Circadian changes of ambulatory blood pressure in an unselected population

Ambulatory blood pressure monitoring does not interfere with the night-time blood pressure and heart rate reduction, typical haemodynamic effects of sleep. An unselected population of 186 subjects was split into quartiles by age to assess the age related changes in 24-h blood pressure profile. From ambulatory blood pressure monitoring data we calculated day-time and night-time blood pressure and heart rate average values, as well as their percent difference. Results show that there is no difference with regard to nocturnal heart rate reduction (on average, 15%) between age groups or sexes, whereas nocturnal blood pressure reduction (on average, 10%) is significantly lower in elderly males, but not females, when compared with young people. This flat 24-h blood pressure profile is associated with hypertension. Circadian changes of ambulatory blood pressure are very different in elderly hypertensive men and provide a marker of diffuse arterial damage.