title: Sleep duration and plasma leptin concentrations in early pregnancy among lean and overweight/obese women: a cross sectional study.
abstract: BACKGROUND
  Early-pregnancy short sleep duration is predictive of gestational diabetes and preeclampsia; mechanisms for these associations are unknown. Leptin, an adipocyte-derived peptide involved in regulating food intake and energy expenditure, may play a role in these observed associations. Given inconsistent reports linking short sleep duration with leptin, and absence of studies among pregnant women, we examined the association of maternal sleep duration with plasma leptin in early pregnancy.
  
  
  METHODS
  This cross-sectional study included 830 pregnant women. Plasma leptin was measured in samples collected around 13 weeks gestation. Sleep duration was categorized as: ≤5, 6, 7-8 (reference), and ≥9 hours. Differences in leptin concentrations across categories were estimated using linear regression. Analyses were completed for lean and overweight/obese women.
  
  
  RESULTS
  Overall, women with long sleep duration had elevated plasma leptin (p-value = 0.04). However, leptin concentrations were not statistically significantly elevated in women with a short sleep duration. There was no association of leptin with sleep duration among lean women. Among overweight/obese women, a U-shaped relation between leptin and sleep duration was observed: Mean leptin was elevated (β = 21.96 ng/ml, P < 0.001) among women reporting ≤5 hour of sleep compared with reference group; and women reporting ≥9 hours of sleep also had elevated leptin (β = 4.29 ng/ml, P = 0.09).
  
  
  CONCLUSIONS
  Short sleep duration, and to a lesser extent long sleep duration, were associated with elevated leptin among overweight/obese women. These data add some evidence to help understand mechanistic relationships of sleep duration with pregnancy complications.
authors.affiliation: Center for Perinatal Studies, Swedish Medical Center, 1124 Columbia Street, Suite 750, Seattle, WA 98104, USA. Chun-fang.Qiu@Swedish.org.
authors.forename: Chunfang
authors.initials: C
authors.lastname: Qiu
authors.forename: Ihunnaya O
authors.initials: IO
authors.lastname: Frederick
authors.forename: Tanya K
authors.initials: TK
authors.lastname: Sorensen
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Enquobahrie
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Williams
mesh_terms: D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D002940:Circadian Rhythm; D015897:Comorbidity; D003430:Cross-Sectional Studies; D016640:Diabetes, Gestational / Q000503:physiopathology / Q000517:prevention & control; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood* / Q000378:metabolism; D009765:Obesity / Q000097:blood / Q000453:epidemiology; D050177:Overweight / Q000097:blood* / Q000453:epidemiology; D011225:Pre-Eclampsia / Q000503:physiopathology / Q000517:prevention & control; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood* / Q000453:epidemiology; D011261:Pregnancy Trimester, First / Q000097:blood*; D011262:Pregnancy Trimester, Second / Q000097:blood*; D012307:Risk Factors; D012636:Secretory Rate; D007319:Sleep Initiation and Maintenance Disorders / Q000097:blood* / Q000453:epidemiology; D013851:Thinness / Q000097:blood* / Q000453:epidemiology; D014861:Washington / Q000453:epidemiology
chemical_list: D001786:Blood Glucose; D020738:Leptin