British doctors question guidelines on blood pressure and cholesterol levels

Jun 27 2005

A new study suggests that the thresholds for "normal" blood pressure and cholesterol levels have been set so low healthy people might be put on unnecessary medication.

The guidelines on cardiovascular disease prevention currently in use, were drawn up in 2003 by the European Society of Cardiology.

High blood pressure can be a sign of disease.

Now two British doctors, GPs Steinar Westin and Iona Heath, say under these guidelines as many as 90% of people over 50 could be labelled at risk, and end up on drugs.

The GPs are concerned that many people might end up taking drugs which would be of little benefit to them.

The present guidelines set the following thresholds: Blood pressure should not be above 140/90 mm Hg and serum cholesterol no more than 5 mmol/l.

In defense, the European Society of Cardiology says the concerns were based on a "fundamental misunderstanding" of the purpose of the guidance, saying it was intended to help identify people who could benefit from modifying their lifestyle to reduce risk and not to label people as sick.

They also questioned the merits of the Norway study, and said other studies did not estimate that such a high number of people would be defined as being at risk.

The guidance however does not recommend intensive therapy for people whose blood pressure and cholesterol levels were higher than the threshold levels.

However when the guidelines were applied to adults in Norway, 76% of the population were defined as being at risk, including half of all 24-year-olds, and this is despite the average life expectancy in Norway being 78.9 years.

According to the researchers the proportions are likely to be even higher if the same thresholds are applied to the UK where average life expectancy is 78.1 years.

The researchers are concerned that not only do the drugs potentially cause physical side effects, there may also be psychological effects from being labelled as vulnerable to heart disease.

They say there is far too little understanding of the psychological impact and the wider health consequences of being labelled at risk.

Other doctors have also raised concern about too many people being labelled as being at risk.

In 1999, more than 800 doctors, pharmacists and scientists from 42 countries signed an open letter expressing concern that World Health Organization hypertension guidelines would result in increased use of drugs at great expense and for little benefit.

They said that simple lifestyle measures are the basis of management, with drugs held in reserve for only the highest risk people.

Medical spokesperson for the British Heart Foundation, Cathy Ross, says that the limits suggested should act as guidelines in the assessment of risk and should be used in combination with lifestyle advice.

She says it is better for patients to be made aware of their risk, and to take action to lower it, than to keep the threshold high simply to avoid an unfortunate label.

The study is published in the British Medical Journal.