Effects of Dietary Lipid Modification on Adrenoceptor-Mediated Cardiovascular Responsiveness and Baroreflex Sensitivity in Normotensive Subjects

Straznicky NE, Howes LG, Barrington VE, Lam W, Louis WJ. Effects of dietary lipid modification on adrenoceptor-mediated cardiovascular responsiveness and baroreflex sensitivity in normotensive subjects.To examine the effects of short-term dietary lipid modification on alpha- and beta-adrenoceptor-mediated cardiovascular responsiveness, 19 normal volunteers consumed either a high-fat or a low-fat diet for 2 weeks in an open, randomized, crossover study of 6 weeks' duration. Diets were balanced for sodium and potassium content. Adrenoceptor-mediated cardiovascular responsiveness was assessed by measuring blood pressure and heart rate responses to incremental infusions of phenylephrine ad isoprenaline. Baroreflexes were studied by examining heart rate responses to phenylephrine and to the Valsalva manoeuvre. Total plasma cholesterol and low-density lipoprotein cholesterol levels both fell significantly (by 22% and 26%, respectively), on the low-fat compared with the high-fat diet, as did resting supine blood...