The Connection Between Heart Disease and HIVThe announcement linking HIV and heart disease is not the first example of the connection. In 2005, a European study examined the impact of HIV medications on the human body. This study is thought to be the first that suggested HIV had an effect on cardiac health. Specifically, the study showed that people infected with HIV were twice as likely to have a heart attack than people not infected with HIV. This was confirmed in a study whose results were reported in 2007. Again, the study confirmed that HIV positive people were twice as likely to suffer a heart attack than HIV negative people. But this study showed much more. For instance, a woman's risk for a heart attack tripled after she became HIV infected and a man had a 40% increase in risk after being HIV infected. So it is becoming more obvious that HIV has an impact on cardiac health. But why is that the case?
Metabolic Syndrome and How it Relates to HIV and Cardiac DiseaseWhile there are many theories regarding the impact of HIV on cardiac disease risk factors, HIV medications have emerged as the biggest culprits. Protease Inhibitors have been identified as increasing cardiac risk factors such as cholesterol and triglycerides levels. Most recently, as mentioned above, two drugs from the Nucleoside Reverse Transcriptase Inhibitor class have been shown to increase the risk of heart attack in HIV patients taking them. And as we have heard many times, certain factors increase the risk of cardiac disease regardless of HIV status. If a person exhibits three or more of these risk factors, he is considered to have Metabolic Syndrome. These risk factors include:
- central obesity (fat accumulation around the waist
- hypertension (high blood pressure) (>130/85)
- elevated triglycerides (serum triglycerides >150)
- low HDL (<40)
- high triglycerides
- elevated fasting serum glucose (>100)
The presence of metabolic syndrome increases the risk of heart disease in people with or without HIV. But in HIV, metabolic syndrome takes on some unique characteristics. For instance, alterred fat distribution is more exaggerated in HIV. Fat is redistributed to the abdomen, neck and back from the face and extremities. HIV medications can significantly alter cholesterol and triglyceride levels. Finally, blood sugar changes and hypertension are associated with HIV above and beyond what we see in the HIV negative population. Because of this fact, HIV specialists have become very aggressive in their management of metabolic syndrome.
Assess The RiskTypically, in HIV negative patients, the co-existence of elevated cholesterol, lowered HDL ("good cholesterol"), elevated LDL ("bad cholesterol")and elevated triglycerides would be criteria to initiate lipid-lowering treatment. However, other factors in the HIV positive patient makes assessing cardiac risk much more difficult.
One difficulty assessing cardiac risk in the HIV positive patient is that most HIV positive people are young. Under normal circumstances, age is a heavily weighed cardiac risk factor. Because of the young age of many HIV positive people, cholesterol abnormalities may not be considered to be a risk according to established cardiac risk assessment tools. Yet the cardiac risk in these people are real and should be agressively managed. Lipid Specialist Dr. Devi Nair of the Royal Free Hospital in Great Britain takes an aggressive approach when managing lipid abnormalities in her HIV infected patients.
- "If a patient has a lipid problem, I count up the risk factors. If they have more than one risk factor, I take the problem seriously. If they have three or four risk factors, I treat them."
Page 2 looks at what we should do to address those identified risks.