High blood pressure can be healthy

High blood pressure for people aged 85 and above need not necessarily be a problem.  On the contrary: reducing their blood pressure can have fatal consequences. These are the findings of PhD research by Thomas van Bemmel.

Previous history

Van Bemmel studied 571 people aged 85 and above, 223 of whom had a previous history of high blood pressure. In the four years of this study, a total of 290 of the participants died. The total death rate in both groups was the same. What was striking was that people with a history of high blood pressure remained healthy provided their blood pressure stayed high. If their blood pressure was reduced using medication, the risk of death increased.

Blood circulation

The conclusion to be drawn from this is that people who have always had high blood pressure but have never been treated for the condition, should not automatically be treated. Van Bemmel: ‘A person can, for example have a systolic blood pressure level of 120 at age 20, 160 at age 60, 180 at age 80 and 160 at age 85.  In fact, 160 is still too high but if you intervene to reduce the level, this can be dangerous for the person's circulation, which can in turn affect his or her whole system.' On the other hand, people who have always had normal blood pressure and who at the age of 85 suddenly have an upper figure of 160, certainly should be treated,' is the inference of Van Bemmel and his research team.

Cognitive capacity

It is important to know the patient's previous medical history, which is in many cases not available. We therefore need to develop a method that will allow us to distinguish between those people whose blood pressure is showing a rising trend and those whose blood pressure is falling in order to be able to adapt the treatment appropriately. 'This also means defining the optimum level to which their blood pressure should be lowered,' Van Bemmel proposes.  He is now studying the possibilities of setting up such a study in the Gelre hospitals.

Called into question

There is in any event one thing about which Van Bemmel is convinced: 'The general guideline for blood pressure, namely the lower the better, is called into question by this study, at least for the older group of patients. Particularly because we also demonstrated that those people above 85 who had high blood pressure had better kidney function and their memory and cognitive capacity were also at a higher level.'

Leiden 85-plus Study

Van Bemmel's research is part of the Leiden 85-plus Study among all the inhabitants of Leiden who reached the age of 85 in the period from 1997 and 1999. A total of 571 people took part in the study. Participants were interviewd every year to determine how they functioned physically, functionally, psychologically and socially. The aim of this Leiden 85-plus Study was to understand the determinants for successful ageing, and whether these could be influenced.  

PhD defence: Thursday 4 February
Thomas van Bemmel
High blood pressure at old age
Faculty: Medicine
Supervisors: Professor R.G.J. Westendorp and Professor J. Gussekloo

(5 February 2010/LUMC)