Influence of Dietary Saturated Fat Intake on Endothelial Fibrinolytic Capacity in Adults

Approximately 50% of middle-aged and older adults in the United States regularly consume a diet high in saturated fat. High dietary saturated fat intake has been linked to promote atherothrombotic vascular disease. We tested the hypothesis that endothelial fibrinolytic function is diminished in middle-aged and older adults who habitually consume a diet high in saturated fat. Twenty-four healthy, sedentary middle-aged, and older adults (54 to 71 years) were studied: 10 (8 men and 2 women) with a dietary saturated fat intake <10% (lower saturated fat) of total calories and 14 (9 men and 5 women) with a dietary saturated fat intake >= 10% of total calories (high saturated fat). Net endothelial release of tissue-type plasminogen activator (t-PA), the primary activator of fibrinolysis, was determined, in vivo, in response to intrabrachial infusions of bradykinin (12.5 to 50.0 ng/100 ml tissue/min) and sodium nitroprusside (1.0 to 4.0 mu g/100 ml tissue/min). Capacity of the endothelium to release t-PA in response to bradykinin was similar to 30% less (p < 0.05) in the high (from -0.7 +/- 0.6 to 36.9 +/- 3.3 ng/100 ml tissue/min) compared with the lower (from -0.3 +/- 0.3 to 53.4 +/- 7.8 ng/100 ml tissue/min) dietary saturated fat group. Moreover, total amount of t-PA released was significantly less (similar to 30%) (201 +/- 22 vs 274 +/- 29 ng/100 ml tissue) in the adults who reported consuming a diet high in saturated fat. These results indicate that the capacity of the endothelium to release t-PA is lower in middle-aged and older adults who habitually consume a diet high in saturated fat. In conclusion, endothelial fibrinolytic dysfunction may underlie the increased atherothrombotic disease risk with a diet high in saturated fat. (C) 2014 Elsevier Inc. All rights reserved.