Plasminogen Activator Inhibitor-1, Body Fat and Insulin Action in Aging Women

Plasminogen activator inhibitor-1 (PAI-1) over-expression is linked to obesity, insulin resistance, and age. We hypothesized that aerobically trained women athletes would have reduced PAI-1 regardless of age compared to sedentary controls and levels would be associated with hyperinsulinemia. Plasma PAI-1 was measured in women athletes who were young (YA, n=19, VO_2max=53.7±1.1ml/kg/min) and older (OA, n=18, VO_2max=46.6±1.5ml/kg/min) and compared to 19 sedentary controls (YC, n=6, VO_2max=35.9±1.2ml/kg/min; OC, n=13, VO_2max=22.1±1.7ml/kg/min). PAI-1 levels did not differ between YA and OA but was 23% higher in OC compared to OA (P<0.05). PAI-1 was inversely associated with VO_2max, directly to %body fat, and subcutaneous abdominal fat, fasting leptin, insulin, and first-phase and second-phase insulin response during a hyperglycemic clamp. The current results suggest that older athletes have low PAI-1 levels possibly due to high levels of physical fitness, reduced body fat, and increased insulin action and may contribute to low atherothrombosis and improved cardiovascular health.