INSULIN-RESISTANCE SYNDROME AND FIBRINOLYTIC-ACTIVITY - THE NORTHERN SWEDEN MONICA STUDY

Background. Many studies have, in small and highly selected study popu lations, described how cardiovascular risk factors tend to cluster in subjects with insulin resistance. Recently, interest has focused on po ssible relationships between this insulin resistance syndrome and fibr inolysis, and the role of triglycerides in this association. The prese nt study addresses these issues in a general population. Methods. A su bsample of participants in the population-based Northern Sweden MONICA (MONItoring of trends and determinants in CArdiovascular diseases) St udy, consisting of 353 men and 403 women in the 25-64 year age range, was investigated. Insulin resistance was estimated indirectly from the fasting levels of insulin and glucose. Fibrinolytic activity was meas ured both as plasminogen activator inhibitor type 1 (PAI-1) activity a nd tissue plasminogen activator (tPA) activity. Results. Insulin resis tance was highly correlated with those cardiovascular risk factors tha t have been associated with the insulin resistance syndrome, and to th e measures of fibrinolytic activity. Subjects in the upper tertile of insulin resistance had a PAI-1 activity that was three times higher th an that of the lower third in men and twice as high in women. There wa s a strong interaction between insulin resistance and serum triglyceri des. Low versus high levels of both variables together were associated with a fivefold difference in PAI-I activity in men and a threefold d ifference in women. The tPA activity was inversely correlated to both insulin resistance and serum triglycerides. Conclusions. In a general population, the 'insulin resistance syndrome' is closely associated wi th low fibrinolytic activity. Serum triglyceride levels interact with insulin resistance to predict fibrinolytic activity.