HIV drug linked to accelerated and early aging

By Dr. Ananya Mandal, MDJun 27 2011

New research published this Sunday reveals that a class of generic AIDS drugs often used to treat HIV in Africa and other poor regions can cause premature aging and lead to age-related illnesses such as heart disease and dementia.

The study appeared in the journal Nature Genetics where British researchers found that the drugs, known as nucleoside analog reverse-transcriptase inhibitors, or NRTIs, damage DNA in the patient's mitochondria - the “batteries” that power cells. The commonest drug of this class is Zidovudine or AZT. The researchers add that it was unlikely that newer cocktails of AIDS drugs made by firms like Gilead, Merck, Pfizer and GlaxoSmithKline would inflict similar levels of damage, since they are thought to be less toxic to mitochondria. But more research is needed to be certain.

Patrick Chinnery of the Institute of Genetic Medicine at Newcastle University said, “It takes time for these side effects to become apparent, so there is a question mark about the future and whether or not the newer drugs will cause this problem. They are probably less likely to, but we don't know because we haven't had time to see.”

For their study, Chinnery's team studied muscle cells from HIV-infected adults, some of whom had previously been given NRTIs. They found that patients who had been treated with NRTIs - even as long as 10 years previously - had damaged mitochondria similar to that of a healthy older person.

Researchers write that this study helps to explain why HIV-infected people treated with older antiretroviral AIDS drugs sometimes show advanced signs of frailty and diseases such as heart disease and dementia at an early age. Study leader Chinnery said, “The DNA in our mitochondria gets copied throughout our lifetimes and, as we age, naturally accumulates errors. We believe these HIV drugs accelerate the rate at which these errors build up. So over the space of, say, 10 years, a person's mitochondrial DNA may have accumulated the same amount of errors as a person who has naturally aged 20 or 30 years.”

An estimated 33.3 million people worldwide had the human immunodeficiency virus (HIV) that causes AIDS in 2009, according to the latest United Nations data, and 22.5 million of those live in Africa.

“These drugs may not be perfect, but we must remember that when they were introduced they gave people an extra 10 or 20 years when they would otherwise have died…In Africa, where the HIV epidemic has hit hardest and where more expensive medications are not an option, they are an absolute necessity,” said Brendan Payne of Newcastle's Royal Victoria Infirmary, who also worked on the study.

The study was funded by the Medical Research Council, the British Infection Society, the Newcastle Healthcare Charity, the UK NIHR Biomedical Research Centre for Aging and Age-related Disease and the Wellcome Trust.