Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. Mar-Apr 2018;6(2):545-554.e4.
doi: 10.1016/j.jaip.2017.05.032. Epub 2017 Aug 31.

Baseline Features of the Severe Asthma Research Program (SARP III) Cohort: Differences With Age

Affiliations
Free PMC article

Baseline Features of the Severe Asthma Research Program (SARP III) Cohort: Differences With Age

W Gerald Teague et al. J Allergy Clin Immunol Pract. .
Free PMC article

Abstract

Background: The effect of age on asthma severity is poorly understood.

Objectives: The objective of this study was to compare the baseline features of severe and nonsevere asthma in the Severe Asthma Research Program (SARP) III cohort, and examine in cross section the effects of age on those features.

Methods: SARP III is a National Institutes of Health/National Heart Lung Blood Institute multisite 3-year cohort study conducted to investigate mechanisms of severe asthma. The sample included 188 children (111 severe, 77 nonsevere) and 526 adults (313 severe, 213 nonsevere) characterized for demographic features, symptoms, health care utilization, lung function, and inflammatory markers compared by age and severity.

Results: Compared with children with nonsevere asthma, children with severe asthma had more symptoms and more historical exacerbations, but no difference in body weight, post-bronchodilator lung function, or inflammatory markers. After childhood, and increasing with age, the cohort had a higher proportion of women, less allergen sensitization, and overall fewer blood eosinophils. Enrollment of participants with severe asthma was highest in middle-aged adults, who were older, more obese, with greater airflow limitation and higher blood eosinophils, but less allergen sensitization than adults with nonsevere asthma.

Conclusions: The phenotypic features of asthma differ by severity and with advancing age. With advancing age, patients with severe asthma are more obese, have greater airflow limitation, less allergen sensitization, and variable type 2 inflammation. Novel mechanisms besides type 2 inflammatory pathways may inform the severe asthma phenotype with advancing age.

Keywords: Asthma phenotypes; Severe asthma.

Figures

Figure 1
Figure 1
SARP III screening, consort procedures, characterization procedures, and schematic of the longitudinal cohort study. Potential enrollees who did not complete the initial screening questionnaire are not counted among the 948 who underwent airway physiology screen testing. Potential enrollees with more than one screen failure are also not included.
Figure 2
Figure 2
Histograms of enrollee counts and age for A) severe and B) non-severe asthma. Enrollees < 18 years of age are shaded in light green. Due to pre-specified recruiting goals of 25% children and equal numbers of children between 6 −11 years and 12–17 years, comparison of the empirical distributions for severe and non-severe asthma was limited to adult enrollees shaded in blue (p = 0.002) by the two-sample Kolmogorov-Smirnoff test.
Figure 3
Figure 3
Logistic regression curves with cubic splines and bootstrap confidence limits for the percent of female participants by age and asthma severity. The age effect is significant (p < 0.0001; likelihood ratio test), but the shape of the curves with age do not differ significantly by severity (p= n.s. for age by severity interaction).
Figure 4
Figure 4
Logistic regression curves with cubic splines and bootstrap confidence limits for the percentage of obesity by age at enrollment and asthma severity. The age effect is significant (p < 0.0001; likelihood ratio test), but the shapes of the curves do not differ by severity (p=ns for age by severity interaction).
Figure 5
Figure 5
A. Logistic regression curves and confidence limits for the percentage of pre-BD airflow limitation by age and asthma severity. The age effect is not significant (n= ns; likelihood ratio test). B. Logistic regression curves and confidence limits for the percentage of post-BD airflow limitation by age and asthma severity. The age effect is significant (p < 0.0001; likelihood ratio test), but the slopes of the curves do not differ significantly by severity (p = ns for age by severity interaction).
Figure 6
Figure 6
Linear regression lines and confidence limits for the absolute change in FEV1% post-BD by age and asthma severity. The age effect is significant (p< 0.0001; likelihood ratio test), and the slopes differ significantly by severity (p = 0.03; for age by severity interaction).
Figure 7
Figure 7
A. Logistic regression curves with cubic splines and bootstrap confidence limits for the percentage of enrollees with total blood eosinophil count > 300 cells per ul of blood by age and asthma severity. The age effects is significant (p< 0.0001; likelihood ratio test), but the shapes of the curves do not differ significantly by severity (p = ns for age by severity interaction). B. Logistic regression curves and confidence limits for the percent of enrollees with four or more positive blood allergen-specific IgE tests by age and asthma severity. The age effect is significant (p < 0.0001; likelihood ratio test). Additionally the slopes differ by severity (p = 0.03 for age by severity interaction.

Similar articles

  • Inflammatory and Comorbid Features of Patients with Severe Asthma and Frequent Exacerbations.
    Denlinger LC, Phillips BR, Ramratnam S, Ross K, Bhakta NR, Cardet JC, Castro M, Peters SP, Phipatanakul W, Aujla S, Bacharier LB, Bleecker ER, Comhair SA, Coverstone A, DeBoer M, Erzurum SC, Fain SB, Fajt M, Fitzpatrick AM, Gaffin J, Gaston B, Hastie AT, Hawkins GA, Holguin F, Irani AM, Israel E, Levy BD, Ly N, Meyers DA, Moore WC, Myers R, Opina MT, Peters MC, Schiebler ML, Sorkness RL, Teague WG, Wenzel SE, Woodruff PG, Mauger DT, Fahy JV, Jarjour NN; National Heart, Lung, and Blood Institute’s Severe Asthma Research Program-3 Investigators. Denlinger LC, et al. Am J Respir Crit Care Med. 2017 Feb 1;195(3):302-313. doi: 10.1164/rccm.201602-0419OC. Am J Respir Crit Care Med. 2017. PMID: 27556234 Free PMC article. Clinical Trial.
  • Identification of asthma phenotypes in a tertiary care medical center.
    Kuhlen JL Jr, Wahlquist AE, Nietert PJ, Bains SN. Kuhlen JL Jr, et al. Am J Med Sci. 2014 Dec;348(6):480-5. doi: 10.1097/MAJ.0000000000000346. Am J Med Sci. 2014. PMID: 25319436 Free PMC article.
  • Clinical heterogeneity in the severe asthma research program.
    Moore WC, Fitzpatrick AM, Li X, Hastie AT, Li H, Meyers DA, Bleecker ER. Moore WC, et al. Ann Am Thorac Soc. 2013 Dec;10 Suppl(Suppl):S118-24. doi: 10.1513/AnnalsATS.201309-307AW. Ann Am Thorac Soc. 2013. PMID: 24313761 Free PMC article.
  • A review of obesity and asthma across the life span.
    Khalid F, Holguin F. Khalid F, et al. J Asthma. 2018 Dec;55(12):1286-1300. doi: 10.1080/02770903.2018.1424187. Epub 2018 Feb 8. J Asthma. 2018. PMID: 29420086 Review.
  • Omalizumab for asthma in adults and children.
    Normansell R, Walker S, Milan SJ, Walters EH, Nair P. Normansell R, et al. Cochrane Database Syst Rev. 2014 Jan 13;(1):CD003559. doi: 10.1002/14651858.CD003559.pub4. Cochrane Database Syst Rev. 2014. PMID: 24414989 Review.
See all similar articles

Cited by 31 articles

See all "Cited by" articles

Publication types

MeSH terms

Feedback