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Comparison of mannitol and methacholine to predict exercise-induced bronchoconstriction and a clinical diagnosis of asthma.
Respir Res 2009; 10:4RR

Abstract

BACKGROUND

Asthma can be difficult to diagnose, but bronchial provocation with methacholine, exercise or mannitol is helpful when used to identify bronchial hyperresponsiveness (BHR), a key feature of the disease. The utility of these tests in subjects with signs and symptoms of asthma but without a clear diagnosis has not been investigated. We investigated the sensitivity and specificity of mannitol to identify exercise-induced bronchoconstriction (EIB) as a manifestation of BHR; compared this with methacholine; and compared the sensitivity and specificity of mannitol and methacholine for a clinician diagnosis of asthma.

METHODS

509 people (6-50 yr) were enrolled, 78% were atopic, median FEV1 92.5% predicted, and a low NAEPPII asthma score of 1.2. Subjects with symptoms of seasonal allergy were excluded. BHR to exercise was defined as a > or = 10% fall in FEV1 on at least one of two tests, to methacholine a PC20 < or = 16 mg/ml and to mannitol a 15% fall in FEV1 at < or = 635 mg or a 10% fall between doses. The clinician diagnosis of asthma was made on examination, history, skin tests, questionnaire and response to exercise but they were blind to the mannitol and methacholine results.

RESULTS

Mannitol and methacholine were therapeutically equivalent to identify EIB, a clinician diagnosis of asthma, and prevalence of BHR. The sensitivity/specificity of mannitol to identify EIB was 59%/65% and for methacholine it was 56%/69%. The BHR was mild. Mean EIB % fall in FEV1 in subjects positive to exercise was 19%, (SD 9.2), mannitol PD15 158 (CI:129,193) mg, and methacholine PC20 2.1(CI:1.7, 2.6) mg/ml. The prevalence of BHR was the same: for exercise (43.5%), mannitol (44.8%), and methacholine (41.6%) with a test agreement between 62 & 69%. The sensitivity and specificity for a clinician diagnosis of asthma was 56%/73% for mannitol and 51%/75% for methacholine. The sensitivity increased to 73% and 72% for mannitol and methacholine when two exercise tests were positive.

CONCLUSION

In this group with normal FEV1, mild symptoms, and mild BHR, the sensitivity and specificity for both mannitol and methacholine to identify EIB and a clinician diagnosis of asthma were equivalent, but lower than previously documented in well-defined populations.

TRIAL REGISTRATION

This was a multi-center trial comprising 25 sites across the United States of America.

Authors+Show Affiliations

Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Missenden Road, Camperdown, NSW 2050, Australia. sandya@med.usyd.edu.auNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Comparative Study
Journal Article
Multicenter Study
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

19161635

Citation

Anderson, Sandra D., et al. "Comparison of Mannitol and Methacholine to Predict Exercise-induced Bronchoconstriction and a Clinical Diagnosis of Asthma." Respiratory Research, vol. 10, 2009, p. 4.
Anderson SD, Charlton B, Weiler JM, et al. Comparison of mannitol and methacholine to predict exercise-induced bronchoconstriction and a clinical diagnosis of asthma. Respir Res. 2009;10:4.
Anderson, S. D., Charlton, B., Weiler, J. M., Nichols, S., Spector, S. L., & Pearlman, D. S. (2009). Comparison of mannitol and methacholine to predict exercise-induced bronchoconstriction and a clinical diagnosis of asthma. Respiratory Research, 10, p. 4. doi:10.1186/1465-9921-10-4.
Anderson SD, et al. Comparison of Mannitol and Methacholine to Predict Exercise-induced Bronchoconstriction and a Clinical Diagnosis of Asthma. Respir Res. 2009 Jan 23;10:4. PubMed PMID: 19161635.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Comparison of mannitol and methacholine to predict exercise-induced bronchoconstriction and a clinical diagnosis of asthma. AU - Anderson,Sandra D, AU - Charlton,Brett, AU - Weiler,John M, AU - Nichols,Sara, AU - Spector,Sheldon L, AU - Pearlman,David S, AU - ,, Y1 - 2009/01/23/ PY - 2008/10/20/received PY - 2009/01/23/accepted PY - 2009/1/24/entrez PY - 2009/1/24/pubmed PY - 2009/3/6/medline SP - 4 EP - 4 JF - Respiratory research JO - Respir. Res. VL - 10 N2 - BACKGROUND: Asthma can be difficult to diagnose, but bronchial provocation with methacholine, exercise or mannitol is helpful when used to identify bronchial hyperresponsiveness (BHR), a key feature of the disease. The utility of these tests in subjects with signs and symptoms of asthma but without a clear diagnosis has not been investigated. We investigated the sensitivity and specificity of mannitol to identify exercise-induced bronchoconstriction (EIB) as a manifestation of BHR; compared this with methacholine; and compared the sensitivity and specificity of mannitol and methacholine for a clinician diagnosis of asthma. METHODS: 509 people (6-50 yr) were enrolled, 78% were atopic, median FEV1 92.5% predicted, and a low NAEPPII asthma score of 1.2. Subjects with symptoms of seasonal allergy were excluded. BHR to exercise was defined as a > or = 10% fall in FEV1 on at least one of two tests, to methacholine a PC20 < or = 16 mg/ml and to mannitol a 15% fall in FEV1 at < or = 635 mg or a 10% fall between doses. The clinician diagnosis of asthma was made on examination, history, skin tests, questionnaire and response to exercise but they were blind to the mannitol and methacholine results. RESULTS: Mannitol and methacholine were therapeutically equivalent to identify EIB, a clinician diagnosis of asthma, and prevalence of BHR. The sensitivity/specificity of mannitol to identify EIB was 59%/65% and for methacholine it was 56%/69%. The BHR was mild. Mean EIB % fall in FEV1 in subjects positive to exercise was 19%, (SD 9.2), mannitol PD15 158 (CI:129,193) mg, and methacholine PC20 2.1(CI:1.7, 2.6) mg/ml. The prevalence of BHR was the same: for exercise (43.5%), mannitol (44.8%), and methacholine (41.6%) with a test agreement between 62 & 69%. The sensitivity and specificity for a clinician diagnosis of asthma was 56%/73% for mannitol and 51%/75% for methacholine. The sensitivity increased to 73% and 72% for mannitol and methacholine when two exercise tests were positive. CONCLUSION: In this group with normal FEV1, mild symptoms, and mild BHR, the sensitivity and specificity for both mannitol and methacholine to identify EIB and a clinician diagnosis of asthma were equivalent, but lower than previously documented in well-defined populations. TRIAL REGISTRATION: This was a multi-center trial comprising 25 sites across the United States of America. SN - 1465-993X UR - https://www.unboundmedicine.com/medline/citation/19161635/Comparison_of_mannitol_and_methacholine_to_predict_exercise_induced_bronchoconstriction_and_a_clinical_diagnosis_of_asthma_ L2 - https://respiratory-research.biomedcentral.com/articles/10.1186/1465-9921-10-4 DB - PRIME DP - Unbound Medicine ER -