Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Final Activity Report Summary - SLEEP RESTRICTION (The biomedical and sociological effects of sleep restriction)

The decreasing time spent in sleep, as well as the increasing number of people suffering from sleep disturbances, prompted us to study the effects of sleep restriction both experimentally and in patients with disturbed sleep. A new aspect to sleep was the inclusion of also sociological studies. Using various sleep restriction experiments performed in controlled conditions in sleep laboratories we showed that sleep curtailment could induce inflammatory process as well as oxidative stress in healthy young subjects. Our data indicate thus that sleep restriction in healthy subjects triggers mechanisms involved in cardiovascular disease.

In one study sleep of young, healthy men was restricted to four hours per night during five days, mimicking a normal working week. After the restriction they were allowed to sleep normally for two nights, mimicking week-end. Their performance was monitored and blood samples were collected. The results revealed that sleep restriction induced changes in the functions of energy metabolism, immune system and autonomic nervous system. Based on these results we introduce a model which could explain the increased risk for cardiac diseases in connection with sleep restriction. Recovering from sleep loss is a process taking more than one night of normal sleep. Indeed, after five nights of sleep restricted to five hours per night, inflammatory markers were not normalised after two nights of recovery in young healthy subjects. To investigate the impact of sleep disorders on metabolic, endocrine, and immune functions we studied a total of 97 subjects including healthy controls, patients with obstructive sleep apnea syndrome, restless legs syndrome and patients with primary insomnia.

The most intriguing finding was that glucose tolerance was disturbed in OSAS and RLS patients. The degree of disturbance was negatively related to measures of sleep continuity. Within sociology, there had previously been little empirical sociological research on sleep. Findings on sociology of sleep have shown how women's caring roles in Italy throughout their life course have a negative impact on their sleep, including care for young children, adult children, for partners, and especially for older frail and disabled parents. These adverse effects on sleep are particularly significant in Italy because of the lack of welfare provision for frail older people through residential care homes and state / voluntary domiciliary support. Hitherto sleep researchers were unaware of the extent of socio-economic inequalities in sleep disturbance.

The sociology quantitative analysis showed strong linkages between disadvantaged social status and high levels of sleep problems. We also demonstrated how long working hours and long commutes to work are associated with short sleep duration.

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