THE EFFECT OF TRIGLYCERIDE INFUSION ON THE REGULATORS OF FIBRINOLYSIS

Circulating triglyceride levels have been found to be positively assoc iated with plasminogen activator inhibitor-1 (PAI-1) activity in patie nts with non-insulin dependent diabetes mellitus (NIDDM). The aim of t his study was to examine the independent effect of raised triglyceride levels on the regulators of fibrinolysis in healthy subjects, while m aintaining circulating insulin levels comparable to those observed in the fasting state in NIDDM, Eight healthy men were studied on separate occasions. Intralipid(TM) 10% (lipid) or sodium chloride infusion 0.9 % (control) were administered intravenously at 45 ml/h for 180 min in random order, On each occasion, insulin was infused at 0.0075 U/kg/h a nd blood glucose levels clamped at fasting values. During the clamp, s erum triglyceride levels were significantly higher in the lipid study (1.79+/-0.39 [mean+/-SEM] vs 0.83+/-0.16 mmol/l; p<0.005), while serum insulin levels were comparable (14.2+/-0.7 and 13.2+/-0.8 mU/l). Howe ver, there were no significant differences between the lipid and contr ol studies for PAI-1 activity, PAI-1 antigen, tissue-type plasminogen activator (t-PA) activity and t-PA antigen levels during the clamp bef ore and after 10 min venous occlusion, We conclude, therefore, that an acute elevation in circulating triglyceride levels does not influence the regulators of fibrinolysis in the presence of low circulating ins ulin levels.