title: G(-2548)A leptin gene polymorphism in obese subjects is associated with serum leptin concentration and bone mass.
abstract: BACKGROUND
  Clinical studies have shown either positive or in some other cases negative correlations between leptinemia and bone mineral density (BMD) or bone mineral content (BMC).
  
  
  OBJECTIVE
  The aim of the present study was to assess whether these discrepancies might be associated with the effect of G(-2548)A leptin or A326G and A668G leptin receptor gene polymorphisms on serum leptin concentrations or BMD and BMC.
  
  
  METHODS
  The study included 72 obese patients (39 women and 33 men, aged 46 +/-8.8 years; body mass index [BMI] >30 kg/m2). In all subjects, serum creatinine, glucose, lipids, leptin, and insulin were determined. Total fat mass (TFM), BMC, and BMD were assessed using dual energy X-ray absorptiometry (Lunar DPX-L).
  
  
  RESULTS
  No significant correlations were observed between body mass composition parameters (TFM, lean mass, BMC) or BMD in relation to genotypes. A positive correlation was found between serum leptin concentration and BMI. An inverse association was observed between leptin concentrations and BMC. Multiple regression analysis showed independent correlations of leptinemia with sex (P <0.001), TFM (P <0.000 001), BMC (P = 0.0001), and the presence of (-2548)A allele of the leptin gene (P <0.05). These parameters together accounted for 83% of variability in serum leptin concentrations.
  
  
  CONCLUSIONS
  In obese patients, serum leptin concentration shows an independent inverse correlation with BMD and male sex, but positively with TFM and the presence of -2548A allele of leptin gene. These parameters are responsible for 83% of leptin concentration variability. No correlations between the examined polymorphisms and BMC or BMD were found.
authors.affiliation: Department of Internal Diseases, Endocrinology and Diabetology, Central Clinical Hospital, Ministry for Internal Affairs, Warsaw, Poland. edward.franek@cskmswia.pl
authors.forename: Edward
authors.initials: E
authors.lastname: Franek
authors.forename: Jacek
authors.initials: J
authors.lastname: Nowak
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Safranow
authors.forename: Grazyna
authors.initials: G
authors.lastname: Adler
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Bińczak-Kuleta
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ciechanowicz
authors.forename: Andrzej
authors.initials: A
authors.lastname: Wiecek
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015519:Bone Density; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D020738:Leptin