The effect of in-laboratory polysomnography on sleep and objective daytimesleepiness

MSLT guidelines recommend performing MSLTs following polysomnography (PSG) to document the preceding night's sleep. We tested the hypothesis that pati ents are objectively sleepier after in-laboratory full diagnostic PSG than after a sleep recording at home. Sixteen patients with the sleep apnea/hypo pnea syndrome (SAHS; AHI 35+/-SD 28 per hour slept) were recruited into a r andomized crossover study. To monitor sleep with minimal disruption at home , only sleep was recorded on 2 consecutive nights, the first for acclimatiz ation. The laboratory limb followed standard PSG. Bath study nights were fo llowed next day by MSLT and MWT. There were no differences in MSLT (12.0 SD 5.1 home, 11.6+/-4.7 min laboratory; p=0.7), MWT (32.7+/-8.7, 31.6+/-9.3 m in; p=0.6) or total sleep time (362+/-53, 343+/-51 min; p=0.15) between hom e and laboratory limbs. However, on the home night, fewer microarousals (31 +/-14, 54+/-25/hr slept; p<0.0001) and less % wake (15+/-10, 24+/-11; p=0.0 06) were found. On the home study night, patients had greater % REM sleep, slow-wave sleep and sleep efficiency (all p<0.009). This study does not sup port the hypothesis that patients are sleepier after laboratory PSG compare d to home study night. However, the improved sleep at home raises the quest ion whether laboratory-based polysomnography is always required prior to MS LT/MWT testing or whether less obtrusive monitoring of sleep duration at ho me would sometimes suffice.