title: Chronic mucus hypersecretion: prevalence and risk factors in younger individuals.
abstract: METHODS
  Chronic mucus hypersecretion (CMH) is a common condition in patients with chronic respiratory diseases. Little is known about the incidence, prevalence and determinants of CMH in younger individuals.
  
  
  OBJECTIVE
  To determine prevalence, incidence and risk factors for CMH in a young general population.
  
  
  METHODS
  A cohort of Danish twins (aged 12-41 years) was prospectively examined using questionnaires in 1994 (n = 29 180) and in 2002 (n = 21 130). Prevalence and incidence of CMH were determined, and risk factors for the condition were assessed using logistic regression.
  
  
  RESULTS
  Lifetime prevalence of CMH was 8.6% in females and 6.9% in males in 1994, and the cumulative incidence among females and males was respectively 10.7% and 8.7% during the study period. Smoking and asthma were risk factors for CMH, with a dose-response effect of tobacco consumption, and smoking habits also predicting incidence of CMH.
  
  
  CONCLUSIONS
  Among the young, CMH is a condition related to asthma and smoking, with a dose-response relationship with tobacco consumption and a relation between smoking habits and incidence. Female susceptibility to development of CMH was observed, as well as signs of greater susceptibility related to young age.
authors.affiliation: Respiratory and Allergy Research Unit, Department of Respiratory Medicine L, Copenhagen University Hospital, Bispebjerg, Denmark. l.harmsen@dadlnet.dk
authors.forename: L
authors.initials: L
authors.lastname: Harmsen
authors.forename: S F
authors.initials: SF
authors.lastname: Thomsen
authors.forename: T
authors.initials: T
authors.lastname: Ingebrigtsen
authors.forename: I E
authors.initials: IE
authors.lastname: Steffensen
authors.forename: L R
authors.initials: LR
authors.lastname: Skadhauge
authors.forename: K O
authors.initials: KO
authors.lastname: Kyvik
authors.forename: V
authors.initials: V
authors.lastname: Backer
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001249:Asthma / Q000453:epidemiology* / Q000378:metabolism; D002648:Child; D003718:Denmark / Q000453:epidemiology; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008297:Male; D009093:Mucus / Q000378:metabolism*; D016017:Odds Ratio; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000378:metabolism; D020545:Respiratory Mucosa / Q000378:metabolism*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000378:metabolism; D011795:Surveys and Questionnaires; D055815:Young Adult