The clinical significance of sleep apnoea in workers exposed to organic solvents: implications for the diagnosis of organic solvent encephalopathy

Abstract

Among 51 patients referred for investigation of possible organic solvent encephalopathy 20 (39%) had pathological sleep apnoea [apnoea index (AI) greater than 5], compared with 5 of 16 house painters exposed to solvents (31%) who were screened for the disorder, and 1 of 18 (6%) age-matched controls. Twelve of the patients with AI greater than 5 were retested after 2 or more weeks without exposure to solvents, and showed a significant drop in AI. Likewise, significantly lower AI was seen in patients who were no longer exposed to solvents, compared with recently exposed patients. The implications of these findings for diagnostic evaluation of solvent encephalopathy and sleep apnoea are discussed.

Sleep apnea and occupational exposure to solvents

“…This finding supports the theory that disturbances in the sleep-wake rhythm aggravate sleep apnea. This mechanism may also be the means for interpreting the observations made by Monstad et al (18), who documented the fall in an apnea index among 12 workers after the end of their exposing occupation.…”

“…The hypothesis that solvents induce sleep apnea is mainly based on three Scandinavian studies (17)(18)(19). In the first study, subjects who had been exposed to solvents were observed in a sleeping laboratory; they suffered from sleep apnea far more frequently than expected.…”

“…A Norwegian study revealed an increased prevalence of obstructive sleep apnea among a group of 51 persons with solvent exposure in comparison with 18 unexposed referents (18). A prevalence of 30% for obstructive sleep apnea among exposed persons, compared with 6% for unexposed persons, was determined.…”

Occupational Exposure to Organic Solvents and Sleep-Disordered Breathing

“…Increased fre quency of sleep apnea as compared to referents was demonstrated in a small group of workers with high exposure to trichloroethane [15]. There are several studies in which solventexposed patients with suspected or confirmed chronic toxic encephalopathy have been found to have higher frequencies of sleep apnea than referents [15][16][17].…”

“…Higher preva lences of sleeping problems and poor sleep quality have been reported among men occu pationally exposed to solvents [10][11][12][13], A case of sleep apnea was reported in a worker with high exposure to trichloroethane [ 14] and there are other studies in which occupational expo sure to organic solvents has been implicated as a possible cause of sleep apnea [15,16]. In an earlier study we have also found an increased prevalence of sleep apnea among men occupa tionally exposed to organic solvents [17].…”