Two studies that will be presented later this morning as oral presentations shed light on the associations between sleep and weight gain.
One study (#0981) used data from 1,797 twins with an average age of 37 years to show that body mass index (BMI) varied as a function of habitual sleep duration. Results show that twins who slept between 7 and 8.9 hours each night had a lower mean BMI (25.0 kg/m2) compared with those who regularly slept either more (25.2 kg/m2) or less (26.4 kg/m2) per night. The findings remained significant even after careful adjustment for genetics and shared environment.
Analyzing data from the Sleep Heart Health Study, another study (#0515) suggests that there is a positive association between the severity of obstructive sleep apnea and subsequent change in BMI over approximately five years. The study involved 3,001 people with an average age of 62 years. Compared with participants who did not have sleep apnea, individuals with baseline moderate to severe sleep apnea had a mean change in BMI of 0.52 kg/m2; those with mild sleep apnea had a BMI change of 0.22 kg/m2. The association was significant despite adjustments for age, gender and race.
You can download the SLEEP 2009 abstract supplement as an 11 MB file in PDF format.