Plasma melatonin levels in hip fracture patients with and without delirium: A confirmation study.

Background: Melatonin plays a major role in maintaining circadian rhythm. Changes in melatonin metabolism might lead to circadian rhythm disturbances which are often observed in delirious patients.

Aim: To assess if high morning plasma melatonin concentrations were associated with delirium.

Physiological melatonin levels in healthy older people: A systematic review.

Objective: Melatonin plays a major role in maintaining circadian rhythm. Previous studies showed that its secretion pattern and levels could be disturbed in persons with dementia, psychiatric disorders, sleep disorders or with cancer. Also ageing is a factor that could alter melatonin levels, although previous research provides contradicting results.