The EU-backed researchers not only looked at the physical and mental state of the sleep deprived, but also the sociological aspects to determine how this can affect human behaviour and health.
The project, led by the University of Helsinki´s Dr Tarja Porkka Heiskanen,used various sleep restriction experiments within the controlled conditions of their sleep laboratories. In one study, the sleeping patterns of young, healthy men were restricted to just four hours per night over a period of five days, followed by two nights of normal sleep.
The results concluded that sleep restriction induced changes in the body´s energy metabolism, immune system and autonomic nervous system. It also revealed that sleep curtailment could cause inflammation and oxidative stress, and consequently trigger mechanisms involved in cardiovascular disease.
The study also investigated a further 97 people to determine the impact of sleep disorders on the metabolic, endocrine and immune functions. Project scientists conducted experiments with patients who experienced various sleep disorders, including obstructive sleep apnea, restless legs syndrome and patients with primary insomnia.
They discovered that the degree of disturbance was negatively related to measures of sleep continuity. When they studied the sociological aspect of sleep deprivation, they found that the quantitative analysis revealed a connection between disadvantaged social status and high levels of sleep problems. Long working hours and long commutes to work were also associated with shorter sleeps among those studied.
A survey of middle-aged British women also revealed that women with a lower socio-economic status, and particularly women with lower levels of education, are more likely to suffer from disturbed sleep.
Additional research studies show that habitually sleeping more than nine hours is also associated with poor health.
Some of these issues will be addressed at the ´European Basic and Clinical Sleep Research Towards Horizon 2020´ today in Brussels. This meeting is part of the program for the Month of the Brain, that will be organised in May 2013 at the initiative of the DG Research and Innovation (Health Directorate) of the EU Commission. .