American doctors are less likely to prescribe key recommended medications for the prevention of cardiovascular disease to HIV-positive people compared to HIV-negative people, according to a new study based on representative national sources.

The researchers looked at the healthcare that was provided to people aged 40 to 79 who had already had heart disease and related problems, or had risk factors for these problems occurring. This would include people with raised cholesterol or high blood pressure, and people who had had heart failure, heart attacks or stroke.

The study included data from the medical appointments of 1631 people living with HIV and over 200,000 people who don’t have HIV.

Antiplatelet medicines reduce the risk of blood clots forming. Examples of antiplatelet medicines include aspirin (a different dose to that needed for a headache), clopidogrel, prasugrel and ticagrelor. Guidelines recommend these medicines for people who’ve had cardiovascular disease and for older adults at risk of it.

But the researchers found that only 5% of eligible people with HIV were prescribed antiplatelets, compared to 14% of eligible people who don’t have HIV.

Statins lower the amount of cholesterol in the blood, especially the harmful type known as LDL cholesterol. This helps prevent a build up of fatty deposits in the arteries, so reducing the risk of heart attacks and strokes. Statins include atorvastatin, pravastatin and simvastatin. Some statins interact with some anti-HIV drugs, so it is important that a doctor prescribing a statin knows if you are on HIV treatment.

In the study, rates of statin use among people with diabetes, cardiovascular disease or high lipids were markedly lower for people with HIV (23%) than people without HIV (35%).

Several types of medicine are used to treat high blood pressure. They include ACE inhibitors, angiotensin-II receptor antagonists, calcium-channel blockers and diuretics.

More encouragingly the study found that use of these drugs in people with high blood pressure was similar whether people had HIV (53%) or not (58%).

And doctors gave similar support to people to help them stop smoking, have a more active lifestyle or eat more healthily, regardless of HIV status.

But the researchers say that one of the reasons why rates of heart attacks, strokes and other forms of cardiovascular disease are high in people with HIV might be that they are not getting all the preventative drug treatments that they need.

Another study looked at the presence of 'silent' cerebral vascular disease: damage or blockage of small blood vessels in the brain, which can lead to strokes or neurocognitive problems such as memory loss and dementia. The study found that one in five people living with HIV had evidence of severe small-vessel disease, compared to one in seven people without HIV of a similar age.

The study found that silent cerebral vascular disease was strongly associated with older age, lower CD4 cell count prior to treatment and high blood pressure.

Small-vessel disease is more likely to lead to lead to a stroke than large-vessel disease in people with high blood pressure, the authors say, underlining the importance of detecting and treating high blood pressure in people with HIV.

For more information, read NAM’s factsheets ‘Cholesterol’ and ‘High blood pressure’.

A new analysis tracks the improvement in people’s CD4 counts after starting HIV treatment. The CD4 count is a key measure of the strength of the immune system. The study shows that people who are able to start treatment with a relatively high CD4 count have better results long term, with greater increases in CD4 counts over five and ten years.

The data come from 7600 people who started HIV treatment in European countries between 2003 and 2014. In all cases the approximate date at which they acquired HIV was known, which makes these study findings more reliable than some previous estimates.

Generally, CD4 counts improved rapidly in the first two to three months after starting treatment. Most people’s CD4 counts continued to gradually improve for the next five years.

The CD4 count before starting treatment was the most important factor predicting improvement in CD4 counts with treatment. Nonetheless, there was considerable variation in results between participants, even after this had been taken into account.

• For people beginning treatment with a CD4 count of 200, the average CD4 after five years of treatment was around 500. There was a range of results – most people’s counts were between 250 and 850.

• For people beginning treatment with a CD4 count of 350, the average CD4 after five years of treatment was around 700. Results typically ranged between 350 and 1050.

• For people beginning treatment with a CD4 count of 500, the average CD4 after five years of treatment was around 800. Results typically ranged between 500 and 1450.

A number of other factors were associated with better results. People who started treatment soon after acquiring HIV (seroconversion), especially people who started treatment within four months, did well. An unexpected finding was that, once the CD4 count had been taken into account, people who had a higher viral load tended to do better. Younger people, gay men, those who did not have hepatitis C and people treated with a drug from the integrase inhibitor class were also more likely to do well.

The study adds to the evidence that it is best to begin treatment as soon after HIV diagnosis as possible. This gives people the best chance of a good recovery of the immune system.

For more information, read NAM's factsheet 'CD4 cell counts'.

Type 2 diabetes – raised blood sugar as a result of a failure in the body’s ability to regulate or take up glucose into cells – can lead to kidney damage, loss of eyesight and heart disease. It is more common in people who are older or in people who are overweight. There is some evidence that type 2 diabetes is more common in people with HIV.

A recent study from Canada provides some reassurance that living with HIV does not in itself increase the chance of developing diabetes for people who have started treatment with newer antiretroviral drugs since 2010.

The study looked at 1035 people who received HIV treatment at Vancouver’s HIV clinic since 1997 and looked at the risk of developing diabetes according to age, treatment history and other known risks factors such as body weight and hepatitis C infection. The study only looked at people who were aged 50 years or older in 2015.

The Canadian researchers found that only two people over the age of 50 had developed type 2 diabetes since 2010 and that development of diabetes was very strongly linked to taking older antiretroviral drugs in the period 1997 to 2004. During this period people commonly took several antiretroviral drugs now known to disrupt the body’s production of insulin, the hormone that keeps blood sugar levels in check. These drugs include stavudine (d4T), the first generation protease inhibitors nelfinavir or indinavir, and the protease inhibitor lopinavir (Kaletra).

Previous treatment history had a much greater influence on the risk of developing diabetes than the well-established risk factors of body weight and hepatitis C infection.

The study authors say that they expect the onset of new cases of type 2 diabetes to decline among older people living with HIV who started treatment more recently with newer drugs.

For more information, read NAM’s factsheet 'Type 2 diabetes and HIV'.