title: Role of baseline leptin and ghrelin levels on body weight and fat mass changes after an energy-restricted diet intervention in obese women: effects on energy metabolism.
abstract: BACKGROUND
  Hormones related to energy balance control may play an important role on weight loss resistance after low-caloric diet (LCD) intervention.
  
  
  OBJECTIVE
  To investigate the predictive value of baseline leptin and ghrelin on body fat mass (FM) loss after 12 wk of LCD intervention and to study whether these associations could be related to changes in resting metabolic rate (RMR).
  
  
  METHODS
  The study comprised a total of 78 obese women (age 36.7 ± 7 yr). We measured, before and after the LCD intervention, FM (dual-energy x-ray absorptiometry) and RMR (kilojoules per kilogram body weight per day, indirect calorimetry). We also analyzed fasting serum leptin and ghrelin, and leptin to ghrelin ratio was calculated.
  
  
  METHODS
  FM and RMR changes (data at baseline - data after the intervention) were assessed.
  
  
  RESULTS
  Baseline serum leptin (r = -0.301; age- and baseline FM-adjusted P = 0.009) and ghrelin (r = 0.314, adjusted P = 0.014) levels as well as leptin to ghrelin levels (r = -0.331; adjusted P = 0.009) were significantly correlated with FM changes. Leptin to ghrelin ratio was significantly correlated with RMR at baseline and after the LCD (both P < 0.010). Baseline leptin to ghrelin ratio significantly predicted changes in RMR after the LCD (r = 0.298; P = 0.019) regardless of age, baseline RMR, and total body weight (r = 0.307; P = 0.016) or FM loss (r = 0.312; P = 0.015).
  
  
  CONCLUSIONS
  Obese women with higher leptin and lower ghrelin levels at baseline seem to be more resistant to FM loss. The leptin to ghrelin ratio could be proposed as a biomarker for predicting metabolic adaptations to energy restriction treatment and, if confirmed in future studies, as a predictor of treatment success/failure.
authors.affiliation: Department of Nutrition and Food Science, University of the Basque Country, Paseo de la Universidad, 7.01006 Vitoria, Spain. idoia.labayen@ehu.es
authors.forename: Idoia
authors.initials: I
authors.lastname: Labayen
authors.forename: Francisco B
authors.initials: FB
authors.lastname: Ortega
authors.forename: Jonatan R
authors.initials: JR
authors.lastname: Ruiz
authors.forename: Arrate
authors.initials: A
authors.lastname: Lasa
authors.forename: Edurne
authors.initials: E
authors.lastname: Simón
authors.forename: Javier
authors.initials: J
authors.lastname: Margareto
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology*; D002153:Calorimetry, Indirect; D004038:Diet, Reducing; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D020738:Leptin / Q000097:blood*; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy* / Q000378:metabolism*
chemical_list: D054439:Ghrelin; D020738:Leptin