Improving sleep in aging 

Tom de Boer (LUMC)
Maria Panagiotou (LUMC)

In modern society, average age and maximal life span increases due to reduced birth rates and improved medical care throughout life. The increasing demands of medical care for the elderly call for high care efficiency and place healthy aging as an important central topic in affluent societies for strategic, economic, and ethical reasons. Sleep and circadian rhythm disturbances are one of the key problems in aging and are a serious threat to the health and well being of the elderly population, 25 leading to institutionalization. Although treatments have been suggested to improve circadian rhythms and sleep quality there is a strong need for validation, expansion, and mechanistic confirmation before they can be widely used in medical practice. Here, we start to elaborate mechanisms behind these observations.

With this project we will provide new investigative models and environmental/behavioral protocols that will counteract age-induced decrement in functionality of the circadian system and sleep quality with its negative consequences for general health. As animals and humans age, the amplitude of their day-night rhythm deteriorates and their sleep becomes more fragmented. Sleep fragmentation results in increased sleep pressure and hence, elderly people feel sleepier. We have previously shown that changes in sleep pressure influence the amplitude of the neuronal activity of the circadian clock in the suprachiasmatic nucleus (SCN). Other results from our laboratory show that the ability of the circadian clock to respond to a phase shifting stimulus correlates positively with the amplitude of SCN neuronal activity. These results suggest that disturbed sleep and increased sleep pressure reduces the functioning of the endogenous circadian clock. In return sleep structure will be fragmented, starting a vicious circle of reduced sleep quality and circadian clock functioning.

In the current project we want to investigate whether this cycle may be stopped through two non-invasive techniques that are known to affect SCN functioning in non-aged animals: appropriate light treatment and scheduled exercise.