Bone mineral density changes in protease inhibitor-sparing vs. nucleoside reverse transcriptase inhibitor-sparing highly active antiretroviral therapy: data from a randomized trial.
OBJECTIVE
The aim of the study was to compare changes in bone mineral density (BMD) over 144 weeks in HIV-infected patients initiating nucleoside reverse transcriptase inhibitor (NRTI)-sparing or protease inhibitor-sparing highly active antiretroviral therapy (HAART).


METHODS
Sixty-three HAART-naïve patients were randomized to zidovudine/lamivudine+efavirenz or lopinavir/ritonavir+efavirenz. We performed dual energy X-ray absorptiometry (DEXA) at baseline and at weeks 24, 48, 96 and 144 to evaluate lumbar spine and femoral neck (hip) BMD.


RESULTS
At baseline, 33 patients (55.9%) had low BMD (T-score < -1.0) and of these eight had osteoporosis (T-score < -2.5). Spine BMD declined in both arms until week 24, before stabilizing. In the NRTI-sparing arm, the mean percentage change from baseline was -2.7% [95% confidence interval (CI) -3.9 to -1.4] at week 24 and -2.5% (95% CI -5.4 to 0.3) at week 144, compared with -3.2% (95% CI -4.4 to -2.1) and -1.9% (95% CI -3.5 to -0.3) in the protease inhibitor-sparing arm. Hip BMD declined until week 48 before stabilizing. In the NRTI-sparing arm, BMD had decreased by -5.1% (95% CI -7.1 to -3.1) at week 48 and -4.5% (95% CI -6.9 to -2.1) at week 144, compared with -6.1% (95% CI -8.2 to -4.0) and -5.0% (95% CI -6.8 to -3.1) in the protease inhibitor-sparing arm. There were no significant differences between arms. Low baseline CD4 cell count was independently associated with spine (P=0.007) and hip (P=0.04) BMD loss and low body mass index with hip BMD loss (P=0.03).


CONCLUSIONS
Spine and hip BMD declined rapidly 24 to 48 weeks after initiating HAART, independent of the assigned drug class, but thereafter BMD values remained stable.
Hansen
A B
AB
Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark. ann-brit.eg.hansen@rh.regionh.dk
Obel
N
N
Nielsen
H
H
Pedersen
C
C
Gerstoft
J
J
D015502:Absorptiometry, Photon; D000328:Adult; D000480:Alkynes; D023241:Antiretroviral Therapy, Highly Active; D048588:Benzoxazines / Q000627:therapeutic use; D015519:Bone Density; D003521:Cyclopropanes; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use; D061466:Lopinavir; D008297:Male; D011744:Pyrimidinones / Q000627:therapeutic use; D019438:Ritonavir / Q000627:therapeutic use; D015215:Zidovudine / Q000627:therapeutic use
D000480:Alkynes; D048588:Benzoxazines; D003521:Cyclopropanes; D011744:Pyrimidinones; D061466:Lopinavir; D019259:Lamivudine; D015215:Zidovudine; C098320:efavirenz; D019438:Ritonavir