title: North African reference equation for peak nasal inspiratory flow.
abstract: OBJECTIVE
  To assess, in healthy North African subjects, the applicability and reliability of a previously published reference equation and normal values for peak nasal inspiratory flow, and to calculate a peak nasal inspiratory flow reference equation in this population.
  
  
  METHODS
  Anthropometric data were recorded in 212 volunteers (100 females and 112 males) aged 13-27 years. Peak nasal inspiratory flow was measured several times. Univariate and multiple linear regression analyses were used to determine the reference equation.
  
  
  RESULTS
  The previously published reference equation and normal values did not reliably predict peak nasal inspiratory flow in the study population. In our subjects, the reference equation (r2 = 30 per cent) for peak nasal inspiratory flow (l/min) was 1.4256 × height (m) + 33.0215 × gender (where 0 = female, 1 = male) + 1.4117 × age (years) - 136.6778. The lower limit of normal was calculated by subtracting from the peak nasal inspiratory flow reference value (84 l/min).
  
  
  CONCLUSIONS
  This is the first published study to calculate a reference equation for peak nasal inspiratory flow in North African subjects. This equation enables objective evaluation of nasal airway patency in patients of North African origin.
authors.affiliation: Laboratory of Physiology, Faculty of Medicine, Sousse Ibn El Jazzar, Farhat Hached Hospital, Sousse, Tunisia. myriam_denguezli2@yahoo.fr
authors.forename: M Denguezli
authors.initials: MD
authors.lastname: Bouzgarou
authors.forename: H
authors.initials: H
authors.lastname: Ben Saad
authors.forename: A
authors.initials: A
authors.lastname: Chouchane
authors.forename: I Ben
authors.initials: IB
authors.lastname: Cheikh
authors.forename: A
authors.initials: A
authors.lastname: Zbidi
authors.forename: J F
authors.initials: JF
authors.lastname: Dessanges
authors.forename: Z
authors.initials: Z
authors.lastname: Tabka
mesh_terms: D000293:Adolescent; D000328:Adult; D000352:Africa, Northern / Q000208:ethnology; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D001699:Biometry / Q000379:methods*; D056808:Biostatistics; D044383:Black People; D001827:Body Height / Q000502:physiology; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000502:physiology*; D015508:Nasal Obstruction / Q000503:physiopathology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D012016:Reference Values; D012044:Regression Analysis; D015203:Reproducibility of Results; D025363:Rhinomanometry / Q000379:methods* / Q000592:standards; D012727:Sex Characteristics; D055815:Young Adult