PERSISTENT WHEEZE IN GRAIN ELEVATOR WORKERS SHOULD NOT BE IGNORED

We investigated the relationship between annual change in pulmonary fu nction and changes in respiratory symptoms among male grain elevator w orkers who participated in a health surveillance program mandated by L abour Canada. The surveillance was conducted every 3 yr starting from the period 1978 to 1981.The 1,211 workers who participated in the seco nd (1981 to 1984) and fifth (1990 to 1993) surveillance were included in the analysis and the mean duration of the follow-up was 8.6 yr. In the analysis we also included the pulmonary function measurements that were available for some subjects at the third and fourth surveillance . The subjects who reported persistent wheeze had the largest mean ann ual rate change in FEV(1) (-44.4 ml/yr) and FVC (-55.3 ml/yr). When ad justed for age, height, weight change, smoking, baseline lung function , location of grain elevators, and duration of employment, the subject s with persistent wheeze had an annual rate change of -28.3 ml/yr (SE 10.5; p = 0.007) in FEV(1) and -37.3 ml/yr (SE = 12.3; p = 0.003) in F VC in comparison to subjects without any respiratory symptoms. The sub jects who reported new onset of wheeze had significantly greater annua l rate changes only in FEV(1) (-13.7 ml/yr; SE 6.0; p = 0.02) in compa rison to asymptomatic subjects' symptoms. Persistent wheeze is an impo rtant predictor of decline in lung function among grain elevator worke rs and should not be ignored in surveillance programs or clinical eval uations.