With the advent of the highly active antiretroviral (ARV) therapy era, patients with human immunodeficiency virus (HIV) have had significantly decreased mortality and morbidity. Concomitant with more patients chronically taking antiretroviral therapy, there has been an increase in atherogenic lipoprotein profiles (high cholesterol, high triglycerides, low HDL's), insulin resistance, fat redistribution and coronary artery disease. HIV viral replication, anti-retroviral treatment regimens, lipids, glucose intolerance, host immune response or a combination of factors may contribute to the increase in cardiovascular risk factors. HIV positive patients, independent of the effect on lipids, appear to have increased cardiovascular risk. Studies are not entirely consistent, but the most convincing study to date, the D.A.D. study from EURO-SIDA, shows a 27% relative increased rate of myocardial infarction per year of exposure over the first seven years of ART. Lopinavir-ritonavir is one of the most commonly used antiretroviral therapy. It also produces lipid abnormalities. Thus, an important part of the investigating factors contributing to atherosclerosis would be to determine if this drug can adversely influence endothelial cells in the absence of HIV infection or low CD4 counts. This would suggest that this drug directly or indirectly could predispose to atherosclerosis. Endothelial function is an important contributor to atherosclerosis. Invasive and non-invasive methods to evaluate endothelial cell function have been validated as predictors of coronary artery disease. These techniques have been used at NIH for clinical investigation for many years. This protocol is designed to determine whether there is a pathologic effect on endothelial function from the lopinavir/ritonavir. By measuring endothelial function in HIV non-infected subjects both before and after four weeks of therapy, we will be able to investigate whether the medications have a direct toxic effect on the endothelium. Collection of metabolic data will allow us to evaluate whether endothelial function occurs in conjunction or separate from lipoprotein and glucose metabolic changes. As ARV options increase, it may be possible to choose specific regimens that may minimize acceleration of cardiovascular risk factors associated with endothelial dysfunction, especially in patients with other cardiovascular risk factors. These findings may help elucidate the pathophysiology of premature cardiovascular disease in HIV positive patients and also plan interventions to minimize endothelial dysfunction and subsequent cardiovascular disease.
INCLUSION CRITERIA: Age 18-40. Healthy by medical history and physical examination. Negative serum pregnancy test for females. Females willing to use two forms of birth control including barrier contraception during period of study (lopinavir/ritonavir decreases ethinyl estradiol levels). Able to provide informed consent. Laboratory values on screening visit within: AST less than 40 units/liter, serum creatinine less than 1.5mg/dl; CPK less than 387, hemoglobin greater than 11.0 g/dL (females) or greater than 12.6 g/dL (males), platelets greater than 154,000/mm(3), total bilirubin less than or equal to 1.5 mg/d Total cholesterol less than 200 mg/dL, LDL cholesterol less than 160 mg/dL, HDL cholesterol greater than 30mg/dL, triglycerides less than 200 mg/dL. Non-smoker or not having smoked for the past 6 weeks. Negative for HIV by ELISA within 4 weeks of study participation. EXCLUSION CRITERIA: Concomitant therapy with any prescription, over-the-counter or alternative medication except intermittent use of acetaminophen, non-steroidal anti-inflammatory medications, loperamide or oral contraceptives. Inability to obtain venous access for sample collection. Presence of diabetes mellitus or fasting blood sugar greater than 126 mg/dL, or abnormal oral glucose tolerance test (2 hour post blood sugar greater than 200 mg/dL). Human immunodeficiency virus (HIV) infection. Cardiac disease, congestive heart disease, coronary artery disease, angina, carotid stenosis, peripheral vascular disease, cerebrovascular disease, myocardial disease, clinically significant valvular heart disease. Any other condition that may interfere with the interpretation of the study results or not be in the best interest of the subject in the opinion of the investigator. Hypertension (systolic blood pressure greater than 140 mmHg or diastolic blood pressure greater than 90 mmHg) on screening visit. Observed abnormalities on EKG tracings that are significant in the opinion of the investigator (examples include, AV block, multifocal atrial tachycardia, frequent premature ventricular contractions, etc.). Hypotension (systolic blood pressure less than 80 mmHG). Pregnant or breastfeeding female. Inability to abstain from caffeine use (coffee, tea or soda) or alcohol for 12 hours prior to a blood flow study until the conclusion of the study. Heavy alcohol ingestion (4 or more drinks a day) or current substance abuse. Hypo or hyper thyroidism. Allergy to lidocaine. History of hepatitis or other liver disease.