Am. J. Respir. Crit. Care Med., Vol 153, No. 2, 02 1996, 701-705.
Persistent wheeze in grain elevator workers should not be ignored
A Senthilselvan, P Pahwa, P Wang, HH McDuffie and JA Dosman
Department of Medicine, University of Saskatchewan, Saskatoon, Canada.
We investigated the relationship between annual change in pulmonary
function and changes in respiratory symptoms among male grain elevator
workers who participated in a health surveillance program mandated by
Labour Canada. The surveillance was conducted every 3 yr starting from the
period 1978 to 1981. The 1,211 workers who participated in the second (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 annual rate change in FEV1
(-44.4 ml/yr) and FVC (- 55.3 ml/yr). When adjusted for age, height, weight
change, smoking, baseline lung function, location of grain elevators, and
duration of employment, the subjects with persistent wheeze had an annual
rate change of -28.3 ml/yr (SE 10.5; p = 0.007) in FEV1 and -37.3 ml/yr (SE
= 12.3; p = 0.003) in FVC in comparison to subjects without any respiratory
symptoms. The subjects who reported new onset of wheeze had significantly
greater annual rate changes only in FEV1 (-13.7 ml/yr; SE 6.0; p = 0.02) in
comparison to asymptomatic subjects' symptoms. Persistent wheeze is an
important predictor of decline in lung function among grain elevator
workers and should not be ignored in surveillance programs or clinical
evaluations.
