Blood pressure medication and the risk of dementia - HIV update, 29 February 2024

Blood pressure medication and the risk of dementia

Dementia is a group of symptoms connected to the decline of brain functioning. Symptoms of dementia include loss of memory, difficulty thinking (for example planning or concentrating) and problems with language.

Having HIV can increase your risk of cognitive disorders, including dementia. But people with HIV also have the same risk factors for dementia as people without HIV – for example, old age, high blood pressure, coronary artery disease, diabetes, smoking and heavy alcohol use.

Lowering blood pressure can help reduce the risk of developing dementia. One type of blood pressure medication is called ACE inhibitors. ACE inhibitors can be divided into two categories: those that can penetrate the brain and those that can’t. This is also called crossing the blood-brain barrier.

Some studies have found that ACE inhibitors that cross the blood-brain barrier lower the risk of dementia, compared to other types of blood pressure medication, in people who don’t have HIV. However, this had not previously been studied in people living with HIV. 

That’s why researchers in the US investigated if these medications also lower the risk of dementia in people living with HIV. They used electronic health records to look at over 18,000 people who were diagnosed with high blood pressure after being diagnosed with HIV and had at least one year of follow-up after their high blood pressure diagnosis.

The results show that ACE inhibitors that cross the blood-brain barrier reduce the risk of dementia by around 15% in people living with HIV – that’s a very impressive number!

It’s important to note that these findings were published as a pre-print but await peer review. That means the publication still needs to be checked for accuracy by other independent researchers.

Other limitations are that the study did not include many female participants and did not look at how long people took the medications for before their risk of dementia was reduced. Those are two things future research could focus on.

The researchers say that choosing ACE inhibitors that penetrate the blood-brain barrier over those that don’t may help prevent dementia in people living with HIV. Ultimately, this could have a very positive impact on quality of life of many people.

If you’re worried about your blood pressure or your risk of dementia, or if you want to discuss the medications you’re taking, we recommend you speak to a member of your healthcare team.

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Importance of CD4/CD8 testing

Our immune system helps to protect us from infections and illnesses. CD4 and CD8 cells are two types of cells that are very important for our immune system. CD4 cells (also known as T-helper cells) help co-ordinate our immune response by telling other immune cells (like CD8 cells) to fight infections. CD8 cells recognise and destroy cells infected with bacteria or viruses.

HIV causes changes in the numbers of CD4 cells and CD8 cells. It causes CD4 cells to decrease and CD8 cells to increase. That means the ratio of CD4 cells to CD8 cells declines. The CD4/CD8 ratio is calculated by dividing the CD4 cell count by the CD8 cell count. For example, a ratio of 2 would indicate that there are 2 CD4 cells for every 1 CD8 cell. A normal ratio is between 1 and 3. Taking HIV treatment can help improve the ratio in people living with HIV.

In the early years of the AIDS epidemic, before treatment became available, the CD4/CD8 ratio was measured routinely. But in recent years, the test has been used less often.

However, several recent studies have shown that people with a lower CD4/CD8 ratio have a higher risk of health problems, including diseases of the heart and blood vessels, and some types of cancer.

Researchers in Spain reviewed existing research literature. They found that the CD4/CD8 ratio may be a good tool to identify who should be offered cancer screening. By offering screening to people at high risk of cancer, some cancer cases could be detected and treated much earlier.

The CD4/CD8 ratio can also affect how you respond to some vaccines, like hepatitis B, yellow fever and COVID vaccines. A low CD4/CD8 ratio also increases the risk of getting bacterial infections and tuberculosis.

Despite this evidence, different national and international guidelines make contradicting recommendations about CD4/CD8 tests. Some guidelines say that it’s unnecessary and others recommend it as a useful test. The British HIV Association says CD4 count monitoring is optional for people who’ve been virally suppressed for at least a year. They do not mention CD8 count monitoring.

The researchers from Spain say that the CD4/CD8 ratio is a widely available test that adds little cost. It may help screening people at higher risk of illnesses and cancers. They suggest that due to the slow pace of change in the CD4/CD8 ratio, measuring it once a year would be enough.

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Telling a young person about their HIV status

Telling a child or young person that they’re living with HIV can feel daunting. Many caregivers (including parents) aren’t sure how to tell a young person about their HIV status.

But telling young people about their HIV status is important. It has been linked to better health and prevention outcomes, because it helps them to understand how to protect themselves and others.

Understanding teenagers’ and young people’s perspective on being told about having HIV is essential to improve their experiences and to provide better support. That’s why researchers in Kenya collected data from 375 young people aged 12-24 attending HIV clinics that did not have consistent practices for sharing their HIV status to young people. Nurses interviewed these young people about their experiences of being told that they were living with HIV.

Over half (55%) of teenagers and young adults learned about their HIV status from a caregiver and 41% from a healthcare worker. Four per cent found out on their own. The majority (78%) said they preferred to be told about their HIV by the age of 12. This would be in line with World Health Organization guidelines.

More than half of the young adults (57%) thought that children should be told about their HIV status by a caregiver, like a parent, whereas 40% chose healthcare workers, and 3% preferred a family member. The World Health Organization recommends that healthcare workers and caregivers should do this together.

The majority (86%) of young adults were satisfied with the way they were told about their HIV status. Young people who felt they had support from either the clinic or their caregivers before and after disclosure tended to be more satisfied with the disclosure process. Teenagers and young adults who suspected they were HIV positive before disclosure were less satisfied compared to those who never suspected.

Being told about their HIV status had various positive impacts, for example:

• improved adherence to medication (taking it as prescribed) for 78%
• better clinic attendance for 45%
• increased happiness for 40%
• improved communication with healthcare workers for 26%
• improved communication with caregivers for 20%.

Additionally, 47% subsequently shared their HIV status with someone else, for example a sexual partner.

The study shows us how telling young people about their HIV status can affect adherence, engagement in care, sexual behaviour, and sharing their HIV status with others. It also shows us that caregivers, like parents, need more support on how to tell young people about their HIV status.

If want to read more about children and young people living with HIV, you can find helpful resources from the Children’s HIV Association (CHIVA).

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HIV medications and weight gain in pregnant women with HIV

Gaining weight during pregnancy is normal and can help to reduce risks of negative pregnancy outcomes, for example premature birth or a small baby. Not gaining enough weight during pregnancy can increase the risk. But gaining too much weight during pregnancy can also lead to complications.

Previous research has shown people living with HIV are more likely to gain weight when starting treatment with widely used HIV medication dolutegravir (marketed as Tivicay, and included in the tablets Dovato, Juluca and Triumeq) compared to efavirenz (marketed as Sustiva). Dolutegravir is also recommended as first-line treatment in all adults (including during pregnancy) by the World Health Organization.

Researchers have now looked at the relationship between different types of HIV treatment regimens, changes in weight during pregnancy and adverse birth outcomes. They recruited 643 women in Botswana, Brazil, India, South Africa, Tanzania, Thailand, Uganda, United States and Zimbabwe.

The women were all between 14 and 28 weeks pregnant and were assigned to one of three different types of antiretroviral therapy (ART) regimens at random (like the flip of a coin).

The results showed that:

• Women who took a combination of dolutegravir, tenofovir alafenamide and emtricitabine gained most weight during pregnancy. This was followed by women who took a combination of dolutegravir, tenofovir disoproxil and emtricitabine.
• Women who took a combination of efavirenz, tenofovir disoproxil and emtricitabine gained the least amount of weight.
• Not putting on much weight before giving birth was associated with a 44% higher risk of adverse birth outcomes.
• Although greater weight gain during pregnancy was associated with a lower risk of adverse outcomes, higher weight at the beginning of the pregnancy was associated with an increased risk.

The researchers say that the results contradict the idea that weight gain caused by ART is always bad. But more research is needed to fully understand how different ART regimens influence pregnancy outcomes.

Focusing on a healthy body weight, both before you get pregnant and during pregnancy, can help improve your baby’s and your health during and after the pregnancy. If you’re thinking about getting pregnant or worried about your weight during pregnancy, we recommend speaking to your doctor or pharmacist.

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