High risk and probability of progression to osteoporosis at 10 years in HIV-infected individuals: the role of PIs.

Background: Osteoporotic fractures still remain very infrequent and physicians rarely evaluate bone health. We wanted to assess the magnitude of this problem in the near future by determining the risk and likelihood of progression to osteoporosis. Methods: We estimated the risk of progression to osteopenia/osteoporosis among HIV-infected patients with at least 2 DXA scans (3726 scans from 875 patients). Time-non-homogeneous bidirectional multistate models based on three states (normal bone mineral density, osteopenia and osteoporosis) were used to model the progression of bone mineral density as a function of age and to study the association between the risk of bone loss and antiretroviral use. Results: The HRs associated with age (>45 versus ≤45 years) were: (i) from normal bone mineral density to osteopenia, 0.71 (95% CI 0.45-1.11) for men and 1.06 (95% CI 0.55-2.05) for women; and (ii) from osteopenia to osteoporosis, 0.83 (95% CI 0.51-1.35) for men and 0.99 (95% CI 0.38-2.56) for women. The transition probabilities from osteopenia to osteoporosis over 10 years among men aged 30 and 50 years were 14.9% (95% CI 10.5%-20.4%) and 19% (95% CI 14.3%-24.3%), respectively; and for women, 6.9% (95% CI 3.1%-14.4%) and 30.1% (95% CI 19.8%-41.8%), respectively. An increased osteoporosis risk was observed for PIs and PIs + tenofovir disoproxil fumarate; darunavir was associated with a higher risk of osteoporosis among men (HR 3.9; 95% CI 2-7.5) and women (HR 4.5; 95% CI 1.4-14.7); and atazanavir was associated with a higher risk of osteoporosis among women (HR 4.2; 95% CI 1.3-14). Conclusions: Our results highlight the importance of monitoring bone mineral density given the high probability of progression to osteopenia/osteoporosis, especially in women. In the future, changes in antiretrovirals other than tenofovir, such as PIs, should be recommended to reduce the risk of fracture.

Peak bone mass in young HIV-infected patients compared with healthy controls.

INTRODUCTION: Peak bone mass (PBM) is the amount of bone present at the end of skeletal maturation. It is an important determinant of osteoporotic fracture risk. Data on the PBM in the HIV-infected population are lacking. DESIGN AND METHODS: We performed a multicenter (6 centers in Spain), case-control study to assess PBM using dual-energy x-ray absorptiometry. We studied HIV-infected patients aged 20-30 years and compared them with age- and gender-matched non-HIV-infected controls. We also assessed the predictive factors for a low PBM. RESULTS: We included 307 subjects: 232 HIV-infected patients and 75 non-HIV-infected controls. Bone mineral density was similar in both groups although differences were seen in the total femur T-score (-0.15SD versus +0.50SD, respectively, P = 0.018). The percentage of osteopenia and osteoporosis was higher in the HIV-infected patients (56.5% and 10.7%, respectively) than in the controls (50.7% and 4%, respectively; P = 0.019). Osteoporosis was more frequent in HIV-infected men than in control men and HIV-infected women (12.2% versus 5.5% and 4.8%, P = 0.033). Protease inhibitors and nadir CD4 T-cells were negatively associated with PBM, whereas fat and lean mass were positively associated with PBM. CONCLUSIONS: Bone mineral density was similar between HIV-infected patients aged 20-30 years than in age- and gender-matched controls. However, lower femoral T-scores and higher rate of osteopenia and osteoporosis were seen in HIV-infected men. Therapy with protease inhibitors, nadir CD4 counts, and fat and lean mass were predictive factors of PBM. Given that these patients will be living with HIV infection for many years, every effort should be made to modify risk factors.

Impact of switching from lopinavir/ritonavir to atazanavir/ritonavir on body fat redistribution in virologically suppressed HIV-infected adults.

Changes in body fat distribution in virologically suppressed HIV-infected patients switching from lopinavir/ritonavir (LPV/r) to atazanavir/ritonavir (ATV/r) were assessed. A prospective comparative study was conducted of 37 patients receiving LPV/r regimens switching to ATV/r with 46 patients continuing with LPV/r. Body composition was assessed with whole-body dual-energy x-ray absorptiometry (DXA). Abdominal CT scans were also performed in a subset of patients. Groups were comparable in baseline demographic, clinical, and anthropometric characteristics. After 12 months, peripheral fat did not change significantly, but an increase in trunk fat was observed only in the ATV/r group (0.87 kg, p = 0.021). The percentage of patients with an increase ≥20% in total fat was 37.8% and 15.2% in the ATV/r and LPV/r groups, respectively (p = 0.018). In the ATV/r group, the increase in trunk fat (9.4%) was significantly higher than in peripheral fat (3.7%) (p = 0.007), leading to a significant increase in fat mass ratio (3.76%, p = 0.028), whereas no significant differences were found among LPV/r patients. CT scans showed that abdominal fat increase corresponded to both visceral (28%, p = 0.008) and subcutaneous fat (42%, p = 0.008). These data suggest that switching from LPV/r to ATV/r is associated with increased trunk fat, both subcutaneous and visceral.

High prevalence of and progression to low bone mineral density in HIV-infected patients: a longitudinal cohort study.

BACKGROUND: Low bone mineral density (BMD) is an emerging metabolic condition in HIV-infected patients; however, data on progression of this disease are scarce. METHODS: We studied 671 patients with at least one dual-energy X-ray absorptiometry scan (391 of them ≥2 scans) to determine the prevalence and progression of BMD and establish related factors. Linear regression and logistic polytomic regression were used for the cross-sectional study and mixed effects and generalized estimating equations were used for the longitudinal study. RESULTS: Osteopenia and osteoporosis were diagnosed in 47.5 and 23%, respectively. Progression to bone demineralization was observed in 28% of the patients over a median of 2.5 years (12.5% progressed to osteopenia and 15.6% to osteoporosis). In the 105 patients with at least 5 years of follow-up, progression was 47% (18% to osteopenia; 29% to osteoporosis). Factors associated with bone loss and progression were age [odds ratio (OR) 1.07; 95% confidence interval (CI) 1.05-1.08; P < 0.0001], male sex (OR 2.23; 95% CI 1.77-2.8; P < 0.0001), low body mass index (OR 1.14; 95% CI 1.11-1.17; P < 0.0001), time on protease inhibitor (OR 1.18; 95% CI 1.12-1.24; P < 0.0001), time on tenofovir (OR 1.08; 95% CI 1.03-1.14; P < 0.0019), and current use of protease inhibitors (OR 1.64; 95% CI 1.35-2.04; P < 0.0001). CONCLUSIONS: Our results show a high prevalence of and considerable progression to osteopenia/osteoporosis in our cohort. Our findings support the importance of applying adequate strategies to prevent bone demineralization and of close monitoring of BMD in HIV-infected patients, specifically in at-risk patients who are taking antiretrovirals that affect bone mineralization.

Reversal of HIV-1-associated osteoporosis with once-weekly alendronate.

HIV-1-infected patients with osteoporosis were randomly assigned to alendronate 70 mg once-weekly plus dietary counselling (n = 11) or diet counselling alone (n = 14). At week 96, 27% of patients on alendronate versus 96% of controls presented with osteoporosis. Spine bone mineral density (BMD) increases were detected at week 48, and progressed thereafter. Improvements in trochanter BMD were obtained after 2 years. Once-weekly oral alendronate may be an effective and safe treatment for HIV-1-associated osteoporosis.