title: Postprandial lipaemia does not affect resting haemodynamic responses but does influence cardiovascular reactivity to dynamic exercise.
abstract: Postprandial lipaemia impairs endothelial function, possibly by changes in oxidative stress, but whether this affects cardiac output and/or systemic vascular resistance (SVR) at rest and in response to dynamic exercise remains uncertain. The present study set out to investigate the effects of a high-fat meal (HFM) v. a low-fat, high-carbohydrate meal (HCM) on cardiac output and SVR. A HFM (50 g fat) and an isoenergetic HCM (5 g fat) were randomly fed to thirty healthy adults using a crossover design. Cardiac output, heart rate and blood pressure (BP) were measured, and stroke volume and SVR were calculated over a 3 h rest following the meal, during exercise 3 h postprandially and for 45 min post-exercise. Blood samples were collected at fasting, 3 h postprandially and immediately post-exercise. Plasma TAG increased by 63.8 % 3 h following the HFM, and NEFA fell by 94.1% 3 h after the HCM. There was a 9.8% rise in plasma 8-isoprostane-F2alpha concentration following the HFM, and a 6.2% fall following the HCM. Cardiac output increased postprandially, but the difference between meals at rest or exercise was not statistically significant. The HFM resulted in a 3.2 mmHg (95% CI 0.7, 5.7) smaller increase in exercise mean arterial BP compared with the HCM due to a greater fall in exercise SVR. Postprandial lipaemia induced by a HFM does not affect cardiac output and/or SVR at rest, but it blunts the increase in BP during exercise.
authors.affiliation: Nutritional Sciences Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK. victoria.rontoyanni@kcl.ac.uk
authors.forename: Victoria G
authors.initials: VG
authors.lastname: Rontoyanni
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Chowienczyk
authors.forename: Thomas A B
authors.initials: TA
authors.lastname: Sanders
mesh_terms: D000328:Adult; D001794:Blood Pressure; D002302:Cardiac Output; D018592:Cross-Over Studies; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D006949:Hyperlipidemias / Q000503:physiopathology*; D008297:Male; D019518:Postprandial Period / Q000502:physiology; D016037:Single-Blind Method; D013318:Stroke Volume; D014280:Triglycerides / Q000097:blood; D014655:Vascular Resistance; D055815:Young Adult
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D014280:Triglycerides; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost