Fig. 2.

Melatonin profiles in day workers (DW) and night workers (NW) before and after moderate alcohol consumption. Blood was drawn every hour under dim light (<5 lux) and dim light melatonin onset (DLMO) was calculated by the 3k method as described in methods. A: there was a nonsignificant 7-min phase advance in the DW after alcohol consumption. There was a significant 1 h 57 min phase delay in the NW group, P < 0.01 by group (B). A circular plot of the time of each DLMO in the DW group before (C) and after (D) alcohol and in the NW group before (E) and after (F) alcohol shows a phase delay in the NW group.