title: Plasma leptin association with body composition and energy expenditure in sickle cell disease.
abstract: OBJECTIVE
  To examine the association between fasting plasma leptin concentrations and the hypercatabolic state observed in sickle cell disease (SCD).
  
  
  METHODS
  Plasma leptin concentration and resting energy expenditure (REE) were measured in 37 SCD patients (10 men, 12 boys 14 to 18 years-old, seven women, and eight girls 14 to 18 year-old) and in 37 age, gender and fat mass (FM) matched controls. Body composition was measured hydrostatically, REE by whole room-indirect calorimeter, and plasma leptin using an RIA kit.
  
  
  RESULTS
  Plasma leptin concentration and leptin normalized for body fat (ng/dL*kg FM(-1)) were significantly lower in SCD patients than in non-SCD controls (4.00+/-3.23 vs. 9.94+/-14.69, p=0.021 and 0.406+/-0.260 vs. 0.643+/-0.561, p=0.024, respectively). A positive linear association between log plasma leptin and FM was observed in both males and females, adjusting for age and SCD status. The strength of this association was greater in females compared with males (slope=0.699 and 0.382 log ng/mL per 10 kg FM, respectively; p=0.013). SCD patients on average demonstrated a higher REE, adjusting for FFM (p<0.0001). Log plasma leptin and FM were not statistically significant predictors of REE after adjustment for FFM and SCD.
  
  
  CONCLUSIONS
  Once corrected for body composition, mean plasma leptin concentration was significantly lower among female SCD patients than among non-SCD matched controls. Although REE was higher in SCD patients, there is no simple association between leptin and REE in SCD.
authors.affiliation: Center for Nutrition at Meharry Medical College, Nashville, Tennessee 37208, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Buchowski
authors.forename: L A
authors.initials: LA
authors.lastname: Simmons
authors.forename: K Y
authors.initials: KY
authors.lastname: Chen
authors.forename: P J
authors.initials: PJ
authors.lastname: Flakoll
authors.forename: B G
authors.initials: BG
authors.lastname: Mellen
authors.forename: E A
authors.initials: EA
authors.lastname: Turner
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000378:metabolism*; D001481:Basal Metabolism; D044383:Black People; D001823:Body Composition; D015992:Body Mass Index; D004032:Diet; D002149:Energy Intake; D004734:Energy Metabolism; D005215:Fasting; D005260:Female; D006801:Humans; D020738:Leptin / Q000032:analysis*; D008297:Male; D012727:Sex Characteristics
chemical_list: D020738:Leptin