London School of Hygiene & Tropical Medicine

Current UK guidance on drug treatment for high blood pressure - which differs depending on a patient’s age and ethnicity - could be simplified in line with other international guidelines, suggests a study published by The BMJ.

Researchers from the London School of Hygiene & Tropical Medicine (LSHTM) found that three major drug types resulted in similar reductions in blood pressure in people of all ages and ethnicities, suggesting that  factors other than age and ethnicity might be better used to guide drug choice.

High blood pressure, or hypertension, affects more than one in four adults globally and is a major risk factor for illness and death.

Current guidelines from the National Institute for Health and Care Excellence (NICE) recommend that for non-diabetics, high blood pressure is initially treated with calcium channel blockers (CCBs) for those aged 55 and older and for people of black African or African-Caribbean family ethnicity, and angiotensin converting enzyme inhibitors  (ACEIs) or angiotensin receptor blockers (ARBs) for non-black people younger than 55.

According to the study, previous research shows that older people and black people of African or African-Caribbean ethnicity typically have lower levels of renin, a protein that regulates blood pressure and fluid balance. Therefore the NICE guidance is based on evidence that CCB drugs will be more effective than ACEIs and ARBs in people with lower levels of renin.

However, since the current guidance was developed other research has suggested that ACEI and ARB drugs may have additional benefits in certain groups of people. In addition the value of basing choice of drug treatments on ethnicity has been questioned.

The study, funded by the Wellcome Trust, analysed UK primary care and hospital records to identify over 150,000 new users of hypertension drugs (CCBs, ACEIs/ARBs and thiazides), without diabetes, from 2007 to 2017.

After taking account of factors that could influence treatment choice or response, such as age, sex, smoking, alcohol use, weight (BMI) and underlying conditions, the researchers found similar reductions in blood pressure associated with both CCBs, and ACEIs/ARBs in people aged above and below 55, suggesting age might not be the best factor to determine drug choice.

In further analyses, they found that CCBs were associated with greater reductions in blood pressure than ACEIs/ARBs, but only in people aged 75 and older.

In addition, The study found that first-line treatment with ACEIs/ARBs and CCBs was associated with similar reductions in blood pressure in both people of black African or African-Caribbean family ethnicity, and non-black people..

Dr Laurie Tomlinson, Associate Professor at LSHTM, said: “The current UK approach to treating hypertension recommends drugs based on age and ethnicity, but our findings show that these drugs result in similar reductions in blood pressure for the majority of people, regardless of these factors.

“We hope that this research will encourage broader discussion about the role of age and ethnicity in determining optimal blood pressure medication and, alongside other evidence, lead to reappraisal of the current recommendations,.”

In the study, the researchers acknowledge the limitations of the research, such as not being able to analyse patients’ adherence to their drugs and small numbers of black people included in the study. 

Publication

S-J Sinnott, I J Douglas, L Smeeth, E Williamson, L A Tomlinson. First line drug treatment for hypertension and reductions in blood pressure according to age and ethnicity: cohort study in UK primary care. BMJ. DOI: 10.1136/bmj.m4080