Original ArticleEpidemiologicalDifferential Impact of Sleep Duration on Fasting Plasma Glucose Level According to Work Timing
Introduction
Sleep is a representative physiologic process determined by circadian rhythm (1). Modern society, sometimes called a ‘24/7’ society, is characterized by widespread use of electricity, which leads to changes of timing and type of work and duration and patterns of sleep. Specifically, sleep duration has significantly decreased worldwide. Mean sleep duration in Korea was reported to be less than 7 h, and a substantial proportion of Koreans reported less than 6 h; similar patterns have been reported in other populations (2).
Over the past decade, a large body of evidence has suggested that short sleep duration is an independent risk factor for the development of glucose intolerance, insulin resistance, and impairment of insulin secretion, ultimately leading to type 2 diabetes mellitus (T2DM) 3, 4. Although there is controversy regarding the effect of long sleep duration on glucose metabolism, several studies have also shown that people who sleep more than 9 h per night also exhibit an increased risk of developing T2DM and impaired glucose tolerance (IGT) 5, 6.
Disrupted circadian rhythm by abnormal timing of sleep in addition to abnormal sleep duration is also associated with abnormal glucose metabolism (7). Non-traditional work timing such as shift and night work is one way in which the normal synchrony among the light-dark cycle, sleeping, and eating is disturbed. Shift work and circadian misalignment have been associated with impairment of glucose homeostasis 8, 9.
However, to our knowledge, whether there is a differential impact on blood glucose level of sleep duration in people with traditional regular daytime work vs. shift work has not been clarified. Moreover, there are very limited studies focusing on the association among fasting blood glucose (FBG) or impaired fasting glucose (IFG), sleep duration, and work timing 3, 10, 11, 12. Therefore, the current analysis evaluated the differential contribution of sleep duration to FBG level in subjects without diabetes who work traditional daytime work schedules vs. shift work.
Section snippets
Study Participants
Data from the KNHANES (Korea National Health and Nutrition Examination Survey), gathered from 2010–2015, was used for this study. Among a total of 28,534 subjects aged above 20 and less than 65 years who underwent a health examination and finished the self-reported questionnaires, we excluded those who were not wage workers (n = 15,025); those who lacked work time data (n = 2,349); those who had diabetes or met the diagnostic criteria—FBG over 126 mg/dL or HbA1c over 6.5% (n = 382); those who
Results
There were significant differences in the prevalence of sleep duration, age group, occupation, family income, smoking, and regular exercise between regular daytime workers and shift workers (Supplemental Table 1). However, there were no significant differences in sex or body mass index (BMI) between groups. General characteristics of the subjects by sleep duration are presented in Supplemental Table 2. Subjects with long sleep duration showed a greater tendency to perform shift work, were
Discussion
The current analysis evaluated the relationship among sleep duration, work timing, and FBG level. This study showed that the impact of sleep duration on glucose level differs according to whether the participants were shift workers or regular daytime workers. That is, long sleep duration (>8 h/d) was associated with lower FBG level compared to adequate sleep duration (6–8 h/d) in shift workers; whereas there was a negative impact on FBG in traditional regular daytime workers. Numerous
Acknowledgment
This study was supported by a grant from Soonchunhyang University.
References (28)
- et al.
Short sleep duration is associated with the development of impaired fasting glucose: the Western New York Health Study
Ann Epidemiol
(2010) - et al.
Sleep duration as a risk factor for incident type 2 diabetes in a multiethnic cohort
Ann Epidemiol
(2009) - et al.
Sleep duration as a risk factor for the development of type 2 diabetes or impaired glucose tolerance: analyses of the Quebec Family Study
Sleep Med
(2009) - et al.
Short and long sleep are positively associated with obesity, diabetes, hypertension, and cardiovascular disease among adults in the United States
Soc Sci Med
(2010) - et al.
The impact of extended sleep on daytime alertness, vigilance, and mood
Sleep Med
(2004) - et al.
The effects of sleep extension on sleep and cognitive performance in adolescents with chronic sleep reduction: an experimental study
Sleep Med
(2013) - et al.
Circadian rhythms, sleep, and metabolism
J Clin Invest
(2011) 2012 Bedroom Poll
- et al.
Association between sleep duration and impaired fasting glucose in Korean adults: results from the Korean National Health and Nutrition Examination Survey 2011–2012
Korean J Fam Med
(2016) - et al.
Incidence of diabetes in middle-aged men is related to sleep disturbances
Diabetes Care
(2004)
Association of sleep time with diabetes mellitus and impaired glucose tolerance
Arch Intern Med
Sleep duration as a risk factor for the development of type 2 diabetes
Diabetes Care
Habitual sleep duration and insomnia and the risk of cardiovascular events and all-cause death: report from a community-based cohort
Sleep
Exposure to shift work as a risk factor for diabetes
J Biol Rhythms
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2020, International Journal of Environmental Research and Public HealthAssociation between sleep duration and impaired fasting glucose according to work type in non-regular workers: Data from the first and second year (2016, 2017) of the 7th Korean national health and nutrition examination (KNHANE) (a cross-sectional study)
2020, Annals of Occupational and Environmental MedicineSleep at Work: The Economic and Societal Argument for Workplace-Based Health Promotion Tailored to Shift Workers
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These authors contributed equally to this work.