Objective: To compare 48-week changes in body fat distribution and bone mineral density (BMD) between patients switching from a ritonavir-boosted protease inhibitor (PI/r) to raltegravir (RAL) and patients continuing with PI/r.
Design: Substudy of the prospective, randomized, open-label, multicenter SPIRAL study.
Methods: Patients were randomized (1 : 1) to continue with the PI/r-based regimen or switch to RAL, maintaining the rest of the treatment unchanged. Dual-energy X-ray absorptiometry and computed tomography scans were performed at baseline and after 48 weeks to measure body fat and bone composition, analyzing intragroup and intergroup differences.
Results: Eighty-six patients were included and 74 patients (39 RAL, 35 PI/r) completed the substudy. Significant increases in median [interquartile range (IQR)] visceral adipose tissue (VAT) [20.7 (−2.4 to 45.6) cm2, P = 0.002] and total adipose tissue (TAT) [21.4 (−1.3 to 55.4) cm2, P = 0.013] were seen within the PI/r group. No significant changes in body fat were seen with RAL or between treatment groups. Regarding bone composition, total BMD [0.01 (0 to 0.02) g/cm2, P = 0.002], total hip BMD [0.01 (0 to 0.03) g/cm2, P = 0.015] and total hip T score [0.12 (−0.05 to 0.21) SD, P = 0.004] significantly increased with RAL, with no significant changes within the PI/r group. Differences between treatment groups were significant in femoral neck BMD [0.01 (−0.02 to 0.02) g/cm2, P = 0.032] and T score [0.01 (−0.18 to 0.18) SD, P = 0.016].
Conclusion: Although there were no significant changes in body fat between groups, maintaining a PI/r-based regimen was associated with a significant increase in VAT and TAT. Switching to RAL led to a significant increase in femoral neck BMD when comparing between groups.
aHospital Universitari Vall d’Hebron, Universitat Autònoma de Barcelona, Infectious Diseases Department
bHospital Clinic i Provincial, Infectious Diseases Department
cHospital Universitari de Bellvitge, HIV Unit, Infectious Diseases Department, L’Hospitalet de Llobregat
dCETIR, Nuclear Medicine Department
eHospital Universitari Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Infectious Diseases Department, Barcelona, Spain.
Correspondence to Adrian Curran, MD, Infectious Diseases Department, Hospital Universitari Vall d’Hebron, Universitat Autònoma de Barcelona, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain. Tel: +34 93274 6090; fax: +34 9348 94091; e-mail: email@example.com
Received 27 September, 2011
Revised 9 November, 2011
Accepted 14 November, 2011