LAUSR

Insomnia disorder has a very weak link to polysomnography (PSG) and so does sleep problems in the general population. The reason for this is not clear. One possibility is that the perception of disturbed sleep may be related to immune activation or anxiety/depression, without impairment of objective sleep. 400 women participated, constituting a representative sample of the city of Uppsala with oversampling of snorers. Insomniacs (N=41) were compared with normal sleepers in terms of polysomnography (PSG), immune parameters, anxiety and depression The results (after adjustment for age and BMI) show that C-reactive protein (CRP) reached a higher level (4.4±.5) in insomniacs (vs 2.3±.2 for normal sleepers) (p=.003) and lower subjective health (p=.000), while anxiety (p=.000) and depression (p=.000) (Hospital Anxiety and Depression Scale (HAD)) showed higher levels. PSG sleep continuity variables lacked association with insomnia, as did all sleep stage variables except for REM%, with a lower level in the insomnia group (p=.021). Interleukin 6 and Tumor Necrosis Factor alpha were not related to insomnia. CRP levels did not correlate significantly with anxiety or depression, but with subjective health (r=-.21, p=.000). A logistic regression analysis (excluding the variable subjective health) with insomnia as outcome (0/1) yielded as predictors CRP (OR=1.14, Ci= 1.05; 1.24, p=.000), depression (OR=1.21, Ci=1.06;1.38, p=.000) and anxiety (OR=1.15, Ci=1.02;1.30, p=.021). It was concluded that increased CRP levels may be part of the subjective experience of insomnia. No external funding