Relationships of plasminogen activator inhibitor-1 to anthropometry, serum insulin, triglycerides and adipose tissue fatty acids in healthy men

Abstract

Increased plasma levels of plasminogen activator inhibitor-1 (PAI-1), responsible for reduced fibrinolytic activity, have been shown to be an important risk factor for cardiovascular disease. PAI-1 plasma levels are influenced by several factors which have not yet been fully clarified, including dietary fat intake. The relationships of PAI-1 with other cardiovascular risk factors are still not well known. In a random sample of 38-year-old healthy men ( n = 94), the association of PAI-1 plasma levels (measured as activity and antigen) with anthropometric parameters, serum lipids, fasting and 2 h insulin and glucose concentration after oral glucose-load was analysed. Furthermore, the fatty acid composition of subcutaneous adipose tissue, as an objective and reliable index of dietary fat intake, was measured. The univariate analysis showed that plasma levels of PAM were significantly associated with body mass index (BMI) ( r = 0.37, P < 0.001), waist/hip ratio (WHR) ( r = 0.26, P < 0.01), serum triglycerides ( r = 0.47, P < 0.0001), HDL/total cholesterol ratio ( r = −0.35, P < 0.001), fasting and 2-h insulin ( r = 0.27, P < 0.01 and r = 0.34, P < 0.001) and glucose concentrations ( r = 0.25, P < 0.05 and r = 0.28, P < 0.01). PAI-1 plasma levels were weakly and positively associated with both total amount of monounsaturated fatty acids ( r = 0.31, P < 0.05) and oleic acid ( r = 0.28, P < 0.05), while both total polyunsaturated fatty acids and linoleic and α- linolenic acids were strongly and negatively associated with PAI-1 plasma concentration ( r = −0.34, r = −0.33, P < 0.01 and r = −0.43, P < 0.001, respectively). When BMI, WHR, serum triglyceride and insulin concentrations were included as independent variables in a multivariate analysis, only serum triglycerides showed a positive and independent association with plasma levels of PAI-1 ( P < 0.0001). Furthermore, after adjustment for triglyceride concentration, the relationship of PAI-1 to adipose tissue fatty acids was no longer significant, except to a-linolenic acid which maintained a significant inverse association with PAI-1 plasma levels ( r = −0.43; P < 0.001). The present study has verified the relationships of PAI-I plasma levels to anthropometric measurements, serum insulin, blood lipids and nutritional (fatty acid composition of adipose tissue) parameters and has shown that, at least in 38-year-old healthy men, serum triglycerides and the content of a-linolenic acid in adipose tissue are the only two parameters whose independent contribution, negative for serum triglycerides and positive for the adipose tissue fatty acid, might explain plasma fibrinolytic activity.