OBJECTIVE: To examine the relationship of obesity, body fat distribution, and fasting plasma insulin concentrations with the plasma levels of both pro-thrombotic and anti-thrombotic factors in premenopausal women. SUBJECTS: 32 obese women with BMI b 28 and 33 age-matched non-obese women with BMI`25. MEASUREMENTS: (i) plasma concentrations of plasminogen activator inhibitor-1 antigen (PAI-1 Ag), plasminogen activator inhibitor-1 activity (PAI-1 activity), ®brinogen, von Willebrand factor antigen (vWF Ag), von Willebrand factor activity (vWF activity), and factor VII activity as pro-thrombotic factors; (ii) plasma concentrations of tissue plasminogen activator antigen (t-PA Ag), protein C, and antithrombin III as anti-thrombotic factors; (iii) fasting plasma insulin and glucose concentrations, and the lipid pattern (triglycerides, total and HDL-cholesterol) as metabolic parameters. The body fat distribution was evaluated by measuring the waist circumference and the waist-to-hip ratio (WHR). RESULTS: Obese subjects had higher plasma concentrations of all pro-thrombotic factors as compared to non-obese controls (PAI-1 Ag, P`0.001; PAI-1 activity, P`0.05; ®brinogen, P`0.001; vWF Ag, P`0.001; vWF activity, P`0.05; factor VII, P`0.05). The plasma concentrations of PAI-1 Ag and vWF Ag were directly correlated with the waist circumference independently of other metabolic and non-metabolic variables (P`0.05). Obese women were also characterized by higher plasma concentrations of anti-thrombotic factors such as t-PA Ag and protein C as compared to non-obese controls (P`0.001 and P`0.001, respectively), although these factors were not independently correlated with the waist circumference or the WHR. CONCLUSION: Plasma concentrations of the pro-thrombotic factors are increased in obese women as compared to non-obese controls, and plasma levels of PAI-1 Ag and vWF Ag correlate with central fat accumulation speci®cally. Plasma concentrations of anti-thrombotic factors (namely protein C and t-PA Ag) are also raised in obese women, but they are not correlated with parameters of body fat distribution. The increase in protein C levels may represent a protective response partly counteracting the increase in pro-thrombotic factors in these individuals.

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OBJECTIVE: Increased thickness of the intima ± media complex of the common carotid artery (IMT-CCA) is an early marker of atherosclerosis. The aim of the present study was to investigate the relationship between insulin resistance and IMT-CCA in premenopausal women. SUBJECTS: 86 young women, aged 18 ± 31 y, were recruited for the study: 28 were normal weight (BMI`25 kgam 2 ), 23 were overweight (BMI 25 ± 30 kgam 2 ) and 35 were obese (BMI b 30 kgam 2 ). MEASUREMENTS: The IMT-CCA was measured by high resolution`B-mode' ultrasonography; insulin sensitivity was determined by insulin tolerance test (ITT) and quantitated by calculation of K ITT. Fasting plasma glucose and lipids (triglycerides, total and HDL-cholesterol) were also measured by enzymatic methods. Central fat accumulation was evaluated by measuring waist circumference (WC). RESULTS: IMT-CCA showed an inverse association with K ITT (P`0.05). When the IMT-CCA was considered as the dependent variable in a forward stepwise multiple regression analysis, it maintained an independent association with K ITT (P`0.05), after adjusting data for age, BMI, WC, mean blood pressure levels and plasma glucose and lipids. CONCLUSION: These results suggest that IMT-CCA is signi®cantly associated with insulin resistance, independent of other well-known CVD risk factors. Since the IMT-CCA is an earlier asymptomatic sign of atherosclerosis, this study indicates that insulin resistance per se may accelerate atherogenesis.

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