Over 40 Pct of Those Content with Sleep Hours Lack Sleep: Study

Tokyo, Jan. 15 (Jiji Press)--A Japanese research team has found that more than 40 pct of people feeling they slept enough actually lacked sleep.

The team led by Masashi Yanagisawa, professor and director of the University of Tsukuba’s International Institute for Integrative Sleep Medicine, said Tuesday there were gaps in many cases between self-assessments of sleep length and quality and the results of analyses such as those by brain wave examinations.

The team concluded that it was hard to make diagnoses of sleep condition based only on self-reported information and that objective measurement is important. The study results are to be published in an online edition of the U.S. journal Proceedings of the National Academy of Sciences.

The team conducted a survey of 421 people aged 20-79 living in Japan who were not receiving treatment for sleep disorders. It analyzed gaps between their answers on sleep length and quality and doctors’ assessments based on brain wave and blood oxygen saturation level data.

The survey revealed that approximately 45 pct of respondents who said they slept enough were suspected of actually lacking sleep. On the other hand, some 66 pct of respondents who complained about insomnia, including difficulty falling asleep, objectively had no problem.

[Copyright The Jiji Press, Ltd.]