HIV
and Hepatitis.com Coverage of the 14th
Annual Conference on Retroviruses and Opportunistic Infections (14th CROI) February
25 - 28, 2007, Los Angeles, CA
HIV
Positive Patients Respond Less Well to Lipid-lowering Therapy
Kaiser Permanente has 3 million members in Northern
California; the system has cared for a total of 17,000 HIV positive
patients, of whom 5400 are current members.
Researchers assesseddifferences in response to lipid lowering therapy (LLT) according to HIV status
and type of antiretroviral therapy. They identified HIV
positive and HIV negative patients treated with LLT from 1996 through 2005
in 3 cohorts defined by type of dyslipidemia:
Cohort 1 --6862 patients (907 HIV
positive): total cholesterol
(TC) ≥ 240 mg/dL;
Cohort 2 -- 6496 patients (695 HIV positive):
LDL (“bad”) cholesterol ≥ 160 mg/dL, or ≥130 if
patient had 2 or more other CHD risk factors, or ≥ 100 if patient had a
history of CHD;
In each cohort, they estimated
changes in lipids by HIV status 1 year after starting LLT, controlling for factors
including patient sex, age, baseline lipid levels, prior CHD, diabetes, liver
disease, CHD risk factors, type and duration of LLT, and type of HAART. They also
calculated the adjusted odds ratio for achieving the National Institutes of Health’s
National Cholesterol Education Program Adult Treatment Panel III (ATP III) lipid goals.
Result
In all 3 cohorts, the most commonly used LLT agents were statins
(87%, 89%, and 52%, respectively).
Dosing of individual LLT agents was similar regardless
of HIV status, but different drugs tended to be used in HIV positive and HIV negative
patients.
After 1 year, HIV positive patients experienced
significantly smaller declines in all 3 lipid parameters compared with HIV negative individuals:
TC: 18.1% vs
22.5% decrease;
LDL: 21.6% vs
23.4% decrease;
TG: 35.9% vs
53.5% decrease.
Differences in percentage change between HIV positive
and HIV negative patients were largest for TG (17.4%), intermediate for TC (4.4%),
and smallest for LDL (1.8%).
HIV positive patients taking regimens containing
both a PI and a NNRTI (nearly 25%) had the smallest decreases in TC and TG, although
no significant difference was observed for LDL.
HIV positive patients were less likely than HIV
negative individuals to achieve the recommended
ATP-III lipid goals for TC, LDL, and TG (43%, 19%, and 61% less likely, respectively).
HIV positive patients had an improved likelihood
of attaining these goals in more recent years.
However, the chances of doing so decreased
with every additional year on LLT.
Conclusion
“Declines in LDL in response to LLT are similar in HIV
positive and HIV negative patients, but declines in TC and TG levels are less
prominent in HIV positive patients,” the researcher concluded.
They suggested that, “Differences
in choice of LLTs among HIV positive [patients] due
to concerns [about] drug-drug
interactions and toxicity may explain
[the] results for TC.”
In particular, HIV positive
patients were more likely to receive pravastatin (Pravachol)
or atorvastatin (Lipitor),
while HIV negative individuals more often received simvastatin
(Zocor) or lovastatin (Mevacor), which interact more strongly with PIs.
The researchers also noted that, overall,
HIV positive patients had their blood lipids monitored more frequently and were
treated for dyslipidemia more often than HIV negative
individuals of a similar age and sex, no doubt due to growing awareness and concern
about increased risk of cardiovascular disease among patients on HAART.
References
M Silverberg, W Leyden, M Horberg, and others.Lipid-lowering
Therapy Responses in HIV+ and HIV-Dyslipidemic
Patients Enrolled in a Large Integrated Healthcare Delivery System. 14th Conference on
Retroviruses and Opportunistic Infections; February 25-28, 2007; Los Angeles, California.Abstract 814 (poster).
