Fractures after antiretroviral initiation

Comparative risk of fracture in men and women with HIV

CONTEXT

Men and women with HIV have an increased risk of fracture compared with individuals without HIV; however, it is unknown if women with HIV fracture at higher rates than men.

OBJECTIVE

We aimed to compare the incidence rates (IR) of fractures between men and women with HIV.

DESIGN

The study was designed as a cohort study, examining medical records from November 2001 to August 2012.

SETTING

The study was performed using records from two tertiary-care hospitals in Boston, Massachusetts.

PATIENTS

The study patients were adults with HIV: this was defined by diagnosis codes for HIV on two visits, at least one prescription for antiretroviral therapy, and at least 18 years of age.

INTERVENTION

IRs per 1000 person-years of all fractures and fractures at osteoporotic sites were calculated. We calculated IRs within age and gender strata and estimated IR ratios (IRR) between men and women.

MAIN OUTCOME MEASURE

The main outcome measure was fracture at any site.

RESULTS

We identified a cohort of 3161 HIV-infected patients (869 women and 2292 men) with a total of 587 fractures. The IRR of all fractures was 1.00 (95% confidence interval [CI] 0.83-1.19) between men and women. The IR of fractures at osteoporotic sites among men was 15.2 (95% CI 12.7-17.6) per 1000 person-years compared with 12.1 (95% CI 8.6-15.6) in women, with IRR of 1.26 (95% CI 0.90-1.75). Men had similar or higher IRs than women for osteoporotic site fractures across most age groups.

CONCLUSIONS

This study found similar rates of fracture in men and women with HIV. Further studies validating these findings are required to determine whether men with HIV should be screened for osteoporosis.

Complications related to fracture treatment in HIV patients: a case report

We present the case report of a 40-year-old woman who was HIV-positive in Highly Active Anti-Retroviral Therapy (HAART) and affected by femural pertrochanteric fracture, which was treated by endomedullary nailing. Two years after the surgical operation, the woman developed an aseptic symptomatic osteolysis around the implant. Hardware removal was resolutive. Aseptic and septic hardware mobilization, hardware removal, and implant decision in HIV patients with pertrochanteric fractures is discussed. The authors suggest close follow-up and prompt hardware removal, as soon as X-rays demonstrate healing signs, in HIV patients with fracture fixation, if general condition allows.

Bones, Fractures, Antiretroviral Therapy and HIV

The course of HIV infection has been dramatically transformed by the success of antiretroviral therapy from a universally fatal infection to a manageable chronic disease. With these advances in HIV disease management, age-related comorbidities, including metabolic bone disease, have become more prominent in the routine care of persons living with HIV infection. Recent data have highlighted the role of HIV infection, initiation of antiretroviral therapy, and hepatitis C virus coinfection in bone mineral density loss and fracture incidence. Additionally, the underlying mechanism for the development of metabolic bone disease in the setting of HIV infection has received considerable attention. This review highlights recently published and presented data and synthesizes the current state of the field. These data highlight the need for proactive prevention for fragility fractures.

Low baseline CD4+ count is associated with greater bone mineral density loss after antiretroviral therapy initiation

BACKGROUND

Bone mineral density (BMD) decreases 2%-6% in the 2 years after antiretroviral therapy (ART) initiation. Pre-ART immune deficiency and early immune recovery may contribute to this loss.

METHODS

We pooled data from 3 studies of ART initiation in treatment-naive patients in which serial whole-body dual-energy X-ray absorptiometry scans were performed. We used linear regression to evaluate effects of baseline CD4(+) and 16-week CD4(+) change (both absolute and relative) on 96-week total BMD change from baseline. We performed multivariable linear regression to assess associations between baseline variables of age, sex, race/ethnicity, body mass index (BMI), hepatitis C status, parent study, human immunodeficiency virus type 1 (HIV-1) RNA level, and assignment to a protease inhibitor (PI)- or tenofovir-containing regimen on 96-week total BMD change.

RESULTS

The included 796 subjects had mean 96-week total BMD loss of 2.0%. In multivariable analysis, baseline CD4(+) cell count was significantly associated with 96-week BMD loss; individuals with baseline CD4(+) <50 cells/µL lost significantly more BMD compared to those with CD4(+) ≥500 cells/µL. A greater relative, but not absolute, 16-week increase in CD4(+) count was significantly associated with greater declines in BMD, but not after controlling for baseline CD4(+) count. In multivariable analysis, older age, female sex, lower BMI, higher HIV-1 RNA levels, and PI and tenofovir assignment were also associated with greater BMD decline.

CONCLUSIONS

Low pretreatment CD4(+) count, but not greater CD4(+) count increase, is a strong and independent risk factor for bone loss after ART initiation. ART initiation at higher CD4(+) counts may reduce the burden of osteoporosis and fragility fractures.

Bone mineral density in HIV participants randomized to raltegravir and lopinavir/ritonavir compared with standard second line therapy

OBJECTIVE

To compare changes over 48 weeks in bone mineral density (BMD) between participants randomized to lopinavir/ritonavir (LPV/r) + raltegravir (RAL) or LPV/r + 2-3 nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs) as second line therapy.

DESIGN

48-week open-label sub-study of the Second Line trial conducted in South Africa, India, Thailand, Malaysia and Argentina.

METHODS

Dual energy X-ray absorptiometry scans of proximal femur and lumbar spine were performed at baseline and week 48. Linear regression was used to compare means of differences between arms. McNemars test compared osteopenia and osteoporosis. Associations between percentage BMD changes and baseline variables were assessed by multivariate linear regression.

RESULTS

Two hundred and ten participants were randomized. Analyses were adjusted for sex, BMI and smoking status. Mean (95% CI) proximal femur BMD% reduced over 48 weeks by -5.2% (-6.7 to -3.8%) in the LPV/r+2-3N(t)RTIs arm and by -2.9% (-4.3 to -1.5%) in the LPV/r+RAL arm (P = 0.0001). Lumbar spine BMD reduced by -4.2% (-5.7 to -2.7%) in the LPV/r+2-3N(t)RTIs arm and by -2.0% (-3.5 to -0.6%) in the LPV/r+RAL arm (P = 0.0006). The incidence of osteopenia (7.6%) and osteoporosis (2.0%) assessed over 48 weeks were similar between arms. Reduced BMD over 48 weeks was significantly associated with longer duration of tenofovir on study [% change (SE) -1.58 (0.38) femur, -1.65 (0.38) spine, P = 0.0001] and low baseline BMI [% change (SE) 0.5 (0.13) femur, 0.17 (0.07) spine; P < 0.01].

CONCLUSION

An N(t)RTI-sparing antiretroviral regimen of LPV/r and raltegravir as second line therapy is associated with less bone loss than a LPV/r regimen containing N(t)RTIs.

Incident fractures in HIV-infected individuals: a systematic review and meta-analysis

OBJECTIVE(S)

Some but not all studies indicate that individuals with HIV infection are at an increased risk of fracture. We systematically reviewed the literature to investigate whether incidence of fracture (both overall and fragility) differs between individuals with and without HIV.

DESIGN

A systematic review and meta-analysis.

METHODS

Medline, Scopus and the Cochrane Library databases for all studies ever published up to 28 September 2012 and electronically available conference abstracts from CROI, ASBMR, IAS and AIDS were searched. All studies reporting incidence of all fracture and fragility fracture in HIV-infected adults were included. A random effects model was used to calculate pooled estimates of incidence rate ratios (IRRs) for studies that presented data for HIV-infected and controls. For all studies, incidence rates of fracture and predictors of fracture among HIV-infected individuals were summarized.

RESULTS

Thirteen eligible studies were analysed, of which seven included controls. Nine studies reported all incident fractures and 10 presented incident fragility fractures. The pooled IRR was 1.58 [95% confidence interval (CI) 1.25-2.00] for all fracture and 1.35 (95% CI 1.10-1.65) for fragility fracture. Smoking, white race and older age were consistent predictors for fragility fractures.

CONCLUSION

Our results indicate that HIV infection is associated with a modest increase in incident fracture. Future research should focus on clarifying risk factors, designing appropriate interventions and the long-term implications of this increased risk for an ageing HIV-infected population.

Bone health in children and adolescents with perinatal HIV infection

The long-term impact on bone health of lifelong HIV infection and prolonged ART in growing and developing children is not yet known. Measures of bone health in youth must be interpreted in the context of expected developmental and physiologic changes in bone mass, size, density and strength that occur from fetal through adult life. Low bone mineral density (BMD) appears to be common in perinatally HIV-infected youth, especially outside of high-income settings, but data are limited and interpretation complicated by the need for better pediatric norms. The potential negative effects of tenofovir on BMD and bone mass accrual are of particular concern as this drug may be used more widely in younger children. Emphasizing good nutrition, calcium and vitamin D sufficiency, weight-bearing exercise and avoidance of alcohol and smoking are effective and available approaches to maintain and improve bone health in all settings. More data are needed to inform therapies and monitoring for HIV-infected youth with proven bone fragility. While very limited data suggest lack of marked increase in fracture risk for youth with perinatal HIV infection, the looming concern for these children is that they may fail to attain their expected peak bone mass in early adulthood which could increase their risk for fractures and osteoporosis later in adulthood.