7th IAS Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2013)


WELBB05 - Oral Abstract

Changes in bone mineral density over 48 weeks among participants randomised to either lopinavir/ritonavir (LPV/r) + 2-3N(t)RTI or LPV/r + raltegravir as second-line therapy: a sub-study of the SECONDLINE trial

Presented by Jennifer Hoy (Australia).

J. Hoy1, A. Martin2, C. Moore2, P. Mallon3, S. Emery2, W. Belloso4, P. Phanuphak5, S. Ferret6, D. Cooper2, M. Boyd2, SECOND-LINE study team

1Monash University, Melbourne, Australia, 2University of New South Wales, Kirby Institute, Sydney, Australia, 3UCD School of Medicine and Medical Science, Dublin, Ireland, 4CICAL, Buenos Aires, Argentina, 5Thai Red Cross AIDS Research Center, Bangkok, Thailand, 6Hopital Saint-Louis, Paris, France

Background: The effects of integrase inhibitors on bone mineral density (BMD) have not been well defined. We compared BMD changes in participants randomised to lopinavir/ritonavir (LPV/r) + raltegravir (RAL) or LPV/r+2-3 nucleoside reverse transcriptase inhibitors (N(t)RTIs) as second-line therapy. It was hypothesised LPV/r+RAL would demonstrate smaller reductions in BMD.
Methods: Participants were randomised 1:1 to LPV/r+RAL (n=108) or LPV/r+2-3N(t)RTIs (n=102). The sub-study was conducted at 8 sites in South Africa, India, Thailand, Malaysia and Argentina. Dual energy x-ray absorptiometry scans were performed at baseline and week 48 to measure proximal femur and lumbar spine BMD. We determined the mean absolute difference in BMD changes between the two regimens. Unpaired t-tests compared means of differences (week 0 to 48). McNemars test for paired proportions compared osteopenia/osteoporosis BMD variables. Associations between percent BMD changes with baseline variables were assessed by multivariate linear regression. Analysis was by intention to treat.
Results: 51.4% Asian, 43.3% African, 3.3% Caucasian, 1.4% Hispanic population. Analyses were adjusted for gender (52% female), baseline BMI and smoking status. Data are expressed as mean (95% CI).

Right Femur BMDLPV/r+ 2-3N(t)RTILPV/r + RAL% DifferenceP-value
Week 0 (g/cm2)0.97 (0.9, 1.1)0.95 (0.9, 1.0) 
Week 48 (g/cm2)0.92 (0.8, 1.0)0.93 (0.8, 1.0) 
% Change from W0 to 48-5.2 (-6.7, -3.8)-2.9 (-4.3, -1.5)-2.4 (-3.5, -1.2)0.0001
Lumbar Spine BMD 
Week 0 (g/cm2)1.06 (0.9, 1.2)1.07 (1.0, 1.2) 
Week 48 (g/cm2)1.00 (0.9, 1.1)1.04 (0.9, 1.2) 
% Change from W0 to 48-4.2 (-5.7, -2.7)-2.0 (-3.5, -0.6)-2.1 (-3.3, -0.9)0.0006
[Table 1]

Significantly greater loss of BMD was observed in the LPV/r+2-3N(t)RTI group compared to LPV/r+RAL. The incidence of osteopenia (7.6%) and osteoporosis (2.0%) assessed at the proximal femur over the 48 weeks were similar between groups. Longer duration of tenofovir on study (β -1.58 (0.38) femur, -1.65 (0.38) spine, p=0.0001) and low baseline BMI (β 0.5 (0.13) femur, 0.17 (0.07) spine; p< 0.01) were predictive of reduced femur and spine BMD.
Conclusions: An innovative antiretroviral regimen of LPV/r + raltegravir as second-line therapy is associated with less bone loss than a regimen containing N(t)RTIs.

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