title: Circadian variation of cardiopulmonary disease onset in the general population: an emergency care system perspective from Berlin.
abstract: OBJECTIVE
  The objective of the present study was to determine the circadian pattern of onset of acute pulmonary emergencies in the general population and to analyze the influence of age and sex on these patterns.
  
  
  METHODS
  Analysis of all 47,082 emergency calls during the years 1987 and 1988 of the Berlin emergency medical system. Analysis of circadian variation in incidence of subgroups with the leading symptom of respiratory distress, chest pain, or sudden unconsciousness. All cases of nontraumatic sudden death were analyzed. All missions were evaluated with regard to sex and age dependence.
  
  
  RESULTS
  There is a circadian variation in acute cardiopulmonary emergencies with the highest incidence between 6 AM and noon. This applies to subpopulations of chest pain (9,068), respiratory distress (13,732), sudden unconsciousness (7,829), resuscitation attempts (4,787), and persons found dead without resuscitation attempts (4,780). Cases of chest pain, respiratory distress, and resuscitations show a second evening peak. Patients 65 years old or less have the highest rates in the afternoon, whereas those aged over 65 show a single morning peak (P < .0001). These relations are independent of sex and presenting complaint.
  
  
  CONCLUSIONS
  Unselected populations show circadian variations in the incidence of cardiopulmonary emergencies. Age-related differences suggest different pathophysiological age-dependent mechanisms, eg, hormonal factors or lifestyle-dependent trigger mechanisms. Emergency medical systems should adjust the availability of emergency services to the distinct circadian differences of life-threatening cardiovascular and pulmonary diseases.
authors.affiliation: Department of Medicine, Klinikum Steglitz, Free University of Berlin.
authors.forename: H R
authors.initials: HR
authors.lastname: Arntz
authors.forename: S N
authors.initials: SN
authors.lastname: Willich
authors.forename: R
authors.initials: R
authors.lastname: Stern
authors.forename: T
authors.initials: T
authors.lastname: Linderer
authors.forename: T
authors.initials: T
authors.lastname: Brüggemann
authors.forename: K
authors.initials: K
authors.lastname: Kelinski
authors.forename: R
authors.initials: R
authors.lastname: Schröder
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000787:Angina Pectoris / Q000503:physiopathology; D001604:Berlin / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000503:physiopathology*; D002940:Circadian Rhythm; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000453:epidemiology / Q000503:physiopathology*; D008297:Male; D012131:Respiratory Insufficiency / Q000503:physiopathology; D014474:Unconsciousness / Q000503:physiopathology