Several reports indicated that HIV-1 infected people have lower bone mineral density (BMD) than general population, independently of traditional osteoporosis risk factors. TDF-including regimens have been associated with greater loss of BMD than other regimens.
Objective: To identify low bone mineral density associated factors in African patients on a protease inhibitor (PI)-based second line antiretroviral treatment (ART).
It is a sub-study (ANRS 12250) of a multicenter randomized phase 3 trial that compared efficacy and safety of three second line combinations in Africa (ANRS 12169). Patients from Bobo-Dioulasso (Burkina Faso), Yaounde (Cameroun) and Dakar (Senegal) were randomized to receive either TDF/FTC/LPVr, ABC/ddI/LPVr or TDF/FTC/DRVr. The BMD was assessed by calcaneum quantitative ultrasound (Achilles, GE Healthcare) at baseline and every 6 months. Stiffness index was used to evaluate BMD and associated factors were determined by multiple linear regressions. Mixed models with random effects were used to determine associated factors during the follow-up.
Out of 228 patients, 158 (69%) were included in Yaounde and 168 (74%) were women. At baseline, mean age was 40 ± 10 years, mean T-CD4 counts was 218 ± 139 cells/µl and mean viral load, 4.5 ± 0.7 log/ml. The mean duration of the first line ART was 55 ± 24 months and the mean baseline stiffness index was 103 ± 22. Independent factors associated with baseline BMD were sex (β=-10.57 [-17.90,-3.23] for women), age (β=-0.87 [-1.24,-0.50] per year), body mass index (BMI) (β=+0.80 [-0.07,1.52] per unit of BMI) and study site (β=+12.81 [6.48,19.14] for Yaounde). After 24 months of second line therapy, a reduction of 7.3% of mean stiffness index was observed, compared to baseline. The factors associated with BMD during the follow-up were similar to those found at baseline (table). Exposure to TDF or to LPV was not associated with greater loss of BMD over time.
BMD decreases after second line ART initiation in African patients independently of TDF or LPV exposition. Factors associated with BMD were age, sex, baseline BMI, study site and time of follow up.