NOCTURNAL OXYGEN DESATURATION, AS ASSESSED BY HOME OXIMETRY, IN LONG-TERM SOLVENT-EXPOSED WORKERS

Recent studies have suggested that occupational exposure to solvents m ay be a cause of sleep apnea. Digital oximetry during one night was pe rformed in solvent-exposed offset printers (n = 21) and in a control g roup (n = 21), using a Palco 400 Pulse Oximeter. the threshold for rec ording was set at an arterial oxygen saturation (SaO(2)) of 90%. Furth ermore, computerized neurobehavioral tests (NES) and a solvent-related complaints questionnaire (NSC-60) were administered. The mean exposur e time was 15 years (SD = 10). Hygiene measurements revealed a large n umber of different solvents and a cumulative exposure between 15% and 97% of the ''cumulative TLV.'' The exposed workers had more solvent-re lated complaints, especially regarding mood (analysis of covariance, P = 0.02), than the nonexposed workers. The neurobehavioral tests indic ated that hand-eye coordination was significantly worse in the exposed group (analysis of covariance, P = 0.03). The frequency of nocturnal desaturation was significantly higher in the printers (1.7 events/hr /- SD = 1.5) than in the controls (0.6) events/hr +/- SD = 1.3) (Mann- Whitney test, P < 0.01). Also, the duration of desaturation was longer in the exposed workers: 3.2 min/hr (SD = 3.2) vs 1.2 min/hr (SD = 2.3 ) (Mann-Whitney test, P < 0.01). In the analysis of covariance, exposu re (P = 0.04) and the interaction between smoking and exposure (P = 0. 02) were shown to contribute significantly to the excess of nocturnal desaturation in the exposed. The same was true for the mean duration o f desaturation (exposure: P = 0.02 and interaction exposure smoking: P = 0.02). The significant interaction was due to a more pronounced eff ect of solvent exposure among the nonsmoker group. No relation was fou nd between the excess of complaints or the neuroperformance effects an d the oximetry data. These data reinforce the presumption that occupat ional solvent exposure might contribute to sleep-disordered breathing. (C) 1997 Wiley-Liss, Inc.