Insomnia symptoms and risk of bloodstream infections: prospective data from the prospective population-based HUNT Study, Norway

Abstract

AbstractObjectivePrevious research suggest decreased immune function and increased risk of infections in persons with insomnia. We examined the effect of insomnia symptoms on risk of bloodstream infections (BSI) and BSI-related mortality in a population-based prospective study.MethodsA total of 53,536 participants in the Norwegian HUNT2 study (1995–97) were linked to prospective data on clinically relevant BSIs until 2011. In Cox regression, we estimated hazard ratios (HRs) with 95% confidence interval (CI) for a first-time BSI and for BSI related mortality (BSI registered ≤30 days prior to death) associated with insomnia symptoms.ResultsCompared with participants who reported “no symptoms of insomnia”, participants reporting having “difficulty initiating sleep” often/almost every night had a HR for a first-time BSI of 1.14 (95% CI 0.96–1.34). Participants reporting “difficulties maintaining sleep” often/almost every night had a HR of 1.19 (95% CI 1.01–1.40), whereas those having a “feeling of non-restorative sleep” once a week or more had a HR of 1.23 (95% CI 1.04–1.46). Participants experiencing all three above insomnia symptoms frequently had a HR of 1.39 (1.04–1.87) and being troubled by insomnia to a degree that affected work performance was associated with a HR of 1.41 (95% CI 1.08–1.84). The HRs for BSI related mortality suggest an increased risk with increasing insomnia symptoms, but confidence intervals are wide and inconclusive.ConclusionsWe found that frequent insomnia symptoms and insomnia symptoms that affected work performance was associated with a weak positive increased risk of BSI.