Levels of sleep problems in the developing world are approaching those seen in developed nations, linked to an increase in problems like depression and anxiety.
According to the first ever pan-African and Asian analysis of sleep problems, led by Warwick Medical School at the University of Warwick, an estimated 150 million adults are suffering from sleep-related problems across the developing world.
The results are published in a study in the journal Sleep.
Warwick Medical School researchers have found a rate of 16.6 per cent of the population reporting insomnia and other severe sleep disturbances in the countries surveyed - close to the 20 per cent found in the general adult population in the West, according to nationwide surveys in Canada and the US.
The researchers, which also included academics from the INDEPTH Network in Ghana and the University of the Witwatersrand in South Africa, looked at the sleep quality of 24,434 women and 19,501 men aged 50 years and over in eight locations in rural populations in Ghana, Tanzania, South Africa, India, Bangladesh, Vietnam and Indonesia, and an urban area in Kenya.
They examined potential links between sleep problems and social demographics, quality of life, physical health and psychiatric conditions.
The strongest link was found between psychiatric conditions like depression and anxiety and sleep problems, mirroring trends seen in the developed world.
There was striking variation across the countries surveyed - Bangladesh, South Africa and Vietnam had extremely high levels of sleep problems, in some cases surpassing Western sleeplessness rates.
However India and Indonesia reported relatively low levels of severe sleep problems.
The research also found a higher prevalence of sleep problems in women and older age groups, consistent with patterns found in higher income countries.
Dr Saverio Stranges was the leading author of the manuscript at Warwick Medical School and colleague Ngianga-Bakwin Kandala performed the analyses.
Dr Stranges said: "Our research shows the levels of sleep problems in the developing world are far higher than previously thought.
"This is particularly concerning as many low-income countries are facing a double burden of disease with pressure on scarce financial resources coming from infectious diseases like HIV, but also from a growing rate of chronic diseases like cardiovascular diseases and cancer.
"This new study suggests sleep disturbances might also represent a significant and unrecognised public health issue among older people, especially women, in low-income settings.
"Also it seems that sleep problems are not linked to urbanisation as the people surveyed were mostly living in rural settings.
"We might expect even higher figures for people living in urban areas."
One of the most striking elements of the analysis was the differences between countries analysed.
Bangladesh had the highest prevalence of sleep problems among the countries analysed - with a 43.9 per cent rate for women - more than twice the rate of developed countries and far higher than the 23.6 per cent seen in men.
Bangladesh also saw very high patterns of anxiety and depression.
Vietnam too had very high rates of sleep problems - 37.6 per cent for women and 28.5 per cent for men.
Meanwhile in African countries, Tanzania, Kenya and Ghana saw rates of between 8.3 per cent and 12.7 per cent.
However South Africa had double the rate of the other African countries - 31.3 per cent for women and 27.2 per cent for men.
India and Indonesia both had very low prevalence of sleep issues - 6.5 per cent for Indian women and 4.3 per cent for Indian men.
Indonesian men reported rates of sleep problems of 3.9 per cent and women had rates of 4.6 per cent.
The study, Sleep Problems: an Emerging Global Epidemic? Findings from the INDEPTH WHO-SAGE study among over 40,000 older adults from eight countries across Africa and Asia, was published in the journal Sleep.
It was supported by the World Health Organisation and funded by the National Institute on Aging of the National Institutes of Health, USA and by the Wellcome Trust, UK.
The study was authored by Saverio Stranges, Ngianga-Bakwin Kandala, Margaret Thorogood and Willam Tigbe of Warwick Medical School at the University of Warwick and Francesc Xavier Gómez-Olivé of MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), University of the Witwatersrand South Africa.
The authors gratefully acknowledge the INDEPTH Network, Accra, Ghana, and the Health Statistics and Informatics from the World Health Organization, Geneva, Switzerland, for publicly providing the INDEPTH WHO-SAGE multicentre study data.
Notes to editors
The study can be found at http://dx.
For a draft copy of this study or for further information:
Dr Saverio Stranges is available on +44 (0) 2476151153 or S.Stranges@warwick.ac.uk
Or you can contact Anna Blackaby, University of Warwick press officer, on +44 (0)2476 575910 or +44 (0) 7785 433155 or firstname.lastname@example.org