IAS: Cardiovascular disease and diabetes increasing as causes of death for people with HIV in Brazil

Deaths from cardiovascular disease and diabetes appear to be on the increase in the post-HAART era according to a Brazilian analysis of national mortality data presented to the 4^th IAS Conference in Sydney on Wednesday. However the researchers admit that their data have limitations, and can only reflect estimates of temporal trends rather than actual mortality rates.

In 1996, Brazil became the first developing country to provide free and universal access to highly active antiretroviral therapy (HAART). However, although death rates in HIV-positive individuals have dropped significantly since then, there are no published studies on temporal changes in causes of death in Brazil following the introduction of HAART.

More than 30 years ago, the ministry of health in Brazil set up a national information system for all deaths. Subsequently, death certificates, with no personal identifier, are publicly available online, and since 1999 have recorded both primary and secondary causes of death.

Antonio Pacheco and colleagues from the Departamento de Epidemiologia e Métodos Quantitativos em Saúde (Department of Epidemiology and Quantitative Methods in Health) in Rio de Janeiro used this data to estimate temporal trends of death due to cardiovascular disease and diabetes as well as all non-HIV-related mortality (comprising the former two causes plus non-HIV-related cancers, digestive and genital-urinary diseases and external causes), between 1999 and 2004 in people who had HIV or AIDS noted as the primary or secondary cause of death on their death certificate.

During that time over 5.8 million deaths were reported in the country and of these 67,249 (1.15%) had HIV or AIDS mentioned on the death certificate. (UNAIDS estimated that in 2005, 14,000 deaths occurred in HIV-positive individuals, so this is likely to be an underestimation of actual deaths in HIV-positive individuals.) The researchers then used multivariate logistic regression models to compare temporal trends of these causes of death in those officially reported to have HIV or AIDS, with the rest of the population, controlling for age, gender, year of death, and state of residence as potential confounders.

They found an 8% year-on-year increase in non-HIV-related mortality in individuals whose death certificate mentioned HIV or AIDS compared with 3% in those whose death certificates did not mention HIV or AIDS. Compared with 1999, people with HIV or AIDS recorded on their death certificates were 1.6 times more likely to have died of non-HIV-related causes in 2004 than those whose death certificates did not mention HIV or AIDS (p

Similarly, there was an 8% and 12% year-on-year increase in deaths from cardiovascular disease and diabetes, respectively, in individuals whose death certificates mentioned HIV or AIDS compared to 0.8% and 2.8%, respectively, in those whose death certificates did not mention HIV or AIDS.

Compared with 1999, people with HIV or AIDS recorded on their death certificates were 1.47 times more likely to have died of cardiovascular disease and 2.15-times more likely to have died of diabetes in 2004 than those whose death certificates did not mention HIV or AIDS (both p

Mr Pacheco said these data “show that the frequency of cardiovascular disease and diabetes - as well as other conditions generally not associated with HIV or AIDS – is increasing faster in those infected with HIV than in the general population.”

However, he pointed out several limitations to his study; the main one being that only data officially recorded on death certificates were used. “These lack sensitivity and specificity,” Mr Pacheco noted, “but these shortcomings are minimised by the fact that we are not trying to infer rates, themselves, but temporal trends within a relatively short time-span.”

He also admitted that, “other confounding variables could not be measured directly, such as smoking and other risk factors for cardiovascular disease. Additionally,” he added, “we could not control for evolving differences in the likelihood of mentioning HIV or AIDS in the death certificates, but this is unlikely to have occurred given the stability of the rates that we found during the study period.”

He concluded by saying that their data showed the “need to combine prevention, early diagnosis and treatment of other chronic illnesses in the management of people with HIV,” and noted that, “these results may also serve to alert other developing countries who are scaling up the use of HAART to prepare for changes in morbidity and mortality amongst HIV-infected individuals.”