Influence of age, hypertension or myocardial infarction on cardiovascular responses to changes in body position : a population-based study in 30-, 50- and 60-year-old men

Sammanfattning: An age-related attenuation of the normal increase in diastolic blood pressure and heart rate upon standing has previously been observed in man. Whether this is due to aging as such or is a consequence of a higher prevalence of cardiovascular disease in older compared to younger subjects is unclear. This population-based study addresses this question and presents the blood pressure and heart rate responses to sudden changes in body position in representative groups of men aged 30 (n=50), 50 (n=44) and 60 (n=69) years, as well as in 60-year-old men with hypertension (n=75) or previous myocardial infarction (n=39) and in a control group (n=41) free from these diseases. Blood pressure and heart rate were measured during three seven-minute periods (supinestanding-supine), using an unbiased non-invasive method. Whereas there was an initial decrease in systolic blood pressure upon standing in men aged 50 and 60 years, an increase was seen in the 30-year-olds. The diastolic blood pressure increased in all age groups, but less in the older compared to the younger men. In all age groups, the change in systolic blood pressure upon standing was transient, while the changes in the diastolic blood pressure lasted during the entire observation period. The heart rate increased to a similar extent upon standing in all age groups. After resuming the supine position, both blood pressure and heart rate returned to the levels initially recorded. The cardiovascular responses were both qualitatively and quantitatively similar in all three groups of 60-year-old men (with or without hypertension or previous myocardial infarction). In conclusion, this population-based study confirmed previous observations of an age-related attenuation of the blood pressure response to change in body position. However, 60-year-old men with hypertension or previous myocardial infarction had blood pressure responses similar to those of men of the same age and free from these diseases. This indicates that the attenuated response in older compared to younger subjects is not explained by the higher prevalence of these cardiovascular diseases in the elderly, but appears to be the result of normal aging.