title: Daily physical activity, fasting glucose, uric acid, and body mass index are independent factors associated with serum fibroblast growth factor 21 levels.
abstract: OBJECTIVE
  Fibroblast growth factor 21 (FGF21) levels have been linked with beneficial effects on glucose and lipid metabolism in animals. It is elevated in humans with the metabolic syndrome. This study investigates independent factors associated with serum FGF21 levels.
  
  
  METHODS
  Cross-sectional study done in healthy blue-collar workers.
  
  
  METHODS
  A medical history was taken, and FGF21 (measured using an ELISA commercial kit), glucose, uric acid, plasma lipids, total/high-molecular weight (HMW) adiponectin, and retinal-binding protein 4 (RBP4) were measured in 210 individuals with (n=81) and without (n=129) metabolic syndrome.
  
  
  RESULTS
  The median of serum FGF21 levels were higher in subjects with metabolic syndrome (339.5 vs 276.4 ng/l, P=0.01). Serum FGF21 levels correlated positively with body mass index (BMI; r=0.23, P=0.001) and age (r=0.17, P=0.01). After adjusting for age and BMI, a significant positive correlation persisted for fasting glucose, uric acid, and physical activity in both males (r=0.21, r=0.11, and r=0.19, all P<0.05) and females (r=0.20, r=0.19, and r=0.14, all P<0.05). In addition, FGF21 also correlates negatively with RBP4 (r=-0.27, P=0.02), total (r=-0.26, P=0.03), and HMW adiponectin (r=-0.30, P=0.01) in women. A multiple linear regression model analysis identified that BMI (standardized beta (SB)=0.247; P=0.008), glucose (SB=0.226; P=0.003), uric acid (SB=0.191; P=0.04), and physical activity (SB=0.223; P=0.004) are independent factors influencing serum FGF21 levels (F=10.05, r(2)=0.19, P<0.001). In addition, fasting hyperglycemia > or =100 mg/dl, excess body weight with BMI > or =25 kg/m(2), and uric acid > or =5.5 mg/dl predicted higher serum FGF21 levels.
  
  
  CONCLUSIONS
  Serum FGF21 levels are influenced by BMI, fasting glycemia, uric acid, and physical activity.
authors.affiliation: Department of Endocrinology and Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubiran, Vasco de Quiroga 15, Seccion XVI, Tlalpan, 14000 Mexico DF, Mexico.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cuevas-Ramos
authors.forename: Paloma
authors.initials: P
authors.lastname: Almeda-Valdes
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Gómez-Pérez
authors.forename: Clara Elena
authors.initials: CE
authors.lastname: Meza-Arana
authors.forename: Ivette
authors.initials: I
authors.lastname: Cruz-Bautista
authors.forename: Olimpia
authors.initials: O
authors.lastname: Arellano-Campos
authors.forename: Mariana
authors.initials: M
authors.lastname: Navarrete-López
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Aguilar-Salinas
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis* / Q000502:physiology; D015992:Body Mass Index; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005215:Fasting / Q000097:blood*; D005260:Female; D005346:Fibroblast Growth Factors / Q000097:blood* / Q000502:physiology; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000517:prevention & control; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D013997:Time Factors; D014527:Uric Acid / Q000097:blood*
chemical_list: D001786:Blood Glucose; C414620:fibroblast growth factor 21; D014527:Uric Acid; D005346:Fibroblast Growth Factors