Early and universal initiation of antiretroviral therapy (ART) among HIV-infected adults has resulted in near normalization of the life expectancy of people living with HIV. Consequently, there has been a marked reduction in AIDS-associated deaths and in AIDS-related malignancies, among other AIDS-associated conditions.1,2 Furthermore, the development of safer ART has markedly reduced the complications of lipoatrophy, hyperlipidemia, lactic acidosis, and renal disease that often complicated treatment in the early ART era. Despite these overall improvements, nearly all ART initiation trials demonstrated a decline in bone mineral density (BMD), most pronounced in the first 48–96 weeks after starting ART.3–5 HIV-infected men and women continue to remain at increased risk for fractures during long-term follow-up, due in part to continued low BMD, low bone quality,6,7 and a high rate of falls.8,9
Data on long-term changes in BMD and clinical factors that impact such changes, particularly among women, are limited. Among 97 HIV-infected participants (86% men) on ART for at least 96 weeks, we found a greater decline in lumbar spine BMD but not hip BMD compared with uninfected controls. Lean mass and concomitant BMD-lowering medications but not HIV-associated characteristics or ART were associated with BMD decline in this cohort, an average of 7.5 years after ART initiation.10 A separate small study of 44 HIV-infected men with at least 3 months of ART found a significantly greater increase in lumbar spine BMD over more than 2 years among HIV-infected men compared with HIV-uninfected controls (5.3% versus 0.3%) and, again, no differences in BMD change at the total hip (−0.6% among HIV-infected versus −1% among HIV-uninfected men). In this cohort, BMD changes did not differ between participants with or without tenofovir disoproxil fumarate (TDF) use.11 A metaanalysis of studies with BMD measurements at least 48 weeks apart found that BMD tended to stabilize or even increase after the first year of ART initiation.3 In the European UPBEAT Study, HIV-infected participants had significant declines in femoral neck and total hip BMD, but these changes did not differ significantly from HIV-uninfected controls. Among HIV-infected participants older than 30 years, being Caucasian, and ART initiation within 3 months or no ART was associated with greater BMD declines in multivariate models.12 Thus, the limited existing data suggest stable rates of BMD change. However, these studies are small and include few women. Therefore, the goals of this study were to compare long-term changes in BMD in a large cohort of HIV-infected men and women and to determine sex-specific risk factors for BMD decline.
The multidisciplinary Modena HIV Metabolic Clinic (MHMC), at the University of Modena and Reggio Emilia, Italy, was initiated in 2004 to assess metabolic changes among people with HIV and has been described elsewhere.13 Participants from the MHMC underwent dual-energy X-ray absorptiometry (DXA) scans approximately every 6–12 months, beginning in 2004. The current study is a longitudinal secondary analysis of existing data. All participants with at least 2 DXA scans were included. In participants starting a bisphosphonate, data were censored at the time of bisphosphonate initiation. All procedures followed were in accordance with the ethical standards of Comitato Etico Provinciale di Modena and with the Helsinki Declaration of 1975, as revised in 2000; all participants provided written informed consent.
Data were collected from the MHMC electronic database. Data on age, sex, smoking (number of cigarettes/day), alcohol consumption (grams of alcohol/day), physical activity [none, mild (<4 hours weekly), and intensive (≥4 hours weekly)], diabetes mellitus (based on self-reported physician's diagnosis and/or use of antidiabetic medications), metabolic syndrome (diagnosed according to the clinical criteria proposed by the NCEP-Adult Treatment Panel III),14 use of testosterone therapy, hypogonadism (defined as serum total testosterone <300 ng/dL),15 and menopausal (defined as estradiol <30 pg/mL + follicular stimulating hormone persistently >30 UI/mL), HIV diagnosis date, risk factors for HIV transmission, nadir CD4 T lymphocyte count, and antiretroviral medications were collected from subjects at enrollment using a structured questionnaire. Body weight was measured using a digital scale to the nearest 0.1 kg with subjects wearing light clothes without shoes. Height was measured using a wall-mounted stadiometer to the nearest 0.1 cm. Measurements for body weight and height were completed in triplicate and the mean recorded. Body mass index (BMI) was defined as the weight (kilograms) divided by the height (meters) squared.
Blood was drawn from all subjects for determination of hepatitis C virus (HCV) antibody (anti-HCV; Abbott HCV EIA 3.0 enzyme immunoassay; Abbott Laboratories), HIV RNA (Abbott RealTime HIV-1 assay; Abbott Laboratories; lower limit of detection: 50 copies/mL), CD4+ T lymphocyte count, and 25-hydroxyvitamin D (DiaSorin 25-hydroxyvitamin D chemiluminescence immunoassay; Stillwater, MN). Vitamin D insufficiency was defined as 25-OH vitamin D level <30 ng/mL. Bone mineral density was measured by DXA at the lumbar spine (L1–L4) and femoral neck. All participants were scanned using the same single densitometer (Hologic Discovery W, Inc., Waltham, MA). The instrument was calibrated daily with a hydroxyapatite phantom. The in vivo coefficients of variation of the DXA measures at the lumbar and femoral sites were less than 2%.
Descriptive statistics were used to characterize the sample. To account for correlation within patients in outcome measures, mixed effect regression models were created assuming compound symmetry variance–covariance structure for combined men and women to determine the sex-adjusted effect and then in sex-stratified models to determine whether factors that are associated with lower BMD differ between men and women. Regression models with random intercept and slope were adjusted for sex (for combined model), and the following time-updated variables: time on study, BMI, total duration of integrase strand transfer inhibitor therapy (INSTI), total duration of TDF, age group by 5-year increments compared with younger than 35 years, self-reported physical activity level as none, moderate, or vigorous, hypogonadism or postmenopausal status, history of AIDS wasting, vitamin D insufficiency, metabolic syndrome, and HCV. Last, we tested the addition of a sex × time interaction term to derive slopes of change by sex. Additional variables were considered for inclusion, but either excluded because of extent of missing data or lack of significance in univariable models (P > 0.10) and included duration of ART, duration of HIV, CD4+ T lymphocyte nadir, current CD4+ T lymphocyte count, total exposure to protease inhibitors, nucleoside/nucleotide reverse transcriptase inhibitor, nonnucleoside reverse transcriptase inhibitor, risk for HIV acquisition, smoking (pack/year), use of testosterone, and diabetes. Stepwise (backward and forward) model selection method was used in building final models. The covariates identified in the combined model were used in the sex-stratified models to examine their association with the outcomes in women and men separately. P value <0.05 was considered statistically significant, and all analyses were conducted using SAS 9.4 (Cary, NC).
At least 2 DXA scans were contributed by 839 women and 1759 men [median number of scans 5 (interquartile range 3–7)], with a median of 4.68 (interquartile range 2.13–7.71) years of follow-up. All participants were Caucasian, most were 50 years and younger (82%) and had HIV-1 RNA ≤50 copies per milliliter (76%) at the initial assessment; 30% of women and 27% of men had HCV coinfection. At baseline, 7% of men had hypogonadism, and 15% of women were postmenopausal, with 24% categorized as postmenopausal during any point after baseline. Additional baseline characteristics by sex are shown in Table 1. Baseline mean BMD was 1.138 (SD 0.120) for total body, 0.833 (SD 0.153) at the femoral neck, and 1.055 (SD 0.168) at the lumbar spine; sex-specific measurements are shown in Table 1.
In combined mixed effect models, femoral but not lumbar spine BMD was significantly lower among women than men (Table 2). Lower femoral neck BMD was also associated with longer TDF exposure, older age (ages 46–50, 51–55, or >55 versus <35 years), no self-reported physical activity, hypogonadism or postmenopausal status, vitamin D insufficiency, and HCV. Longer duration of INSTI, greater BMI, and a higher HIV-1 RNA were associated with higher BMD. Associations with lower lumbar spine BMD were similar, however, only ages 51–55 (versus <35 years) were statistically significant, and both no and moderate (versus intense) physical activities were associated with low BMD, compared to vigorous activity (Table 2).
When we introduced a sex × time interaction term to the model, the adjusted slopes in BMD among women and men were significantly different at both the femoral neck [women −0.00897 (SE 8.85 × 10−4) versus men −0.00422 (SE 8.88 × 10−4) g/cm2 per year; P < 0.001] and L-spine [women −0.0127 (SE 7.60 × 10−4) versus men −0.00763 (SE 9.01 × 10−4) g/cm2 per year; P < 0.001]; Figure 1.
Sex-stratified models (Tables 3 and 4) yielded similar results with a few exceptions: among women, metabolic syndrome was associated with lower lumbar spine BMD (estimate −0.0193, SE 0.0061, P = 0.0025); physical activity was not associated with lumbar spine or femoral neck BMD. Among men, neither lumbar spine nor femoral neck BMD was associated with HCV.
In a large cohort of HIV-infected men and women on long-term ART, BMD at both the femoral neck and lumbar spine, a significant predictor of fracture risk, declined twice as quickly among HIV-infected women compared with men, even after adjusting for other covariates. Notably, most of our study population were younger than 50 years, and only 15% of female participants were menopausal at baseline and 24% during follow-up. Thus, with aging and menopause, the rate of BMD decline among HIV-infected women is expected to be even more pronounced, as suggested by our sex × time differences.
Few studies report long-term changes in BMD among HIV-infected persons, regardless of sex. Compared with both HIV-infected and HIV-uninfected populations, our participants tended to have lower baseline BMD but a similar rate of annual decline. The UPBEAT study of 384 HIV-infected and 474 HIV-uninfected (176 and 210 with multiple DXA scans; median age 39 years, 39% women) reported a median baseline BMD of 1.024 and 1.055 g/cm2 at the femoral neck and 1.164 and 1.238 g/cm2 at the lumbar spine.12 Annual decreases of −0.0063 g/cm2 at the femoral neck and 0.0024 g/cm2 at the lumbar spine for HIV-infected participants were not significantly different from HIV-uninfected controls. Sex-specific rates of decline were not reported, although adjustment for sex minimally affected rates of decline.12 In the AIDS Clinical Trials Group study A5318, hip BMD decreased by 1.56%/year and lumbar spine by 0.76%/year between baseline and week 96, slowing to decreases of 0.31%/year and 0.25%/year, respectively, after week 96. With a small proportion of women (14%), this study lacked statistical power to compare sex-specific rate of BMD change in a meaningful way. Among participants in the Women's Interagency HIV Study (WIHS), BMD decline was similar among premenopausal women regardless of HIV status and accelerated among HIV-infected compared to HIV-uninfected postmenopausal women.16 Rates of decline among postmenopausal women were similar but slightly smaller than changes observed in women in our cohort (LS: −0.010 and FN −0.007).17 Importantly, a markedly increased fracture risk has also been described among postmenopausal versus premenopausal HIV-infected women in multiple studies.17–19
Our large sample size allowed us to explore the impact of risk factors on BMD changes and contrast these effects by sex. Several findings with the potential to impact clinical care should be emphasized: first, age-associated changes in BMD were most pronounced after age 45, even after adjusting for postmenopausal or hypogonadal state, supporting the current HIV guidelines to screen for BMD starting at age 50.20 Next, a protective effect of INSTI therapy (nearly entirely raltegravir use in this cohort) was apparent among both men and women and has been demonstrated in multiple previous studies with raltegravir initiation or switch4,21,22 and in limited data with other INSTIs.23–25 Third, the effect of HCV on BMD was similar to that of 5 additional years of aging and was most significant among the women, as has been reported in previous studies.26,27 Hepatitis C virus is increasingly recognized as an independent risk factor for low BMD, with rates of osteoporosis among HCV-monoinfected individuals ranging 14%–28% and greater losses in BMD seen with increasing liver disease severity.28,29 A recent metaanalysis30 found a 1.63 greater odds of osteoporosis with HCV/HIV coinfection versus HIV infection alone and a 1.77 greater odds for fracture with HCV/HIV coinfection versus HIV infection alone. The impact of direct-acting HCV therapies on BMD after eradication of HCV is currently not known but may prove to be an effective (albeit costly) treatment intervention to preserve BMD with aging, particularly among HIV/HCV coinfected women.28
The protective effects of increased BMI and detrimental effect of AIDS wasting were expected31,32 and, in our cohort, were independent of a protective effect of moderate or vigorous physical activity. Several previous studies among HIV-infected adults have demonstrated that lean body mass is the BMI component with the most protective effect on BMD.10,33 Notably, although physical activity is a well-established intervention to attenuate bone loss with aging, regular physical activity (with the exceptions of high-intensity loading or resistance exercise) seldom reverses BMD loss, especially among postmenopausal women or hypogonadal men.34 We do suspect that the association with metabolic syndrome but not physical activity among the women and the opposite among men may reflect colinearity with these variables, such that metabolic syndrome effects were attenuated by exercise among the men. Our finding of greater BMD with higher HIV-1 RNA likely reflects greater BMD seen before ART initiation. Last, the loss of an age association among men at the lumbar spine and loss of significance within some age categories at the femoral spine is notable and emphasizes that much of the age-associated declines in this population are explained by changes that occur in the women, likely driven, in part, by the menopausal transition period.
Several important strengths and limitations of the analysis should be recognized. Foremost, the large number of participants, with nearly 50% women, in addition to the extent of DXA follow-up, surpasses any previous published data on BMD trajectories among HIV-infected adults. The Modena Cohort is, however, a large clinical database and is subject to missing data and variability in timing and frequency of DXA ascertainment. The cohort reflects the racial/ethnic background of Italy and may not be generalizable to more diverse populations. Surprisingly, low rates of alcohol use may suggest underreporting of some substances, which may have limited our ability to detect additional important associations with BMD. Last, without an HIV-uninfected comparison group, we cannot determine whether the slopes that we found are accelerated or consistent with normal aging.
In the largest and longest study of BMD changes among HIV-infected men and women to date, we have found nearly double the rate of BMD decline among HIV-infected women compared with HIV-infected men, with rates of BMD decline among HIV-infected men mirroring findings of smaller, previously published cohorts.10,12 Our results highlight BMD losses among women, independent of menopause, effects that require future consideration with ART selection, particularly when prioritizing switch from TDF to tenofovir alafenamide. Several modifiable risk factors provide potential targets for intervention to slow decline including treatment of HCV, replacement of vitamin D, consideration for hormone replacement if the benefits outweigh the risks, augmenting a low BMI, and moderate to vigorous activity, likely including resistance training. Importantly, low BMD is one of the several risk factors for fracture. Therefore, the interventions likely to have the greatest impact in this aging population are those that both attenuate BMD losses and minimize fracture risk through reduced falls.35
1. Lima VD, Lourenco L, Yip B, et al. AIDS incidence and AIDS-related mortality in British Columbia, Canada, between 1981 and 2013: a retrospective study. Lancet HIV
2. Smith CJ, Ryom L, Weber R, et al. Trends in underlying causes of death in people with HIV
from 1999 to 2011 (D: A:D): a multicohort collaboration. Lancet. 2014;384:241–248.
3. Bolland MJ, Wang TK, Grey A, et al. Stable bone density in HAART-treated individuals with HIV
: a meta-analysis. J Clin Endocrinol Metab. 2011;96:2721–2731.
4. Brown TT, Moser C, Currier JS, et al. Changes in bone mineral density
after initiation of antiretroviral treatment with tenofovir disoproxil fumarate/emtricitabine plus atazanavir/ritonavir, darunavir/ritonavir, or raltegravir. J Infect Dis. 2015;212:1241–1249.
5. Arribas JR, Thompson M, Sax PE, et al. Brief report: randomized, double-blind comparison of tenofovir alafenamide (TAF) vs tenofovir disoproxil fumarate (TDF), each coformulated with elvitegravir, cobicistat, and emtricitabine (E/C/F) for initial HIV
-1 treatment: week 144 results. J Acquir Immune Defic Syndr. 2017;75:211–218.
6. Guerri-Fernandez R, Molina-Morant D, Villar-Garcia J, et al. Bone density, microarchitecture and tissue quality following long-term treatment with tenofovir/emtricitabine or abacavir/lamivudine. J Acquir Immune Defic Syndr. 2017.
7. Sellier P, Ostertag A, Collet C, et al. Disrupted trabecular bone micro-architecture in middle-aged male HIV
-infected treated patients. HIV
8. Erlandson KM, Allshouse AA, Jankowski CM, et al. Risk factors for falls in HIV
-infected persons. J Acquir Immune Defic Syndr. 2012;61:484–489.
9. Erlandson KM, Plankey MW, Springer G, et al. Fall frequency and associated factors among men and women
with or at risk for HIV
10. Grant PM, Kitch D, McComsey GA, et al. Long-term bone mineral density
changes in antiretroviral-treated HIV
-infected individuals. J Infect Dis. 2016;214:607–611.
11. Bolland MJ, Grey A, Horne AM, et al. Stable bone mineral density
over 6 years in HIV
-infected men treated with highly active antiretroviral therapy (HAART). Clin Endocrinol. 2012;76:643–648.
12. Tinago W, Cotter AG, Sabin CA, et al. Predictors of longitudinal change in bone mineral density
in a cohort of HIV
-positive and negative patients. AIDS. 2017;31:643–652.
13. Guaraldi G, Orlando G, Squillace N, et al. Multidisciplinary approach to the treatment of metabolic and morphologic alterations of HIV
-related lipodystrophy. HIV
Clin Trials. 2006;7:97–106.
14. Expert Panel on Detection E, Treatment of High Blood Cholesterol in Adults. Executive summary of the third report of the national cholesterol education program (NCEP) expert Panel on detection, evaluation, and treatment of high blood cholesterol in adults (adult treatment Panel III). JAMA. 2001;285:2486–2497.
15. Rochira V, Guaraldi G. Hypogonadism in the HIV
-infected man. Endocrinol Metab Clin North Am. 2014;43:709–730.
16. Cortes YI, Yin MT, Reame NK. Bone density and fractures in HIV
-infected postmenopausal women
: a systematic review. J Assoc Nurses AIDS Care. 2015;26:387–398.
17. Sharma A, Cohen HW, Freeman R, et al. Prospective evaluation of bone mineral density
among middle-aged HIV
-infected and uninfected women
: association between methadone use and bone loss. Maturitas. 2011;70:295–301.
18. Sharma A, Shi Q, Hoover DR, et al. Increased fracture incidence in middle-aged HIV
-infected and HIV
: updated results from the Women
's interagency HIV
study. J Acquir Immune Defic Syndr. 2015;70:54–61.
19. Jacobson DL, Spiegelman D, Knox TK, et al. Evolution and predictors of change in total bone mineral density
over time in HIV
-infected men and women
in the nutrition for healthy living study. J Acquir Immune Defic Syndr. 2008;49:298–308.
20. McComsey GA, Tebas P, Shane E, et al. Bone disease in HIV
infection: a practical review and recommendations for HIV
care providers. Clin Infect Dis. 2010;51:937–946.
21. Bernardino JI, Mocroft A, Mallon PW, et al. Bone mineral density
and inflammatory and bone biomarkers after darunavir-ritonavir combined with either raltegravir or tenofovir-emtricitabine in antiretroviral-naive adults with HIV
-1: a substudy of the NEAT001/ANRS143 randomised trial. Lancet HIV
22. Curran A, Martinez E, Saumoy M, et al. Body composition changes after switching from protease inhibitors to raltegravir: SPIRAL-LIP substudy. AIDS. 2012;26:475–481.
23. Negredo E, Estrada V, Domingo P, et al. Switching from a ritonavir-boosted PI to dolutegravir as an alternative strategy in virologically suppressed HIV
-infected individuals. J Antimicrob Chemother. 2017;72:844–849.
24. Tebas P, Kumar P, Hicks C, et al. Greater change in bone turnover markers for efavirenz/emtricitabine/tenofovir disoproxil fumarate versus dolutegravir + abacavir/lamivudine in antiretroviral therapy-naive adults over 144 weeks. AIDS. 2015;29:2459–2464.
25. Trottier B, Lake JE, Logue K, et al. Dolutegravir/abacavir/lamivudine versus current ART in virally suppressed patients (STRIIVING): a 48-week, randomized, non-inferiority, open-label, Phase IIIb study. Antivir Ther. 2017;22:459–460.
26. Lawson-Ayayi S, Cazanave C, Kpozehouen A, et al. Chronic viral hepatitis is associated with low bone mineral density
-infected patients, ANRS CO 3 Aquitaine Cohort. J Acquir Immune Defic Syndr. 2013;62:430–435.
27. Lo Re V III, Guaraldi G, Leonard MB, et al. Viral hepatitis is associated with reduced bone mineral density
but not men. AIDS. 2009;23:2191–2198.
28. Yin MT, Brown TT. HIV
and bone complications: understudied populations and new management strategies. Curr HIV
/AIDS Rep. 2016;13:349–358.
29. Bedimo R, Maalouf NM, Lo Re V III. Hepatitis C virus
coinfection as a risk factor for osteoporosis
and fracture. Curr Opin HIV
30. Dong HV, Cortes YI, Shiau S, et al. Osteoporosis
and fractures in HIV
/hepatitis C virus
coinfection: a systematic review and meta-analysis. AIDS. 2014;28:2119–2131.
31. Fairfield WP, Finkelstein JS, Klibanski A, et al. Osteopenia in eugonadal men with acquired immune deficiency syndrome wasting syndrome. J Clin Endocrinol Metab. 2001;86:2020–2026.
32. Huang JS, Wilkie SJ, Sullivan MP, et al. Reduced bone density in androgen-deficient women
with acquired immune deficiency syndrome wasting. J Clin Endocrinol Metab. 2001;86:3533–3539.
33. Erlandson KM, Kitch D, Tierney C, et al. Weight and lean body mass change with antiretroviral initiation and impact on bone mineral density
. AIDS. 2013;27:2069–2079.
34. Kohrt WM, Bloomfield SA, Little KD, et al. American College of Sports M. American College of Sports medicine position stand: physical activity and bone health. Med Sci Sports Exerc. 2004;36:1985–1996.
35. Erlandson KM, Guaraldi G, Falutz J. More than osteoporosis
: age-specific issues in bone health. Curr Opin HIV