It wasn't too long ago that the annual mortality from HIV infection exceeded 20 percent/yr. Much to the credit of the scientific community which aggressively researched this disease and to the credit of our society as a whole for accepting the reality of HIV and making it a major public health issue, the annual mortality rate is now less than 2 percent/yr in just over a decade of therapy. The continued development of highly active antiretroviral therapy (HAART) is largely responsible for this dramatic reduction in death.
As HIV infected people are enjoying much longer life, unfortunately they are now at risk for developing other diseases associated with HIV and HAART. One of these conditions is abnormal cholesterol levels and an increased risk of cardiovascular disease.
Before the advent of HAART, it has been well documented that HIV had a significant effect on cholesterol levels. People with advanced HIV tended to have reduced total cholesterol, lower HDL, lower LDL, and higher triglycerides just prior to developing AIDS.
There was a direct relationship between the HIV viral load and the degree of increased triglycerides. It is unclear whether these changes resulted in a net increase in heart disease since most of these people died from HIV/AIDS related illnesses and not heart attacks.
HAART has been linked to the development of various metabolic disorders including lipid abnormalities. When HAART was first introduced, people began to notice changes in fat distribution over time. Specifically, some people on HAART began to lose fat peripherally such as in their face and extremities but accumulated fat centrally such as in their waist or back. This change in fat distribution has been termed "lipodystrophy." Lipodystrophy is associated with significant increases in total cholesterol, total LDL, and triglycerides.
When 10 year heart disease risk was compared between HIV patients on HAART who developed lipodystrophy vs. HIV negative patients, lipodystrophy patients had a significantly increased risk. Interestingly, when the 2 groups were matched for similar waist-to-hip ratio, the heart disease rates were similar. And, HIV patients on HAART who did not develop lipodystrophy did not appear to have an increased risk of heart disease.
It would seem that the fat redistribution itself may be the cause of the cholesterol abnormalities and the increased risk of heart disease.
Currently, there are numerous classes of HAART as well as numerous drugs within each class. One particular class of HAART called protease inhibitors appears to have the greatest negative impact on cholesterol levels. However, certain protease inhibitors such as atazanivir do not have any significant effect on cholesterol. The other classes of HAART such as the nonnucleoside reverse transcriptase inhibitors (NNRTI) and nucleoside analogs have also been associated with increased cholesterol and triglycerides.
In summary, people with HIV are living much longer and healthier lives largely in part due to HAART. HIV and HAART are associated with significant changes in lipids, and specifically HAART associated lipodystrophy can markedly worsen cholesterol and triglyceride levels and increase the risk of heart disease.
All HIV patients who are starting HAART should have a baseline fasting lipid profile checked, a repeat test in 3 to 6 months, and then a test annually. Counseling on heart healthy diet and exercise are also recommended.
If significant lipid abnormalities develop on HAART, the initial response is often to change the HAART regimen to use drugs not associated with significant cholesterol changes. However, if the cholesterol levels are still too high, then treatment with cholesterol lowering medication such as a statin or fibrate is recommended. The levels at which to initiate drug therapy and the targeted goals are same for both HIV infected and non-HIV infected individuals.