title: Associations of body mass index and insulin resistance with leptin, adiponectin, and the leptin-to-adiponectin ratio across ethnic groups: the Multi-Ethnic Study of Atherosclerosis (MESA).
abstract: OBJECTIVE
  Associations of adiponectin and leptin and their ratio with body mass index (BMI) and homeostasis model assessment of insulin resistance (HOMA-IR) have been investigated in different ethnic groups but variability in both assays and statistical methods have made cross-study comparisons difficult. We examined associations among these variables across four ethnic groups in a single study.
  
  
  METHODS
  Adiponectin and leptin were measured in a subset of participants from the Multi-Ethnic Study of Atherosclerosis study. We calculated associations (using both partial correlations and adjusted linear regression) in each ethnic group and then compared the magnitude of these associations across groups.
  
  
  RESULTS
  After we excluded individuals with type 2 diabetes, there were 714 white, 219 Chinese, 332 African-American, and 405 Hispanic subjects in the study sample. Associations of BMI with adiponectin and leptin differed significantly (P < .05) across the ethnic groups in regression analyses, whereas associations of HOMA-IR with adiponectin and leptin did not differ across ethnic groups. The leptin-to-adiponectin ratio was not associated with a greater amount of adiposity or HOMA-IR variance than leptin or adiponectin in any ethnic group.
  
  
  CONCLUSIONS
  Given the consistency of HOMA-IR and adipokine associations, the differing means of adiponectin and leptin across ethnic groups may help to explain ethnic differences in mean insulin resistance.
authors.affiliation: Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA. ljrtorvik@northwestern.edu
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Rasmussen-Torvik
authors.forename: Christina L
authors.initials: CL
authors.lastname: Wassel
authors.forename: Jingzhong
authors.initials: J
authors.lastname: Ding
authors.forename: Jeffery
authors.initials: J
authors.lastname: Carr
authors.forename: Mary
authors.initials: M
authors.lastname: Cushman
authors.forename: Nancy
authors.initials: N
authors.lastname: Jenny
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Allison
mesh_terms: D052242:Adiponectin / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000097:blood / Q000208:ethnology*; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005006:Ethnicity; D005260:Female; D006706:Homeostasis; D006801:Humans; D007333:Insulin Resistance / Q000208:ethnology*; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D014481:United States
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; D020738:Leptin