Increased PAI activity and PAI-1 antigen occurring with an oral fat load: associations with PAI-1 genotype and plasma active TGF-beta levels

Atherosclerosis. 1998 Sep;140(1):45-53. doi: 10.1016/s0021-9150(98)00108-7.


Whether the post-prandial lipemic response is linked to potentially pro-atherogenic and/or prothrombotic changes in plasminogen activator inhibitor (PAI) and transforming growth factor-beta (TGF-beta) is uncertain. The aim of our study was to determine whether PAI-1 antigen and PAI activity were elevated during post-prandial lipemia following a standard fat tolerance test. We also investigated changes in TGF-beta1 antigen and TGF-beta activity, to determine whether changes in TGF-beta activity were associated with changes in PAI measurements. Lastly, the influence of genotype at a common insertion/deletion polymorphism in the PAI-1 promoter on changes in PAI activity and PAI-1 antigen was examined. Fat tolerance tests were undertaken in 57 healthy middle-aged men to investigate associations between plasma concentrations of lipoproteins, PAI (antigen and activity) and TGF-beta. PAI-1 concentration increased by 76% after 8 h (P < 0.0001). PAI activity also increased by 64% (P = 0.0054) and TGF-beta activity decreased by 10% (P < 0.0001). Increases in PAI-I antigen and PAI activity varied markedly between individuals. To investigate these heterogeneous responses we examined whether genotype at the common insertion/deletion polymorphism of the PAI-1 promoter accounted for these differences. Individuals with at least one 4G (deletion) allele showed potentially pro-atherogenic changes in both PAI-1 and TGF-beta, compared to individuals who were homozygous for the 5G (insertion) allele. In conclusion, increased PAI and decreased TGF-beta activity occur during a fat tolerance test and this effect may be modulated by a common insertion/deletion polymorphism in the PAI-1 promoter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alleles
  • Body Mass Index
  • Dietary Fats / administration & dosage*
  • Dietary Fats / pharmacology
  • Genotype
  • Humans
  • Male
  • Middle Aged
  • Plasminogen Activator Inhibitor 1 / genetics
  • Plasminogen Activator Inhibitor 1 / metabolism*
  • Plasminogen Inactivators / metabolism*
  • Postprandial Period
  • Promoter Regions, Genetic
  • Transforming Growth Factor beta / blood*
  • Triglycerides / blood


  • Dietary Fats
  • Plasminogen Activator Inhibitor 1
  • Plasminogen Inactivators
  • Transforming Growth Factor beta
  • Triglycerides