Adverse bone health and abnormal bone turnover among perinatally HIV-infected Asian adolescents with virological suppression

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.

Adults with Perinatally Acquired HIV; Emerging Clinical Outcomes and Data Gaps

In resourced settings, adults living with perinatally acquired HIV are approaching the 5th decade of life. Their clinical and psychological outcomes highlight potential future issues for the much larger number of adolescents growing up with HIV in sub-Saharan Africa, and will inform the development of appropriate healthcare services. Lifelong exposure to HIV, and increasingly to antiretroviral therapy throughout growth and development, contrasts with adults acquiring HIV in later life. This review describes the clinical outcomes for adults living with perinatally acquired HIV including post transition mortality, morbidity and retention in care. Rates of viral suppression, drug resistance and immunological function are explored. Co-morbidities focus on metabolic, cardiovascular, respiratory and bone health with quality-of-life data including neurocognitive functioning and mental health. Sexual and reproductive health including vaccine-preventable disease and the prevention of onward transmission to partners and infants are considered. The data gaps and future research questions to optimise outcomes for this emerging adult cohort are highlighted.

A Three-Year Follow-Up of Bone Density Among Thai Adolescents With Perinatally Acquired HIV After Completion of Vitamin D and Calcium Supplementation

PURPOSE

To determine changes in bone mineral density (BMD) and bone metabolism-related biomarkers among Thai adolescents with perinatally acquired HIV infection (PHIVA) at 3 years following completion of vitamin D and calcium (VitD/Cal) supplementation.

METHODS

An observational follow-up study was conducted among PHIVA who received 48-week VitD/Cal supplementation (either high-dose [3,200 IU/1,200 mg daily] or standard-dose [400 IU/1,200 mg daily]). Lumbar spine BMD (LSBMD) was assessed by dual-energy x-ray absorptiometry. Serum 25-hydroxyvitamin D, intact parathyroid hormone, and bone turnover markers were measured. Changes in LSBMD z-scores and other bone parameters at 3 years after stopping VitD/Cal supplementation compared with baseline or week 48 of supplementation were assessed among participants previously receiving high-dose and standard-dose VitD/Cal supplementation.

RESULTS

Of 114 enrolled PHIVA, 46% and 54% had previously received high-dose and standard-dose VitD/Cal supplementation, respectively. The median age was 20 years; 53% were male. At 3 years after completion of VitD/Cal supplementation, we observed a significant decline in 25-hydroxyvitamin D and increase in intact parathyroid hormone but no significant rebounds of C-terminal telopeptides of collagen type I and procollagen type I amino-terminal propeptides and no significant changes in LSBMD z-scores among PHIVA in both treatment groups, compared with the measurements at week 48 of supplementation. Notably, LSBMD z-scores at 3 years after stopping VitD/Cal supplements were not significantly altered from baseline evaluations in both PHIVA groups.

DISCUSSION

Three years after completion of high-dose or standard-dose VitD/Cal supplementation, LSBMD z-scores of our Thai PHIVA were not significantly changed from baseline and week 48 of supplementation. VitD/Cal supplementation of PHIVA during periods of peak bone mass accrual may have sustained and long-term skeletal benefits.

Gender and sex considerations in HIV and bone health

PURPOSE OF REVIEW

People with HIV (PWHIV) are at increased risk for osteoporosis and fractures, because of the effects of HIV and inflammation and antiretroviral therapy (ART) initiation as well as traditional risk factors. This review from recent literature focuses on sex differences in rates of bone disease, risk of fractures, and effects of ART.

RECENT FINDINGS

Women with HIV in resource-constrained settings experience bone loss because of the additive effect of initiating TDF-containing ART during pregnancy, lactation, and menopause. Children and adolescents experience lower bone accrual during the pubertal growth years. There has been less focus on bone health in recent trials of ART containing tenofovir alafenamide and/or integrase inhibitors. Very few clinical trials or studies compare sex-specific changes in inflammation, immune activation, response to ART and bone turnover or change in BMD resulting in significant knowledge gaps.

SUMMARY

More data is needed to determine changes in prevalence of osteopenia, osteoporosis, and fractures in the era of immediate initiation of ART at high CD4 cell counts and the use of more bone-friendly ART. The long-term effects of ART and low bone mass on fractures in the ageing population of PWHIV is yet to be realized.

Height adjustment reduces occurrence of low bone mineral density in children and adolescents with HIV

OBJECTIVE

The aim of this study was to quantify the reduction of bone mineral density with and without height adjustment.

METHODS

A cross-sectional study was performed with 69 Brazilian children and adolescents vertically infected by HIV. Bone mineral density was measured by dual-energy absorptiometry in the lumbar spine. Anthropometric, demographic, and clinical variables were analyzed. A specific calculator was used for height adjustment.

RESULTS

The majority of participants (52.2%) were adolescents and did not present with immunological alterations (61%). Reduced bone mineral density (Z-score <-1) was present in 23.2% and low bone mass (Z-score <-2) in 5.8%. After height adjustment, these occurrences decreased to 11.6% and 0%, respectively. Patients with reduced bone mineral density had a higher mean age and lower body mass index than patients with normal bone mineral density.

CONCLUSION

The occurrence of reduced bone mineral density decreased after adjustment for height.

Persistently lower bone mass and bone turnover among South African children living with well controlled HIV

OBJECTIVE

We evaluated longitudinal trends and associations between bone mass, bone turnover and inflammatory markers among South African children living with HIV (CLHIV) and controls.

DESIGN

We previously reported decreased bone mass among CLHIV independent of marked inflammation and increased bone turnover. The goal of this study was to evaluate longitudinal changes in bone mass, bone turnover and inflammation over 2 years.

METHODS

Longitudinal analyses were conducted among 220 CLHIV and 220 controls. Anthropometric measurements, physical activity, antiretroviral regimen, virologic and immunologic status, whole body (WB) and lumbar spine (LS) bone mineral content (BMC) and bone mineral density (BMD) were collected (enrollment, 12 and 24 months). Bone turnover markers including C-telopeptide of type I collagen (CTx) and procollagen type I N-terminal propeptide (P1NP) and inflammatory markers including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), soluble CD14 and high-sensitivity C-reactive protein (hsCRP) were collected at enrollment and 24 months.

RESULTS

Compared with controls, CLHIV had significantly lower mean WB-BMC, WB-BMD, WB-BMC z scores, LS-BMC and LS-BMD as well as lower bone formation (P1NP) and resorption (CTx), and higher hsCRP and soluble CD14 over 24 months. CLHIV on efavirenz (EFV) had consistently lower TNF-alpha and IL-6 compared with those on ritonavir-boosted lopinavir (LPV/r) at all time points.

CONCLUSION

Over 2 years of follow-up, South African CLHIV had persistently lower bone mass, bone turnover, and macrophage activation. Lower bone mass and higher pro-inflammatory cytokine profiles were consistently observed among those on LPV/r-based compared with EFV-based regimens.

Bone outcomes in virally suppressed youth with HIV switching to tenofovir disoproxil fumarate

Background

Tenofovir disoproxil fumarate (TDF) is included in first-line antiretroviral treatment (ART) for adolescents living with HIV (ALWH). Associated toxicities remain a concern.

Objective

We evaluated bone and renal safety outcomes in virologically suppressed South African ALWH after switching to TDF.

Method

We recruited virally suppressed (< 100 copies/mL) adolescents, aged 15-20 years, who switched from an abacavir (ABC)-based to a TDF-based efavirenz regimen. Bone mass and renal function were assessed at Week 0 and at Week 24 after the switch to TDF using dual-energy X-ray absorptiometry (DXA) and serum renal markers. A change in the lumbar spine (LS) and the whole-body less head (WBLH) bone mineral density (BMD) Z-scores and the estimated glomerular filtration rate (eGFR) between the two measures were compared (paired t-tests) and stratified by sex.

Results

Fifty participants (48% male), with a median duration of prior ART of 11.4 years, were enrolled. Among 47 participants with 24-week DXA results, 15 (32%) had either no change or a decreased LS-BMD after the switch, with a mean change of -1.6%. Overall, more female participants experienced this outcome: 58% versus 4%, P < 0.0001. The mean change (standard deviation) in the LS-Z-score was -0.03 (0.25) and in the WBLH-Z-score was 0.02 (0.24). A decrease in the eGFR from 132.2 to 120.4 was observed (P = 0.0003); however, the levels remained clinically acceptable.

Conclusion

South African ALWH switching from abacavir to TDF-based ART experienced statistically significant decreases in eGFR but not in LS and WBLH BMD. Female ALWH were more likely to experience a decrease in LS-BMD and may require closer monitoring.

Impact of vitamin D and calcium supplementation on bone mineral density and bone metabolism among Thai adolescents with perinatally acquired HIV infection: A randomized clinical trial

BACKGROUND

To evaluate the impact of vitamin D and calcium supplementation(VitD/Ca) on lumbar spine bone mineral density(LSBMD) and bone metabolism among Thai adolescents with perinatally acquired HIV(PHIVA).

METHODS

A multicenter, randomized, active-control, open-labeled trial was conducted. PHIVA(aged10-20years) who were on stable cART were enrolled. Baseline LSBMD status was defined as low(z-score≤-2) and normal(z-score>-2). Eligible PHIVA were randomly assigned to receive standard-dose VitD/Ca (400IU/1,200mg daily), or high-dose VitD/Ca supplementation (400IU/1,200mg daily plus ergocalciferol 20,000IU weekly) for 48 weeks (ratio 1:1,stratified by baseline LSBMD). Study outcomes were the changes in LSBMD, LSBMD z-scores, and bone metabolism-related biomarkers (25-hydoxyvitamin D[25OHD], intact parathyroid hormone[iPTH], C-terminal telopeptide[CTX], procollagen type I amino-terminal propeptide[PINP]) from baseline to week48.

RESULTS

Among 200 enrolled PHIVA, a median age was 16 (IQR:14-18)years; 61% were on NNRTI-based cART. The median 25OHD level was 25.5 (IQR:20.8-33.0)ng/ml. After a 48-week VitD/Ca supplementation, LSBMD significantly increased in both treatment groups (high-dose,median:+0.07g/cm 2,IQR:+0.04 to +0.11g/cm 2,P<0.001; standard-dose,median:+0.09g/cm 2, IQR:+0.03 to +0.13g/cm 2,P<0.001). Notably, the change in LSBMD z-scores was significantly greater in high-dose versus standard-dose groups (median:+0.4,IQR:-0.1 to +0.9 versus median:+0.1,IQR:-0.4 to +0.7;P=0.02). The levels of 25OHD increased, whereas iPTH, CTX, and PINP declined significantly in both groups(P<0.05); but no between-group differences were demonstrated.

CONCLUSIONS

Over the 48-week VitD/Ca supplementation, significant increase in LSBMD, and significant decreases in bone metabolism-related markers were observed among our Thai PHIVA in both treatment groups. The improvement in LSBMD z-score was more enhanced with high-dose VitD/Ca supplementation compared with standard-dose. High-dose VitD/Ca supplementation might be considered to promote bone health in this population.

Fractures in children and adolescents living with perinatally acquired HIV

BACKGROUND

Across numerous settings, bone mineral density for age and sex is lower in children/adolescents living with perinatally-acquired HIV (PHIV) compared to uninfected peers. We assessed incidences of any fracture/any long bone fracture, and osteoporosis prevalence in PHIV and HIV-exposed uninfected (PHEU) participants in the Pediatric HIV/AIDS Cohort Study (PHACS).

METHODOLOGY

Lifetime history of fracture events from birth up to age 20 years was obtained by chart review and/or interview, including age at fracture, mechanism, and bone(s) fractured. Poisson regression models were fit comparing fracture incidence by HIV status adjusted for age, sex, and race, with effect modification by age (<6, ≥6 yr).

RESULTS

PHIV (N = 412) were older (median 17.5 vs 16.7 yr) and more frequently reported black race (72% vs 61%) than PHEU children/adolescents (N = 206). 17% of PHIV and 12% of PHEU ever reported a fracture. Among children <6 yr, the adjusted incidence rate ratio of ≥1 fracture was higher (7.23; 95% CI 0.98, 53.51) in PHIV than PHEU, but similar among children/adolescents ≥6 years (1.20; 95% CI: 0.77, 1.87). Results were similar for long bone fracture. The most common fracture mechanisms were falling to the ground from a standing height (23.6% PHIV vs 8.8% PHEU) and sports injuries (21.3% vs 32.4%), and the most commonly fractured sites were the forearm and small bones of the wrist/hands. None of the children had osteoporosis.

CONCLUSIONS

Among children/adolescents ≥6 yr of age, fractures were similar by perinatal HIV status. Prospective, targeted collection of fracture history will be necessary to determine rates of fracture as PHIV and PHEU age into adulthood.

SUMMARY

Lifetime fracture history was collected in children/adolescents living with perinatally-acquired HIV (PHIV) and HIV-exposed uninfected (PHEU) children from birth up to age 20 years. Fracture incidence was higher in PHIV compared to PHEU among children <6 years old, but not among older children/adolescents.

Bone turnover markers in children and adolescents with environmentally determined short stature, living in the oil and gas processing region

In conditions of intensive development of gas fields, environmental safety issues are becoming increasingly important. High rates of gas production and growth of its chemical processing have turned gas industry enterprises into a powerful source of environmental pollution, which poses a real threat to public health and contributes to an increase in morbidities and environmentally determined pathological conditions. The development of methods for the diagnosis, treatment and prevention of such conditions is an important task for modern science. The aim of the research is to make a comprehensive assessment of serum markers of bone synthesis and resorption in children with short stature living in the oil and gas processing regions. A total of 240 children aged 8-17 years, living in the oil and gas processing region (Kenkiyak), and 409 schoolchildren (8-17 years old), living in the environmentally favourable region (Kobda village), during 3 years were examined. It was established that emissions of pollutants by oil processing enterprises account for almost 80% of all emissions into the atmosphere. Gas flaring at oil production sites plays a special role in this process. Speaking of the effects of environmental factors on children's health, it should be noted that there is no consensus on the mechanisms and consequences of exposure to low doses of chemical atmospheric pollutants in children and adolescents so far.

Chronic comorbidities in children and adolescents with perinatally acquired HIV infection in sub-Saharan Africa in the era of antiretroviral therapy

Globally, 1·7 million children are living with HIV, of which 90% are in sub-Saharan Africa. The remarkable scale-up of combination antiretroviral therapy has resulted in increasing numbers of children with HIV surviving to adolescence. Unfortunately, in sub-Saharan Africa, HIV diagnosis is often delayed with children starting antiretroviral therapy late in childhood. There have been increasing reports from low-income settings of children with HIV who have multisystem chronic comorbidities despite antiretroviral therapy. Many of these chronic conditions show clinical phenotypes distinct from those in adults with HIV, and result in disability and reduced quality of life. In this Review, we discuss the spectrum and pathogenesis of comorbidities in children with HIV in sub-Saharan Africa. Prompt diagnosis and treatment of perinatally acquired HIV infection is a priority. Additionally, there is a need for increased awareness of the burden of chronic comorbidities. Diagnostic and therapeutic strategies need to be collectively developed if children with HIV are to achieve their full potential.

Tenofovir Has Minimal Effect on Biomarkers of Bone Health in Youth with HIV Receiving Initial Antiretroviral Therapy

Both HIV infection and tenofovir disoproxil fumarate (TDF) treatment adversely impact bone metabolism and may lead to osteopenia, which has critical implications for youth with HIV (YWH). This study evaluates changes in the biomarkers of bone metabolism and inflammation among YWH receiving initial treatment with TDF- and non-TDF-containing antiretroviral therapies (ARTs). YWH [n = 23, median age 21 years (range 18-24), 87% male, 61% African American] were assessed for inflammatory and bone metabolism biomarkers at enrollment, after 48 weeks of TDF-containing ART, and 96 weeks of ART without TDF with continued viral suppression. Spearman's rank correlation evaluated biomarker associations. Bone alkaline phosphatase, parathyroid hormone, and osteopontin increased after TDF treatment. All fell after TDF was discontinued. Levels of RANKL and osteoprotegerin did not change throughout the study. There was little correlation between biomarkers of bone metabolism and either macrophage or lymphocyte activation at any time point. Our results establish baseline associations between bone metabolism and immune biomarkers for this population, and find that before CD4 T cell decline chronic inflammation does not perturb biomarkers of bone metabolism among YWH. The adverse effects of TDF on bone health may be marginal for YWH at the early stages of disease.

Growth and pubertal development in HIV-infected adolescents

PURPOSE OF REVIEW

We present an overview of recent research in the inter-related areas of growth and pubertal development among adolescents with HIV. Growth deficits early in childhood can lead to delayed puberty, with subsequent effects on pubertal growth spurts and bone health.

RECENT FINDINGS

Impaired growth remains a critical concern, particularly in low-resource settings, where stunting, wasting and underweight remain pervasive. Antiretroviral treatment (ART) initiation results in improved growth, with greatest growth recovery in the first years and more improvement in weight than in height. However, even years after ART initiation, growth deficits persist in low-resource settings (LRS), and adolescents appear at particularly increased risk. The high prevalence of stunting translates to delays in pubertal onset and sexual maturity. In contrast, HIV-infected adolescents in developed countries do not demonstrate persistent wasting, yet still have delayed pubertal development. Impaired growth increases the risk for mortality, virologic failure, and abnormal bone health, as well as increased depression and stigma.

SUMMARY

Early initiation of ART across all age groups regardless of immunological status is essential for restoring growth. Coordination of ART initiation, nutritional supplementation programs, and concurrent prophylaxis is required to ameliorate growth deficits and pubertal delays, particularly in LRS.

Growing up with perinatal HIV

: The World Health Organization estimates that over four million children have been infected with HIV, most via perinatal transmission. The availability of safe and effective antiretroviral therapy (ART) has radically reduced mortality in this population and most that have access to ART are now thriving. However, long-term effects of HIV infection and its therapy have significant impact on aging adolescents and young adults with perinatal HIV infection. Many of the complications of long-term HIV infection seen in adults are also present, although the main impact of long-standing HIV infection and its treatment in children has been on growth and development, including neurodevelopment. A better understanding of the complexities of growing up with perinatal HIV will help prepare low and middle-income countries of the world where ART is now available to successfully manage their aging up populations of adolescents and young adults with perinatal HIV infection.

Impact of HIV-1 Infection and Antiretroviral Therapy on Bone Homeostasis and Mineral Density in Vertically Infected Patients

Daily assumption of antiretroviral drugs and HIV-related immune activation lead to important side effects, which are particularly evident in vertically infected patients. Bone homeostasis impairment and reduction of bone mineral density (BMD) is one of the most important side effects. Primary aim of this study is to assess the prevalence of bone homeostasis alterations in a group of vertically infected patients; secondary aim is to analyze the relationship between bone homeostasis alterations and anthropometric data, severity of HIV infection, and antiretroviral therapy. We studied 67 patients with vertically transmitted HIV-1 (aged 6-31 years), followed by the Pediatric Infectious Disease Unit of the University Hospital of Padua, Italy. We analyzed bone turnover markers (P1NP and CTx) and we performed lumbar spine and femoral dual energy X-ray absorption densitometry (DXA). Personal and anthropometric data and information on HIV-infection severity and antiretroviral therapy were collected for all patients. We found that BMD values recorded by DXA showed a significant correlation with age, race, BMI, physical activity, and antiretroviral therapy duration. P1NP was increased in 43% of patients, while CTX in 61% of them. P1NP alteration was related to age, race, BMI, physical activity, therapy duration, and ever use of protease inhibitors and nucleotide reverse transcriptase inhibitors. CTX alteration was found to be correlated only with age. In conclusion, our study confirms that a wide percentage of HIV vertically infected patients show reduced BMD and impaired bone homeostasis. Strict monitoring is needed in order to early identify and treat these conditions.

Noncommunicable diseases in adolescents with perinatally acquired HIV-1 infection in high-income and low-income settings

PURPOSE OF REVIEW

Perinatally HIV-infected adolescents may be at increased risk of noninfectious comorbidities later in life. This review summarizes recent advances in the understanding of noncommunicable diseases (NCD) among HIV-infected adolescents in high-income and lower middle-income countries, and identifies key questions that remain unanswered. We review atherosclerotic vascular disease (AVD), chronic bone disease (CBD), chronic kidney disease (CKD), and chronic lung disease (CLD).

RECENT FINDINGS

Persistent immune activation and inflammation underlie the pathogenesis of AVD, highlighting the importance of treatment adherence and maintenance of viral suppression, and the need to evaluate interventions to decrease risk. Tenofovir disoproxil fumarate (TDF) and trials of vitamin D supplementation have been the focus of recent studies of CBD with limited studies to date evaluating tenofovir alafenamide as an alternative to TDF for decreasing risk for bone and renal adverse effects among HIV-infected adolescents. Recent studies of CKD have focused primarily on estimating prevalence in different settings whereas studies of CLD are limited.

SUMMARY

As perinatally HIV-infected children age into adolescence and adulthood with effective long-term ART, it is necessary to continue to evaluate their risks for noninfectious comorbidities and complications, understand mechanisms underlying their risks, and identify and evaluate interventions specifically in this population.

Decreased bone turnover in HIV-infected children on antiretroviral therapy

In this study, we evaluated the relationships between immune activation, bone turnover, and bone mass in virally suppressed HIV-infected children and HIV-uninfected children in South Africa. We found that decreased bone mass may occur or persist independent of immune activation and altered bone turnover.

PURPOSE

HIV-infected children and adolescents have deficits in skeletal growth which include decreases in bone mass and alterations in bone microarchitecture. However, the mechanism by which HIV infection compromises bone accrual in children and adolescents is unclear. The goal of this study was to evaluate the relationships between immune activation, bone turnover, and bone mass in a group of pre-pubertal HIV-infected children randomized to remain on ritonavir-boosted lopinavir (LPV/r)-based antiretroviral therapy (ART) or switch to efavirenz-based ART in South Africa virally suppressed at the time of this study.

METHODS

This cross-sectional analysis included 219 HIV-infected and 180 HIV-uninfected children enrolled in the CHANGES Bone Study conducted in Johannesburg, South Africa. Whole body (WB) bone mineral content (BMC) was assessed by dual x-ray absorptiometry and WB BMC Z-scores adjusted for sex, age, and height were generated. Bone turnover markers, including C-telopeptide of type 1 collagen (CTx) and procollagen type I N-terminal propeptide (P1NP), were analyzed. Markers of immune activation were also measured, including cytokines IL-6 and TNF-alpha, as well as soluble CD14 and high-sensitivity C-reactive protein (CRP).

RESULTS

Compared to uninfected controls, HIV-infected children had lower WB BMC Z-scores, similar IL-6 and TNF-alpha, higher soluble CD14 and high-sensitivity CRP, and lower markers of bone resorption (CTX) and bone formation (P1NP). Bone turnover markers were not different in those remaining on LPV/r or switched to efavirenz.

CONCLUSIONS

Our findings suggest that in HIV-infected children with viral suppression, decreased bone accrual may occur or persist independent of immune activation and altered bone turnover.

A review of transition experiences in perinatally and behaviourally acquired HIV-1 infection; same, same but different?

Introduction: Despite sharing common psychosocial and developmental experiences, adolescents living with perinatally and behaviourally acquired HIV-1 infection are different in terms of timing of HIV infection and developmental stage at infection. Therefore, it is of interest to identify similarities and differences between these two groups of adolescents living with HIV in their experiences, facilitators and barriers during the transition process.

Methods: A detailed literature search of peer-reviewed published papers was conducted on PubMed to identify relevant original research or viewpoints published up to September 2016. Conference abstracts and other unpublished data sources were not included.

Results: Existing published literature, mainly using qualitative methods, explores the transition from paediatric to adult healthcare provision, as experienced by these two groups of young people. Reports highlight the variation and similarities in their experiences and challenges of transition. Findings from the USA and Europe predominate, while experience from Africa and Asia is lacking, despite the importance of these regions in the global epidemic.

Conclusions: Published transition data remain limited, and there are few studies focusing on behaviourally infected adolescents and key population groups (e.g. adolescents who use drugs, lesbian/gay/transgender individuals). Robust definitions of the transition process and standardized outcome measures are required to facilitate cross-study and geographic comparisons.

Impact of tenofovir disoproxil fumarate on bone metabolism and bone mass among perinatally HIV-infected Asian adolescents

BACKGROUND

This study aimed to determine the effect of tenofovir disoproxil fumarate (TDF) on bone metabolism and bone mass in HIV-infected adolescents.

METHODS

This was a sub-study of a cross-sectional multicentre bone health trial that enrolled perinatally HIV-infected Thai and Indonesian adolescents (10-18 years) with viral suppression on antiretroviral therapy. Participants were classified into two groups as TDF users and non-users. Bone metabolism-related markers (25-hydroxyvitamin D [25-OHD], intact parathyroid hormone [iPTH], bone turnover biomarkers), and lumbar spine dual-energy X-ray absorptiometry were assessed. Bone mineral density (BMD)/bone mineral apparent density (BMAD) Z-scores were calculated.

RESULTS

Of 394 adolescents, 136 (34.5%) and 258 (65.5%) were TDF users and non-users, respectively. Among TDF users, median age (IQR) was 16.1 (14.7-17.4) years and TDF treatment duration (IQR) was 2.3 (1.4-3.1) years. Among TDF non-users, median age (IQR) was 14.3 (12.6-16.4) years. BMD and BMAD Z-scores comparing TDF users with non-users were -0.8 and -0.6 (P=0.27), and -0.3 and -0.2 (P=0.58), respectively. The association between TDF use and iPTH elevation was intensified in adolescents with suboptimal vitamin D levels (25-OHD <30 ng/ml; P=0.001). TDF administration was positively associated with bone resorption marker (P=0.04) and negatively associated with bone formation marker (P=0.04). With data up to 4 years, neither association between TDF use and bone mass loss (BMD: P=0.09; BMAD: P=0.22), nor variation of bone mass Z-scores by TDF treatment duration (BMD: P=0.34; BMAD: P=0.58) was demonstrated.

CONCLUSIONS

Recent TDF administration was correlated with PTH elevation and bone turnover dysregulation but not with bone mass reduction in our cohort. A study with extended follow-up to ascertain TDF-associated bone mass deterioration is warranted.