Hypertension: Lowering blood pressure not necessarily healthy
People with high blood pressure are usually advised to lower it, thereby reducing the risk of cardiovascular diseases such as heart attacks. But German researchers have now found that it is not advisable for all patients to adjust their blood pressure to the applicable guidelines.
Death risk increases
Physicians have previously assumed that it is healthier for the elderly if their blood pressure is set below 140/90 mmHg. But researchers from the Charité Hospital Berlin have found that this assumption does not apply to all hypertensive patients. On the contrary: People who are older than 80 or who have had a stroke or heart attack are even more likely to die if their blood pressure is lowered.
Altered blood pressure values
According to the professional association of German internists (BDI), about 70 to 80 percent of over 70-year-olds have high blood pressure, which can lead to long-term life-threatening cardiovascular diseases such as heart attack or stroke.
When deciding whether and how doctors treat people with hypertension, they follow the recommendations of expert associations.
According to European guidelines, blood pressure for over 65 year olds should be set below 140/90 mmHg to protect them against life-threatening heart diseases.
These target values also apply to people over the age of 80, but for them doctors have to consider individual factors such as comorbidities.
New blood pressure guidelines have been in effect in the USA since 2017. Expert associations such as the American College of Cardiology (ACC) and the American Heart Association (AHA) recommend that all hypertensive patients older than 65 years should aim for a blood pressure below 130/80 mmHg.
However, the target values that are actually best for the treatment of older people with hypertension are the subject of a current scientific debate.
No protective effect
Researchers from the Charité Berlin have now been able to show in an observational study that lowering the blood pressure to below 140/90 mmHg – and especially below 130/90 mmHg – does not have a protective effect.
The analysis is based on epidemiological data from more than 1,600 women and men, who were at least 70 years old at the beginning of the study in 2009 and who got treated for hypertension.
The researchers found that those over 80 years of age whose blood pressure was below 140/90 mmHg were 40 percent more likely to die than those whose blood pressure was over 140/90 mmHg.
A similar observation was made by the research team among the study participants who had suffered a stroke or heart attack in the past:
For those whose blood pressure was below 140/90 mmHg, the risk of death increased by as much as 61 percent compared to those whose blood pressure remained above this limit despite the drug treatment.
The study results were published in the journal “European Heart Journal“.
“Our findings make it clear that treatment for high blood pressure should be tailored to these patient groups,” said Dr. Antonios Douros from the Institute of Clinical Pharmacology and Toxicology of the Charité in a press statement.
“We should get away from applying the recommendations of the expert associations to all patient groups on a flat-rate basis,” emphasized the author of the study.
About the study
According to the data, the epidemiological data were analyzed within the framework of the “Berlin Initiative Study”, which was prepared by Prof. Dr. med. Elke Schäffner, Deputy Director of the Charité Public Health Institute.
Her team questioned the study participants every two years about their illnesses and medications, measured blood pressure and kidney function, and analyzed blood and urine.
After six years, statistical methods were used to investigate how the initial blood pressure was related to death.
Influencing factors such as gender, body mass index, smoking status, alcohol consumption, diabetes and the number of antihypertensive agents were also taken into account.
“Next, we want to examine which patient groups actually benefit from lowering blood pressure,” says Prof. Schäffner.