Possible vascular-bed-specific role of interleukin-6 in young women with a history of myocardial infarction, lacunar cerebral infarction and deep vein thrombosis

The level of interleukin-6 (IL-6), a cytokine with prothrombotic properties, and its associations with metabolic, coagulation and fibrinolytic parameters were investigated in 68 young women (23-49 years, mean 40 years old) six months to six years after myocardial infarction (MI, N=22), lacunar cerebral infarction (LACI, N=16) and deep vein thrombosis (VT, N=30); all women were in the reproductive period, aged <45 years at the time of acute thrombotic event. Forty-seven age-matched women comprised a control group. Basic and multivariate analysis disclosed different patterns of IL-6 increase in all three groups of patients. In the MI group IL-6 was significantly elevated independently of factors known to increase IL-6 levels; the increase was most pronounced in patients with high lipoprotein(a). This result suggests a prothrombotic association of lipoprotein(a) with IL-6. In the whole LACI group IL-6 was not significantly increased. However, patients with elevated levels of IL-6 had abdominal obesity and elevated fibrinogen, suggesting the possibility that this combination might represent a specific risk profile. In VT group elevated IL-6 level was found in the group of previous users of oral contraceptives (OC). This might be relevant, since it is known that OC could importantly increase (previously elevated) IL-6 level in selected women. Our results suggest the hypothesis that the role of IL-6 might be vascular-bed-specific and further propose that increased IL-6 level might represent a novel, non-classical risk factor for development of MI, LACI and VT in specific subgroups of young women, which have to be clarified in further studies.