Objective: To determine the effects of switching from lopinavir/ritonavir (LPV/r) to atazanavir/ritonavir (ATV/r) on muscle glucose uptake, glucose homeostasis, lipids, and body composition.
Methods: Fifteen HIV-infected men and women on a regimen containing LPV/r and with evidence of hyperinsulinemia and/or dyslipidemia were randomized to continue LPV/r or to switch to ATV/r (ATV 300 mg and ritonavir 100 mg daily) for 6 months. The primary endpoint was change in thigh muscle glucose uptake as measured by positron emission tomography. Secondary endpoints included abdominal visceral adipose tissue, fasting lipids, and safety parameters. The difference over time between treatment groups (treatment effect of ATV/r relative to LPV/r) was determined by repeated measures ANCOVA.
Results: After 6 months, anterior thigh muscle glucose uptake increased significantly (treatment effect +18.2 ± 5.9 μmol/kg per min, ATV/r vs. LPV/r, P = 0.035), and visceral adipose tissue area decreased significantly in individuals who switched to ATV/r (treatment effect −31 ± 11 cm2, ATV/r vs. LPV/r, P = 0.047). Switching to ATV/r significantly decreased triglyceride (treatment effect −182 ± 64 mg/dl, ATV/r vs. LPV/r, P = 0.02) and total cholesterol (treatment effect −23 ± 8 mg/dl, ATV/r vs. LPV/r, P = 0.01), whereas high-density lipoprotein and low-density lipoprotein did not change significantly. Fasting glucose also decreased significantly following switch to ATV/r (treatment effect −15 ± 4 mg/dl, ATV/r vs. LPV/r, P = 0.002).
Conclusion: Switching from LPV/r to ATV/r significantly increases glucose uptake by muscle, decreases abdominal visceral adipose tissue, improves lipid parameters, and decreases fasting glucose over 6 months.
aProgram in Nutritional Metabolism, USA
bDivision of Infectious Diseases, USA
cDepartment of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
dNational Institutes of Health, Bethesda, Maryland, USA.
Received 26 January, 2009
Revised 11 March, 2009
Accepted 15 March, 2009
Correspondence to Steven K. Grinspoon, MD, Director, Program in Nutritional Metabolism, Massachusetts General Hospital, Boston, MA 02114, USA. Tel: +1 617 724 9109; fax: +1 617 724 8998; e-mail: email@example.com