title: Plasma Leptin Levels and Risk of Incident Cancer: Results from the Dallas Heart Study.
abstract: OBJECTIVE
  Leptin dysregulation has been postulated to affect cancer risk through its effects on obesity and inflammation. Epidemiological data evaluating this relationship are conflicting and studies in non-white cohorts is lacking. Therefore, we examined the association of leptin with the risk of incident cancer in the multiethnic Dallas Heart Study (DHS).
  
  
  METHODS
  Participants enrolled in the DHS without prevalent cancer and with baseline leptin measurements were included. Incident cancer cases were identified through a systematic linkage of the DHS and the Texas Cancer Registry. Leptin was evaluated both as a continuous variable and in sex-specific quartiles. Multivariable Cox proportional hazards modeling was performed to examine the association between leptin levels with incident cancer after adjusting for age, sex, race, smoking status, alcohol use, family history of malignancy, body mass index (BMI), diabetes mellitus and C-reactive protein.
  
  
  RESULTS
  Among 2,919 participants (median age 44 years; 54% women; 70% nonwhite; median BMI 29.4 kg/m2), 190 (6.5%) developed cancer after median follow- up of 12 years. Median leptin levels were 12.9 (interquartile range [IQR] 5.8-29.5) ng/ml in the incident cancer group vs. 12.3 (IQR 5.4-26.4) ng/ml those without an incident cancer (p = 0.34). Leptin was not associated with cancer incidence in multivariable analysis (unit standard deviation increase in log-transformed leptin, hazard ratio 0.95; 95% confidence interval, 0.77-1.16; p = 0.60). No association was observed in analyses stratified by sex, race/ethnicity, diabetes, or obesity status.
  
  
  CONCLUSIONS
  In this study of a predominantly minority population, no association between premorbid leptin levels and cancer incidence was demonstrated. Despite preclinical rationale and positive findings in other studies, this association may not replicate across all racial/ethnic populations.
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Arjun
authors.identifier: http://orcid.org/0000-0003-0875-4731
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Collin College, Preston Road, Frisco, Texas, United States of America.
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Herman
authors.affiliation: Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Colby
authors.initials: C
authors.lastname: Ayers
authors.affiliation: Division of Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Muhammad S
authors.initials: MS
authors.lastname: Beg
authors.affiliation: Department of Clinical Cancer Prevention & Cardiology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: Susan G
authors.initials: SG
authors.lastname: Lakoski
authors.affiliation: Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Shuaib M
authors.initials: SM
authors.lastname: Abdullah
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: David H
authors.initials: DH
authors.lastname: Johnson
authors.affiliation: Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Neeland
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood*; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood*; D012307:Risk Factors; D013781:Texas
chemical_list: D014408:Biomarkers, Tumor; D020738:Leptin