Total and percentage REM sleep correlate with body weight in 36 middle-aged people

Thirty-six volunteers of mean age 52 years had their sleep recorded in the laboratory on 5 consecutive nights. Eight factors were investigated as possible correlates of percentage REM sleep and of total minutes of REM sleep: age, height, weight, bedtime, arising time, oral temperature at bedtime and on arising, and total sleep time. REM percentage correlated significantly with body weight and with oral temperature at bedtime and correlated negatively with age. Owing to intercorrelations among the factors investigated, partial correlational analyses were done and revealed that body weight was the only factor that remained significantly correlated with REM percentage. Similarly, total sleep time and body weight were the only factors that remained significantly correlated with total minutes of REM sleep, whereas age and bedtime temperature just missed significance when other factors were held constant.