In contrast, in a large Norwegian epidemiological study, self-reported sleep disturbances (assessed via only three questions) were significantly but only very modestly associated with CRP levels in men (Spearman’s r ranged 0–0.06 as a function of sleep item), but not in women (Spearman’s r ranged − 0.02–0.05) [85]. This evidence concerns the gene CRP and Sleep disturbance.