title: The effect of age on the relationship between cardiac and vascular function.
abstract: Age-related changes in cardiac and vascular function are associated with increased risk of cardiovascular mortality and morbidity. The aim of the present study was to define the effect of age on the relationship between cardiac and vascular function. Haemodynamic and gas exchange measurements were performed at rest and peak exercise in healthy individuals. Augmentation index was measured at rest. Cardiac power output, a measure of overall cardiac function, was calculated as the product of cardiac output and mean arterial blood pressure. Augmentation index was significantly higher in older than younger participants (27.7 ± 10.1 vs. 2.5 ± 10.1%, P<0.01). Older people demonstrated significantly higher stroke volume and mean arterial blood pressure (P<0.05), but lower heart rate (145 ± 13 vs. 172 ± 10 beats/min, P<0.01) and peak oxygen consumption (22.5 ± 5.2 vs. 41.2 ± 8.4 ml/kg/min, P<0.01). There was a significant negative relationship between augmentation index and peak exercise cardiac power output (r=-0.73, P=0.02) and cardiac output (r=-0.69, P=0.03) in older participants. Older people maintain maximal cardiac function due to increased stroke volume. Vascular function is a strong predictor of overall cardiac function in older but in not younger people.
authors.affiliation: Institute of Cellular Medicine, MoveLab, Medical School, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: David
authors.initials: D
authors.lastname: Houghton
authors.affiliation: Institute of Neurosciences and Newcastle University Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Jones
authors.affiliation: Institute of Cellular Medicine, MoveLab, Medical School, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Sophie
authors.initials: S
authors.lastname: Cassidy
authors.affiliation: Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, UK.
authors.forename: Mario
authors.initials: M
authors.lastname: Siervo
authors.affiliation: Department of Cardiology, Freeman Hospital, Newcastle upon Tyne, UK; Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Guy A
authors.initials: GA
authors.lastname: MacGowan
authors.affiliation: Institute of Cellular Medicine, MoveLab, Medical School, Newcastle University, Newcastle upon Tyne, UK; RCUK Centre for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Trenell
authors.affiliation: Institute of Cellular Medicine, MoveLab, Medical School, Newcastle University, Newcastle upon Tyne, UK; RCUK Centre for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK. Electronic address: djordje.jakovljevic@newcastle.ac.uk.
authors.forename: Djordje G
authors.initials: DG
authors.lastname: Jakovljevic
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D001158:Arteries / Q000502:physiology*; D001794:Blood Pressure; D002302:Cardiac Output; D015444:Exercise; D005080:Exercise Test; D005260:Female; D064368:Healthy Volunteers; D006321:Heart / Q000502:physiology*; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D013318:Stroke Volume; D055815:Young Adult
keywords: Ageing; Cardiac function; Exercise test; Vascular function