Association Between Sleep Timing, Obesity, Diabetes: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Cohort Study.
Recent studies implicate inadequate sleep duration and quality in metabolic disease. Fewer studies have examined the timing of sleep, which may be important because of its potential impact on circadian rhythms of metabolic function. We examined the association between sleep timing and metabolic risk among Hispanic/Latino adults.



Cross-sectional data from community-based study of 13429 participants aged 18-74 years. People taking diabetic medications were excluded. Sleep timing was determined from self-reported bedtimes and wake times. Chronotype was defined as the midpoint of sleep on weekends adjusted for sleep duration on weekdays. Other measurements included body mass index (BMI), fasting glucose levels, estimated insulin resistance (HOMA-IR), glucose levels 2 hours post oral glucose ingestion, and hemoglobin A1c. Survey linear regression models tested associations between sleep timing and metabolic measures. Analyses were stratified by diabetes status and age-group when significant interactions were observed.



Among participants with diabetes, fasting glucose levels were positively associated with bedtime (approximately +3%/hour later, p < .01) and midpoint of sleep (approximately +2%/hour later, p < .05). In participants with and without diabetes combined, HOMA-IR was positively associated with midpoint of sleep (+1.5%/hr later, p < .05), and chronotype (+1.2%/hour later, p < .05). Associations differed by age-group. Among those < 36 years, later sleep timing was associated with lower BMI, lower fasting glucose, and lower HbA1c, but the opposite association was observed among older participants.



Later sleep timing was associated with higher estimated insulin resistance across all groups. Some associations between sleep timing and metabolic measures may be age-dependent.
Center for Circadian and Sleep Medicine, Department of Neurology, Northwestern University.
Kristen L
KL
Knutson
Institute for Minority Health Research, University of Illinois at Chicago.
Donghong
D
Wu
Division of Pulmonary Allergy and Critical Care Medicine, University of Pittsburgh.
Sanjay R
SR
Patel
Department of Medicine, University of California San Diego.
Jose S
JS
Loredo
Division of Sleep and Circadian Disorders, Brigham and Women's Hospital; Division of Pulmonary, Critical Care and Sleep, Beth Israel Deaconess Medical Center; Harvard Medical School.
Susan
S
Redline
Collaborative Studies Coordinating Center, Department of Biostatistics, University of North Carolina at Chapel Hill.
Jianwen
J
Cai
Department of Psychology, San Diego State University.
Linda C
LC
Gallo
Department of Epidemiology & Population Health, Albert Einstein College of Medicine, Bronx, New York.
Yasmin
Y
Mossavar-Rahmani
Department of Neurology, University of Miami, Miller School of Medicine.
Alberto R
AR
Ramos
Collaborative Studies Coordinating Center, Department of Biostatistics, University of North Carolina at Chapel Hill.
Yanping
Y
Teng
Institute for Minority Health Research, University of Illinois at Chicago.
Martha L
ML
Daviglus
Center for Circadian and Sleep Medicine, Department of Neurology, Northwestern University.
Phyllis C
PC
Zee
D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002940:Circadian Rhythm / Q000502:physiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood / Q000503:physiopathology*; D005215:Fasting / Q000097:blood; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006306:Health Surveys; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D007333:Insulin Resistance; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D057566:Self Report; D012890:Sleep / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
D001786:Blood Glucose; D006442:Glycated Hemoglobin
circadian.; diabetes; insulin resistance; sleep timing