title: Lung function impairment increases with age of diagnosis in adult onset asthma.
abstract: BACKGROUND
  Asthma-onset in older individuals has been associated with an accelerated decline in lung function, but direct comparisons with younger adults have not been reported.
  
  
  METHODS
  In a random population sample comprising 4983 individuals from the Copenhagen City Heart Study without asthma at baseline, we compared young (<35 years), middle-aged (35-64 years) and older (>64 years) adults with newly diagnosed asthma during a 10-year follow-up.
  
  
  RESULTS
  The proportion of cases with newly diagnosed asthma during follow-up was similar across age groups (Older adults: 7% (84/1168), middle-aged adults: 7% (223/3147), and young adults: 6% (42/668) (p = ns)). In all three age groups, lung function was reduced at baseline in subjects who were subsequently diagnosed with asthma, but most pronounced in those >35 years. (Mean FEV1%: Young 90.2% (±13.9), middle-aged 80.8% (±20.8), and older adults 80.8% (±24.2), p < 0.001). Furthermore, incident asthma was associated with an accelerated decline in lung function in older adults (young adults 11.0 mL/year, middle-aged adults 18.2 mL/year, and older adults 30.8 mL/year). These differences were independent of FEV1 at baseline and smoking status, and were not explained by undiagnosed asthma in older adults, as the frequency of respiratory symptoms, including wheeze, was similar in all three age groups at baseline.
  
  
  CONCLUSIONS
  Asthma was diagnosed as frequently in older as in younger adults. Preexisting symptoms were equally common, but lung function was more reduced pre-diagnosis, and declined more rapidly in older adults. This emphasizes the need for a high level of therapeutic attention in patients with asthma diagnosed late in life.
authors.affiliation: Department of Respiratory Medicine, Bispebjerg Hospital, Denmark; Institute of Clinical Medicine, University of Copenhagen, Denmark. Electronic address: porsbjerg@dadlnet.dk.
authors.forename: Celeste
authors.initials: C
authors.lastname: Porsbjerg
authors.affiliation: Department of Public Health, University of Copenhagen, Denmark; Department of Respiratory Medicine, Hvidovre Hospital, Denmark; The Copenhagen City Heart Study, Frederiksberg Hospital, Denmark. Electronic address: plange@dadlnet.dk.
authors.forename: Peter
authors.initials: P
authors.lastname: Lange
authors.affiliation: Institute of Clinical Medicine, University of Copenhagen, Denmark; Department of Respiratory Medicine, Hvidovre Hospital, Denmark. Electronic address: csulrik@dadlnet.dk.
authors.forename: Charlotte Suppli
authors.initials: CS
authors.lastname: Ulrik
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D013997:Time Factors; D014797:Vital Capacity / Q000502:physiology*; D055815:Young Adult
keywords: Adult onset; Asthma; Diagnosis; Lung function; Older adults