ml). The odds ratio for moderate/severe BHR was 5.21 and 5.04 in group B and group C, respectively. CONCLUSION Severity of bronchial hyperresponsiveness shows differences according to sensitization to particular allergens. Perennial allergens are more often associated with serious forms of bronchial hyperresponsiveness which also have an impact on the severity and prognosis of bronchial asthma.
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Haynes JM. Debunking myths in pulmonary function testing. CANADIAN JOURNAL OF RESPIRATORY THERAPY : CJRT = REVUE CANADIENNE DE LA THERAPIE RESPIRATOIRE : RCTR 2017; 53:7-11. [PMID: 30996623 PMCID: PMC6422208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Al-Moamary MS, Alhaider SA, Idrees MM, Al Ghobain MO, Zeitouni MO, Al-Harbi AS, Yousef AA, Al-Matar H, Alorainy HS, Al-Hajjaj MS. The Saudi Initiative for Asthma - 2016 update: Guidelines for the diagnosis and management of asthma in adults and children. Ann Thorac Med 2016; 11:3-42. [PMID: 26933455 PMCID: PMC4748613 DOI: 10.4103/1817-1737.173196] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 12/08/2015] [Indexed: 12/21/2022] Open
Abstract
This is an updated guideline for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have guidelines that are up to date, simple to understand and easy to use by nonasthma specialists, including primary care and general practice physicians. SINA approach is mainly based on symptom control and assessment of risk as it is the ultimate goal of treatment. The new SINA guidelines include updates of acute and chronic asthma management, with more emphasis on the use of asthma control in the management of asthma in adults and children, inclusion of a new medication appendix, and keeping consistency on the management at different age groups. The section on asthma in children is rewritten and expanded where the approach is stratified based on the age. The guidelines are constructed based on the available evidence, local literature, and the current situation in Saudi Arabia. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.
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Affiliation(s)
- Mohamed S. Al-Moamary
- Department of Medicine, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Sami A. Alhaider
- Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Majdy M. Idrees
- Department of Medicine, Pulmonary Division, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Mohammed O. Al Ghobain
- Department of Medicine, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Mohammed O. Zeitouni
- Department of Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Adel S. Al-Harbi
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Abdullah A. Yousef
- Department of Pediatrics, College of Medicine, University of Dammam, Dammam, Saudi Arabia
| | - Hussain Al-Matar
- Department of Medicine, Imam Abdulrahman Al Faisal Hospital, Dammam, Saudi Arabia
| | - Hassan S. Alorainy
- Department of Respiratory Care, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohamed S. Al-Hajjaj
- Department of Medicine, Respiratory Division, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Sposato B, Scalese M, Migliorini MG, Di Tomassi M, Scala R. Small airway impairment and bronchial hyperresponsiveness in asthma onset. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2014; 6:242-51. [PMID: 24843800 PMCID: PMC4021243 DOI: 10.4168/aair.2014.6.3.242] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Revised: 09/29/2013] [Accepted: 11/27/2013] [Indexed: 11/27/2022]
Abstract
Purpose Our study tried to find a relationship between baseline FEF25-75% and airway hyperresponsiveness (AHR) and whether a greater FEF25-75% impairment may be a marker of a more severe hyperresponsiveness in subjects with normal FEV1 and FEV1/FVC and suggestive asthma symptoms. Besides, we tried to asses a FEF25-75% cut-off value to identify hyper-reactive subjects. Methods 4,172 subjects (2,042 M; mean age: 38.3±14.9; mean FEV1 % predicted: 100.5±12.7 and FEV1/FVC: 85.4±6.8) were examined after performing a methacholine (Mch) test. All subjects reported a symptom onset within 3 years before the test. Subjects with PD20<400 or >400 µg were arbitrarily considered affected by moderate/severe and borderline AHR, respectively. Results PD20 values were 213 (IQR:86-557), 340 (IQR:157-872) and 433 (IQR:196-1032) µg in subjects with baseline FEF25-75≤50%, FEF25-75 between 50 and 70% and FEF25-75>70% respectively (P<0.0001). Only in moderate/severe hyper-reactive subjects (excluded borderlines), PD20 was lower in the FEF25-75≤50% subgroup than in the 1 with FEF25-75>70%. The hyperreactive subjects percentage, was higher in those with FEF25-75≤50% and lower in those with FEF25-75>70% (P<0.0001). FEF25-75<50% (compared to FEF25-75>70%) was a higher AHR risk factor, especially in subjects with moderate/severe AHR (OR: 2.18 [IQR:1.41-3.37]; P<0.0001). Thresholds yielding the highest combined sensitivity/specificity for FEF25-75% were 75.19 (area under curve [AUC]: 0.653) and 74.95 (AUC:0.688) in subjects with PD20<2,400 and <400 µg respectively. FEV1, FVC, and FEV1/FVC measured in subjects with different FEF25-75≤50%, FEF25-75>50 and ≤70% or FEF25-75>70% levels were similar both in normoreactive and hyperreactive subjects. Conclusions At asthma onset, reduced baseline FEF25-75 values with normal FEV1 and FEV1/FVC may predict AHR. Detectable predictive cut-off values do not exist because even normoreactive subjects can show lower FEF25-75 values. Furthermore, a greater FEF25-75 reduction may be associated to a more severe AHR, suggesting a possible FEF25-75 role in the management of asthma when FEV1 and FEV1/FVC are normal.
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Affiliation(s)
- Bruno Sposato
- Unit of Pneumology, "Misericordia" Hospital, Grosseto, Italy
| | - Marco Scalese
- Institute of Clinical Physiology, National Research Council (CNR), Pisa, Italy
| | | | | | - Raffaele Scala
- Unit of Pneumology and UTIP, "S.Donato" Hospital, Arezzo, Italy
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Abstract
OBJECTIVE The aim of this review was to understand whether FEV1 decline measured during the follow-up of asthmatic subjects (FEV1 variation between two different measurements at a distance of at least 5 years) may have a role in their management. METHODS Articles, commentaries and reviews relating to the topic were searched in PubMed. RESULTS Patients with an accelerated FEV1 decline (>30 ml/year) may be either steroid-resistant/difficult-to-treat asthmatics or not adequately treated because they are either under-perceivers or poorly adherent to their therapy. Sometimes they may be unable to use devices correctly. Untreated rhinitis and incorrect lifestyle (obesity status, a high-fat diet and lack of exercise) must be considered when facing a pulmonary function decline. Identifying asthmatics with an accelerated FEV1 decline, even with well controlled symptoms, may allow us to make possible treatment adjustments or to remove potentially harmful environmental exposure and suggest a correct lifestyle. Depending on FEV1 decline severity, we may detect different asthma phenotypes. One type is characterized by no/low lung function reduction. Among moderate/severe 'declining' subjects, there may be a group that might be responsive to treatment and a second one with a quicker loss in lung function that may be unresponsive to therapy. CONCLUSION FEV1 decline calculation should be assessed early in clinical practice over the course of time in order to make all possible variations in treatment, environmental exposure and lifestyle more efficacious overall for declining subjects responsive to anti-inflammatory therapy. Further studies are necessary to validate this approach to asthma.
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Affiliation(s)
- Bruno Sposato
- Unit of Pneumology, Misericordia Hospital , Grosseto , Italy
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Methacholine challenge test results in children are season dependent. Lung 2013; 191:553-7. [PMID: 23839582 DOI: 10.1007/s00408-013-9486-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 06/12/2013] [Indexed: 01/04/2023]
Abstract
BACKGROUND It is known that several parameters influence the positivity of a methacholine challenge (MCH), including a recent viral disease, allergies, and air pollution. Reports regarding the influence of the season upon the positivity of MCH are scarce. The aim of this study was to assess the percentage of positive MCH tests per season. METHODS We retrospectively evaluated all MCH tests performed in children and adults in a single center over a 30-month period. The percentage of positive tests for summer was compared with that of other seasons. RESULTS A total of 155 challenges were performed in children (under 20 years old) and 527 in adults. Thirty-eight percent of the tests were positive in adults and 71 % in children. The percentage of positive tests in the summer was significantly lower than the percentage of positive results during the rest of the year in children (58.5 vs. 75.4 %, respectively; p = 0.046). By contrast, there was no difference between the seasons in adults (39 vs. 38 %, respectively; p = 0.92). CONCLUSIONS There is a difference of 22.4 % in the percentage of positive tests in the summer months compared to the rest of the year in children, suggesting a reduction in the sensitivity of the MCH test in the hot season. We suggest that in cases where asthma is strongly suspected in a child and the MCH test was negative in the summer, one should consider repeating the MCH test in another season.
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