Fig. 6. Relation between delta sleep (minutes) and concanavalin-A–stimulated production of IL-10 by peripheral blood mononuclear cells at 23:00 hours in control () and alcoholic (•) African American subjects. In the total sample, expression of IL-10 at 23:00 hours was positively correlated with delta sleep amounts (Spearman = 0.46, p < .05).