DUAL-ENERGY X-RAY ABSORPTIOMETRY AND CALCULATED FRAX RISK SCORES MAY UNDERESTIMATE OSTEOPOROTIC FRACTURE RISK IN VITAMIN D-DEFICIENT VETERANS WITH HIV INFECTION

Current Considerations for Clinical Management and Care of People with HIV: Findings from the 11th Annual International HIV and Aging Workshop

The number of people with HIV (PWH) aged 50 years or older continues to steadily increase. The convergence of age- and HIV-related complications in these individuals presents a challenge for both patients and clinicians alike. New findings continue to emerge, as numerous researchers evaluate the combined impact of these two factors on quality of life, physiological systems, and mental health in PWH. Since its first occurrence in 2009, the International Workshop on HIV and Aging has served as a multidisciplinary meeting to share basic biomedical data, clinical trial results, treatment strategies, and epidemiological recommendations, toward better understanding and outcomes among like-minded scientific professionals. In this article, we share a selection of key findings presented in plenary talks at the 11th Annual International Workshop on HIV and Aging, held virtually from September 30, 2020 to October 2, 2020. We will also address the future directions of HIV and aging research, to further assess how the aging process intersects with chronic HIV.

Evaluation of the fracture risk assessment tool for determining bone disease and the impact of secondary causes of osteoporosis in people living with HIV

BACKGROUND

Among HIV-infected individuals, screening for bone disease is encouraged to assess reversible risk factors and plan therapeutic interventions.

OBJECTIVE

We assessed the usefulness of Fracture Risk Assessment (FRAX) tool to identify candidates for dual X-ray absorptiometry (DXA) scan, or individuals with bone loss progression. We further explored how secondary causes of osteoporosis are reflected on FRAX.

METHODS

Longitudinal study of 217 consecutive individuals (mean, 45.8 years, 24% females) included after DXA scan. FRAX was calculated without/with femoral neck bone mineral density (BMD), checking the box of "secondary osteoporosis" for all the individuals.

RESULTS

Low BMD was observed in 133/217 (61%) individuals, of whom 98.5% had not been selected as candidates for DXA by current FRAX thresholds. Specifically, 23% of individuals aged <50 had low BMD but none was candidate for DXA. Adding BMD data, FRAX results increased by 50-100%, with 2/217 individuals (1%) above the thresholds. Classical and HIV-related secondary causes of osteoporosis (observed in 98% overall) correlated with low BMD, modifying significantly FRAX results (HCV coinfection, +124%; longer time of HIV infection, +93%; longer time on antiretroviral therapy, +147%; tenofovir exposure +36%). Individuals with lower BMD and higher FRAX results at inclusion had less bone decline in a follow-up DXA after a median of 3.5 years.

CONCLUSIONS

Currently recommended FRAX thresholds are not useful to select candidates for DXA scan, which could delay its performance in a population with a high prevalence of secondary factors for low BMD. Classical and HIV-related factors alter BMD and fracture risk estimation.

HCV co-infection among people living with HIV Is associated with Higher fracture risk

INTRODUCTION

The purpose of this study was to predict the 10-year risk of fracture among people living with HIV (PLWH) using FRAX™, and to determine the risk factors related to a high probability of fractures.

METHODOLOGY

This study consisted of 288 subjects aged 40 years and above. The ten-year probability of major osteoporotic fractures (MOF) and hip fractures was assessed using the FRAX™ algorithm with bone mineral density (BMD) data. A logistic regression was used to determine risk factors related to a high probability of major osteoporotic fracture and hip fracture.

RESULTS

The median 10-year probability of fracture was 3.7% (IQR 2.2-6.2) for MOF and 0.8% (IQR 0.3-2.5) for hip fractures. In addition to old age, previous fracture history, and low T-scores, HCV co-infection was associated with a higher risk of hip fractures in PLWH (AOR: 4.3, 95% CI: 1.29-14.33). Old age and low T-scores were also associated with a high probability of MOF.

CONCLUSIONS

HCV co-infection among PLWH is associated with a higher risk of hip fracture. Sustained efforts in terms of pharmacologic and non-pharmacologic interventions in PLWH are necessary to prevent osteoporotic fractures, especially in those with HCV co-infections.

Association of Low Vitamin D with Complications of HIV and AIDS: A literature Review

With the advent of combination antiretroviral therapy (cART), the survival of HIV patients has improved dramatically, but the complications of the disease and treatment have become an important issue in the management of HIV patients. Vitamin-D deficiency is common in HIV patients. Low vitamin-D is associated with different comorbidities in the HIV uninfected general population. In this review, we first briefly describe vitamin D synthesis and mechanism of action and we focus on the epidemiological and clinical data dealing with the relationship between vitamin D deficiency in HIV infection with several comorbidities which has been found to be increasingly common in patients living with HIV infection. We searched the PubMed database using the keywords "HIV," "vitamin D" and other common disorders or conditions that are relatively common in HIV infection. The other conditions included in the search were osteoporosis and fracture, cardiovascular disease, diabetes and insulin resistance, active tuberculosis, hepatitis-C co-infection, and HIV disease progression. Articles presenting original data as well as systematic reviews and met analysis related to HIV population were included in our analysis. Vitamin-D deficiency seems to be associated with several adverse outcomes in HIV patients but a definite cause and effect relationship with vitamin-D is yet to be confirmed in most of the cases. However, the literature supporting the efficacy of vitamin-D supplementation is lacking.

Frailty Is an Independent Risk Factor for Mortality, Cardiovascular Disease, Bone Disease, and Diabetes Among Aging Adults With Human Immunodeficiency Virus

BACKGROUND

We characterized associations between frailty and incident cardiovascular disease (CVD), diabetes mellitus (DM), bone disease, and mortality within a cohort of aging persons with human immunodeficiency virus (PWH).

METHODS

Participants underwent frailty evaluations using the Fried frailty assessment (baseline and annually). Frailty was defined as having ≥3 frailty criteria. Clinical outcomes of mortality, CVD events, DM, and bone disease events were recorded throughout the study period (baseline to most recent study or clinic visit, or date of clinical outcome, whichever came first). Poisson regression models were used to evaluate associations between baseline frailty, change in frailty score over 48 weeks, and each clinical outcome.

RESULTS

Among 821 men and 195 women (median age 51 years), 62 (6%) were frail at baseline. Frailty scores increased by ≥1 component among 194 participants (19%) from baseline to 48 weeks. Baseline frailty was associated with an increased risk of incident CVD and DM, with a trend toward a significant association with bone events. Among frailty components, slow gait speed was associated with incident DM and borderline associated with incident CVD. An increase in frailty from baseline to week 48 was associated with mortality but not with the other clinical outcomes.

CONCLUSIONS

Baseline frailty was associated with multiple adverse health outcomes (incident CVD, DM, and bone disease), while increase in frailty score was associated with mortality among PWH engaged in care. Incorporation of frailty assessments into the care of PWH may assist in improvement of functional status and risk stratification for age-related chronic diseases.

HIV and Aging: Reconsidering the Approach to Management of Comorbidities

Health care for older adults with human immunodeficiency virus can be highly complex, resource intensive, and carry a high administrative burden. Data from aging longitudinal cohorts and feedback from the human immunodeficiency virus community suggest that the current model is not meeting the needs of these older adults. We introduce the 6 Ms approach, which acknowledges the multicomplexity of older adults with human immunodeficiency virus, simplifies geriatric principles for non-geriatrics-trained providers, and minimizes extensive training and specialized screening tests or tools. Implementing novel approaches to care requires support at local/national levels.

The Hidden Burden of Fractures in People Living With HIV

The survival of people living with human immunodeficiency virus (HIV) has increased markedly since the advent of antiretroviral therapy (ART). However, other morbidities have emerged, including osteoporosis. The estimated incidence of fractures at any site in people living with HIV ranges from 0.1 per 1000 person‐years to 8.4 per 1000 person‐years: at least twice that of people without HIV. This increased risk seems to be related to HIV itself and its treatment. Risk factors for bone disease in HIV‐positive (HIV⁺) subjects include both classical risk factors for osteoporosis and fracture and factors linked to HIV itself, such as inflammation, reconstitution syndrome, low CD4, ART, and co‐infection with hepatitis B and C viruses. The risk of fractures in these individuals can be at least partially assessed by measurement of BMD and the Fracture Risk Assessment Tool (FRAX™). Only alendronate and zoledronic acid have been studied in HIV⁺ individuals; both show beneficial effects on BMD, although data on fracture reduction are not available. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Ethnic Variations in Serum 25(OH)D Levels and Bone Ultrasound Attenuation Measurements in Blacks and Whites

Vitamin D deficiency is more common in Blacks, yet Blacks have lower prevalence of bone fragility fractures or osteoporosis than Whites. Broadband ultrasound attenuation (BUA) has been used to explore the association between serum 25(OH)D levels and bone quality in White and non-white populations. We investigated serum 25(OH)D status with corresponding BUA measurements assessed cross sectionally in a cohort of 232 Blacks and 260 Whites, aged 30-95 years who were part of the calibration study of the large Adventist Health Study-2 (AHS-2). At the calibration clinics, calcaneal BUA was measured and blood drawn for serum 25(OH)D assessment. In multivariable analyses, BUA was negatively associated with age (β-coefficient = -0.38; p < 0.0001) and positively associated with body mass index (BMI) (p _(trend) < 0.0001) and positively, but non-significantly, associated with serum 25(OH)D levels. Also, as expected, females had lower BUA (β-coefficient = -5.19; p < 0.05) and Blacks had higher BUA (β-coefficient = 4.26; p < 0.05). Gender and race modified the relationship of serum 25(OH)D on BUA with a positive association in males (p _(trend) ≤ 0.05), but no significant association in females after also controlling for menopausal status and hormone therapy. After also controlling for serum 25(OH)D levels, Black males had higher BUA than White men, but such differences were not found among the females. When stratifying on race, a positive association between serum 25(OH)D levels and BUA (p _(trend) ≤ 0.05) was found in Blacks, but not among Whites. Further studies are needed to understand how racial/ethnic differences in serum 25(OH)D levels influence bone health.

Bone Loss in HIV Infection

Human immunodeficiency virus (HIV) infection is an established risk factor for low bone mineral density (BMD) and subsequent fracture, and treatment with combination antiretroviral therapy (cART) leads to additional BMD loss, particularly in the first 1-2 years of therapy. The prevalence of low BMD and fragility fracture is expected to increase as the HIV-infected population ages with successful treatment with cART. Mechanisms of bone loss in the setting of HIV infection are likely multifactorial, and include viral, host, and immune effects, as well as direct and indirect effects of cART, particularly tenofovir disoproxil fumarate (TDF) and the protease inhibitors (PIs). Emerging data indicate that BMD loss following cART initiation can be mitigated by prophylaxis with either long-acting bisphosphonates or vitamin D and calcium supplementation. In addition, newer antiretrovirals, particularly the integrase strand transfer inhibitors and tenofovir alafenamide (TAF), are associated with less intense bone loss than PIs and TDF. However, further studies are needed to establish optimal bone sparing cART regimens, appropriate screening intervals, and preventive measures to address the rising prevalence of fragility bone disease in the HIV population.

Bone health in HIV and hepatitis B or C infections

Chronic infections with human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) add to age-dependent bone loss and may contribute to lower bone strength in the elderly. In this review, we report recent highlights on the epidemiology of bone fragility in chronic viral infections with HIV, HCV and HBV, its physiopathology and discuss the interference of antiviral therapies with bone metabolism. Chronic infections influence bone through the interactions between risk factors for bone fragility and falls (which are highly prevalent in infected patients), virus activity and antiviral drugs. HIV-infected patients are at increased risk of fracture and the risk is higher in cases of co-infection with HIV and untreated chronic viral hepatitis. In HIV patients, the majority of bone loss occurs during virus activity and at initiation of antiretroviral therapy (ART). However, long-term elderly HIV-infected patients on successful ART display bone microstructure alterations only partially captured by dual energy X-ray absorptiometry (DXA). Bone loss is associated with an increase of bone resorption, reflecting the upregulation of the receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) pathways via a crosstalk between virus activity, inflammation and the immune system. The use of some antiviral drugs, such as tenofovir (controlling both HBV and HIV infections) or protease inhibitors, may be associated with higher bone toxicity. The reduction of tenofovir plasma concentrations with the implementation of tenofovir alafenamide (TAF) attenuates bone mineral density (BMD) loss but it remains unknown whether it will contribute to reducing fracture risk in long-term HIV-treated patients. Moreover, to what extent the new direct-acting agents for treatment of HCV, including nucleotide inhibitors and protease inhibitors, may affect bone health similarly as ART in HIV should be investigated.

HIV infection and bone disease

The success of antiretroviral therapy in treating HIV infection has greatly prolonged life expectancy in affected individuals, transforming the disease into a chronic condition. A number of HIV-associated non-AIDS comorbidities have emerged in the ageing HIV-infected population, including osteoporosis and increased risk of fracture. The pathogenesis of fracture is multifactorial with contributions from both traditional and HIV-specific risk factors. Significant bone loss occurs on initiation of antiretroviral therapy but stabilizes on long-term therapy. Fracture risk assessment should be performed in HIV-infected individuals and bone mineral density measured when indicated. Lifestyle measures to optimize bone health should be advised and, in individuals at high risk of fracture, treatment with bisphosphonates considered.