Deakin findings reveal weight loss can improve daytime sleepiness

Winda Ng, a visiting PhD student at Deakin University and the study's first author, said the findings provide health professionals with an alternative treatment strategy in dealing with the common problem of daytime sleepiness and will also pave the way for further important research in the area.

Miss Ng said while sleepiness reduced work and academic performance and increased the risk of accidents, injuries and mortality, little was known about the actual relationship between weight loss and the condition until the findings of the newly-published study.

The systematic review and meta-analysis, which focussed on whether intentional weight loss through surgical and non-surgical means improved daytime sleepiness, drew on data from 42 studies from Australia and around the globe.

"We found that daytime sleepiness clearly improved after participation in weight loss interventions – and that's all kinds of weight loss including surgical, diet or increased physical activity," Miss Ng said.

"Weight loss had a moderate to large effect in the surgical group and small to moderate for non-surgical interventions."

Ms Ng said given the increasing prevalence of obesity, it was important that people understood the consequences of being obese.

"People have looked at many different diseases such as cardiovascular disease but sleep disorders are a neglected area in the research," she said.

"This study provides an alternative treatment strategy for sleepiness and people with obesity, because treatments such as Continuous Positive Airway Pressure may not always be suitable to everyone."

Miss Ng said the next step was to work out the actual pathways where weight loss improved daytime sleepiness in order to provide a more targeted treatment strategy.

The latest findings could also motivate people with obesity to lose weight, reaping other health benefits in the process.

Official figures put the prevalence of obesity across the globe at 10.8 per cent of men and 14.9 per cent of women in 2014, a serious jump on 1975 figures of 3.2 per cent of men and 6.4 per cent of women. Australia's obesity prevalence in 2014 stood at 28.4 per cent of men and 27.4 per cent of women.

Ms Ng said excessive daytime sleepiness was quite common, with up to one in six people affected by the disorder in Australia.

"If you weigh more, then you're more likely to have worse sleepiness - but weight isn’t the only determinant," she said.