HIV update - 19th July 2017

High rate of non-alcoholic fatty liver disease in people living with HIV

Non-alcoholic fatty liver disease (NAFLD) is an umbrella term for a range of liver conditions caused by a build-up of fat in the liver. It is defined by the accumulation of fat in the liver and the presence of triglycerides (a type of fat) in liver cells, without there being another cause such as excess alcohol consumption.

NAFLD is increasingly common around the world, especially in Western countries. It occurs in every age group but especially in people in their 40s and 50s who are at high risk of heart disease because of such risk factors as obesity and type 2 diabetes. The condition is also closely linked to metabolic syndrome, which is a cluster of abnormalities including increased abdominal fat, poor ability to use the hormone insulin, high blood pressure and high blood levels of triglycerides. NAFLD can not only lead to liver problems, including fibrosis (scarring of the liver), but also to changes in the body’s metabolism, such as atherosclerosis (hardening of the arteries).

Until now, much of the liver disease occurring in people living with HIV has been associated with co-infection with hepatitis B or C, but NAFLD is emerging as a new concern for people who do not have hepatitis B or C.

A group of UK researchers have recently conducted a review of existing studies on NAFLD in people living with HIV who do not also have hepatitis B or C. They found that very little research had been done, identifying only ten relevant studies, conducted in North America, Western Europe and Japan.

Based on those studies, they estimate that around one third of people with HIV may have NAFLD – a higher rate than seen in the general population.

Looking into risk factors for NAFLD in people living with HIV, they found that people are at increased risk of it if they are overweight or obese (especially with a lot of fat around the waist), have type 2 diabetes, high fasting glucose levels, high blood pressure, high total cholesterol, low HDL cholesterol, high LDL cholesterol, or high levels of the liver enzymes ALT and AST.

Many of these risk factors are the same as in the general population. But the study highlights the link between raised levels of liver enzymes and NAFLD. Experts say that doctors should properly investigate persistently raised levels of liver enzymes, considering NAFLD as a possible cause.

It is important that NAFLD is diagnosed promptly so that lifestyle changes can be made in good time. While effective drug treatments for NAFLD are not yet available, the researchers call for people with HIV to be included in clinical trials for new drug treatments.

Gastric reflux and proton pump inhibitors

Gastric reflux is a common condition where acid from the stomach leaks up into the oesophagus (gullet). It can cause symptoms such as heartburn and an unpleasant taste in the back of the mouth.

It can be caused by hiatus hernia (when part of your stomach moves up into your chest) or by stress, smoking, coffee, alcohol, fatty or acidic foods, eating too close to bedtime, and by obesity or pregnancy. Gastric reflux can also be a side-effect of some medications used to treat HIV and hypertension.

One type of medication used to manage gastric reflux are known as proton pump inhibitors (PPIs). These drugs, including lansoprazole, pantoprazole and omeprazole, work by suppressing stomach acid production. 

A new study suggests that PPIs should be used with caution in people with HIV. The researchers found that people who received long-term treatment with the drugs failed to gain CD4 cells and experienced more immune activation.

This was a small study, comparing 37 men living with HIV who used PPIs with 40 men living with HIV who did not use the drugs but were otherwise broadly similar. The men using PPIs had been using them for an average of three years.

Men using PPIs lost an average of 18 CD4 cells in the previous year, whereas those not using them had an increase of 54 CD4 cells. Those using PPIs had higher levels of sCD14, which is a marker of immune activation, in other words excess activity of the immune system.

The researchers say that doctors should use PPIs with caution until longer-term studies are completed. These studies should look into whether use of the drugs have any harmful clinical consequences. Research is also needed with women living with HIV.

Lower risk of heart problems with atazanavir

People who started HIV treatment with a drug combination containing atazanavir (Reyataz) were significantly less likely to suffer a heart attack or stroke than people starting treatment with other regimens, according to a recent study.

Atazanavir is a widely used protease inhibitor. Although HIV treatment reduces the risk of cardiovascular disease in people living with HIV, some protease inhibitors have been associated with an increased risk of cardiovascular disease compared to other treatment regimens. These include indinavir, lopinavir/ritonavir (Kaletra) and darunavir/ritonavir.

Atazanavir may have an advantage because its use is associated with smaller increases in LDL (‘bad’) cholesterol and total cholesterol than other protease inhibitors. In addition, atazanavir treatment also results in raised levels of bilirubin which do not cause symptoms but which may be associated with a reduced risk of heart failure.

An American study of 1529 people taking atazanavir and 7971 people taking other HIV medications has found that people treated with atazanavir were approximately 40% less likely to experience a heart attack or a stroke.

Low use of statins in Chicago

Meanwhile, a study from a large HIV clinic in Chicago shows that many patients there who are at high risk of heart disease are not getting the statin preventative treatment that they need.

People living with HIV who already had hardened or blocked arteries did mostly get statins (93%), in line with guidelines. Similarly, 56% of those who had diabetes received statins.

But only 29% of those who had not already had heart disease but who were judged to be at elevated risk of it were receiving treatment with statins. A person's risk of heart disease can be calculated, based on factors like age, race, gender, cholesterol, blood pressure, diabetes and smoking.

This analysis was done on the basis of statin guidelines for the general population. People living with HIV are at greater risk of heart disease than HIV-negative people, but specific statin guidelines for people with HIV do not exist yet, partly because studies on the benefit of statins in people with HIV have not yet been completed. It is probable that future guidelines on preventing heart disease in people living with HIV will encourage a wider use of statins than in the general population.