title: Decline of FEV1 in scuba divers.
abstract: OBJECTIVE
  Obstructive changes in lung function have been reported with cumulative scuba diving exposure. The aim of this study was to investigate the decline in FEV1 in scuba divers over time.
  
  
  METHODS
  Prospective controlled cohort study.
  
  
  METHODS
  German Naval Medical Institute.
  
  
  METHODS
  Four hundred sixty-eight healthy, male, military scuba divers and 122 submariners (control subjects) were entered.
  
  
  RESULTS
  Pulmonary function tests were performed in all subjects on at least three occasions with a minimum interval of 1 year between first and last measurement. The decline in FEV1 was investigated fitting a general linear model to FEV1 across time with a factorial main-effects model for slopes and intercepts with respect to the factors group, smoking status, and baseline FEV1. Mean baseline age of all subjects was 32 years (SD, 9.1), and mean body mass index was 24.7 kg/m2 (SD, 2.4). Subjects were followed up for 5 years (range, 1 to 9 years) on average. Baseline FEV1 exceeded the predicted values in both divers and nondiving control subjects. There was no significant difference in the decline of FEV1 between divers and control subjects. Over time, FEV1 declined more rapidly in smokers than in nonsmokers (p = 0.0064) and declined more rapidly also in subjects with a baseline FEV1 above average compared to subjects below average (p < 0.0001). The annual decline of FEV1 peaked in smoking divers who had a high FEV1 at baseline.
  
  
  CONCLUSIONS
  The data indicate that scuba diving is not associated with an accelerated decline in FEV1. Combined exposure to diving and smoking contributes to the fall of FEV1; therefore, smoking cessation is advised for divers.
authors.affiliation: Medical Clinic and Polyclinic, Department of Sports Medicine, University of Tuebingen Silcherstrasse 5, 72076 Tübingen, Germany. Kay.Tetzlaff@med.uni-tuebingen.de
authors.forename: Kay
authors.initials: K
authors.lastname: Tetzlaff
authors.forename: Jens
authors.initials: J
authors.lastname: Theysohn
authors.forename: Caroline
authors.initials: C
authors.lastname: Stahl
authors.forename: Sabine
authors.initials: S
authors.lastname: Schlegel
authors.forename: Andreas
authors.initials: A
authors.lastname: Koch
authors.forename: Claus M
authors.initials: CM
authors.lastname: Muth
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004242:Diving / Q000009:adverse effects / Q000502:physiology*; D005858:Germany; D006801:Humans; D008137:Longitudinal Studies; D008176:Lung Volume Measurements; D008297:Male