A comparative model: Reaction time performance in sleep-disordered breathing versus alcohol-impaired controls

Objectives/Hypothesis: Patients with sleep-disordered breathing have reacti on time deficits that may lead to catastrophic accidents and loss of Life. Although safety guidelines do not exist for unsafe levels of sleepiness, th ey have been established for unsafe levels of alcohol consumption. Since re action time performance is altered in both, we prospectively used seven mea sures of reaction time performance as a comparative model in alcohol-challe nged normal subjects with corresponding measures in subjects with sleep dis ordered breathing. Study Design: Institutional Review Board-approved, nonra ndomized prospective controlled study, Methods: Eighty healthy volunteers ( 29.1 +/- 7.5 y of age, 56.3% female subjects) performed four reaction time trials using a psychomotor test at baseline and at three subsequent rising alcohol-influenced time points. The same test without alcohol was given to 113 subjects (47.2 +/- 10.8 y of age, 19.3% female subjects) with mild to m oderate sleep-disordered breathing. Results: Mean blood alcohol concentrati ons (BACs) in the alcohol-influenced subjects at baseline and three trials were 0, 0.057, 0.080, and 0.083 g/dL, The sleep-disordered subjects had mea n respiratory disturbance indices of 29.2 events per hour of sleep. On all seven reaction time measures, their performance was worse than that of the alcohol subjects when BACs were 0.057 g/dL, For three of the measures, the sleep disordered subjects performed as poorly as or worse than the alcohol subjects when alcohol levels were 0.080 g/dL. These results could not be ex plained by sex or age differences. Conclusion: The data demonstrate that sl eep-disordered subjects in this study (with a mean age of 47 y) with mild t o moderate sleep-disordered breathing had worse test reaction time performa nce parameters than healthy, nonsleepy subjects (with a mean age of 29 y) w hose BAC is illegally high for driving a commercial motor vehicle in Califo rnia. This comparative model points out the potential risks of daytime slee piness in those with sleep-disordered breathing relative to a culturally ac cepted standard of impairment.