Changes in lung function in Republic of Singapore Navy divers

It is recognized that diving may result in long-term adverse effects on the lungs, In the Republic of Singapore Navy (RSN), divers undergo an annual examination, which includes spirometry to detect early any deterioration in lung function, to ensure that personnel are fit to continue their duties. There are a few Asian studies on lung function, and none on Asian divers.

To analyze the lung function of a group of RSN divers over a five-year period.

This was a retrospective study based on the spirometric results of RSN divers during their annual recertification in 2001 and in 2006. There were 116 subjects who underwent the spirometry at the same centre in both 2001 and 2006.

The divers showed a statistically significant increase in mean forced vital capacity (FVC) from 86.1% to 89.5% of predicted (P < 0.01) over the five-year period. In addition, the mean forced expiratory volume in one second (FEV1) improved significantly from 87.2% to 90.2% of predicted (P < 0.01). However, there was a statistically significant decrease in FEV1/FVC ratio from 87.0% to 85.0% of predicted (P < 0.01). Mean peak expiratory flow rose from 100.1% to 111.00% of predicted (P < 0.01). We did not find any statistically significant relationship between years of service or smoking history and changes in lung function for the divers.

Despite being statistically significant, these findings are probably of minimal clinical significance, but do demonstrate that there is no decline in lung function in these divers over this period of time.