title: Serum leptin concentrations are not related to dietary patterns but are related to sex, age, body mass index, serum triacylglycerol, serum insulin, and plasma glucose in the US population.
abstract: BACKGROUND
  Leptin is known to play a role in food intake regulation. The aim of this study was to investigate the relation between serum leptin concentrations and dietary patterns and demographic, lifestyle, and health factors in the US population.
  
  
  METHODS
  Data from the third National Health and Nutrition Examination Survey, 1988-1994 were used to study the association between fasting serum leptin and dietary patterns, sex, race-ethnicity, smoking, age, energy and alcohol intakes, body mass index (BMI), plasma glucose, serum triacylglycerol, and serum insulin in 4009 individuals. Factor analysis was used to derive three principle factors and these were labeled as Vegetable, Fruit, and Lean Meat, Western, and Mixed dietary patterns.
  
  
  RESULTS
  Serum leptin concentrations were significantly higher in Vegetable, Fruit, and Lean Meat (8.5 fg/L) and Mixed patterns (8.0 fg/L) compared to Western pattern (6.29 fg/L) (P < 0.0001). When analysis was adjusted for confounding variables, no significant association was observed between serum leptin and dietary patterns (P = 0.22). Multivariate adjusted serum leptin concentrations were significantly associated with sex (higher in women than in men; β = -1.052; P < 0.0001), age (direct relation, β = 0.006, P < 0.0001), BMI, (direct relation, β = 0.082, P < 0.0001), fasting plasma glucose (inverse relation, β = -0.024, P = 0.0146), serum triacylglycerol (direct relation, β = 0.034, P = 0.0022), and serum insulin (direct relation, β = 0.003, P < 0.0001) but not with race-ethnicity (P = 0.65), smoking (P = 0.20), energy intake (P = 0.42), and alcohol intake (P = 0.73).
  
  
  CONCLUSIONS
  In this study, serum leptin was not independently associated with dietary patterns. Sex, age, BMI, serum triacylglycerol, plasma glucose, and serum insulin are independent predictors of serum leptin concentrations.
authors.affiliation: Division of Nutrition, School of Health Professions, College of Health and Human Sciences, Georgia State University, Atlanta, GA 30302-3995, USA. vganji@gsu.edu.
authors.forename: Vijay
authors.initials: V
authors.lastname: Ganji
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Kafai
authors.forename: Erin
authors.initials: E
authors.lastname: McCarthy