Association of chronotropic incompetence with reduced cardiorespiratory fitness in older adults with HIV

OBJECTIVE

Understanding the physiological drivers of reduced cardiorespiratory fitness in people with HIV (PWH) will inform strategies to optimize healthspan. Chronotropic incompetence is common in heart failure and associated with low cardiorespiratory fitness yet is understudied in PWH. The objective was to determine the prevalence of chronotropic incompetence and its relationship with cardiorespiratory fitness.

DESIGN

Participants were PWH at least 50 years of age with no prior history of heart failure or coronary heart disease who were enrolled in a randomized exercise trial. Baseline cardiopulmonary exercise testing (CPET) was used to measure cardiorespiratory fitness as peak oxygen consumption (VO2peak) and calculate the chronotropic index from heart rate values. Chronotropic incompetence was defined as an index less than 80%.

RESULTS

The 74 participants were on average 61 years old, 80% Black or African American, and 93% men. Chronotropic incompetence was present in 31.1%. VO2peak was significantly lower among participants with chronotropic incompetence compared with participants without chronotropic incompetence [mean (SD) ml/min/kg: 20.9 (5.1) vs. 25.0 (4.5), P = 0.001]. Linear regression showed that chronotropic incompetence and age were independent predictors of VO2peak, but smoking and comorbidity were not. The chronotropic index correlated with VO2peak (r = 0.48, P < 0.001).

CONCLUSION

Among older PWH without heart failure or coronary heart disease, chronotropic incompetence was present in approximately one-third of individuals and was associated with clinically relevant impaired cardiorespiratory fitness. Investigation of chronotropic incompetence in large cohorts which includes PWH and heart failure may contribute to strategies that promote healthy aging with HIV infection and offer a preclinical window for intervention.

Combining Charlson comorbidity and VACS indices improves prognostic accuracy for all-cause mortality for patients with and without HIV in the Veterans Health Administration

Introduction

As people age with HIV (PWH), many comorbid diseases are more common than among age matched comparators without HIV (PWoH). While the Veterans Aging Cohort (VACS) Index 2.0 accurately predicts mortality in PWH using age and clinical biomarkers, the only included comorbidity is hepatitis C. We asked whether adding comorbid disease groupings from the Charlson Comorbidity Index (CCI) improves the accuracy of VACS Index.

Methods

To maximize our ability to model mortality among older age groups, we began with PWoH in Veterans Health Administration (VA) from 2007-2017, divided into development and validation samples. Baseline predictors included age, and components of CCI and VACS Index (excluding CD4 count and HIV RNA). Patients were followed until December 31, 2021. We used Cox models to develop the VACS-CCI score and estimated mortality using a parametric (gamma) survival model. We compared accuracy using C-statistics and calibration curves in validation overall and within subgroups (gender, age

Results

The analytic sample consisted of 6,588,688 PWoH and 30,539 PWH. Among PWoH/PWH, median age was 65/55 years; 6%/3% were women; 15%/48% were Black and 5%/7% Hispanic. VACS-CCI provided the best discrimination (C-statistic = 0.81) with excellent calibration (predicted and observed mortality largely overlapped) overall and within subgroups. When VACS-CCI was applied to PWH it demonstrated similar discrimination as VACS Index 2.0 (C-statistic = 0.77 for both) but superior calibration among those with CD4 < 200. Discrimination was improved when CD4 and HIV RNA were added VACS-CCI (C-statistic = 0.79). Liver and kidney disease, congestive heart failure, malignancy, and dementia were negatively associated with CD4 (p-trends all <0.0001).

Discussion

Among PWH and PWoH in VA care, age alone weakly discriminates risk of mortality. VACS Index 2.0, CCI, and VACS-CCI all provide better discrimination, but VACS-CCI is more consistently calibrated. The association of comorbid diseases with lower CD4 underscores the likely role of HIV in non-AIDS conditions. Future work will include adding CD4 and HIV RNA to VACS-CCI and validating it in independent data.

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Key Words

• Charlson Comorbidity Index
• HIV
• VACS Index
• mortality
• prediction

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Affiliation(s)

Kathleen A. McGinnis VA Connecticut Healthcare System, West Haven, CT, United States
Amy C. Justice VA Connecticut Healthcare System, West Haven, CT, United States Yale School of Medicine, New Haven, CT, United States
Vincent C. Marconi The Atlanta Veterans Affairs Medical Center, Emory University School of Medicine and Rollins School of Public Health, Atlanta, GA, United States VA Medical Center, Decatur, GA, United States
Maria C. Rodriguez-Barradas Infectious Diseases Section, Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, United States Department of Medicine, Baylor College of Medicine, Houston, TX, United States
Ronald G. Hauser VA Connecticut Healthcare System, West Haven, CT, United States Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT, United States
Krisann K. Oursler Department of Internal Medicine, Virginia Tech Carilion School of Medicine, Roanoke, VA, United States VA Salem Healthcare System, Salem, VA, United States
Sheldon T. Brown James J. Peters VA Medical Center, Bronx, NY, United States
Kendall J. Bryant National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
Janet P. Tate VA Connecticut Healthcare System, West Haven, CT, United States Yale School of Medicine, New Haven, CT, United States
for the Veterans Aging Cohort Study

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Healthy aging: Linking causal mechanisms with holistic outcomes

Identifying and understanding the impact of differing exposures over the lifecourse necessitates contextualizing different levels of influence ranging from genetics, epigenetics, geography, and psychosocial networks.

Update in Human Immunodeficiency Virus and Aging

Effective and consistent antiretroviral therapy has enabled people with human immunodeficiency virus (HIV) (PWH) to survive longer than previously encountered earlier in the epidemic. Consequently, PWH are subject to the struggles and clinical conditions typically associated with aging. However, the aging process in PWH is not the same as for those who do not have HIV. There is a complex interplay of molecular, microbiologic, and pharmacologic factors that leads to accelerated aging in PWH; this leads to increased risk for certain age-related comorbidities requiring greater vigilance and interventions in routine care.

Epigenetic Age Acceleration Markers Are Associated With Physiologic Frailty and All-Cause Mortality in People With Human Immunodeficiency Virus

BACKGROUND

Biomarkers that provide insight into drivers of aging are needed for people with human immunodeficiency virus (PWH). The study objective was to determine if epigenetic age acceleration (EAA) markers are associated with physiologic frailty measured by the Veterans Aging Cohort Study (VACS) Index and predict all-cause mortality for PWH.

METHODS

Epigenome-wide DNA methylation was profiled in VACS total white blood cell samples collected during 2005-2007 from 531 PWH to generate 6 established markers of EAA. The association of each EAA marker was tested with VACS Index 2.0. All-cause mortality was assessed over 10 years. For each EAA marker, the hazard ratio per increased year was determined using Cox regression. To evaluate mortality discrimination, C-statistics were derived.

RESULTS

Participants were mostly men (98.5%) and non-Hispanic Black (84.4%), with a mean age of 52.4 years (standard deviation [SD], 7.8 years). Mean VACS Index score was 59.3 (SD, 16.4) and 136 deaths occurred over a median follow-up of 8.7 years. Grim age acceleration (AA), PhenoAA, HannumAA, and extrinsic epigenetic AA were associated with the VACS Index and mortality. HorvathAA and intrinsic epigenetic AA were not associated with either outcome. GrimAA had the greatest mortality discrimination among EAA markers and predicted mortality independently of the VACS Index. One-year increase in GrimAA was associated with a 1-point increase in VACS Index and a 10% increased hazard for mortality.

CONCLUSIONS

The observed associations between EAA markers with physiologic frailty and mortality support future research to provide mechanistic insight into the accelerated aging process and inform interventions tailored to PWH for promoting increased healthspan.

Biological ageing with HIV infection: evaluating the geroscience hypothesis

Although people with HIV are living longer, as they age they remain disproportionately burdened with multimorbidity that is exacerbated in resource-poor settings. The geroscience hypothesis postulates that a discrete set of between five and ten hallmarks of biological ageing drive multimorbidity, but these processes have not been systematically examined in the context of people with HIV. We examine four major hallmarks of ageing (macromolecular damage, senescence, inflammation, and stem-cell dysfunction) as gerodrivers in the context of people with HIV. As a counterbalance, we introduce healthy ageing, physiological reserve, intrinsic capacity, and resilience as promoters of geroprotection that counteract gerodrivers. We discuss emerging geroscience-based diagnostic biomarkers and therapeutic strategies, and provide examples based on recent advances in cellular senescence, and other, non-pharmacological approaches. Finally, we present a conceptual model of biological ageing in the general population and in people with HIV that integrates gerodrivers and geroprotectors as modulators of homoeostatic reserves and organ function over the lifecourse.

Telehealth Exercise Intervention in Older Adults With HIV: Protocol of a Multisite Randomized Trial

ABSTRACT

People with HIV (PWH) have reduced cardiorespiratory fitness, but a high intensity, easily disseminated exercise program has not yet been successfully developed in older PWH. The purpose of this article is to describe a synchronous telehealth exercise intervention in older PWH, delivered from one medical center to two other centers. Eighty older PWH (≥50 years) on antiretroviral therapy will be randomized to exercise or delayed entry control groups. Functional circuit exercise training, which does not entail stationary equipment, will be provided by real-time videoconferencing, 3 times weekly for 12 weeks, to small groups. Continuous remote telemonitoring of heart rate will ensure high exercise intensity. We hypothesize that telehealth exercise will be feasible and increase cardiorespiratory fitness and reduce sarcopenia and frailty. Findings will provide new insight to target successful aging in older PWH and can also be widely disseminated to PWH of any age or other patient populations.

Assessing Moderate to Vigorous Physical Activity in Older Adults: Validity of a Commercial Activity Tracker

Purpose: Despite the potential for commercial activity devices to promote moderate to vigorous physical activity (MVPA), limited information is available in older adults, a high-priority target population with unique gait dynamics and energy expenditure. The study purpose was to investigate the content validity of the Garmin Vivosmart HR device for step counts and MVPA in adults ≥65 years of age in free-living conditions. Methods: Thirty-five participants (M age= 73.7 (6.3) years) wore Garmin and ActiGraph GT3X+ devices for a minimum of 2 days. Accuracy and intra-person reliability were tested against a hip worn ActiGraph device. Separate analyses were conducted using different accelerometer cut-off values to define MVPA, a population-based threshold (≥2,020 counts/minute) and a recommended threshold for older adults (≥1,013 counts/minute). Results: Overall, the Garmin device overestimated MVPA compared with the hip-worn ActiGraph. However, the difference was small using the lower, age-specific, MVPA cut-off value [median (IQR) daily minutes; 50(85) vs. 32(49), p = 0.35] in contrast to the normative standard (50(85) vs. 7(24), p < 0.001). Regardless of the MVPA cut-off, intraclass correlation showed poor reliability [ICC (95% CI); 0.16(-0.40, 0.55) to 0.35(-0.32, 0.7)] which was supported by Bland-Altman plots. Garmin step count was both accurate (M step difference: 178.0, p = 0.22) and reliable [ICC (95% CI; 0.94) (0.88, 0.97)]. Conclusion: Results support the accuracy of a commercial activity device to measure MVPA in older adults but further research in diverse patient populations is needed to determine clinical utility and reliability over time.

Polypharmacy and frailty among persons with HIV

Polypharmacy is associated with frailty in the general population, but little is known about polypharmacy among persons living with HIV (PLWH) on antiretroviral (ARV) therapy. We determined the association between polypharmacy and an adapted frailty-related phenotype (aFRP) via a cross-sectional study in FY 2009 of 1762 PLWH on ARV with suppressed viral load and 2679 uninfected participants in the Veterans Aging Cohort Study. The primary predictor was number of chronic outpatient non-ARV medications using pharmacy fill/refill data. The outcome was self-report of four aFRP domains: shrinking, exhaustion, slowness, low physical activity. Frailty was defined as reporting 3-4 domains while pre-frailty was 1-2. Frailty was uncommon (2% PLWH, 3% uninfected); a larger proportion demonstrated any aFRP domain (31% PLWH, 41% uninfected). Among PLWH and uninfected, median chronic non-ARV medications was 6 and 16 respectively if having any aFRP domain, and 4 and 10 when without aFRP domains. In adjusted analyses, each additional chronic non-ARV medication conferred an 11% increased odds of having any aFRP domain in PLWH (OR [95% CI] = 1.11 [1.08, 1.14]), and a 4% increase in those uninfected (OR [95% CI] = 1.04 [1.03, 1.04]). The stronger association between polypharmacy and frailty in PLWH warrants further study and potential deprescribing of medications.

Pilot study of functional circuit exercise in older adults

Sustainable exercise strategies are needed for older adults to maintain aerobic capacity and strength. The objective of this pilot in 6 adults ≥ 65 years of age was to determine the feasibility and preliminary efficacy of high-intensity functional circuit training which does not require stationary equipment. Instructor-led small group exercise classes were held 3x/week for 12 weeks using weight-bearing exercises performed in a circuit format at ratings of perceived exertion (RPE) of 6-8/10. All 6 participants completed the pilot and showed significant improvements by the Wilcoxon signed-rank test. The six-minute walk distance increased 10.5%. Timed arm curl and chair stands increased 26.8% and 30.3% (all p ≤ 0.03). These preliminary findings suggest that high-intensity functional circuit exercise is feasible in older adults and increases functional measures of aerobic capacity and strength. Further research is warranted to develop this strategy which has the potential for broad dissemination without the need for a traditional exercise facility.

Feasibility and effects of high-intensity interval training in older adults living with HIV

Adults with HIV on therapy can live a normal lifespan but exhibit advanced ageing which includes reduced cardiorespiratory fitness. Our objective was to determine the feasibility and effects of high-intensity interval training (HIIT) combined with resistance training (RT) in older adults with HIV. We conducted a cross-over pilot study within a randomized exercise trial in sedentary adults with HIV ≥50 years of age. First, participants were randomized to 4 months of continuous high-intensity aerobic exercise (AEX) and RT 3x/week or standard of care control. Then, the control group completed 4 months of HIIT + RT (3x/week). Among the 32 individuals enrolled, 26 eligible participants were randomized. Most participants were African American (63%) and male (95%) with a mean (SD) age of 61.5 (6.7) years and VO₂peak of 24.5 (4.9) ml/kg/min. Attendance and adherence to both exercise training interventions were high. The clinically significant increases in VO₂peak (ml/kg/min) after HIIT (3.09 ±1.04, p=0.02) and AEX (2.09 ±0.72, p=0.01) represented improvements of 17.1% and 7.7%, respectively. Both groups had improvements in exercise endurance (time on the treadmill) and strength (all p< 0.01). This pilot study supports HIIT as an efficient means to deliver high-intensity AEX to improve cardiorespiratory fitness toward the goal of attenuating the accelerated ageing process in adults with HIV.

Gait and Balance Biomechanics in Older Adults With and Without Human Immunodeficiency Virus

Balance deficits impose limitations and can impede safe walking contributing to falls and falls-related complications. The objective of this study was to perform an in-depth balance assessment and compare domains of limitations in older men with and without HIV infection. Fifteen sedentary African American men either with HIV (n = 6) or without HIV (n = 9 controls) participated. Standing balance was assessed under quiet stance on dual synchronized force plates during three 30 s trials with eyes open. Participants also completed standardized clinical instruments of balance, including the Berg Balance Scale (BBS) and Dynamic Gait Index (DGI). Older participants with HIV have lower BBS and DGI scores than controls (both p < .05). Adults with HIV have nearly twice the magnitude greater center of pressure (COP) sway variability than controls (1.42 ± 1.20 cm² vs. 0.71 ± 0.1 cm², p < .05). These data demonstrating differences in COP sway area between groups may further support evidence of potential fall risk and contribute to frailty in older adults with HIV.

Short Communication: Low Muscle Mass Is Associated with Osteoporosis in Older Adults Living with HIV

Sarcopenia, age-related low muscle mass and function, is a well-established independent risk factor for bone fracture in the geriatric population but is understudied in older people living with HIV (PLWH). The objective of this cross-sectional study was to investigate in older PLWH the relationship between muscle mass and bone mineral density (BMD). Sedentary PLWH who were ≥50 years of age, receiving antiretroviral therapy, and enrolled in an exercise intervention trial were included. Established definitions for sarcopenia and osteopenia/osteoporosis were applied to muscle mass data and BMD collected by dual-energy X-ray absorptiometry before exercise training. Participants were 93% male and 33% Caucasian race with median age 61 years, and median CD4 lymphocytes 707 cells/μL. The majority (64%) were overweight and obese by body mass index. Appendicular skeletal muscle index (ASMI) correlated with BMD at the femoral neck (r = 0.49, p < .01), total hip (r = 0.54, p < .01), and lumbar spine (r = 0.48, p < .05). Low BMD at the femoral neck was present in 39% (26% osteopenia, 13% osteoporosis). ASMI was lower among those with low BMD compared with normal BMD (p = .02). Low muscle mass measured by ASMI is associated with low BMD in clinically stable older PLWH. Detailed body composition assessment may help guide lifestyle recommendations to prevent bone fractures in older PLWH.

Adapting the "Resist Diabetes" Resistance Training Intervention for Veterans

PURPOSE

The Resist Diabetes trial demonstrated that twice-per-week resistance training reduced prediabetes prevalence and improved strength among older adults with prediabetes. Our objective was to determine initial perceptions of patients and care providers in a Veterans Affairs Medical Center (VAMC) regarding Resist Diabetes (RD), and ultimately, inform adaptations to improve uptake of RD in the Veterans Health Administration.

METHODS

A mixed-methods approach was utilized. Care providers (n=20) and veterans with prediabetes (n=12) were recruited to gauge perceptions of the RD program and identify barriers and facilitators to the program referral process and program implementation. Care provider perceptions of the acceptability, appropriateness and feasibility were determined using a validated survey. Open-ended questionnaires and interview guides, based upon the Consolidated Framework for Implementation Research, were utilized to determine major and minor themes within the provider and veteran responses. To identify the dissemination potential of RD, the availability of onsite fitness facilities at VAMC facilities nationally (n=159) was assessed.

RESULTS

Providers rated (scaled 1-5; 1=completely disagree, 5=completely agree) the RD program as appealing (4.8+/-0.1), appropriate (4.8+/-0.0), and feasible (4.6+/-0.2). Providers reported that prediabetes/diabetes is a significant problem in the VAMC, and that different prevention programs will appeal to different types of VAMC patients. Patients (n=12; 58% female; aged 65+/-10yrs; BMI 34+/-6 kg/m²; HbA1c 5.7+/-1.8%) expressed interest in an exercise-focused diabetes prevention program and defined key barriers: travel, transportation, and time constraints. Among the responding national VAMC sites, 85% (97/114) reported having an onsite fitness facility.

CONCLUSION

Salem VAMC care providers and veteran patients demonstrated positive perceptions of the Resist Diabetes program. Program adaptations are needed to address barriers to patient participation including travel, transportation and time constraints.

Rapid Transition to Telehealth Group Exercise and Functional Assessments in Response to COVID-19

Exercise is critical for health maintenance in late life. The COVID-19 shelter in place and social distancing orders resulted in wide-scale interruptions of exercise therapies, placing older adults at risk for the consequences of decreased mobilization. The purpose of this paper is to describe rapid transition of the Gerofit facility-based group exercise program to telehealth delivery. This Gerofit-to-Home (GTH) program continued with group-based synchronous exercise classes that ranged from 1 to 24 Veterans per class and 1 to 9 classes offered per week in the different locations. Three hundred and eight of 1149 (27%) Veterans active in the Gerofit facility-based programs made the transition to the telehealth delivered classes. Participants' physical performance testing continued remotely as scheduled with comparisons between most recent facility-based and remote testing suggesting that participants retained physical function. Detailed protocols for remote physical performance testing and sample exercise routines are described. Translation to remote delivery of exercise programs for older adults could mitigate negative health effects.

Association of Diastolic Dysfunction with Reduced Cardiorespiratory Fitness in Adults Living with HIV

Despite the high prevalence of diastolic dysfunction in adults living with HIV, the impact on cardiorespiratory fitness (CRF) is understudied. The objective of this cross-sectional study was to investigate the relationship between cardiac function and CRF in adults with HIV. Adults receiving antiretroviral therapy with no history of coronary artery disease (CAD) or heart failure were eligible to participate. Cardiac function was assessed by resting Doppler echocardiography. CRF was measured by oxygen utilization at peak exercise (VO₂peak). The majority of participants were African American (86%) and male (97%) with a mean [standard deviation (SD)] age of 56.6 (7.1) years and median CD4 lymphocyte count of 492 cells/mL. The mean (SD) VO₂peak was 26.1 (5.5) mL/(kg·min). Age, diabetes, hypertension, and hemoglobin were associated with VO₂peak. Overall, diastolic dysfunction was present in 38% and was associated with lower VO₂peak (p < 0.05). VO₂peak was lower among those with impaired myocardial relaxation (e' <8 cm/s) compared with normal relaxation [mean ± SE mL/(kg·min), 25.2 ± 0.6 vs. 27.7 ± 0.9, p < 0.05]. Adjusted for age and clinical factors, each unit increase in left ventricular relaxation (E/A) was associated with an average 4.4 mL/(kg·min) higher VO₂peak, representing more than one metabolic equivalent. We conclude that diastolic dysfunction is independently associated with clinically significant low CRF in adults with HIV and no history of CAD or heart failure. These results highlight the importance of recognizing diastolic dysfunction in individuals living with HIV regardless of their cardiovascular disease history.

The effect of isolated nocturnal oxygen desaturations on serum hs-CRP and IL-6 in patients with chronic obstructive pulmonary disease

INTRODUCTION

A majority of patients with chronic obstructive pulmonary disease (COPD) die of cardiovascular disease (CVD), yet the mechanisms responsible for this association are not fully understood. It remains unknown if isolated nocturnal oxygen desaturation (iNOD) could be one of the potential pathways by which the 'inflammatory COPD' phenotype leads to CVD.

OBJECTIVES

We aimed to evaluate if COPD patients who meet the Medicare guidelines for nocturnal oxygen therapy (iNOT+) had higher serum hs-CRP and IL-6 than those who did not meet the guidelines for iNOT (iNOT-).

METHODS

Patients with moderate to severe COPD (ie FEV1 < 80% and FEV1/FVC < 70), who were not on oxygen, underwent nocturnal oximetry on room air. Serum IL-6 and hs-CRP were collected the morning after the nocturnal oximetry testing.

RESULTS

A total of 28 patients were included in the study, 8 of whom had more than 5 minutes and 5% of their sleep time spent at oxygen saturation less than 88% and constituted the iNOT+ group. Only serum hs-CRP was significantly higher in iNOT+ than iNOT- (P = 0.050). There was no difference in the rate of COPD exacerbations at one and three months, or five-year survival between the groups (P > 0.3).

CONCLUSION

COPD patients who have more than 5 minutes and 5% of their sleep time spent at oxygen saturation less than 88% have increased hs-CRP, which is associated with increased risk of future CVD.

Providing Rural Veterans With Access to Exercise Through Gerofit

Clinical video telehealth can be used to deliver functional circuit exercise training to older veterans in remote locations.

A pilot randomized aerobic exercise trial in older HIV-infected men: Insights into strategies for successful aging with HIV

BACKGROUND

HIV-infected adults have increased risk for age-related diseases and low cardiorespiratory fitness that can be prevented and improved with exercise. Yet, exercise strategies have not been well studied in older adults with HIV and may require substantial adaptation to this special population.

OBJECTIVE

To determine the safety and efficacy of aerobic exercise in older HIV-infected men in a randomized trial comparing different levels of exercise intensity.

METHODS

We conducted a pilot exercise trial in 22 HIV-infected men ≥50 years of age receiving antiretroviral therapy who were randomized 1:1 to moderate-intensity aerobic exercise (Mod-AEX) or high-intensity aerobic exercise (High-AEX) that was performed three times weekly for 16 weeks in a supervised setting. Primary outcome was cardiorespiratory fitness (VO2peak) measured by treadmill testing. Secondary outcomes were exercise endurance, six-minute walk distance (6-MWD), body composition measured by Dual-energy X-ray absorptiometry (DXA), and fasting plasma levels of lipids and glucose.

RESULTS

VO2peak increased in the High-AEX group (3.6 ±1.2 mL/kg/min, p = 0.02) but not in the Mod-AEX group (0.4 ±1.4 mL/kg/min, p = 0.7) with a significant between group difference (p<0.01). Exercise endurance increased in both the High-AEX group (27 ±11%, p = 0.02) and the Mod-AEX group (11 ±4%, p = 0.04). The 6-MWD increased in both the High-AEX (62 ±18m, p = 0.01) and the Mod-AEX group (54 ±14m, p = 0.01). Changes in VO2peak and 6-MWD were clinically relevant. There were no serious exercise-related adverse events. Dropouts were similar between group (27% overall) and were related to joint pain.

CONCLUSIONS

This pilot exercise trial demonstrates that moderate to high-intensity aerobic exercise in older HIV-infected men increases endurance and ambulatory function. However, increased cardiorespiratory fitness was observed only with high-intensity aerobic exercise despite substantial baseline impairment. Future research is needed to determine exercise strategies in older HIV-infected adults that address advanced aging and comorbidity yet are durable and feasible.

Greater Depressive Symptoms and Higher Viral Load Are Associated with Poor Physical Function among Latino Men Living with HIV

Physical function limitations have been associated with poor health outcomes, which have a negative impact on quality of life of older individuals. This study examined the association between depression, viral load, and acculturation with physical function among Latino men living with HIV. A secondary data analysis was performed using a cross-sectional data of 146 Latino immigrant men living with HIV in New York City and Washington, DC. Physical function was measured using the Short-Form Health Survey (SF-12). Uncontrolled HIV infection and depression were associated with worse physical function, thus implying the importance of adequate health care to address these conditions. Preserving physical function should start during middle adulthood, particularly among people living with HIV because of their greater risk of developing age-related challenges such as depression, diabetes, cardiovascular diseases among others. This study informs future interventions to preserve physical function and achieve the goal of successful aging.

HIV infection, antiretroviral therapy initiation and longitudinal changes in biomarkers of organ function

BACKGROUND

HIV is associated with end-organ diseases of aging via unclear mechanisms. Longitudinally assessing how HIV infection and ART initiation affect biomarkers of end organ function/disease could clarify these mechanisms. We investigated longitudinal changes in clinical biomarkers following 1) HIV infection and 2) ART initiation with evidence of viral suppression.

METHODS

COHORT

Veterans Aging COHORT Study Virtual COHORT (VACS VC). VACS VC is a longitudinal cohort of HIV infected (HIV+) and race-ethnicity, sex, age, and clinical site-matched uninfected Veterans enrolled in the same calendar year.

INCLUSION CRITERIA

a negative and successively positive (>six months) HIV antibody test. We used Wilcoxon signedrank tests to analyze 1) the effect of HIV infection on lipids, renal, hepatic and hematologic/cardiovascular biomarkers and 2)whether ART initiation with HIV-1 RNA<500 cpm reverts any changes back to pre-HIV levels.

RESULTS

422 Veterans had at least 1 biomarker measurement available prior to HIV infection and prior to ART initiation. 297 had at least 1 biomarker measurement available prior to HIV infection and after ART initiation with evidence of viral suppression. Mean age prior to HIV infection was 43 years. HIV infection was associated with reduction in total cholesterol, HDL cholesterol, LDL cholesterol, serum albumin, ALT, platelet count, hemoglobin and elevation of FIB-4 score and triglycerides. These changes occurred without significant changes in BMI. ART initiation (with HIV-1 RNA<500cpm) did not reverse alteration in triglycerides, LDL cholesterol, hemoglobin, or FIB-4 to pre-HIV infection levels.

CONCLUSIONS

HIV infection is associated with longitudinal changes in serum levels of several biomarkers of end-organ function/disease and mortality. Multiple biomarkers (triglycerides, LDL cholesterol, hemoglobin, and FIB-4 ) remain altered from levels prior to HIV infection levels even following inititiation of ART and evidence of viral suppression. These results give insights into underlying mechanisms of increased risk for aging-related chronic diseases in the context of HIV infection.

Comparison of risk and age at diagnosis of myocardial infarction, end-stage renal disease, and non-AIDS-defining cancer in HIV-infected versus uninfected adults

BACKGROUND

Although it has been shown that human immunodeficiency virus (HIV)-infected adults are at greater risk for aging-associated events, it remains unclear as to whether these events happen at similar, or younger ages, in HIV-infected compared with uninfected adults. The objective of this study was to compare the median age at, and risk of, incident diagnosis of 3 age-associated diseases in HIV-infected and demographically similar uninfected adults.

METHODS

The study was nested in the clinical prospective Veterans Aging Cohort Study of HIV-infected and demographically matched uninfected veterans, from 1 April 2003 to 31 December 2010. The outcomes were validated diagnoses of myocardial infarction (MI), end-stage renal disease (ESRD), and non-AIDS-defining cancer (NADC). Differences in mean age at, and risk of, diagnosis by HIV status were estimated using multivariate linear regression models and Cox proportional hazards models, respectively.

RESULTS

A total of 98 687 (31% HIV-infected and 69% uninfected) adults contributed >450 000 person-years and 689 MI, 1135 ESRD, and 4179 NADC incident diagnoses. Mean age at MI (adjusted mean difference, -0.11; 95% confidence interval [CI], -.59 to .37 years) and NADC (adjusted mean difference, -0.10 [95% CI, -.30 to .10] years) did not differ by HIV status. HIV-infected adults were diagnosed with ESRD at an average age of 5.5 months younger than uninfected adults (adjusted mean difference, -0.46 [95% CI, -.86 to -.07] years). HIV-infected adults had a greater risk of all 3 outcomes compared with uninfected adults after accounting for important confounders.

CONCLUSIONS

HIV-infected adults had a higher risk of these age-associated events, but they occurred at similar ages than those without HIV.

Prehypertension, hypertension, and the risk of acute myocardial infarction in HIV-infected and -uninfected veterans

BACKGROUND

Compared to uninfected people, human immunodeficiency virus (HIV)-infected individuals may have an increased risk of acute myocardial infarction (AMI). Currently, HIV-infected people are treated to the same blood pressure (BP) goals (<140/90 or <130/80 mm Hg) as their uninfected counterparts. Whether HIV-infected people with elevated BP have excess AMI risk compared to uninfected people is not known. This study examines whether the association between elevated BP and AMI risk differs by HIV status.

METHODS

The Veterans Aging Cohort Study Virtual Cohort (VACS VC) consists of HIV-infected and -uninfected veterans matched 1:2 on age, sex, race/ethnicity, and clinical site. For this analysis, we analyzed 81 026 people with available BP data from VACS VC, who were free of cardiovascular disease at baseline. BP was the average of the 3 routine outpatient clinical measurements performed closest to baseline (first clinical visit after April 2003). BP categories used in the analyses were based on criteria of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Analyses were performed using Cox proportional hazards regression.

RESULTS

Over 5.9 years (median), 860 incident AMIs occurred. Low/high prehypertensive and untreated/treated hypertensive HIV-infected individuals had increased AMI risk compared to uninfected, untreated normotensive individuals (hazard ratio [HR], 1.60 [95% confidence interval {CI}, 1.07-2.39]; HR, 1.81 [95% CI, 1.22-2.68]; HR, 2.57 [95% CI, 1.76-3.76]; and HR, 2.76 [95% CI, 1.90-4.02], respectively).

CONCLUSIONS

HIV, prehypertensive BP, and hypertensive BP were associated with an increased risk of AMI in a cohort of HIV-infected and -uninfected veterans. Future studies should prospectively investigate whether HIV interacts with BP to further increase AMI risk.

Association of the veterans aging cohort study index with exercise capacity in HIV-infected adults

Physical disability is a major priority in aging, affecting morbidity, mortality, and quality of life. Despite the large number of adults aging with HIV, our understanding of the physiologic and clinical risk factors for disability is limited. Our goal is to determine whether the Veterans Aging Cohort Study (VACS) Index, based on routine clinical blood tests, could serve as a point of care screening tool to identify HIV-infected adults at high risk for physical disability. HIV-infected adults enrolled in the VACS participated in a cross-sectional exercise study with established measures of strength and endurance. The VACS Index was calculated using recent clinical laboratory values and age; a higher score reflects greater mortality risk. Statistical analyses included correlation and linear regression models adjusted for muscle mass. Fifty-five HIV-infected adults, predominantly African-American men, were included with age mean±SD of 52±7 years. Median (IQR) CD4 cell count was 356 cells/mm(3) (212-527). The VACS Index was inversely correlated with quadriceps strength (r=-0.45, p<0.01), grip strength (r=-0.28, p=0.04), and 6-min walk distance (r=-0.27, p=0.05). A 20-point increase in VACS Index score was associated with a 10% lower leg strength (p<0.01), which remained significant after adjustment for muscle cross-sectional area (p=0.02). The VACS Index explained 31% of the variance in specific leg strength. In this group of middle-aged adults with well-controlled HIV infection the VACS Index was significantly associated with upper and lower extremity strength. The VACS Index may be valuable for identification of patients at high risk for disability due to muscle weakness.

Directly administered antiretroviral therapy for HIV-infected individuals in opioid treatment programs: results from a randomized clinical trial

BACKGROUND

Data regarding the efficacy of directly administered antiretroviral therapy (DAART) are mixed. Opioid treatment programs (OTPs) provide a convenient framework for DAART. In a randomized controlled trial, we compared DAART and self-administered therapy (SAT) among HIV-infected subjects attending five OTPs in Baltimore, MD.

METHODS

HIV-infected individuals attending OTPs were eligible if they were not taking antiretroviral therapy (ART) or were virologically failing ART at last clinical assessment. In subjects assigned to DAART, we observed one ART dose per weekday at the OTP for up to 12 months. SAT subjects administered ART at home. The primary efficacy comparison was the between-arm difference in the average proportions with HIV RNA <50 copies/mL during the intervention phase (3-, 6-, and 12-month study visits), using a logistic regression model accounting for intra-person correlation due to repeated observations. Adherence was measured with electronic monitors in both arms.

RESULTS

We randomized 55 and 52 subjects from five Baltimore OTPs to DAART and SAT, respectively. The average proportions with HIV RNA <50 copies/mL during the intervention phase were 0.51 in DAART and 0.40 in SAT (difference 0.11, 95% CI: -0.020 to 0.24). There were no significant differences between arms in electronically-measured adherence, average CD4 cell increase from baseline, average change in log10 HIV RNA from baseline, opportunistic conditions, hospitalizations, mortality, or the development of new drug resistance mutations.

CONCLUSIONS

In this randomized trial, we found little evidence that DAART provided clinical benefits compared to SAT among HIV-infected subjects attending OTPs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00279110 NCT00279110?term = NCT00279110&rank = 1.

HIV status, burden of comorbid disease, and biomarkers of inflammation, altered coagulation, and monocyte activation

BACKGROUND

Biomarkers of inflammation, altered coagulation, and monocyte activation are associated with mortality and cardiovascular disease (CVD) in the general population and among human immunodeficiency virus (HIV)-infected people. We compared biomarkers for inflammation, altered coagulation, and monocyte activation between HIV-infected and uninfected people in the Veterans Aging Cohort Study (VACS).

METHODS

Biomarkers of inflammation (interleukin-6 [IL-6]), altered coagulation (d-dimer), and monocyte activation (soluble CD14 [sCD14]) were measured in blood samples from 1525 HIV-infected and 843 uninfected VACS participants. Logistic regression was used to determine the association between HIV infection and prevalence of elevated (>75th percentile) biomarkers, adjusting for confounding comorbidities.

RESULTS

HIV-infected veterans had less prevalent CVD, hypertension, diabetes, obesity, hazardous drinking, and renal disease, but more dyslipidemia, hepatitis C, and current smoking than uninfected veterans. Compared to uninfected veterans, HIV-infected veterans with HIV-1 RNA ≥500 copies/mL or CD4 count <200 cells/µL had a significantly higher prevalence of elevated IL-6 (odds ratio [OR], 1.54; 95% confidence interval [CI],1.14-2.09; OR, 2.25; 95% CI, 1.60-3.16, respectively) and d-dimer (OR, 1.97; 95% CI, 1.44-2.71, OR, 1.68; 95% CI, 1.22-2.32, respectively) after adjusting for comorbidities. HIV-infected veterans with a CD4 cell count <200 cells/µL had significantly higher prevalence of elevated sCD14 compared to uninfected veterans (OR, 2.60; 95% CI, 1.64-4.14). These associations still persisted after restricting the analysis to veterans without known confounding comorbid conditions.

CONCLUSIONS

These data suggest that ongoing HIV replication and immune depletion significantly contribute to increased prevalence of elevated biomarkers of inflammation, altered coagulation, and monocyte activation. This contribution is independent of and in addition to the substantial contribution from comorbid conditions.

Risk of heart failure with human immunodeficiency virus in the absence of prior diagnosis of coronary heart disease

BACKGROUND

Whether human immunodeficiency virus (HIV) infection is a risk factor for heart failure (HF) is not clear. The presence of coronary heart disease and alcohol consumption in this population may confound this association.

METHODS

To determine whether HIV infection is a risk factor for incident HF, we conducted a population-based, retrospective cohort study of HIV-infected and HIV-uninfected veterans enrolled in the Veterans Aging Cohort Study Virtual Cohort (VACS-VC) and the 1999 Large Health Study of Veteran Enrollees (LHS) from January 1, 2000, to July 31, 2007.

RESULTS

There were 8486 participants (28.2% HIV-infected) enrolled in the VACS-VC who also participated in the 1999 LHS. During the median 7.3 years of follow-up, 286 incident HF events occurred. Age- and race/ethnicity-adjusted HF rates among HIV-infected and HIV-uninfected veterans were 7.12 (95% confidence interval [CI], 6.90-7.34) and 4.82 (95% CI, 4.72-4.91) per 1000 person-years, respectively. Compared with HIV-uninfected veterans, those who were HIV infected had an increased risk of HF (adjusted hazard ratio [HR], 1.81; 95% CI, 1.39-2.36). This association persisted among veterans who did not have a coronary heart disease event or a diagnosis related to alcohol abuse or dependence before the incident HF event (adjusted HR, 1.96; 95% CI, 1.29-2.98). Compared with HIV-uninfected veterans, those who were HIV infected with a baseline Human immunodeficiency virus 1 (HIV-1) RNA level of 500 or more copies/mL had a higher risk of HF (adjusted HR, 2.28; 95% CI, 1.57-3.32), while those with baseline and a recent HIV-1 RNA level less than 500 copies/mL did not (adjusted HR, 1.10; 95% CI,  0.64-1.89; P < .001 for comparison between high and low HIV-1 RNA groups).

CONCLUSIONS

Our data suggest that HIV infection is a risk factor for HF. Ongoing viral replication is associated with a higher risk of developing HF.

Study design and participant characteristics of a randomized controlled trial of directly administered antiretroviral therapy in opioid treatment programs

Background

HIV-infected drug users are at higher risk of non-adherence and poor treatment outcomes than HIV-infected non-drug users. Prior work from our group and others suggests that directly administered antiretroviral therapy (DAART) delivered in opioid treatment programs (OTPs) may increase rates of viral suppression.

Methods/Design

We are conducting a randomized trial comparing DAART to self-administered therapy (SAT) in 5 OTPs in Baltimore, Maryland. Participants and investigators are aware of treatment assignments. The DAART intervention is 12 months. The primary outcome is HIV RNA < 50 copies/mL at 3, 6, and 12 months. To assess persistence of any study arm differences that emerge during the active intervention, we are conducting an 18-month visit (6 months after the intervention concludes). We are collecting electronic adherence data for 2 months in both study arms. Of 457 individuals screened, a total of 107 participants were enrolled, with 56 and 51 randomly assigned to DAART and SAT, respectively. Participants were predominantly African American, approximately half were women, and the median age was 47 years. Active use of cocaine and other drugs was common at baseline. HIV disease stage was advanced in most participants. The median CD4 count at enrollment was 207 cells/mm³, 66 (62%) had a history of an AIDS-defining opportunistic condition, and 21 (20%) were antiretroviral naïve.

Conclusions

This paper describes the rationale, methods, and baseline characteristics of subjects enrolled in a randomized clinical trial comparing DAART to SAT in opioid treatment programs.

Trial Registration

ClinicalTrials.gov: NCT00279110

Association of age and comorbidity with physical function in HIV-infected and uninfected patients: results from the Veterans Aging Cohort Study

HIV clinical care now involves prevention and treatment of age-associated comorbidity. Although physical function is an established correlate to comorbidity in older adults without HIV infection, its role in aging of HIV-infected adults is not well understood. To investigate this question we conducted cross-sectional analyses including linear regression models of physical function in 3227 HIV-infected and 3240 uninfected patients enrolled 2002-2006 in the Veterans Aging Cohort Study-8-site (VACS-8). Baseline self-reported physical function correlated with the Short Form-12 physical subscale (ρ = 0.74, p < 0.001), and predicted survival. Across the age groups decline in physical function per year was greater in HIV-infected patients (β(coef) -0.25, p < 0.001) compared to uninfected patients (β(coef) -0.08, p = 0.03). This difference, although statistically significant (p < 0.01), was small. Function in the average 50-year old HIV-infected subject was equivalent to the average 51.5-year-old uninfected subject. History of cardiovascular disease was a significant predictor of poor function, but the effect was similar across groups. Chronic pulmonary disease had a differential effect on function by HIV status (Δβ(coef) -3.5, p = 0.03). A 50-year-old HIV-infected subject with chronic pulmonary disease had the equivalent level of function as a 68.1-year-old uninfected subject with chronic pulmonary disease. We conclude that age-associated comorbidity affects physical function in HIV-infected patients, and may modify the effect of aging. Longitudinal research with markers of disease severity is needed to investigate loss of physical function with aging, and to develop age-specific HIV care guidelines.

Paradoxical contractile properties in the knee extensors of HIV-infected men treated with antiretroviral therapy

We assessed contractile properties in the knee extensors of 18 men with the human immunodeficiency virus (HIV+) being treated with antiretroviral therapy (ART), and 9 healthy controls matched for age and body mass index. We found significant, divergent differences between groups with regard to force relaxation. Half-times of twitch relaxation were shorter (62.6 ± 5.4 ms vs. 48.9 ± 3.0 ms; p = 0.045) and maximum rates of torque relaxation were slower (0.47% ± 0.04%(s-)1 vs. 1.32% ± 0.10%(s-)1; p < 0.001) in HIV+ individuals. These preliminary findings suggest potential intramuscular impairments in HIV+ individuals on ART, perhaps because of interactions between calcium handling and mitochondrial dysfunction.

HIV infection and risk for incident pulmonary diseases in the combination antiretroviral therapy era

RATIONALE

In aging HIV-infected populations comorbid diseases are important determinants of morbidity and mortality. Pulmonary diseases have not been systematically assessed in the combination antiretroviral therapy (ART) era.

OBJECTIVES

To determine the incidence of pulmonary diseases in HIV-infected persons compared with HIV-uninfected persons.

METHODS

We analyzed data from the Veterans Aging Cohort Study Virtual Cohort, consisting of 33,420 HIV-infected veterans and 66,840 age, sex, race and ethnicity, and site-matched HIV-uninfected veterans. Using Poisson regression, incidence rates and adjusted incidence rate ratios were calculated to determine the association of HIV with pulmonary disease. The Virtual Cohort was merged with the 1999 Veterans Large Health Survey to adjust for self-reported smoking in a nested sample (14%).

MEASUREMENTS AND MAIN RESULTS

Incident chronic obstructive pulmonary disease, lung cancer, pulmonary hypertension, and pulmonary fibrosis, as well as pulmonary infections, were significantly more likely among HIV-infected patients compared with uninfected patients in adjusted analyses, although rates of asthma did not differ by HIV status. Bacterial pneumonia and chronic obstructive pulmonary disease were the two most common incident pulmonary diseases, whereas opportunistic pneumonias were less common. Absolute rates of most pulmonary diseases increased with age, although the relative differences between those with and without HIV infection were greatest in younger persons. Chronic obstructive pulmonary disease and asthma, as well as pulmonary infections, were less likely in those with lower HIV RNA levels and use of ART at baseline.

CONCLUSIONS

Pulmonary diseases among HIV-infected patients receiving care within the Veterans Affairs Healthcare System in the combination ART era reflect a substantial burden of non-AIDS-defining and chronic conditions, many of which are associated with aging.

Towards a combined prognostic index for survival in HIV infection: the role of 'non-HIV' biomarkers

BACKGROUND

As those with HIV infection live longer, 'non-AIDS' condition associated with immunodeficiency and chronic inflammation are more common. We ask whether 'non-HIV' biomarkers improve differentiation of mortality risk among individuals initiating combination antiretroviral therapy (cART).

METHODS

Using Poisson models, we analysed data from the Veterans Aging Cohort Study (VACS) on HIV-infected veterans initiating cART between 1 January 1997 and 1 August 2002. Measurements included: HIV biomarkers (CD4 cell count, HIV RNA and AIDS-defining conditions); 'non-HIV' biomarkers (haemoglobin, transaminases, platelets, creatinine, and hepatitis B and C serology); substance abuse or dependence (alcohol or drug); and age. Outcome was all cause mortality. We tested the discrimination (C statistics) of each biomarker group alone and in combination in development and validation data sets, over a range of survival intervals, and adjusting for missing data.

RESULTS

Of veterans initiating cART, 9784 (72%) had complete data. Of these, 2566 died. Subjects were middle-aged (median age 45 years), mainly male (98%) and predominantly black (51%). HIV and 'non-HIV' markers were associated with each other (P < 0.0001) and discriminated mortality (C statistics 0.68-0.73); when combined, discrimination improved (P < 0.0001). Discrimination for the VACS Index was greater for shorter survival intervals [30-day C statistic 0.86, 95% confidence interval (CI) 0.80-0.91], but good for intervals of up to 8 years (C statistic 0.73, 95% CI 0.72-0.74). Results were robust to adjustment for missing data.

CONCLUSIONS

When added to HIV biomarkers, 'non-HIV' biomarkers improve differentiation of mortality. When evaluated over similar intervals, the VACS Index discriminates as well as other established indices. After further validation, the VACS Index may provide a useful, integrated risk assessment for management and research.

Erectile dysfunction drug receipt, risky sexual behavior and sexually transmitted diseases in HIV-infected and HIV-uninfected men

BACKGROUND

Health care providers may be concerned that prescribing erectile dysfunction drugs (EDD) will contribute to risky sexual behavior.

OBJECTIVES

To identify characteristics of men who received EDD prescriptions, determine whether EDD receipt is associated with risky sexual behavior and sexually transmitted diseases (STDs), and determine whether these relationships vary for certain sub-groups.

DESIGN

Cross-sectional study.

PARTICIPANTS

Two thousand seven hundred and eighty-seven sexually-active, HIV-infected and HIV-uninfected men recruited from eight Veterans Health Affairs outpatient clinics. Data were obtained from participant surveys, electronic medical records, and administrative pharmacy data.

MEASURES

EDD receipt was defined as two or more prescriptions for an EDD, risky sex as having unprotected sex with a partner of serodiscordant or unknown HIV status, and STDs, according to self-report.

RESULTS

Overall, 28% of men received EDD in the previous year. Eleven percent of men reported unprotected sex with a serodiscordant/unknown partner in the past year (HIV-infected 15%, HIV-uninfected 6%, P < 0.001). Compared to men who did not receive EDD, men who received EDD were equally likely to report risky sexual behavior (11% vs. 10%, p = 0.9) and STDs (7% vs 7%, p = 0.7). In multivariate analyses, EDD receipt was not significantly associated with risky sexual behavior or STDs in the entire sample or in subgroups of substance users or men who had sex with men.

CONCLUSION

EDD receipt was common but not associated with risky sexual behavior or STDs in this sample of HIV-infected and uninfected men. However, risky sexual behaviors persist in a minority of HIV-infected men, indicating ongoing need for prevention interventions.

Prediction of cardiorespiratory fitness in older men infected with the human immunodeficiency virus: clinical factors and value of the six-minute walk distance

OBJECTIVES

To investigate factors related to cardiorespiratory fitness in older human immunodeficiency virus (HIV)-infected patients and to explore the utility of 6-minute walk distance (6-MWD) in measuring fitness.

DESIGN

Cross-sectional study in clinic-based cohort.

SETTING

Veterans Affairs Medical Center, Baltimore, Maryland.

PARTICIPANTS

Forty-three HIV-infected men, median age 57 (range 50-82), without recent acquired immunodeficiency syndrome-related illness and receiving antiretroviral (ARV) therapy.

MEASUREMENTS

Peak oxygen utilization (VO(2)peak) according to treadmill graded exercise testing, 6-MWD, grip strength, quadriceps maximum voluntary isometric contraction, cross-sectional area, muscle quality, and muscle adiposity.

RESULTS

There was a moderate correlation between VO(2)peak (mean +/- SD; 18.4 +/- 5.6 mL/kg per minute) and 6-MWD (514 +/- 91 m) (r=0.60, P<.001). VO(2)peak was lower in subjects with hypertension (16%, P<.01) and moderate anemia (hemoglobin 10-13 gm/dL; 15%, P=.09) than in subjects without these conditions. CD4 cell count (median 356 cells/mL, range 20-1,401) and HIV-1 viral load (84% nondetectable) were not related to VO(2)peak. Among muscle parameters, only grip strength was an independent predictor of VO(2)peak. Estimation of VO(2)peak using linear regression, including age, 6-MWD, grip strength, and hypertension as independent variables, explained 61% of the variance in VO(2)peak.

CONCLUSION

Non-AIDS-related comorbidity predicts cardiorespiratory fitness in older HIV-infected men receiving ARV therapy. The 6-MWD is a valuable measure of fitness in this patient population, but a larger study with diverse subjects is needed.

The association between the receipt of lipid lowering therapy and HIV status among veterans who met NCEP/ATP III criteria for the receipt of lipid lowering medication

OBJECTIVE

To examine the association between HIV infection status and the receipt of lipid lowering therapy based on National Cholesterol Education Program/Adult Treatment Panel (NCEP/ATP III) guidelines and to assess whether HIV viral load and hepatitis C (HCV) status alters that association.

PARTICIPANTS AND DESIGN

A cross-sectional analysis of survey, laboratory, and pharmacy data from 1,577 male participants (59% HIV infected) of the Veterans Aging Cohort Five-Site Study, a prospective observational cohort of U.S. veterans with and without HIV infection.

MEASUREMENTS

Receipt of lipid lowering therapy obtained from the VA pharmacy benefits management system was the main outcome.

RESULTS

The prevalence of lipid lowering therapy among HIV-infected and HIV-uninfected veterans was 15.4% vs. 37.9%, respectively, p < 0.01. Among veterans who met NCEP/ATP III criteria for lipid lowering therapy, HIV-infected veterans had a significantly lower prevalence for the receipt of lipid lowering therapy (adjusted odds ratio (OR) = 0.43, 95% confidence interval (C.I.) 0.28-0.67) as compared with HIV-uninfected veterans. Among HIV-infected veterans, log HIV viral load (adjusted OR = 0.57, 95% CI, 0.41-0.81) and HIV-HCV co-infection (adjusted OR = 0.31, 95% CI = 0.13-0.75) were negatively associated with receipt of lipid lowering therapy. Exposure to HAART was not associated with receipt of lipid lowering therapy.

CONCLUSIONS

Among those who met NCEP/ATP III criteria for lipid lowering therapy, HIV-infected veterans, particularly those with high HIV viral loads and HCV co-infection, were significantly less likely to receive lipid lowering therapy. This may be a modifiable mediator of cardiovascular disease among HIV-infected individuals.

Central activation, muscle performance, and physical function in men infected with human immunodeficiency virus

Loss of muscle mass and limitations in activity have been reported in persons infected with human immunodeficiency virus (HIV), even those who are otherwise asymptomatic. The extent to which factors other than muscle atrophy impair muscle performance has not been addressed in depth. The purpose of this study was to determine the extent of neuromuscular activation of the knee extensors and ankle dorsiflexors of 27 men infected with HIV receiving antiretroviral therapy and its relationship to muscle performance. The central activation ratio (CAR) was determined using superimposed electrical stimulation during maximum voluntary contractions. In addition to force and power measurements, muscle cross-sectional area and composition was evaluated using computed tomography. Aerobic capacity was determined from treadmill exercise testing. Eleven of the subjects had an impaired ability to activate the knee extensors (CAR = 0.72 +/- 0.12) that was associated with weakness and decreased specific force. The reduced central activation was not associated with muscle area, body composition, aerobic capacity, CD4 count, or medication regimen. Those individuals with low central activation had higher HIV-1 viral loads and were more likely to have a history of AIDS-defining illness. These results suggest the possibility of a different mechanism contributing to muscle impairment in the current treatment era that is associated with impairment of central motor function rather than atrophy. Further investigation is warranted in a larger, more diverse population before more definitive claims are made.

Association of comorbidity with physical disability in older HIV-infected adults

Comorbidity, aging, and their impact on physical functioning will play an increasingly greater role in HIV medical care as the number of infected adults over 50 years of age grows. The study objective was to investigate the relationship of comorbidity and age with physical functioning in HIV-infected and HIV-negative patients. Eight hundred eighty-nine HIV-infected veterans and 647 HIV-negative veterans from the Veterans Aging Cohort Study conducted between September 2001 and June 2002 were included in the study. Physical functioning was measured by self-reported difficulty with various physical activities. Regression analyses were performed to examine demographic and clinical factors associated with physical functioning. Separate models were used for HIV-infected and HIV negative subjects since these groups differed in demographic makeup. In both patient groups, chronic lung disease, coronary artery disease, hypertension, smoking, and major depression were independently associated with reduced physical functioning in age and race adjusted regression models. Increased age was associated with reduced physical functioning in both HIV-infected and HIV-negative patients. However, when comorbid conditions were entered into the models for both HIV-infected and HIV-negative patients, age coefficients were reduced and were no longer statistically significant. Among the HIV-infected patients, results remained unchanged after controlling for the impact of antiretroviral therapy and HIV disease stage. Our findings demonstrate the important role of general medical comorbidity in physical functioning in both HIV-infected and HIV-negative patients. This suggests the importance of effectively treating comorbid conditions in persons with HIV, in order to reduce the overall impact of disease on physical functioning.

Reduced aerobic capacity and physical functioning in older HIV-infected men

Aerobic capacity and physical functioning decline with age and chronic illness. The extent of physical disability is unknown in older HIV-infected adults, who represent a rapidly growing proportion of HIV/AIDS patients in the United States. We performed functional performance testing including treadmill testing in 32 HIV-infected male veterans aged 40-69 years. Controls were 47 healthy male subjects tested previously in the same exercise laboratory. HIV-infected subjects were classified as younger (40-49 years, n = 12) or older age (50+ years, n = 20). Peak aerobic capacity (VO2peak) was significantly reduced in the older vs. younger HIV subjects [19.1 mL/kg/min +/- 5.7 (mean, SD) vs. 25.2 +/- 4.2, p = 0.01]. VO2peak was reduced 41% +/- 15% (mean, SD) in HIV-infected subjects compared to expected values from age-matched healthy controls. Regression analyses show a similar decline in VO2peak with age in HIV-infected and healthy controls. Mean 6-min walk distance was not significantly different between the HIV-infected age groups, and was reduced only 8% compared to expected values for healthy adults. Current CD4 count and HAART exposure were similar in the two age groups and were not significantly associated with VO2peak. Anemia (HCT <35%) was significantly associated with reduced VO2peak (p = 0.02), but this association was not independent of the effect of age (p = 0.1). We conclude that older HIV-infected adults have markedly impaired aerobic capacity but maintain the capacity to undertake day-to-day activities. Additional physiologic and metabolic testing is needed to measure the effect of HAART toxicity and primary aging on aerobic capacity, and to determine if older HIV-infected adults are at greater risk.