title: Respiratory impairment and the aging lung: a novel paradigm for assessing pulmonary function.
abstract: BACKGROUND
  Older persons have an increased risk of developing respiratory impairment because the aging lung is likely to have experienced exposures to environmental toxins as well as reductions in physiological capacity.
  
  
  METHODS
  Systematic review of risk factors and measures of pulmonary function that are most often considered when defining respiratory impairment in aging populations.
  
  
  RESULTS
  Across the adult life span, there are frequent exposures to environmental toxins, including tobacco smoke, respiratory infections, air pollution, and occupational dusts. Concurrently, there are reductions in physiological capacity that may adversely affect ventilatory control, respiratory muscle strength, respiratory mechanics, and gas exchange. Recent work has provided a strong rationale for defining respiratory impairment as an age-adjusted reduction in spirometric measures of pulmonary function that are independently associated with adverse health outcomes. Specifically, establishing respiratory impairment based on spirometric Z-scores has been shown to be strongly associated with respiratory symptoms, frailty, and mortality. Alternatively, respiratory impairment may be defined by the peak expiratory flow, as measured by a peak flow meter. The peak expiratory flow, when expressed as a Z-score, has been shown to be strongly associated with disability and mortality. However, because it has a reduced diagnostic accuracy, peak expiratory flow should only define respiratory impairment when spirometry is not readily available or an older person cannot adequately perform spirometry.
  
  
  CONCLUSIONS
  Aging is associated with an increased risk of developing respiratory impairment, which is best defined by spirometric Z-scores. Alternatively, in selected cases, respiratory impairment may be defined by peak expiratory flow, also expressed as a Z-score.
authors.affiliation: Department of Internal Medicine, Veterans Affairs Clinical Epidemiology Research Center, West Haven, Connecticut 06516, USA. carlos.fragoso@yale.edu
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Vaz Fragoso
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gill
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000397:Air Pollution / Q000009:adverse effects; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D012129:Respiratory Function Tests; D012143:Respiratory Physiological Phenomena; D012141:Respiratory Tract Infections / Q000503:physiopathology; D012307:Risk Factors