Plasminogen Activator Inhibitor-1 and Diagnosis of the Metabolic Syndrome in a West African Population

BACKGROUND: Metabolic syndrome (MetS) is diagnosed by the presence of at least 3 of the following: obesity, hypertension, hyperglycemia, hypertriglyceridemia, and low high-density lipoprotein. Individuals with MetS also typically have elevated plasma levels of the antifibrinolytic factor, plasminogen activator inhibitor-1 (PAI-1), but the relationships between PAI-1 and MetS diagnostic criteria are not clear. Understanding these relationships can elucidate the relevance of MetS to cardiovascular disease risk, because PAI-1 is associated with ischemic events and directly involved in thrombosis.

METHODS AND RESULTS: In a cross-sectional analysis of 2220 Ghanaian men and women from urban and rural locales, we found the age-standardized prevalence of MetS to be as high as 21.4% (urban women). PAI-1 level increased exponentially as the number of diagnostic criteria increased linearly (P<10(-13)), supporting the conclusion that MetS components have a joint effect that is stronger than their additive contributions. Body mass index, triglycerides, and fasting glucose were more strongly correlated with PAI-1 than with canonical MetS criteria, and this pattern did not change when pair-wise correlations were conditioned on all other risk factors, supporting an independent role for PAI-1 in MetS. Finally, whereas the correlations between conventional risk factors did not vary significantly by sex or across urban and rural environments, correlations with PAI-1 were generally stronger among urban participants.

CONCLUSIONS: MetS prevalence in the West African population we studied was comparable to that of the industrialized West. PAI-1 may serve as a key link between MetS, as currently defined, and the endpoints with which it is associated. Whether this association is generalizable will require follow-up.