Bone Mineral Content Is Lower in Prepubertal HIV-Infected Children:

Health-Related Physical Fitness Evaluation in HIV-Diagnosed Children and Adolescents: A Scoping Review

BACKGROUND

Health-related physical fitness has been widely used to investigate the adverse effects of HIV infection/ART in children and adolescents. However, methods/protocols and cut-points applied for investigating health-related physical fitness are not clear. The aim of this scoping review was to map the literature to identify gaps in knowledge regarding the methods/protocols and cut-points.

METHODS

A scoping review, following the Joana Briggs Institute (JBI) guidelines, was conducted through ten major databases. Search followed the PCC strategy to construct block of terms related to population (children and adolescents), concept (health-related physical fitness components) and context (HIV infection).

RESULTS

The search resulted in 7545 studies. After duplicate removal, titles and abstracts reading and full text assessment, 246 studies were included in the scoping review. Body composition was the most investigated component (n = 244), followed by muscular strength/endurance (n = 23), cardiorespiratory fitness (n = 15) and flexibility (n = 4). The World Health Organization growth curves, and nationals' surveys were the most reference values applied to classify body composition (n = 149), followed by internal cut-points (n = 30) and cut-points developed through small populations (n = 16). Cardiorespiratory fitness was classified through cut-points from three different assessment batteries, as well as cut-points developed through studies with small populations, muscular strength/endurance and flexibility were classified through the same cut-points from five different assessment batteries.

CONCLUSIONS

The research on muscular strength/endurance, cardiorespiratory fitness and flexibility has been scarcely explored. The lack of studies that investigated method usability as well as reference values was evidenced.

Association between bone mineral density and content and physical growth parameters among children and adolescents diagnosed with HIV: a cross-sectional study

BACKGROUND

During childhood and adolescence, there are significant increases in bone mineral content (BMC) and bone mineral density (BMD).

OBJECTIVE

To investigate physical growth parameters associated with BMD and BMC among children and adolescents diagnosed with human immunodeficiency virus (HIV).

DESIGN AND SETTING

Cross-sectional study conducted in Florianópolis, Brazil, among 63 children and adolescents (aged 8-15 years) diagnosed with HIV.

METHOD

BMD, BMC and fat percentage z score were evaluated using dual X-ray absorptiometry. Age/height z score and body mass index (BMI)/age z score were obtained in accordance with international recommendations, and bone age was obtained through hand-wrist radiography. Sex, family income, information on HIV infection (T CD4+ lymphocyte count, viral load and type of antiretroviral therapy, moderate-vigorous physical activity and sedentary behavior) were used as adjustment variables in the analyses. Simple and multiple linear regression analyses were performed, with a significance level of P ≤ 0.05.

RESULTS

Subtotal BMD (without the head region) was directly associated with bone age, BMI/age z score and fat percentage z score, even after adjusting for covariates. Subtotal BMC/height was directly associated with bone age, height/age z score, BMI/age z score and fat percentage z score, even after adjusting for covariates.

CONCLUSION

Subtotal BMD and subtotal BMC/height were directly associated with physical growth indicators among children and adolescents diagnosed with HIV.

Prevalence and predictors of bone health among perinatally HIV-infected adolescents

OBJECTIVES

Long-term complications of HIV including low bone mineral density remain a concern. We studied the prevalence and predictors of low bone mineral density among South African perinatally HIV-infected adolescents (PHIVA) on antiretroviral therapy (ART).

DESIGN

Cross-sectional analysis.

METHODS

Bone health was evaluated by measuring the calcaneus stiffness index among PHIVA on ART. Low stiffness index was defined as z-score less than -2 SD compared with age-matched and sex-matched HIV-uninfected adolescents (HIV-).

RESULT

Overall, 407 PHIVA (median age: 14 years; 50.4% female; median age at ART initiation: 4.2 years) and 92 HIV- (median age: 13.7 years; 54.4% female) were included. Median duration on ART was 9.8 years (interquartile range 6.8-11.5) with 38% initiating ART at 2 years or less of age. Stiffness index was lower in PHIVA (-0.19 vs. 0.43, P ≤ 0.001), respectively. During puberty, mean stiffness index increased with Tanner Stage in both PHIVA and HIV- but these increases were larger among HIV-; Tanner Stage II-III (96 vs. 101, P = 0.009) and Tanner Stage IV-V (104 vs. 112, P = 0.001). Among PHIVA, 52 (13%) had low stiffness index. After adjusting for age, sex and Tanner Stage, use of lopinavir/ritonavir [odds ratio (OR) = 2.31, P = 0.012] and viral load more than 50 copies/ml (OR = 2.06, P = 0.023) were associated with increased risk of low stiffness index, while use of efavirenz (OR = 0.41, P = 0.009) was associated with decreased risk of low stiffness index.

CONCLUSION

Stiffness index was a significantly lower in PHIVA than in HIV-, especially during puberty. Among PHIVA, detectable viral load and use of lopinavir/ritonavir were risk factors for low stiffness index. Further longitudinal studies are important to determine the clinical implications.

Deficits in Bone Architecture and Strength in Children Living With HIV on Antiretroviral Therapy

BACKGROUND

Reduced bone mineral mass by dual x-ray absorptiometry is reported in children living with HIV (CLWH), but few studies of bone microarchitecture, particularly in sub-Saharan Africa, have been conducted. Here, we compare bone architecture and strength in black South African CLWH and uninfected control children by peripheral quantitative computed tomography (pQCT).

SETTING AND METHODS

One hundred seventy-two CLWH on antiretroviral therapy (ART) and 98 controls in the CHANGES Bone Study in Johannesburg, South Africa received pQCT scans of the radius and tibia. Measurements included trabecular and cortical volumetric bone mineral density (vBMD) and bone strength, estimated by the polar strength strain index (SSI), a validated measure of fracture risk.

RESULTS

CLWH (51% boys) and controls (63% boys) were an average of age 10.4 years. Mean ART duration for CLWH was 9.5 years, with 70.9% on an efavirenz-based, 28.5% on a lopinavir/ritonavir-based, and 1 child on an atazanavir/ritonavir-based regimen. Male CLWH had lower trabecular vBMD at the radius than controls after adjustment for age, radial length, and Tanner stage (β = -17.3, standard error = 7.2, P = 0.018). Bone strength by polar SSI was lower in CLWH than controls (778 vs. 972 mm, P < 0.01). CLWH on an LPV/r-based regimen had lower trabecular vBMD (199 vs. 222 mg/cm, P < 0.001) and cortical vBMD (1074 vs. 1093 mg/cm, P = 0.004) than those on an efavirenz-based regimen. No difference in bone strength by polar SSI was observed between treatment groups.

CONCLUSION

CLWH initiated on ART early in life with well-controlled HIV have deficits in bone architecture and reductions in bone strength as detected by pQCT.

Bone Quality Measured Using Calcaneal Quantitative Ultrasonography Is Reduced Among Children with HIV in Johannesburg, South Africa

We evaluated bone quality among South African children with HIV over a 2-year period by quantitative ultrasound (QUS). Children with HIV have persistently lower bone quality compared with controls reflecting increased porosity, reduced strength, and possibly an increased short- and long-term risk of fracture.

Biomarkers of Aging in HIV-Infected Children on Suppressive Antiretroviral Therapy

BACKGROUND

Data on accelerated aging in HIV-infected children are limited. In this study, we assess 2 biomarkers of aging-telomere length and DNA methylation (DNAm) age-in a cohort of early-treated HIV-infected children and compare these aging biomarkers with HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) children.

SETTING

Cross-sectional study of 120 HIV-infected, 33 HEU, and 25 HUU children enrolled in a cohort study in Johannesburg, South Africa. The mean age of children was 6.4 years at the time of measurement. HIV-infected children initiated ritonavir-boosted lopinavir-based antiretroviral therapy before 2 years of age and had been on continuous antiretroviral therapy until biomarker measurement.

METHODS

Telomere length was determined using multiplex quantitative polymerase chain reaction. DNAm was measured using the Illumina 450K array and DNAm age was calculated as the acceleration residual from regressing DNAm age on chronological age.

RESULTS

Telomere length (ln[Kb/genome]) was shorter in HIV-infected children compared with HUU children (4.14 ± 0.85 vs. 4.53 ± 0.79, P = 0.038) and in HEU children compared with HUU children (4.05 ± 0.74 vs. 4.53 ± 0.79, P = 0.023). Age acceleration residual based on DNAm levels was not different between HIV-infected (-0.003 ± 2.95), HEU (0.038 ± 2.39), and HUU (0.18 ± 2.49) children in unadjusted analysis and after adjustment for cell type proportions.

CONCLUSIONS

Unlike reports of accelerated DNAm age in HIV-infected adults, there was no evidence of accelerated biological aging by DNAm levels in this cohort of early-treated HIV-infected children. By contrast, absolute telomere length was shorter in HIV-infected and HEU children compared with HUU children, but did not differ between HIV-infected and HEU children.

Distinct biomarker signatures in HIV acute infection associate with viral dynamics and reservoir size

Estimating the size of the viral reservoir is critical for HIV cure strategies. Biomarkers in peripheral circulation may give insights into the establishment of the viral reservoir in compartments not easily accessible. We therefore measured systemic levels of 84 soluble biomarkers belonging to a broad array of immune pathways in acute HIV infection in both antiretroviral therapy-naive (ART-naive) individuals as well as individuals who began ART upon early detection of HIV infection. These biomarkers were measured longitudinally during acute and chronic infection and their relationship to viral reservoir establishment and persistence was assessed. We observed several distinct biomarker pathways induced following HIV infection such as IFN-γ-signaled chemokines, proinflammatory markers, and TNF-α-family members. Levels of several of these factors directly correlated with contemporaneous viral loads and/or frequency of peripheral blood mononuclear cells harboring HIV DNA during acute HIV infection. MCP-1, MIP-3β, sTNFR-II, and IL-10 levels prior to ART associated with HIV DNA levels after 96 weeks of treatment, suggesting a link between early immune signaling events and the establishment and persistence of the viral reservoir during ART. Furthermore, they offer potentially novel tools for gaining insight into relative reservoir size in acutely infected individuals and the potential of associated risks of treatment interruption.

Low Bone Mineral Density in Vertically HIV-infected Children and Adolescents: Risk Factors and the Role of T-cell Activation and Senescence

BACKGROUND

Our aim was to determine the prevalence and risk factors associated with low bone mineral density (BMD) in vertically HIV-infected patients and to investigate whether low BMD is related to immune activation and senescence induced by HIV infection.

METHODS

A cross-sectional study was performed in 98 vertically HIV-infected patients. BMD was measured by dual-energy radiograph absorptiometry at lumbar spine. Height adjustment of BMD Z score was performed using height-for-age Z score. T-cell immune activation and senescence were analyzed in a subgroup of 54 patients by flow cytometry.

RESULTS

Median age was 15.9 years, 71.4% were Caucasian, 99% received antiretroviral therapy and 80.6% had undetectable viral load. Low BMD (BMD Z score ≤ -2) was present in 15.3% of cases, but after height adjustment in 4.1% of cases. Height-adjusted BMD Z score was positively correlated with body mass index Z score, CD4/CD8 ratio and nadir CD4, and inversely with duration of severe immunosuppression and parathyroid hormone values. In the multivariate model including age, gender, ethnicity, encephalopathy, Tanner stage, nadir CD4, duration of viral suppression, CD4 count, CD4/CD8 ratio, body mass index, cumulative duration of antiretroviral therapy, tenofovir and protease inhibitors exposure, nadir CD4 was independently associated to height-adjusted BMD Z score. No association was found between height-adjusted BMD Z score and T-cell activation or senescence.

CONCLUSIONS

The prevalence of low BMD in vertically HIV-infected patients was low after height adjustment. Nadir CD4, but not T-cell activation or senescence, was an independent predictor for low BMD. Larger and prospective studies are needed to achieve better knowledge of the pathogenesis of low BMD in vertical HIV infection.

Effect of high-dose cholecalciferol (vitamin D3) on bone and body composition in children and young adults with HIV infection: a randomized, double-blind, placebo-controlled trial

It is unknown whether vitamin D supplementation positively impacts body composition and bone outcomes in children and young adults with HIV. This RCT found that despite increasing 25(OH)D concentrations, high dose vitamin D₃ supplementation did not impact bone or body composition in children and young adults with HIV infection.

INTRODUCTION

The objective of this paper was to determine the impact of high-dose daily cholecalciferol (vitamin D₃) supplementation on body composition and bone density, structure, and strength in children and young adults with perinatally acquired (PHIV) or behaviorally acquired (BHIV) HIV infection.

METHODS

Participants were randomized to receive vitamin D₃ supplementation (7000 IU/day) or placebo for 12 months. Serum 25-hydroxyvitamin D [25(OH)D] concentrations, dual energy X-ray absorptiometry (DXA) of the whole body and lumbar spine, and peripheral quantitative computed tomography (pQCT) of tibia sites were acquired at 0, 6, and 12 months. DXA and pQCT outcomes were expressed as sex- and population-ancestry specific Z-scores relative to age and adjusted for height or tibia length, as appropriate.

RESULTS

Fifty-eight participants (5.0 to 24.9 years) received vitamin D₃ supplements (n = 30) or placebo (n = 28). At enrollment, groups were similar in age, sex, population ancestry, growth status, serum 25(OH)D concentrations, body composition, and size-adjusted bone measures. Median 25(OH)D concentrations were similar (17.3 ng/mL in the vitamin D₃ supplementation group vs 15.6 ng/mL in the placebo group), and both groups had mild bone deficits. At 12 months, 25(OH)D rose significantly in the vitamin D supplementation group but not in the placebo group (26.4 vs 14.8 ng/mL, respectively, p < 0.008). After adjusting for population ancestry, sex, antiretroviral therapy use, and season, there were no significant treatment group differences in bone or body composition outcomes.

CONCLUSIONS

Despite increasing 25(OH)D concentrations, 12 months of high-dose vitamin D₃ supplementation did not impact bone or body composition in children and young adults with HIV infection.

Efavirenz is associated with higher bone mass in South African children with HIV

BACKGROUND

We investigate if switching from a ritonavir-boosted lopinavir (LPV/r)-based to an efavirenz-based antiretroviral therapy (ART) regimen is associated with beneficial bone development.

METHODS

The CHANGES Bone Study follows HIV-infected children who participated in a noninferiority randomized trial in Johannesburg, South Africa evaluating the safety and efficacy of preemptive switching to efavirenz (n = 106) compared with remaining on LPV/r (n = 113). HIV-uninfected children were also recruited. Whole-body and lumbar spine bone mineral content (BMC) were assessed by dual-energy X-ray absorptiometry at a cross-sectional visit. BMC Z-scores adjusted for sex, age, and height were generated. Physical activity and dietary intake were assessed. CD4 percentage and viral load were measured. We compared bone indices of HIV-infected with HIV-uninfected children and LPV/r with efavirenz by intent-to-treat.

RESULTS

The 219 HIV-infected (52% boys) and 219 HIV-uninfected (55% boys) children were 6.4 and 7.0 years of age, respectively. Mean ART duration for HIV-infected children was 5.7 years. Whole-body BMC Z-score was 0.17 lower for HIV-infected children compared with HIV-uninfected children after adjustment for physical activity, dietary vitamin D and calcium (P = 0.03). Whole-body BMC Z-score was 0.55 higher for HIV-infected children switched to efavirenz compared with those remaining on LPV/r after adjustment for physical activity, dietary vitamin D and calcium, CD4 percentage, and viral load (P < 0.0001).

CONCLUSION

South African HIV-infected children receiving ART have lower bone mass compared with HIV-uninfected controls. Accrued bone mass is positively associated with switching to efavirenz-based ART compared with remaining on LPV/r, providing additional rationale for limiting LPV/r exposure once viral suppression has been achieved.

Impaired bone mineral accrual in prepubertal HIV-infected children: a cohort study

OBJECTIVE

To evaluate bone mass accrual and determine the influence of clinical, anthropometric, dietary and biochemical parameters on bone mass.

METHODS

A cohort study including 35 prepubertal HIV-infected children, between 7 and 12 years, attended at a referral center. At time 1 (T1) and time 2 (T2), patients were assessed according to clinical, anthropometric, dietary, biochemical parameters and bone mineral density (BMD). At T2, patients were divided into prepubertal and pubertal.

RESULTS

Despite the increase in bone mass absolute values, there was no improvement in lumbar spine BMD (LSBMD) Z-score (p=0.512) and worsening in total body BMD (TBMD) Z-score (p=0.040). Pubertal patients (n=19) showed higher bone mineral content (BMC) (p=0.001), TBMD (p=0.006) and LSBMD (p=0.002) compared to prepubertal patients. After multivariate linear regression analysis, the predictors of bone mass in T1 were age, BMI and HA Z-scores for BMC; BMI Z-score, adequate serum magnesium concentration and dietary calcium intake for TBMD; adequate serum concentration of magnesium, BMI and HA Z-scores for LSBMD. In T2, age, total body fat and lean body mass (kg) for BMC; BMI Z-score and puberty for TBMD; dietary fat intake, BMI Z-score for BMD and puberty for LSBMD.

CONCLUSION

HIV-infected children have compromised bone mass and the presence of puberty seems to provide suitability of these parameters. Adequate intake of calcium and fat appears to be protective for proper bone mass accumulation factor, as well as monitoring nutritional status and serum magnesium concentration.

Long-term efficacy and safety of tenofovir disoproxil fumarate in HIV-1-infected adolescents failing antiretroviral therapy: the final results of study GS-US-104-0321

BACKGROUND

Reports of long-term tenofovir disoproxil fumarate (TDF) treatment in HIV-infected adolescents are limited. We present final results from the open-label (OL) TDF extension following the randomized, placebo (PBO)-controlled, double-blind phase of GS-US-104-0321 (Study 321).

METHODS

HIV-infected 12- to 17-year-olds treated with TDF 300 mg or PBO with an optimized background regimen (OBR) for 24-48 weeks subsequently received OL TDF plus OBR in a single arm study extension. HIV-1 RNA and safety, including bone mineral density (BMD), was assessed in all TDF recipients.

RESULTS

Eighty-one subjects received TDF (median duration 96 weeks). No subject died or discontinued OL TDF for safety/tolerability. At week 144, proportions with HIV-1 RNA <50 copies/mL were 30.4% (7 of 23 subjects with baseline HIV-1 RNA >1000 c/mL initially randomized to TDF), 41.7% (5 of 12 subjects with HIV-1 RNA <1000 c/mL who switched PBO to TDF) and 0% (0 of 2 subjects failed randomized PBO plus OBR with HIV-1 RNA >1000 c/mL and switched PBO to TDF). Viral resistance to TDF occurred in 1 subject. At week 144, median decrease in estimated glomerular filtration rate was 38.1 mL/min/1.73 m (n = 25). Increases in median spine (+12.70%, n = 26) and total body less head BMD (+4.32%, n = 26) and height-age adjusted Z-scores (n = 21; +0.457 for spine, +0.152 for total body less head) were observed at week 144. Five of 81 subjects (6%) had persistent >4% BMD decreases from baseline.

CONCLUSIONS

Some subjects had virologic responses to TDF plus OBR, and TDF resistance was rare. TDF was well tolerated and can be considered for treatment of HIV-infected adolescents.

Metabolic complications of in utero maternal HIV and antiretroviral exposure in HIV-exposed infants

BACKGROUND

Despite a wide body of literature supporting the use of antenatal antiretrovirals (ARV) for the prevention of mother-to-child transmission, there remains a need for continued monitoring as the intrauterine interval is a critical period during which fetal programming influences the future health and development of the child.

METHODS

We conducted a systematic review of the current literature addressing potential metabolic complications of in utero HIV and ARV exposure. We describe studies evaluating metabolic outcomes such as intrauterine and early postnatal growth, bone health and mitochondrial toxicity.

RESULTS

Overall, infants exposed to HIV/ARV do not appear to exhibit vastly compromised intrauterine or early postnatal growth. However, some studies on the effect of combination antiretroviral therapy on small for gestational age and low birth weight outcomes in low-middle income countries show a risk for small for gestational age/low birth weight while those in the United States do not. Postnatal growth to 1 year does not appear to be affected by intrauterine tenofovir exposure in African studies, but a US study found statistically significant differences in length for age z scores (LAZ) at 1 year. Little data exists on long-term bone health. Mitochondrial toxicity including abnormal mitochondrial morphology and DNA content, as well as neurologic deficits and death, have been demonstrated in HIV/ARV-exposed infants.

CONCLUSION

Although gross measures of metabolic well-being appear to be reassuring, careful vigilance of even small risks for potential serious adverse effects to infants exposed to intrauterine HIV/ARVs is warranted as intrauterine fetal metabolic programming may substantially impact the future health of the child.

Lower peak bone mass and abnormal trabecular and cortical microarchitecture in young men infected with HIV early in life

INTRODUCTION

HIV infection and antiretroviral therapy (ART) early in life may interfere with acquisition of peak bone mass, thereby increasing fracture risk in adulthood.

METHODS

We conducted a cross-sectional study of dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HR-pQCT) in 30 HIV-infected African-American or Hispanic Tanner stage 5 men aged 20-25 on ART (15 perinatally infected and 15 infected during adolescence) and 15 HIV-uninfected controls.

RESULTS

HIV-infected men were similar in age and BMI, but were more likely to be African-American (P = 0.01) than uninfected men. DXA-derived areal bone mineral density (aBMD) Z-scores were 0.4-1.2 lower in HIV-infected men at the spine, hip, and radius (all P < 0.05). At the radius and tibia, total and trabecular volumetric BMD (vBMD), and cortical and trabecular thickness were between 6 and 19% lower in HIV-infected than uninfected men (P <0.05). HIV-infected men had dramatic deficiencies in plate-related parameters by individual trabeculae segmentation (ITS) analyses and 14-17% lower bone stiffness by finite element analysis. Differences in most HR-pQCT parameters remained significant after adjustment for race/ethnicity. No DXA or HR-pQCT parameters differed between men infected perinatally or during adolescence.

CONCLUSION

At an age by which young men have typically acquired peak bone mass, HIV-infected men on ART have lower BMD, markedly abnormal trabecular plate and cortical microarchitecture, and decreased whole bone stiffness, whether infected perinatally or during adolescence. Reduced bone strength in young adults infected with HIV early in life may place them at higher risk for fractures as they age.

Metabolic complications and treatment of perinatally HIV-infected children and adolescents

The benefits of long-term antiretroviral therapy (ART) are recognized all over the world with infected children maturing into adults and HIV infection becoming a chronic illness. However, the improved survival is associated with serious metabolic complications, including lipodystrophy (LD), dyslipidemia, insulin resistance, lactic acidosis and bone loss. In addition, the dyslipidemia mainly seen with protease inhibitors may increase the risk of cardiovascular disease in adulthood and potentially in children as they mature into adults. Nucleoside reverse transcriptase inhibitors, particularly stavudine, zidovudine and didanosine are linked to development of LD and lactic acidosis. Perinatally infected children initiate ART early in life; they require lifelong therapy with multiple drug regimens leading to varying toxicities, all potentially impacting their quality of life. LD has a significant impact on the mental health of older children and adolescents leading to poor self-image, depression and subsequent poor adherence to therapy. Reduced bone mineral density (BMD) is reported in both adults and children on ART with the potential for children to develop more serious bone complications than adults due to their rapid growth spurts and puberty. The role of vitamin D in HIV-associated osteopenia and osteoporosis is not clear and needs further study. Most resource-limited settings are unable to monitor lipid profiles or BMD, exposing infected children and adolescents to on-going toxicities with unclear long-term consequences. Improved interventions are urgently needed to prevent and manage these metabolic complications. Longitudinal cohort studies in this area should remain a priority, particularly in resource-limited settings where the majority of infected children reside.

Effect of supplementation with cholecalciferol and calcium on 2-y bone mass accrual in HIV-infected children and adolescents: a randomized clinical trial

BACKGROUND

Skeletal abnormalities have been reported in HIV-infected children and adolescents. Although the etiology is not well understood, vitamin D deficiency may be involved.

OBJECTIVE

The study objective was to evaluate the effect of vitamin D and calcium supplementation on bone mass accrual in HIV-infected youth.

DESIGN

Perinatally HIV-infected children were randomly assigned to receive vitamin D (100,000 IU cholecalciferol given every 2 mo) and calcium (1 g/d) (supplemented group) or double placebo (placebo group) for 2 y. The total-body bone mineral content (TBBMC), total-body bone mineral density (TBBMD), spine bone mineral content (SBMC), and spine bone mineral density (SBMD) were assessed by using dual-energy X-ray absorptiometry at baseline and at 2 annual follow-up visits.

RESULTS

Fifty-nine participants, aged 6-16 y, were randomly assigned to either the supplemented (n = 30) or the placebo (n = 29) group. At enrollment, supplemented and placebo groups did not differ with respect to age, sex, dietary intakes of vitamin D and calcium, mean baseline serum 25-hydroxyvitamin D [25(OH)D] concentration, TBBMC, TBBMD, SBMC, or SBMD. Significant increases in serum 25(OH)D were observed in the supplemented group but not in the placebo group. TBBMC, TBBMD, SBMC, and SBMD increased significantly at 1 and 2 y in both groups. No between-group differences were observed at any time before or after adjustment for stage of sexual maturation by mixed linear model analysis.

CONCLUSION

One gram of calcium per day and oral cholecalciferol at a dosage of 100,000 IU every 2 mo administered to HIV-infected children and adolescents did not affect bone mass accrual despite significant increases in serum 25(OH)D concentrations. This trial was registered at clinicaltrials.gov as NCT00724178.

Younger age at HAART initiation is associated with more rapid growth reconstitution

OBJECTIVES

Patterns of growth following highly active antiretroviral therapy (HAART) administration among children are not well defined. The objective of this study was to determine rates and predictors of growth reconstitution among children on HAART.

METHODS

A study was conducted among HIV-1-infected children initiating HAART at an HIV treatment clinic in Kenya. Kaplan-Meier survival curves and Cox proportional hazards regression models compared catch-up growth (Z-score ≥ 0) at 12 months post-HAART. Multivariate linear mixed-effects models determined rates and predictors of growth following HAART.

RESULTS

One hundred and seventy-three HIV-1-infected children initiated HAART with a median age of 4.7 years [interquartile range (IQR) 2.4, 7.0]. At baseline, children below 3 years had lower weight-for-age (WAZ) and weight-for-height (WHZ) Z-scores than children 3-5 and 6-10 years (WAZ: P = 0.03; WHZ: P = 0.006). Adjusting for baseline growth, children below 3 years were two to three-fold more likely to attain population age-norms (Z-score = 0) than 6-10 years (WAZ: P = 0.055; WHZ: P = 0.005) at 12 months post-HAART. After adjustment, children below 3 years had higher increases in WAZ and WHZ following HAART than 6-10 years (WAZ: P = 0.006; WHZ: P = 0.005). Children at WHO stage at least 3 at baseline experienced more rapid WHZ reconstitution (P = 0.002). Food supplementation while on HAART was associated with increased monthly gains in weight indices (WAZ: P = 0.001; WHZ: P = 0.005), and multivitamins were associated with greater increases in height (P < 0.01).

CONCLUSION

Following HAART initiation, younger children had more rapid catch-up to the population-average weight of their peers than older children, demonstrating growth benefit of earlier HAART. In addition to HAART, food supplementation and multivitamins may also accelerate growth reconstitution.

Growing up with HIV: children, adolescents, and young adults with perinatally acquired HIV infection

Tremendous success in the prevention and treatment of pediatric HIV in high-resource countries has changed the face of the epidemic. A perinatally HIV-infected child now faces a chronic disease rather than a progressive, fatal one. However, these successes pose new challenges as perinatally HIV-infected youth survive into adulthood. These include maintaining adherence to long-term, likely life-long therapy; selecting successive antiretroviral drug regimens, given the limited availability of pediatric formulations and the lack of pharmacokinetic and safety data in children; and overcoming extensive drug resistance in multi-drug-experienced children. Pediatric HIV care now focuses on morbidity related to long-term HIV infection and its treatment. Survival into adulthood of perinatally HIV-infected youth in high-resource countries encourages expansion of pediatric treatment programs in low-resource countries, where most HIV-infected children live, and provides important lessons about how the epidemic changes with increasing access to antiretroviral therapy for children.

Total body and spinal bone mineral density across Tanner stage in perinatally HIV-infected and uninfected children and youth in PACTG 1045

OBJECTIVE

To characterize total body bone mineral content (BMC) and total body and spinal bone mineral density (BMD) in perinatally HIV-infected and uninfected children/youth across puberty.

DESIGN

HIV-infected (7-24 years) were randomly selected from six strata based on Tanner stage/protease inhibitor use. HIV-uninfected were frequency-matched by Tanner group and sociodemographic background to the HIV-infected.

METHODS

Dual-energy X-ray absorptiometry (DXA) measured BMC and BMD. Linear regression models tested differences in bone outcomes by HIV and the interaction of HIV by Tanner group (1-2, 3-4, 5). Models were performed separately by sex and adjusted for DXA scanner, race/ethnicity, height, age and lean body mass.

RESULTS

HIV-infected (N = 236) and uninfected (N = 143) were comparable on sex and race/ethnicity. HIV-infected were slightly older (median 12.6 versus 11.9 years). In adjusted models, HIV-infected males had significantly lower total body BMC and total body and spinal BMD at Tanner 5, lower BMC at Tanner 3-4 and similar BMC and BMD at Tanner 1-2, compared to HIV-uninfected males. HIV-infected and uninfected girls did not differ significantly on any bone outcome, but there was a marginally significant interaction of HIV and Tanner group for spinal BMD. Kaletra/ritonavir was associated with lower BMC and total body BMD and nevirapine was associated with higher spinal BMD in a model with all HIV-infected.

CONCLUSIONS

Perinatally HIV-infected males showed more evidence of lower bone density especially in the final stage of pubertal development than HIV-infected girls and they may be at increased risk for bone disease during adulthood.

Tenofovir treatment of primary osteoblasts alters gene expression profiles: implications for bone mineral density loss

There is strong clinical evidence that implicates tenofovir in the loss of bone mineral density during treatment of human immunodeficiency virus infection. In this study, we sought to test the hypothesis that tenofovir treatment of osteoblasts causes changes in the gene expression profile that would impact osteoblast function during bone formation. Primary osteoblasts were isolated and then treated with the tenofovir prodrug, tenofovir disoproxil fumarate (TDF). Total RNA from TDF-treated and untreated osteoblasts were extracted and used for microarray analysis to assess TDF-associated changes in the gene expression profile. Strikingly, the changes in gene expression profiles involved in cell signaling, cell cycle and amino acid metabolism, which would likely impact osteoblast function in bone formation. Our findings demonstrate for the first time that tenofovir treatment of primary osteoblasts results in gene expression changes that implicate loss of osteoblast function in tenofovir-associated bone mineral density loss.

Osteopenia and osteoporosis in HIV: pathogenesis and treatment

PURPOSE OF REVIEW

Since the introduction of potent antiretroviral therapy, the emphasis in managing HIV patients has changed from treatment and prevention of opportunistic infections to dealing with toxicities of long-term antiretroviral therapy such as bone demineralization. To date, the pathogenic mechanisms underlying the initiation and progression of osteoporosis in HIV patients remain to be elucidated. This review focuses on recent advances in our understanding of the role of both HIV and antiretroviral therapy in driving bone disease and presents an update on current treatment options and new therapeutic agents targeting novel sites.

RECENT FINDINGS

Recent studies explored the role of HIV and individual antiretroviral therapy drugs in modifying the phenotype of bone cells. Studies have demonstrated effects on cell differentiation, maturation and function in response to both HIV and its treatment - effects mediated via direct alterations in both cell signaling and gene and protein expression.

SUMMARY

Evidence from clinical and cell biological investigations has demonstrated the importance of both HIV and antiretroviral therapy in the emergence of osteoporotic bone disease. Continued efforts aimed at deciphering the molecular basis of metabolic bone disease in HIV patients are necessary to ensure optimal treatment of current patients and to create novel therapeutic interventions.

Effect of bimonthly supplementation with oral cholecalciferol on serum 25-hydroxyvitamin D concentrations in HIV-infected children and adolescents

OBJECTIVE

Vitamin D insufficiency occurs commonly in HIV-infected youth in the United States. In light of the importance of vitamin D for skeletal and nonskeletal health, including innate immunity, developing methods for improving vitamin D status in HIV-infected children and adolescents is an important area of clinical research. The objective of this study was to evaluate the effect of administration of oral cholecalciferol, 100,000 IU every 2 months, and 1 g/day calcium on serum 25-hydroxyvitamin D concentrations, serum and urine calcium, and HIV disease progression during a 12-month period.

METHODS

HIV-infected children and adolescents who were aged 6 to 16 years were randomly assigned to receive vitamin D (100,000 IU bimonthly) and calcium (1 g/day; n = 29) or double placebo (n = 27). Serum 25-hydroxyvitamin D concentrations as measured by radioimmunoassay, albumin-corrected calcium concentrations, and spot urinary calcium-creatinine ratios were determined monthly.

RESULTS

No abnormalities in serum calcium concentration were observed. One participant who received placebo developed hypercalciuria. No group differences were seen in the change in CD4 count or CD4% or viral load during 12 months. The overall mean monthly serum 25-hydroxyvitamin D concentrations were higher in the group that received vitamin D and calcium than in the placebo group, as was the monthly serum 25-hydroxyvitamin D area under the curve. After completing 12 months of study, 2 (6.7%) participants in the group that received vitamin D and calcium had a trough serum 25-hydroxyvitamin D concentration <20 ng/mL compared with 14 (50%) in the placebo group. Twelve (44.4%) in the group that received vitamin D and calcium had a trough serum 25-hydroxyvitamin D concentration of > or =30 ng/mL compared with 3 (11.1%) in the placebo group.

CONCLUSIONS

Administration of oral cholecalciferol to HIV-infected children and adolescents at a dosage of 100,000 IU every 2 months, together with 1 g/day calcium, is safe and results in significant increases in serum 25-hydroxyvitamin D concentrations.

Alterations in circulating osteoimmune factors may be responsible for high bone resorption rate in HIV-infected children and adolescents

OBJECTIVES

Bone metabolism derangements have been reported in HIV-infected children and adolescents. Nuclear factor kappa B ligand (RANKL) and osteoprotegerin potently stimulate and inhibit, respectively, osteoclast formation and activity. We investigated the possible role of RANKL and osteoprotegerin on bone metabolism alterations in paediatric patients.

DESIGN

A prospective controlled longitudinal study. Measurements were obtained before and 6 months after switching antiretroviral regimen.

METHODS

We studied 27 vertically HIV-infected children and adolescents (aged 4.9-17.3 years) on long-term HAART (70.1 +/- 1.5 months). All patients received lamivudine, stavudine and one protease inhibitor (PI). During follow-up, the PI was replaced with efavirenz and stavudine with tenofovir. We also enrolled 336 healthy children, aged 4.8-17.9 years. Concentrations of bone-specific alkaline phosphatase (BALP), N-terminal telopeptide of type I collagen (NTx), RANKL, and osteoprotegerin were measured at baseline and 6 months after switching.

RESULTS

BALP serum concentrations and NTx urine levels of HIV-infected patients were significantly higher than those of healthy children both at baseline and after 6 months (P < 0.001). Baseline osteoprotegerin and RANKL concentrations of HIV-infected patients were significantly higher than in healthy children (P < 0.0001). Both concentrations decreased after 6 months, and RANKL levels were no longer different to controls. At baseline the RANKL/osteoprotegerin ratio was significantly higher (P = 0.02) in HIV-infected children (0.27 +/- 0.07) compared with healthy children (0.078 +/- 0.01).

CONCLUSION

A marked alteration in the RANKL/osteoprotegerin system is present in patients receiving PI-based HAART. Short-term data indicate that replacing stavudine and PI with tenofovir and efavirenz restores the RANKL/osteoprotegerin equilibrium, and may thus lead to a reduction in the bone resorption rate.

Tenofovir disoproxil fumarate and an optimized background regimen of antiretroviral agents as salvage therapy: impact on bone mineral density in HIV-infected children

OBJECTIVE

Tenofovir disoproxil fumarate, a nucleotide analog HIV reverse transcriptase inhibitor with demonstrated activity against nucleoside-resistant HIV, is approved for use in adults but not children. Metabolic bone abnormalities have been seen in young animals given high-dose tenofovir and HIV-infected adults that were treated with oral tenofovir disoproxil fumarate. However, tenofovir disoproxil fumarate is being used in children despite a lack of bone safety data. We hypothesized that, given the higher rate of bone turnover that is associated with normal skeletal growth, the potential for TDF-related bone toxicity may be greater in children than in adults.

METHODS

Fifteen highly antiretroviral-experienced HIV-infected children who were 8 to 16 years of age (mean +/- SD: 12 +/- 2) and required a change in therapy received tenofovir disoproxil fumarate 175 to 300 mg/m2 per day (adult dose equivalent) as part of highly active antiretroviral therapy for up to 96 weeks. Bone mineral density of the lumbar spine, femoral neck, and total hip by dual-energy x-ray absorptiometry and blood and urine markers of bone metabolism were measured at 0, 24, 48, 72, and 96 weeks.

RESULTS

Median z score (SD score compared with age, gender, and ethnicity-matched control subjects) of the lumbar spine, femoral neck, and total hip were decreased from baseline at 24 weeks and 48 weeks and then stabilized. Lumbar spine bone mineral apparent density (which estimates volumetric bone mineral density independent of bone size) z scores also decreased at 24 weeks. Absolute decreases in bone mineral density were observed in 6 children; the mean age of these children was significantly younger than the bone mineral density stable group (10.2 +/- 1.1 vs 13.2 +/- 1.8 years). The change in lumbar spine bone mineral density correlated with decreases in HIV plasma RNA during treatment. Metabolic markers of bone formation and resorption were variable. Two children in whom tenofovir disoproxil fumarate was discontinued because of bone loss that exceeded protocol allowances demonstrated partial or complete recovery of bone mineral density by 96 weeks.

CONCLUSIONS

Tenofovir disoproxil fumarate use in children seems to be associated with decreases in bone mineral density that, in some children, stabilize after 24 weeks. Increases in bone markers and calcium excretion suggest that tenofovir disoproxil fumarate may stimulate bone resorption. Bone turnover is higher in children than in older adolescents and adults because of skeletal growth, potentially explaining the greater effect seen in young children. Decreases in bone mineral density correlate with decreases in viral load and young age, suggesting that young responders may be at greater risk for bone toxicity.

Osteoporosis in children and adolescents: etiology and management

Bone mass increases progressively during childhood, but mainly during adolescence when approximately 40% of total bone mass is accumulated. Peak bone mass is reached in late adolescence, and is a well recognised risk factor for osteoporosis later in life. Thus, increasing peak bone mass can prevent osteoporosis. The critical interpretation of bone mass measurements is a crucial factor for the diagnosis of osteopenia/osteoporosis in children and adolescents. To date, there are insufficient data to formally define osteopenia/osteoporosis in this patient group, and the guidelines used for adult patients are not applicable. In males and females aged <20 years the terminology 'low bone density for chronologic age' may be used if the Z-score is less than -2. For children and adolescents, this terminology is more appropriate than osteopenia/osteoporosis. Moreover, the T-score should not be used in children and adolescents. Many disorders, by various mechanisms, may affect the acquisition of bone mass during childhood and adolescence. Indeed, the number of disorders that have been identified as affecting bone mass in this age group is increasing as a consequence of the wide use of bone mass measurements. The increased survival of children and adolescents with chronic diseases or malignancies, as well as the use of some treatment regimens has resulted in an increase in the incidence of reduced bone mass in this age group. Experience in treating the various disorders associated with osteoporosis in childhood is limited at present. The first approach to osteoporosis management in children and adolescents should be aimed at treating the underlying disease. The use of bisphosphonates in children and adolescents with osteoporosis is increasing and their positive effect in improving bone mineral density is encouraging. Osteoporosis prevention is a key factor and it should begin in childhood. Pediatricians should have a fundamental role in the prevention of osteoporosis, suggesting strategies to achieve an optimal peak bone mass.

Tenofovir disoproxil fumarate and an optimized background regimen of antiretroviral agents as salvage therapy for pediatric HIV infection

OBJECTIVES

Highly active antiretroviral therapy has altered the course of HIV infection among children, but new antiretroviral agents are needed for treatment-experienced children with drug-resistant virus. Tenofovir disoproxil fumarate (DF) is a promising agent for use in pediatric salvage therapy, because of its tolerability, efficacy, and resistance profile. We designed this study to provide preliminary pediatric safety and dosing information on tenofovir DF, while also providing potentially efficacious salvage therapy for heavily treatment-experienced, HIV-infected children.

METHODS

Tenofovir DF, alone and in combination with optimized background antiretroviral regimens, was studied among 18 HIV-infected children (age range: 8.3-16.2 years) who had progressive disease with > or = 2 prior antiretroviral regimens, in a single-center, open-label trial. Tenofovir DF monotherapy for 6 days was followed by the addition of individualized antiretroviral regimens. Subjects were monitored with HIV RNA reverse transcription-polymerase chain reaction, flow cytometry, and routine laboratory studies; monitoring for bone toxicity included measurement of lumbar spine bone mineral density (BMD) with dual-energy x-ray absorptiometry. Subjects were monitored through 48 weeks.

RESULTS

Two subjects developed grade 3 elevated hepatic transaminase levels during monotherapy and were removed from the study. The remaining 16 subjects had a median of 4 antiretroviral agents (range: 3-5 agents) added to tenofovir DF. HIV plasma RNA levels decreased from a median pretreatment level of 5.4 log10 copies per mL (range: 4.1-5.9 log10 copies per mL) to 4.21 log10 copies per mL at week 48 (n = 15), with 6 subjects having < 400 copies per mL, including 4 with < 50 copies per mL. The overall median increases in CD4+ T cell counts were 58 cells per mm3 (range: -64 to 589 cells per mm3) at week 24 and 0 cells per mm3 (range: -274 to 768 cells per mm3) at week 48. The CD4+ cell responses among the virologic responders were high and sustained. The major toxicity attributed to tenofovir DF was a >6% decrease in BMD for 5 of 15 subjects evaluated at week 48, necessitating the discontinuation of tenofovir DF therapy for 2; all 5 subjects experienced >2 log10 copies per mL decreases in HIV plasma RNA levels.

CONCLUSIONS

Tenofovir DF-containing, individualized, highly active antiretroviral therapy regimens were well tolerated and effective among heavily treatment-experienced, HIV-infected children. Loss of BMD may limit tenofovir DF use among prepubertal patients.

Bone disease and HIV infection

The high prevalence of bone demineralization among human immunodeficiency virus (HIV)-infected patients in the current therapeutic era has been described in multiple studies, sounding the alarm that we may expect an epidemic of fragility fractures in the future. However, despite noting high overall prevalences of osteopenia and osteoporosis, recent longitudinal studies that we review here have generally not observed accelerated bone loss during antiretroviral therapy beyond the initial period after treatment initiation. We discuss the continued progress toward understanding the mechanisms of HIV-associated bone loss, particularly the effects of HIV infection, antiretroviral therapy, and host immune factors on bone turnover. We summarize results of clinical trials published in the past year that studied the safety and efficacy of treatment of bone loss in HIV-infected patients and provide provisional opinions about who should be considered for bone disease screening and treatment.

Bone quality in perinatally HIV-infected children: role of age, sex, growth, HIV infection, and antiretroviral therapy

Appropriate supportive care and identification of long-term sequels of therapy are of paramount importance in HIV-infected pediatric patients. As low bone mineral quality (BMQ) in patients can be considered a marker of possible degeneration in osteopenia and osteoporosis in adulthood, we evaluated bone features in a pediatric population. Forty-four patients (23 females, 21 males; aged 3-17 years) were compared with a control population (1227 healthy children: 568 females, 641 males; aged 3-18 years). Seven patients were CDC stage C, 18 B, and 18 A. All patients were vertically infected; four were naive to any antiretroviral treatment, seven were taking two NRTIs, and 32 were on HAART. BMQ was assessed by a quantitative ultrasound (QUS) technique. It measures the amplitude-dependent speed of sound (AD-SoS, m/sec) and the bone transmission time (BTT, microsec). QUS values were significantly lower in cases than in controls, even after adjustment for age and body size (AD-SoS: 1924.7 +/- 64.9 and BTT: 0.97 +/- 0.3 in controls; AD-SoS: 1879.7 +/- 57.2 and BTT: 0.80 +/- 0.32 in cases; p < or = 0.001). The associations of AD-SoS and BTT with gender, type of therapy, and CDC stages were not significant. AD-SoS and BTT were significantly associated with age (r = 0.59, p < 0.0001), skeletal age SDS (r = 0.46, p = 0.002), height (r = 0.66, p < 0.0001), and therapy duration (r = 0.31, p = 0.04). Both AD-SoS and BTT values in patients fell below mean values of controls. Follow-up of bone mineral density is important in patients to prevent long-term problems of skeletal status.

Predictors of bone mineral density in human immunodeficiency virus-1 infected children

OBJECTIVES

To compare bone mineral density (BMD) among human immunodeficiency virus (HIV)-infected children with population norms and to determine predictors of BMD in HIV-infected children.

METHODS

Total body BMD was measured by dual energy x-ray absorptiometry in 37 HIV-infected children and nine sibling controls at baseline. Clinical, dietary and anthropometric data were obtained at the time of the dual energy x-ray absorptiometry examination. Age- and gender-adjusted z scores were calculated for BMD, body mass index, weight and height from population standards. Age-adjusted percentiles were determined for dietary intake of calcium and vitamin D. Differences in BMD z scores between HIV-infected children and sibling controls were determined and adjusted for height and weight, as were independent risk factors for lower BMD among infected children. Eighteen HIV-infected children and 5 controls had serial BMD measures.

RESULTS

Compared with population norms, HIV-infected children had significantly lower BMD z scores (-0.51 SD, P = 0.004), in contrast with controls who had normal z scores (0.38 SD, P = 1.0). However, there was no difference in BMD z scores between HIV-infected children and the small number of sibling controls, adjusted for height and weight. Among HIV-infected children, lower BMD z scores were independently associated with lower weight z scores (P < 0.0001), lower height z scores (P = 0.01), advanced (stage B or C) HIV stage (P = 0.01) and age greater than 8 years (P < 0.0001). In the same model, multivitamin use (P = 0.009) and African American race (P = 0.001) were associated with better BMD z scores, with nevirapine use showing borderline positive effect (P = 0.06). All results were adjusted for Tanner stage. Change in BMD z score over time showed that there was no change or an increase in BMD in 100% of controls but in only 44% of the HIV-infected children (P = 0.09).

CONCLUSION

When compared with population norms, HIV-infected children had lower than expected bone mass for their age and gender that may be attributable to delays in growth, sexual maturity, time (length of HIV infection), ethnicity and disease severity. Dietary intake of calcium and vitamin D were not associated with bone loss, but most children had suboptimal intake. However, multivitamin use was strongly associated with better bone mineral density.

Analysis of bone mineral content in horizontally HIV-infected children naïve to antiretroviral treatment

Low bone mass is a frequent finding in HIV-infected individuals. Reduced bone mass has been found in vertically infected children who are receiving antiretroviral treatment. Little is known about bone mass in horizontally infected young patients who are naïve to antiretroviral therapy. We measured the bone mineral content (BMC) at the lumbar spine and in the whole skeleton by using dual-energy X-ray absorptiometry (DXA) in 16 HIV-infected children (age 9.3 +/- 3.9 years) naïve to antiretroviral treatment, and in 119 healthy children (age 9.7 +/- 3.3 years). Thirteen patients were also pair-matched by anthropometric measures, sex, and age with healthy children. Median spine BMC of HIV-infected children was 14.9 g (8.2-39.2 g), and whole body BMC was 1106.1 g (55.5-2344.1 g). Spine BMC of healthy children was 18.6 g (6.8-52.2 g), and whole body BMC was 1213.5 g (541.0-2722.0 g). Multivariate analysis showed a mean difference of spine BMC values of 0.004 g (P = 0.64) between the two groups. Similarly, the whole body BMC difference between the two groups (0.001 g) was not statistically significant (P = 0.55). Mean spine BMC measurements in the case-control evaluation were 21.1 g (9.7 g) (patients), and 22.3 g (6.9 g) (controls). Whole body BMC measurements of patients and controls were 1258.5 g (539.6 g) and 1311.1 g (479.2 g), respectively. In both cases the differences were not significant. The duration of HIV infection did not relate to BMC values. In conclusion, horizontally HIV-infected children naïve to antiretroviral therapy have bone mineral measurements comparable to those of healthy children.

Adverse effects of antiretroviral therapy: focus on bone density

Osteopenia and osteoporosis are the most important bone disorders affecting patients with HIV infection. The available data indicate that HIV-infected patients have a high prevalence of low bone mineral density. Reduced bone mass and alterations of bone metabolism have been found in HIV-infected children, adolescents and adults. The variety and complexity of changes in bone metabolism in patients with HIV infection and the different possible mechanisms triggering bone mineral loss, as well as the different stages of disease and cumulative exposure to antiretroviral drugs at the time of clinical evaluation, may contribute to the wide range of mineral loss observed and to the uncertainty of the role of specific antiretroviral medications.

Bone Disorders Associated with the Human Immunodeficiency Virus: Pathogenesis and Management

Bone disorders such as osteopenia, osteoporosis, and osteonecrosis have been reported in patients infected with the human immunodeficiency virus (HIV), but the etiology and mechanism of these disorders are unknown. The prevalence estimates vary widely among studies and may be influenced by the presence or absence of antiretroviral therapy and lipodystrophy, severity of HIV disease, and overlapping bone loss risk factors. Addressing potential underlying bone disease risk factors (e.g., smoking and alcohol intake), evaluating calcium and vitamin D intake, and performing dual x-ray absorptiometry in patients with HIV who have risks for bone disease are important strategies in preventing osteopenia and osteoporosis in HIV-infected patients. Management of osteopenia and osteoporosis is still being evaluated. Administration of bisphosphonates (e.g., alendronate), with calcium and vitamin D supplementation, may be reasonable in treating osteoporosis; however, surgical intervention is the only method for treating symptomatic osteonecrosis.

[Decreased bone mineral density in HIV-infected children receiving highly active antiretroviral therapy]

BACKGROUND

In developed countries, the introduction of highly active antiretroviral therapy (HAART) has greatly improved survival and quality of life in HIV-infected children. Nevertheless, worrisome metabolic and bone alterations are beginning to be observed.

OBJECTIVE

To evaluate the prevalence of alterations in bone mineral density and possible associated factors in a cohort of HIV-infected children receiving HAART.

PATIENTS AND METHODS

Bone dual energy X-ray absorptiometry (DEXA) was performed in 50 HIV-infected children in a tertiary hospital in Madrid after a median length of HAART of 54 months. Subsequently, the group with bone mineral loss was compared with the group without bone mineral loss.

RESULTS

Forty percent of the children studied had decreased bone mineral density, of which 36 % had osteopenia (18/50) and 4 % had osteoporosis (2/50). No statistically significant differences were found between the two groups in any of the factors analyzed.

CONCLUSIONS

The prevalence of decreased bone mineral density in our cohort of HIV-infected children receiving HAART is high. The etiology and factors associated with this alteration are still not well known.

[Update on antiretroviral treatment in HIV infection]

In recent years, major advances have been made in the care of HIV-infected children, particularly in antiretroviral treatment, which have dramatically improved survival and quality of life. The goal of highly active antiretroviral therapy (HAART), which includes at least three potent drugs, is the maximal and most durable suppression of viral replication possible, which is often not achieved despite clear immunologic and clinical improvement. There are still major barriers to achieving this goal, mainly the difficulty of permanent adherence to complex regimens and treatment-related toxicities. Adverse events are frequent, including a high prevalence of metabolic complications with unknown consequences in the future. These drawbacks of antiretroviral treatment are leading to a more conservative initial approach, as well as to research into simpler and less toxic therapeutic options. New strategies should continue to be developed to overcome the still important limitations of current antiretroviral treatment.