Although many people living with HIV receive effective antiretroviral therapy, their life expectancy is 7 years shorter than the life expectancy of individuals without HIV infection. Whether this is due to HIV itself or the antiretroviral therapy is uncertain. A new study shows that people living with HIV have a 70% greater risk of having type 2 diabetes. One theory is that the types of antiretroviral therapy used previously redistributed fat depots and increased the risk of cardiovascular disease and type 2 diabetes. Doctors should therefore pay even more attention to signs of noncommunicable diseases among people living with HIV.
When the HIV epidemic began in about 1980, research focused on understanding HIV and keeping it in check so that it did not destroy the immune system of those affected and lead to AIDS. More than 40 years later, people living with HIV can live largely normal lives if they receive effective treatment. Unfortunately, people living with HIV live an average of 7 years less than the rest of the population. Researchers attempting to find and remedy the causes of decreased longevity have demonstrated a link between HIV infection and type 2 diabetes.
“For years, people living with HIV have been suspected of having increased risk of type 2 diabetes, but the data have been conflicting. Our study is one of the first to investigate the prevalence of type 2 diabetes in a large group of people living with HIV receiving effective treatment, and it shows that their risk of having type 2 diabetes is 70% higher than for people without HIV infection. We do not know the reason for this, but one theory is that the antiretroviral therapy used before 2000 changed people’s fat depots. These medications are not used anymore, but the antiretroviral medicines used seem to have long-lasting or perhaps permanent effects. ” explains the lead author, Julie Høgh, a PhD student from the Department of Infectious Diseases at Rigshospitalet, Copenhagen.
70% increased risk
The new study is far from the first of its kind. However, previous studies that have examined associations between HIV infection and type 2 diabetes have provided conflicting evidence, probably because of the composition of the study cohorts, with not all participants optimally treated with the existing antiretroviral medicine. For example, in one study, 20% of the participants were coinfected with hepatitis C, which creates difficulty in interpreting and comparing the results directly.
“In our research, we had the opportunity to compare a large cohort of people living with HIV receiving effective treatment with people without HIV who participated in the Copenhagen General Population Study. We compared the difference in the prevalence of type 2 diabetes, and since we examined the people living with HIV at 2-year intervals, we also determined the prevalence of type 2 diabetes in this group,” says Julie Høgh.
Through blood tests, the researchers measured the individuals’ long-term blood glucose (HbA1c). HbA1c reflects the glucose concentration in the blood plasma over a longer period of time. HbA1c exceeding 48 mmol/mol is considered the cut-off for type 2 diabetes, the study found a larger proportion of people living with HIV had values exceeding the cut-off
“The risk of having type 2 diabetes was 70% higher, and perhaps the most remarkable thing was that we found no correlation between HIV-specific risk factors and the risk of having type 2 diabetes. So the strength of the immune system did not seem to affect the prevalence of type 2 diabetes,” explains Susanne Dam Poulsen, Professor, Department of Clinical Medicine and Department of Infectious Diseases, Rigshospitalet, Copenhagen.
Has dramatically increased overall longevity
The study does not confirm any direct cause of the markedly increased risk of type 2 diabetes among people living with HIV, but a previous study by the same group of researchers indicates fat depots as a possible link between HIV infection and an increased risk for both type 2 diabetes but also other noncommunicable diseases such as cardiovascular disease.
“The previous study pointed out that antiretroviral therapy containing thymidine analogues and didanosine is associated with changes both in the distribution of adipose tissue and in other cardiovascular risk factors such as the presence of the kind of lipoproteins that transport cholesterol. And these changes are apparently long-lasting and can therefore be measured years after receiving treatment,” says Susanne Dam Poulsen.
Preventing HIV infection is according to the researchers clearly most important. One way of doing this is through pre-exposure prophylaxis (PrEP) to avoid acquiring HIV. But for those already living with HIV, there is a need to become more knowledgeable about their comorbidities.
"This can also increasingly ensure optimal prevention and regular screening for people living with HIV who are at higher risk of comorbidities. Today, 6000 people are living with HIV in Denmark, but as they live longer because of the improvements in treatment, we should more strongly emphasise the need for enhanced preventive efforts to combat these comorbidities,” concludes Susanne Dam Poulsen.