Aim: Elderly multimorbid care home dwellers are a heterogenic group of frail individuals that exhibit sleep disturbances and a range of co-morbidities. The project aimed to study the possible effect of indoor circadian-adjusted LED-lighting (CaLED) in the elderly residents' care home on their sleeping patterns and systemic biomarkers associated with inflammation.

Methods: A 16-week trial study was performed to follow the intervention and control groups using the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) to monitor sleep and daytime sleepiness, and biomarkers IL-6, TNF-α and suPAR, to estimate the levels of inflammation.

Results: There was no significant impact on sleep improvement after the short intervention time when analyzing the PSQI and ESS results. However, we found several challenges using these tools for this specific group of individuals. Thus, important knowledge was gained for future studies in elderly care home dwellers. The inflammation state throughout the entire study period was stable for most of the elderly and no significant change was detected from before to after the intervention. This study represents a first-to-date attempt to ameliorate the adverse effects of sleep disturbances that characterize a randomly chosen group of elderly multimorbid subjects, by using circadian-adjusted LED-lighting in a natural care home environment.

Conclusion: In this pragmatic randomized study of home dwelling individuals we were not able to demonstrate an improved sleep pattern as judged by PSQI, ESS or a change in inflammatory state.

Keywords: Circadian; LED-lighting; elderly; inflammation; multimorbidity; sleep.