Globally, long-term viral suppression rates are higher among older people starting antiretroviral therapy than younger people—even though their baseline viral load is higher and their initial CD4 gain is lower, a massive meta-analysis found.
The examination of 40 studies involving 888,151 participants worldwide was published in the Journal of Acquired Immune Deficiency Syndromes.
It showed that after starting antiretroviral therapy, people age 50 and older experienced rates of virologic suppression similar to those of younger people through 6, 12, and 24 months. At the three-year mark, however, older people had a small (4%) but statistically significant greater likelihood of being virally suppressed.
On the other hand, older people were also found to have higher baseline viral loads, higher non-AIDS-related mortality, and slightly higher AIDS-related mortality than younger people.
The authors of the meta-analysis theorized that the higher viral loads and lower CD4 cell count recoveries seen among older people were related to the natural decline of the immune system as people age; meanwhile, their better viral suppression may indicate greater treatment adherence.
In most of the world, baseline CD4 count did not differ by age, possibly because the decline in immune function caused by HIV may mask the natural decline of the immune system, the researchers suggested. In Europe, however, baseline CD4 counts were significantly lower among older adults. “Earlier diagnosis and treatment may reveal differences in the baseline CD4 counts between older and younger adults,” they hypothesized.
The authors called for earlier diagnosis and treatment of older people living with HIV (PLWH), as well as further studies of the biological mechanisms involved in the observed differences.