Neurocognitive impairment in people with HIV – loss of memory, poor concentration and declining mental ability – is most likely to be happening for the same reasons as in the wider population, and the risk of impairment does not appear to be associated with HIV infection, a French cohort study has found.
Older age, anxiety and depression, cardiovascular disease and a
history of brain injury were strongly associated with neurocognitive impairment, which was detected in 59% of a cohort of French people with HIV.
“Most of the cases were related to
non-HIV-related determinants,” comment the authors. “The high prevalence of NCI
[neurocognitive impairment] observed in our cohort was neither associated with
incomplete viral suppression nor current nor nadir CD4 count. Furthermore, we
did not find any association with the current cART [combination antiretroviral
There is considerable interest in the
frequency and causes of neurocognitive impairment in people with HIV.
Some studies have suggested that the
majority of people, even in the era of modern antiretroviral treatment, have
some form of impairment.
However, much of the existing research is
limited because it was conducted in highly selected groups of participants who
often had pre-existing cognitive complaints.
Researchers in southern France therefore
designed a study involving a broad spectrum of people receiving routine HIV
To be eligible for the study, participants were
required to be aged over 18 and medically stable. Recruitment took place between 2007 and
2009 and a total of 400 people joined the study.
Their neurocognitive function was assessed
using standardised tests, which were administered by trained psychologists.
Information was also gathered from medical records regarding known risk factors
for neurocognitive impairment, such as older age, level of educational
attainment, cardiovascular disease, mental health problems such as depression
and a history of head injury.
Approximately half the participants also had an
MRI scan to see if there was an association between neurocognitive function and
atrophy of grey matter in the brain.
The participants had a median age of 47 years
and 79% were men. Most (89%) were taking antiretroviral therapy, and 93% of
these people had a viral load below 500 copies/ml. Current median CD4 cell
count was 515 cells/mm3 and the median nadir CD4 cell count was 260
cells/mm3. Approximately a fifth (19%) of participants had high
cholesterol, 4% had a history of cardiovascular disease and 29% were
co-infected with hepatitis B or hepatitis C virus.
Neurocognitive testing found a high
prevalence of impairment (59%). This was asymptomatic in 20% of participants and mild
in 31%; 7% had HIV-associated dementia.
People with impairment were significantly
older (p = 0.02), and were more likely to have other health complaints, including
a history of cardiovascular disease (p = 0.01), elevated cholesterol (p =
0.04), a history of stroke, brain trauma or neurological disease (p <
0.001), depression (p < 0.001), anxiety (p < 0.001), diagnosis with an
AIDS-related neurocognitive condition (p < 0.001), or lower levels of
education (p < 0.001).
After controlling for confounding factors,
the investigators found that a number of traditional risk factors were
associated with an increased risk of impairment.
These included lower levels of education, a
history of cardiovascular disease, high cholesterol, anxiety, depression, a
history of neurological disease or trauma, and diagnosis with an AIDS-defining
neurological disease. No HIV-related factor such as CD4 cell count, viral load,
duration of infection with the virus, or use of antiretroviral therapy had a
significant association with the risk of impairment.
When the investigators restricted their
analysis to the 192 participants without anxiety, depression, a history of brain
damage and who also had a higher level of education, they found that only 19%
had symptomatic impairment. Restricting analysis further to people without a
history of cardiovascular disease reduced the prevalence to just 10%.
The authors believe their results have clinical
significance and show the importance of screening for cardiovascular disease,
anxiety and depression and when detected, offering appropriate treatment.
The results of the MRI scans showed that
people with impairment had significantly lower grey matter volume (p =
0.006). This remained the case after exclusion of participants with the neurological
manifestations of AIDS and a history of head trauma (p = 0.03).
“Our study shows for the first time in a
large sample a strong association between a reduced volume of grey matter and
any stage of NCI,” comment the investigators. “Such results are important for
better understanding HIV-associated neurocognitive disorders since they suggest
that the cognitive defects in HIV-infected patients are not only due to the functional
changes in neural circuitry but could also be the consequence of
macrostructural brain lesions.”
They conclude: “All together, our findings
suggest that, in patients that are well controlled for HIV infection,
cardiovascular and psychiatric disease, in addition to any brain damage
including neuroAIDS, and low level of education are related to NCI…screening
for cognitive impairment should be accompanied by screening for cardiovascular
and psychiatric co-morbidities, in particular depression and anxiety disorders.”