Rob H.P. Henst, from the University of Cape Town in South Africa, and colleagues conducted a systematic literature review to assess the effects of sleep extension interventions on cardiometabolic risk in adults.
The researchers identified seven studies evaluating at least one cardiometabolic risk factor and included a combined sample size of 138 participants (including 14 healthy, 92 healthy short-sleeping, 10 overweight short-sleeping, and 22 prehypertensive or hypertensive short-sleeping). Evaluated interventions ranged from a duration of three days to six weeks. All evaluated interventions successfully increased total sleep time (range, 21 to 177 minutes). Increases in the length of sleep time were associated with improved direct and indirect measures of insulin sensitivity; decreased leptin and peptide tyrosine-tyrosine; and reductions in overall appetite, desire for sweet and salty foods, intake of daily free sugar, 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,” Henst said in a statement.