Sleep Medicine Research (Aug 2011)

Change in Individual Chronotype Over a Lifetime: A Retrospective Study

  • Jung Hie Lee,
  • In Soo Kim,
  • Seong Jae Kim,
  • Wei Wang,
  • Jeanne F Duffy

DOI
https://doi.org/10.17241/smr.2011.2.2.48
Journal volume & issue
Vol. 2, no. 2
pp. 48 – 53

Abstract

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Background and Objective Sleep disturbances resulting from a mismatch between the sleep-wake schedule and an individual’s chronotype can influence work or school performance and numerous health outcomes. Individual chronotype can be determined by genetic factors, and is influenced by environmental factors which could change throughout life. We aimed to examine self-reported changes in chronotype during three different periods of life (childhood, teenage years, and adulthood). Methods Three hundred forty-three (age: 37.8 ± 11.6 years, range: 18–82; F: M = 214: 129) adult visitors to a National Museum in Korea were recruited for this study. The Korean version of the Horne-Östberg Morningness-Eveningness Questionnaire (MEQ-K) was administered and standard MEQ-K scores were used to categorize subjects as morning type (MT), evening type (ET), or neither type (NT). Binary logistic regression analyses were applied to examine the relationships of gender, current age, and childhood/teenager ME type with change in chronotype between childhood, teenage years, and adulthood. Results The ages, gender distribution, and years of education were different between the chronotype groups (p < 0.01). Individuals who reported childhood MT or ET had a lower probability of changing their chronotype between childhood and their teenage years compared with individuals reporting childhood NT (p < 0.0001), whereas individuals reporting teenage MT or ET had a higher probability (p < 0.0001). Furthermore, older individuals had a lower probability of reporting a chronotype change between childhood or teenage years and adulthood (p < 0.01). Conclusions Most individuals reported the same chronotype from childhood to their teenage years but a different chronotype between the teenage years and adulthood. Older age was associated with a lower probability of reporting a different chronotype during childhood or teenage years.

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