title: Long sleep duration and afternoon napping are associated with higher risk of incident diabetes in middle-aged and older Chinese: the Dongfeng-Tongji cohort study.
abstract: BACKGROUND
  In this study, we investigated the independent and combined effects of sleep duration and afternoon napping on the risk of incident diabetes among a cohort of middle-aged and older Chinese adults.
  
  
  METHODS
  Information of sleep and napping was obtained by questionnaires during face-to-face interviews. We categorized sleep duration into <7 h, 7∼<8 h (reference), 8∼<9 h, 9∼<10 h, and ≥ 10 h. Afternoon napping was divided into no napping (0 min) (reference), 1-30 min, 31-60 min, 61-90 min, and > 90 min. Cox proportional hazard regression models were used.
  
  
  RESULTS
  Compared with referential sleeping group, subjects sleeping ≥10 h had a 42% higher risk of developing diabetes. The HR was 1.28 for napping > 90 min when compared with no napping. These associations were more pronounced in individuals without hypertension. Combined effects of long sleep duration and afternoon napping were further identified. Individuals with both sleep duration ≥ 10 h and napping > 60 min had a 72% higher risk of incident diabetes than those with sleeping 7∼<8 h and napping 0 min (all above p < 0.05).
  
  
  CONCLUSIONS
  Both long sleep duration and afternoon napping were independently and jointly associated with higher risk of incident diabetes. Key messages Sleep duration was associated with diabetes, but whether it is a real cause of incident diabetes especially in Chinese still remains to be elucidated. The association of afternoon napping and diabetes was not consistent and definite, we clarified this association in a large prospective study. Long sleep duration and afternoon napping were independently and jointly associated with higher risk of incident diabetes.
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Xu
authors.initials: X
authors.lastname: Han
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: An
authors.initials: A
authors.lastname: Pan
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Yaru
authors.initials: Y
authors.lastname: Li
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Hua
authors.initials: H
authors.lastname: Hu
authors.affiliation: b Dongfeng Central Hospital, Dongfeng Motor Corporation and Hubei University of Medicine , Shiyan , Hubei , China ;
authors.forename: Xiulou
authors.initials: X
authors.lastname: Li
authors.affiliation: b Dongfeng Central Hospital, Dongfeng Motor Corporation and Hubei University of Medicine , Shiyan , Hubei , China ;
authors.forename: Kun
authors.initials: K
authors.lastname: Yang
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Ping
authors.initials: P
authors.lastname: Yao
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Miao
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Sheng
authors.initials: S
authors.lastname: Wei
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Youjie
authors.initials: Y
authors.lastname: Wang
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liang
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Huan
authors.initials: H
authors.lastname: Guo
authors.affiliation: b Dongfeng Central Hospital, Dongfeng Motor Corporation and Hubei University of Medicine , Shiyan , Hubei , China ;
authors.forename: Handong
authors.initials: H
authors.lastname: Yang
authors.affiliation: c Departments of Nutrition and Epidemiology , Harvard T.H. Chan School of Public Health , Boston , MA, USA.
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Tangchun
authors.initials: T
authors.lastname: Wu
authors.affiliation: a Institute of Occupational Medicine and The Ministry of Education Key Lab of Environment and Health , School of Public Health, Huazhong University of Science and Technology , Wuhan , China ;
authors.forename: Meian
authors.initials: M
authors.lastname: He
mesh_terms: D000368:Aged; D044466:Asian People; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D012890:Sleep / Q000502:physiology*; D013997:Time Factors
keywords: Incident diabetes; afternoon napping; combined effects; prospective study; sleep duration