Lindahl B, Nilsson T K, Asplund K, Hallmans G
Department of Nutritional Research, Umeå University, Sweden.
Metabolism. 1998 Apr;47(4):384-90. doi: 10.1016/s0026-0495(98)90047-6.
Increased plasma levels of insulin and the fibrinolytic inhibitor, plasminogen activator inhibitor type 1 (PAI-1), are two new cardiovascular risk factors. The extent to which these two risk factors can be affected by nonpharmacological intervention modalities has not been convincingly proven in subjects at high risk for cardiovascular disease. This study assesses the effects on fasting plasma insulin and plasma PAI-1 activity of an intervention program including a low-fat, high-fiber diet and regular daily physical exercise. The intervention was implemented by a 1-month learning and training session in a full-boarding wellness center and included a follow-up evaluation after 12 months. The study was conducted on 108 subjects (31 men and 77 women) referred for multiple risk factor treatment. After 1 month of intense intervention, the physical condition improved significantly, and this effect was maintained during the year. The body mass index (BMI), fasting plasma insulin, and plasma lipids were significantly decreased. In women, PAI-1 activity was significantly reduced. At follow-up study in both sexes, the BMI and fasting insulin were still significantly decreased. In women, PAI-1 activity reverted to the preintervention level. In subjects with multiple risk factors, ie, the insulin resistance syndrome, the plasma insulin level can be reduced by an intense nonpharmacological program. Also, at least in women, plasma PAI-1 activity can be modestly modified. However, the magnitude of the decrease in PAI-1 activity was probably too small to reverse the hypofibrinolytic state characteristic of these subjects.