Increasing the duration of sleep could be good for the heart. While much research on the subject already exists, this latest meta-analysis focuses specifically on cardiometabolic risk -- or the risk of heart disease and metabolic disorders.
Published in the Journal of Sleep Research and led by researchers at the University of Cape Town, South Africa, this meta-analysis reviewed seven studies that focused on prolonging sleep duration in adults. "Increasing sleep duration may be an appropriate strategy to reduce cardiometabolic risk in short‐sleeping individuals," the study authors explain in the paper's opening summary.
The studies covered a total of 138 adults who were either healthy, healthy short-sleeping, overweight short-sleeping, or pre- or hypertensive short-sleeping individuals. Interventions to extend sleep ranged from three days to six weeks in duration, increasing total sleep time by between 21 and 177 minutes.
Among other things, sleep extension was associated with reductions in appetite, desire for sweet and salty foods and percentage of daily caloric intake from protein.
"Given the overwhelming evidence that sleeping less than seven hours is associated with an increased cardiometabolic risk, it is surprising that so few studies have explored whether extending sleep duration can lower cardiometabolic risk," said lead author and Ph.D. candidate, Rob Henst.
"Although we have focused on studies with sleep extension interventions in this review, it is now apparent that poor sleep quality may be an equally important risk factor for cardiometabolic disease," added senior author Dr. Dale Rae. "Thus future studies testing interventions aimed at improving sleep quality are also required."