Impaired Bone Architecture in Peripubertal Children With HIV, Despite Treatment With Antiretroviral Therapy: A Cross-Sectional Study From Zimbabwe

Updates on bone health in people living with HIV: global impact, prediction tools, and treatment

PURPOSE OF REVIEW

Osteoporosis and fragility fractures continue to be a concern for aging people living with HIV (PLWH), despite newer antiretroviral (ART) formulations that are associated with reduced bone toxicity. The aim of this review is to evaluate recent literature focusing on estimates of osteoporosis and fractures in various study populations, efficacy of current fracture risk assessment tools, and interventions to improve bone health outcomes.

RECENT FINDINGS

Prevalence of low bone mineral density (BMD) remains higher among PLWH globally, with new estimates ranging from 24 to 59%. The FRAX tool underestimates rate of major osteoporotic fractures in PLWH; some studies suggest that modifications can improve accuracy. Bone quality assessments with trabecular bone score may also improve prediction of vertebral fractures in PLWH. Preexposure prophylaxis (PrEP) with TDF/FTC is generally safe for maternal and infant bone health. Denosumab treatment effectively improves bone mass in PLWH.

SUMMARY

Despite advancements in ART, osteoporosis and fragility fractures remain common among PLWH. There is a need for continued research on development of fracture risk assessment tools including use of clinical data, imaging studies and biomarkers, and implementation of preventive and treatment strategies for at-risk subgroups.

Changes in peripheral quantitative computed tomography measured bone density, size, and strength in Zimbabwean children with and without HIV over one year: a cohort study

Understanding bone accrual in adolescents may inform approaches to improve skeletal health and reduce adult fracture risk. We investigated the effect of HIV on bone mineral accrual assessed by peripheral quantitative computed tomography (pQCT). Children with HIV (CWH) on ART for ≥2 years, and children without HIV (CWOH), aged 8-16 years (n = 609), had tibial pQCT scans at 0 and 12 months. Linear regression estimated sex-stratified differences in change (∆) and mean pQCT bone density (trabecular and cortical), size (total cross-sectional area [CSA]), and strength (SSI) between CWH and CWOH, adjusting for socio-economic status (SES) and orphanhood and incorporating an interaction term for baseline pubertal status (Tanner 1-2[pre/early] vs 3-5[mid/late]). Structural equation modeling tested whether baseline height-for-age-Z-scores (HAZ) mediate the effect of HIV on ∆bone outcomes. CWH were more likely than CWOH to be orphans (44% vs 7%), of lower SES (43% vs 27%), and be stunted (30% vs 8%); but similar in age. At baseline and follow-up, CWH had lower trabecular density, CSA, and SSI than CWOH. After adjustment, bone density and strength increased similarly in CWH and CWOH. CWH in mid/late puberty at baseline had greater 12 months increases in CSA than CWOH, particularly males (mean difference [31.3(95%CI:-3.1, 65.6) mm2 in mid/late puberty vs -2.04(-23.8, 19.7) mm2 in pre/early puberty; interaction p-value = 0.013]). HAZ mediated the effect of HIV on ∆bone outcomes only in females. as follows: indirect pathways from HIV to ∆trabecular density [-2.47 (-4.4, -0.5) mg/cm3], ∆cortical density [-3.26 (-5.5, -0.9) mg/cm3], and ∆SSI [-15.76 (-27.3, -4.2) mm3]. In conclusion, CWH show bone deficits at follow-up. Investigations of bone mineral accrual earlier in life and post-puberty to peak bone mass are needed.

Relationship between Body Mass Index and Health-Related Physical Fitness Components in HIV-Diagnosed Children and Adolescents

BACKGROUND/OBJECTIVES

There is a need to monitor physical fitness in HIV-diagnosed children and adolescents, and body mass index (BMI) could be an option for this due to its usability for assessing nutritional status and fat mass. The present study aimed to explore the relationship between BMI and physical fitness in HIV-diagnosed children and adolescents.

METHODS

A cross-sectional study was conducted with 86 HIV-diagnosed children and adolescents aged 5-15, with participants from two research protocols (Study I, n = 65; Study II, n = 21). Physical fitness was assessed through body composition (anthropometric measurements and dual energy X-ray absorptiometry), cardiorespiratory fitness (peak oxygen consumption [VO2peak]), muscle strength/endurance (handgrip strength, standing broad jump, and abdominal and modified push-up endurance), and flexibility (sit-to reach test). The relationship between BMI and physical fitness components was analyzed through correlation and simple and multiple linear regression analysis.

RESULTS

Eutrophic participants (mean age 11.44 ± 2.20) presented a normal fat mass percentage and overweight participants (mean age 11.50 ± 2.54) presented adequate handgrip strength. The adjusted models could explain 71% of fat-free mass, 57% of fat mass percentage, 70% of bone mineral content, 72% of bone mineral density, and 52% of handgrip strength.

CONCLUSIONS

Increases in BMI were associated with increases in fat-free mass, fat mass percentage, bone mineral content, bone mineral density, and handgrip strength. BMI was capable of distinguishing those presenting a normal fat mass percentage and those presenting adequate handgrip strength.

Perinatal HIV infection is associated with deficits in muscle function in children and adolescents in Zimbabwe

OBJECTIVES

To determine how muscle strength, power, mass, and density (i.e. quality) differ between children living with HIV (CWH) and those uninfected, and whether antiretroviral therapy (ART) regime is associated with muscle quality.

DESIGN

A cross-sectional study in Harare, Zimbabwe.

METHODS

The study recruited CWH aged 8-16 years, taking ART for at least 2 years, from HIV clinics, and HIV-uninfected children from local schools. Muscle outcomes comprised grip strength measured by hand-held Jamar dynamometer, lower limb power measured by standing long-jump distance, lean mass measured by dual-energy X-ray absorptiometry, and muscle density (reflecting intramuscular fat) by peripheral quantitative computed tomography. Linear regression calculated adjusted mean differences (aMD) by HIV status.

RESULTS

Overall, 303 CWH and 306 without HIV, had mean (SD) age 12.5 (2.5) years, BMI 17.5 (2.8), with 50% girls. Height and fat mass were lower in CWH, mean differences (SE) 7.4 (1.1) cm and 2.7 (0.4)kgs, respectively. Male CWH had lower grip strength [aMD 2.5 (1.1-3.9) kg, P  < 0.001], long-jump distance [7.1 (1.8-12.5) cm, P  = 0.006], muscle density [0.58 (0.12-1.05) mg/cm 3 , P  = 0.018, but not lean mass 0.06 (-1.08 to 1.21) kg, P  = 0.891) versus boys without HIV; differences were consistent but smaller in girls. Mediation analysis suggested the negative effect of HIV on jumping power in boys was partially mediated by muscle density ( P  = 0.032). CWH taking tenofovir disoproxil fumarate (TDF) had lower muscle density [0.56 (0.00-1.13)mg/cm 3 , P  = 0.049] independent of fat mass, than CWH on other ART.

CONCLUSION

Perinatally acquired HIV is associated, particularly in male individuals, with reduced upper and lower limb muscle function, not mass. Intra-muscular fat (poorer muscle quality) partially explained reductions in lower limb function. TDF is a novel risk factor for impaired muscle quality.