Lack of sleep may cause heart disease in poor: Study

Insufficient sleep is one reason why people with a lower socioeconomic status are at a higher risk of heart disease, according to a study published on Thursday.

Researchers from the University Centre of General Medicine and Public Health (Unisante) in Switzerland noted that economically disadvantaged people sleep less for a variety of reasons.

They may do several jobs, work in shifts, live in noisy environments, and have greater levels of emotional and financial stress.

The study, published in the journal Cardiovascular Research, is the first to examine whether lack of sleep could partly explain why poor people have more heart disease.

It found that short sleep explained 13.4 per cent of the link between occupation and coronary heart disease in men.

"The absence of mediation by short sleep in women could be due to the weaker relationship between occupation and sleep duration compared to men," said Dusan Petrovic, of the University Centre of General Medicine and Public Health.

The researchers noted that structural reforms are needed at every level of society to enable people to get more sleep.

Attempts should be made to reduce noise, for example, which is an important source of sleep disturbance, with double glazed windows, limiting traffic, and not building houses next to airports or highways, they said.

The study pooled data from eight groups totalling 1,11,205 participants from four European countries.

Socioeconomic status was classified as low, middle, or high according to father's occupation and personal occupation.

History of coronary heart disease and stroke was obtained from clinical assessment, medical records, and self-report.

Average sleep duration was self-reported and categorised as recommended or normal sleep -- 6 to 8.5 hours, short sleep (six hours), and long sleep -- more than 8.5 hours per night.