|
L-Carnitine
helps normalize the redox state of the brain, and facilitates liver urea
synthesis.
The
main symptoms of carnitine deficiency are high triglycerides and muscular
fatigue. It is likely that the phenomenon known as futile cycling (of free
fatty acids), which occurs in HIV disease, is either caused or at least
exacerbated by carnitine deficiency. Futile cycling is the cyclical reformation
of fat from free fatty acids with subsequent breakdown back to free fatty
acids-thus fats are recycled burning up protein in the process. In HIV
disease, the result is unusually high usage of protein to provide energy
and relatively high storage of fat leading to loss of muscle mass.
WHAT
DO PEOPLE WITH HIV USE THIS SUPPLEMENT FOR?
To protect and enhance
immune cell function: Carnitine supplements may affect immune cell
function and numbers. After test-tube studies suggested that carnitine
might reduce levels of apoptosis (cell death) in HIV-positive individuals,
a small trial of intravenous carnitine involving 11 HIV-positive men was
conducted. The study showed dramatic improvements in CD4 T-cells after
four months of daily six gram injections. Participants began the study
with CD4 T-cell counts between 200 and 500, although all had experienced
a decline in their CD4 T-cell count during the previous 12 months. Participants
had no symptoms of HIV and had chosen not to take antiretroviral drugs.
Increases in CD4 T-cells appeared to be due to a decrease in cell apoptosis.
To decrease blood levels
of triglycerides and cholesterol: After 12 weeks of treatment with
L-carnitine there was a drop in both total cholesterol (from a median of
250 mg/dl to 219 mg/dl) and low density lipoprotein cholesterol (from a
median of 177 mg/dl to 132 mg/dl) levels. Interestingly, the researchers
noted that the cholesterol-lowering effect of L-carnitine is not seen in
HIV-negative patients with lipid disorders.
Peripheral neuropathy:
This is a common side effect of the HIV drugs Videx {didanosine} (ddI),
Hivid {zalcitadine} (ddC), and Zerit {stavudine} (d4T). Symptoms of peripheral
neuropathy include numbness, burning, and tingling in the hands and feet.
In severe cases, peripheral neuropathy can become debilitating. Research
has demonstrated that subjects who developed peripheral neuropathy while
staying on the above medications had acetyl-carnitine deficiency. Carnitine
deficiency may impact on energy and lipid metabolism, causing mitochondrial
and immune dysfunction. The role of acetyl-carnitine for the metabolism
and function of the peripheral nerves supports the view that the acety-carnitine
deficiency found in HIV-positive individuals may contribute to the neurotoxicity
of ddI, ddC, and d4T, even though the interference with mitochondrial DNA
synthesis is regarded as the main cause of their toxicity.
Editors Note: This
information gives an overview of carnitine and its use in people living
with HIV disease. In a future issue of the HIV Nutrition Update we will
publish a more comprehensive research article on carnitine.
|
|
