Determinants of peak flow rate among Hutterite farmers.

: Observations from respiratory studies of over 1000 Hutterites and 200 control subjects indicated that the percent predicted peak flow rate values were 20% lower among Hutterites than control subjects. The purpose of this study was to determine if the decreased peak flow rate values among male Hutterites were a function of decreased airway patency or decreased respiratory muscle strength. Peak flow rate, muscle and lung function and the prevalence of respiratory symptomatology and disease were evaluated in 27 males from two Hutterite colonies. In one group almost all members consistently used masks while performing farming tasks, while 41% of members from the other colony used masks intermittently. Results suggest that peak flow rate values are decreased predominantly due to decreased airway patency associated with a higher prevalence of respiratory symptoms and disease and are not limited by respiratory muscle strength.