Perspective on HIV infection and aging: emerging research on the horizon

Trichomonas vaginalis infection in southern Ghana: clinical signs associated with the infection

Trichomonas vaginalis is the causative agent for the most prevalent non-viral sexually transmitted infection (STI) among women of child-bearing age. In Ghana, although the infection is prevalent, there is a dearth of data on the risk factors and symptoms associated with T. vaginalis infection. This study was conducted on 492 women visiting gynaecological and STI clinics in the Volta Region (VR) and Greater Accra Region (GAR) in southern Ghana. Wet mount microscopy and polymerase chain reaction (PCR) were used to diagnose T. vaginalis infection. Infection prevalence was 13.2% and 18.1% by WMM and PCR, respectively. Diagnosis by PCR was significantly more sensitive (McNemar's test, p=0.0003). The regional prevalence of T. vaginalis infection by PCR was 21.7% in the VR and 12.8% in the GAR. There was a significant difference in prevalence between the two regions (Fisher's exact test, p=0.02). T. vaginalis infection was associated with vaginal itch (odds ratio [OR]=1.71, p=0.04) and a history of engaging in oral sex (OR 1.90, p=0.04). A high prevalence of T. vaginalis infection was recorded among women visiting gynaecological and STI clinics in southern Ghana. There was no consistent association of infection with any recorded clinical signs and no clear risk factors for infection were identified.

HIV infection is an independent risk factor for decreased 6-minute walk test distance

Background

Ambulatory function predicts morbidity and mortality and may be influenced by cardiopulmonary dysfunction. Persons living with HIV (PLWH) suffer from a high prevalence of cardiac and pulmonary comorbidities that may contribute to higher risk of ambulatory dysfunction as measured by 6-minute walk test distance (6-MWD). We investigated the effect of HIV on 6-MWD.

Methods

PLWH and HIV-uninfected individuals were enrolled from 2 clinical centers and completed a 6-MWD, spirometry, diffusing capacity for carbon monoxide (DL_CO) and St. George’s Respiratory Questionnaire (SGRQ). Results of 6-MWD were compared between PLWH and uninfected individuals after adjusting for confounders. Multivariable linear regression analysis was used to determine predictors of 6-MWD.

Results

Mean 6-MWD in PLWH was 431 meters versus 462 in 130 HIV-uninfected individuals (p = 0.0001). Older age, lower forced expiratory volume (FEV₁)% or lower forced vital capacity (FVC)%, and smoking were significant predictors of decreased 6-MWD in PLWH, but not HIV-uninfected individuals. Lower DL_CO% and higher SGRQ were associated with lower 6-MWD in both groups. In a combined model, HIV status remained an independent predictor of decreased 6-MWD (Mean difference = -19.9 meters, p = 0.005).

Conclusions

HIV infection was associated with decreased ambulatory function. Airflow limitation and impaired diffusion capacity can partially explain this effect. Subjective assessments of respiratory symptoms may identify individuals at risk for impaired physical function who may benefit from early intervention.

Immunosenescence Modulation by Vaccination

A decline in immune function is a hallmark of aging that leads to complicated illness from a variety of infectious diseases, cancer and other immune-mediated disorders, and may limit the ability to appropriately respond to vaccination. How vaccines might alter the senescent immune response and what are the immune correlates of protection will be addressed from the perspective of (1) stimulating a previously primed response as in the case of vaccines for seasonal influenza and herpes zoster, (2) priming the response to novel antigens such as pandemic influenza or West Nile virus, (3) vaccination against bacterial pathogens such as pneumococcus and pertussis, (4) vaccines against bacterial toxins such as tetanus and Clostridium difficile, and (5) vaccine approaches to mitigate effects of cytomegalovirus on immune senescence. New or improved vaccines developed over recent years demonstrate the considerable opportunity to improve current vaccines and develop new vaccines as a preventive approach to a variety of diseases in older adults. Strategies for selecting appropriate immunologic targets for new vaccine development and evaluating how vaccines may alter the senescent immune response in terms of potential benefits and risks in the preclinical and clinical trial phases of vaccine development will be discussed.

Age-period-cohort analysis of infectious disease mortality in urban-rural China, 1990-2010

BACKGROUND

Although a number of studies on infectious disease trends in China exist, these studies have not distinguished the age, period, and cohort effects simultaneously. Here, we analyze infectious disease mortality trends among urban and rural residents in China and distinguish the age, period, and cohort effects simultaneously.

METHODS

Infectious disease mortality rates (1990-2010) of urban and rural residents (5-84 years old) were obtained from the China Health Statistical Yearbook and analyzed with an age-period-cohort (APC) model based on Intrinsic Estimator (IE).

RESULTS

Infectious disease mortality is relatively high at age group 5-9, reaches a minimum in adolescence (age group 10-19), then rises with age, with the growth rate gradually slowing down from approximately age 75. From 1990 to 2010, except for a slight rise among urban residents from 2000 to 2005, the mortality of Chinese residents experienced a substantial decline, though at a slower pace from 2005 to 2010. In contrast to the urban residents, rural residents experienced a rapid decline in mortality during 2000 to 2005. The mortality gap between urban and rural residents substantially narrowed during this period. Overall, later birth cohorts experienced lower infectious disease mortality risk. From the 1906-1910 to the 1941-1945 birth cohorts, the decrease of mortality among urban residents was significantly faster than that of subsequent birth cohorts and rural counterparts.

CONCLUSIONS

With the rapid aging of the Chinese population, the prevention and control of infectious disease in elderly people will present greater challenges. From 1990 to 2010, the infectious disease mortality of Chinese residents and the urban-rural disparity have experienced substantial declines. However, the re-emergence of previously prevalent diseases and the emergence of new infectious diseases created new challenges. It is necessary to further strengthen screening, immunization, and treatment for the elderly and for older cohorts at high risk.

Shifting Patterns of the HIV Epidemic in Southwest China: A Case Study Based on Sentinel Surveillance, 1995-2012

The HIV epidemic is experiencing a rapid shift in transmission profile in China. This study aims to examine the changes in magnitude, transmission pattern, and trend of the HIV epidemic in a typical Southwest Chinese prefecture over the period of 1995-2012. HIV surveillance data from the web-based reporting system were analyzed during this period. We investigated the temporal trends in the changing characteristics of HIV transmission, the HIV disease burden in key affected populations, and assessed the impacts on HIV disease progression due to scale-up of antiretroviral treatment. A total of 3556 HIV/AIDS cases were reported in Yuxi prefecture, Yunnan, over the study period. The number of HIV tests conducted has dramatically increased from 1041 in 1995 to 247,859 in 2012, resulting in a substantial increase in HIV diagnoses from 11 cases to 327 cases over the same period. Since 2005, cumulatively 1250 eligible people living with HIV (PLHIV) have received combination antiretroviral therapy which reduced AIDS disease progression from 9.0% (95% CI: 6.7-11.4%) in 1995 to 0.1% (0-0.3%) in 2012 (ptrend=0.0002). The primary mode of HIV transmission has been shifted from injection sharing (71.9% diagnoses in 1995-2004) to unsafe sexual contacts (82.6% diagnoses in 2012). Yuxi prefecture is experiencing a concentrated but shifting HIV epidemic. Scale-up of HIV testing is essential to effective sentinel surveillance and enhancing early diagnosis and treatment in PLHIV.

Longitudinal Trends in Sexual Behaviors with Advancing Age and Menopause Among Women With and Without HIV-1 Infection

We assessed changes in self-reported sexual activity (SA) over 13 years among HIV-infected and uninfected women. The impact of aging and menopause on SA and unprotected anal or vaginal intercourse (UAVI) was examined among women in the Women's Interagency HIV Study (WIHS), stratifying by HIV status and detectable viral load among HIV-infected women. Generalized mixed linear models were fitted for each outcome, adjusted for relevant covariates. HIV-uninfected women evidenced higher levels of SA and UAVI than HIV-infected. The odds of SA declined by 62-64 % per decade of age. The odds of SA in a 6-month interval for women aged 40-57 declined by 18-22 % post-menopause (controlling for age). Among HIV+/detectable women only, the odds of any UAVI decreased by 17 % per decade of age; the odds of UAVI were unchanged pre-menopause, and then decreased by 28 % post-menopause. Elucidating the factors accounting for ongoing unprotected sex among older women should inform interventions.

Prevalence and factors associated with late HIV diagnosis

While highly active antiretroviral therapy has been successful in delaying progression into AIDS, late HIV diagnosis remains a major contributor to the mortality and morbidity of AIDS. An epidemiological study was conducted to evaluate the prevalence and factors of late diagnosis and the characteristics of those individuals with late diagnosis in Liuzhou city. Patients with late diagnosis were defined as either those who were diagnosed with AIDS at the time of HIV diagnosis or as those who developed AIDS no more than 1 year after HIV diagnosis. Of 899 participants, 72.6% had a late diagnosis. Common characteristics of those who experienced late diagnosis included older participants, those who were unexpectedly diagnosed while seeking other medical attention, participants who believed they could not acquire HIV from their regular heterosexual partners, those who never considered getting tested for HIV, and patients with unexplained weight loss, angular cheilitis, or prolonged fever prior to HIV diagnosis. On the other hand, those participants who were diagnosed via testing at compulsory rehabilitation centers and those whose annual household income was greater than 30,000 Yuan were less likely to be diagnosed late. These results suggested that late HIV diagnosis is common in Liuzhou city, and it is essential to promote appropriate strategies to detect HIV infections earlier. Strategies that require HIV/AIDS patients to notify their spouse/sexual-partners about their HIV-positive results within one month and start provider-initiated HIV testing and counseling in medical facilities are beneficial to earlier HIV diagnosis.

Risk Factors for Early Mortality on Antiretroviral Treatment of Elderly People Infected with HIV in Burkina Faso

BACKGROUND

Age is a key determinant of mortality due to diseases including HIV infection.

METHODS

A retrospective and descriptive cohort study used a computerized database to compare HIV-infected patients diagnosed in late adulthood to a group of patients diagnosed before their 49 years of age, without matching the characteristics of HIV infection. The study included patients who visited the day hospital (outpatient clinic) of the Sanou Souro Teaching Hospital of Bobo-Dioulasso, in Burkina Faso, from January 2007 to December 2011. Older adults were defined as those aged 50 years and more.

RESULTS

Participants in the study consisted of 2572 patients (265 older adults and 2307 young patients living with HIV. Based on Markov chain method, 32.1% of the older adults living with HIV were found to be seroconvert at 50 years or older. The median follow-up time on antiretroviral treatment (ART) was 32.7 months (range 0.03-65.4 months). Two hundred and ninety-five (11.5%) patients died, including 21.1% of older adults and 10.4% of young (P < .01). World Health Organization stage 3 or 4 and the lowest CD4 count reached <200 cells/mm(3) were the factors associated with early mortality of older adults on ART.

CONCLUSION

Mortality rate of older adult patients living with HIV in Burkina Faso is high. Early diagnosis, early treatment, and primary prevention of HIV infection in the older adults are the main keys that could help reduce such mortality.

Severe morbidity according to sex in the era of combined antiretroviral therapy: the ANRS CO3 Aquitaine Cohort

OBJECTIVE

To describe trends and determinants of severe morbidity in HIV-infected women and men.

DESIGN

A French prospective cohort of HIV-infected patients of both sexes and all transmission categories.

METHODS

We used hospital admission data from January 2000 to December 2008. A severe morbid event (SME) was defined as a clinical event requiring hospitalization for ≥48 h, several events could be reported during hospitalization. Yearly incidence rates of SME were estimated and compared using Generalized Estimating Equations.

RESULTS

Among 4,987 patients (27% women), followed for a median of 8.7 years, 1,473 (30%) were hospitalized (3,049 hospitalizations for 5,963 SME). The yearly incidence rate of hospitalization decreased in men, from 155 in 2000 to 80/1,000 person-years (PY) in 2008 and in women, from 125 to 71/1,000 PY, (p<0.001). This trend was observed for all SME except for hepatic events, stable in men (15 to 13/1,000 PY) and increasing in women (2.5 to 11.5), cardiovascular events increasing in men (6 to 10/1,000 PY) and in women (6 to 14) and non-AIDS non-hepatic malignancies increasing in men (4 to 7/1,000 PY) and stable in women (2.5). Intraveneous drug users, age >50 years, HIV RNA >10,000 copies, CD4 <500/mm3, AIDS stage, hepatitis C co-infection and cardiovascular risk factors (diabetes, high blood pressure, and tobacco use) were associated with SME.

CONCLUSIONS

HIV-infected individuals in care in France require less and less frequently hospitalization. Women are now presenting with severe hepatic and cardio-vascular events. Disparities in SME between men and women are primarily explained by different exposure patterns to risk factors. Women should be targeted to benefit cardiovascular prevention policies as well as men.

Evidence informing the intersection of HIV, aging and health: a scoping review

The growing number of people over age 50 with HIV requires research, policy, and practice to develop a more comprehensive understanding of the health consequences of HIV in older individuals. We conducted a scoping review of peer-reviewed and grey literature published since 1996 to explore the impacts of aging on the health of older people with HIV (50 years or older). We included 209 studies (two systematic reviews, 174 quantitative studies, 28 qualitative studies, and five mixed methods studies). Health topics addressed include: HIV- and aging-related comorbidities, disease progression, neurocognitive functioning, mental health conditions, psychological well-being, social supports, stigma, antiretroviral adherence, health care utilization/access, and sexual risk behaviour. We recommend that future research takes a broader view of health, looks at aging from a strength-based perspective and examines the issue using diverse perspectives (i.e., geographic location, multiple methods, time of diagnosis, time on antiretroviral therapy (ART), demographic diversity).

Clinical impact of altered T-cell homeostasis in treated HIV patients enrolled in a large observational cohort

OBJECTIVE(S)

We investigated the probability of transitioning in or out of the CD3⁺ T-cell homeostatic range during antiretroviral therapy, and we assessed the clinical impact of lost T-cell homeostasis (TCH) on AIDS-defining illnesses (ADIs) or death.

DESIGN

Within the Canadian Observational Cohort (CANOC), we studied 4463 antiretroviral therapy (ART)-naive HIV-positive patients initiating combination ART (cART) between 2000 and 2010.

METHODS

CD3⁺ trajectories were estimated using a four state Markov model. CD3⁺ T-cel percentage states were classified as follows: very low (<50%), low (50-64%), normal (65-85%), and high (>85%). Covariates associated with transitioning between states were examined. The association between CD3⁺ T-cell percentage states and time to ADI/death from cART initiation was determined using Cox proportional hazards models.

RESULTS

A total of 4463 patients were followed for a median of 3 years. Two thousand, five hundred and eight (56%) patients never transitioned from their baseline CD3⁺ T-cell percentage state; 85% of these had normal TCH. In multivariable analysis, individuals with time-updated low CD4⁺ cell count, time-updated detectable viral load, older age, and hepatitis C virus (HCV) coinfection were less likely to maintain TCH. In the multivariable proportional hazards model, both very low and high CD3⁺ T-cell percentages were associated with increased risk of ADI/death [adjusted hazard ratio=1.91 (95% confidence interval, CI: 1.27-2.89) and hazard ratio=1.49 (95% CI: 1.13-1.96), respectively].

CONCLUSION

Patients with very low or high CD3⁺ T-cell percentages are at risk for ADIs/death. To our knowledge, this is the first study linking altered TCH and morbidity/mortality in cART-treated HIV-positive patients.

Impact of age on markers of HIV-1 disease

Aging is a complicated process characterized by a progressive loss of homeostasis, which results in an increased vulnerability to multiple diseases. HIV-1-infected patients demonstrate a premature aging phenotype and develop certain age-related diseases earlier in their lifespan than what is seen in the general population. Age-related comorbidities may include the development of bone disease, metabolic disorders, neurologic impairment and immunosenescence. Age also appears to have an effect on traditional markers of HIV-1 disease progression, including CD4+ T-cell count and viral load. These effects are not only a consequence of HIV-1 infection, but in many cases, are also linked to antiretroviral therapy. This review summarizes the complex interplay between HIV-1 infection and aging, and the impact that aging has on markers of HIV-1 disease.

Thyroid function in newly diagnosed HIV-infected patients

BACKGROUND

A variety of HIV-related endocrine dysfunctions including adrenal, gonadal and thyroid disorders have been reported. We aimed to compare between the markers of thyroid function in newly diagnosed HIV-infected patients and healthy volunteers as a control group. The prevalence of the thyroid abnormalities in HIV-infected patients was assessed and the levels of thyroid autoantibodies were also determined.

METHODS

A total of 100 newly diagnosed HIV-infected patients having a CD4 cell count of 180-350 cells/mm(3) were enrolled in the study. Same number of healthy volunteers were also included for comparison. Measurements of thyroid function tests including thyroid-stimulating hormone (TSH), free thyroxin and free triiodothyronine levels beside thyroid autoantibodies, including antithyroglobulin (ATBG) and antithyroid peroxidase (ATPO), were carried out for all patients and volunteers.

RESULTS

In total, 70% of HIV-infected patients had normal thyroid function tests when compared with control individuals, while 30% of HIV-infected patients had abnormal thyroid function. Of the 30 cases, 11 cases had abnormal TSH values, with increased TSH predominant (7% of HIV cases) than decreased TSH (4% of patients) values. Incidence of thyroid abnormalities ranging from hypothyroidism (subclinical and overt: 6% and 1%, respectively) to hyperthyroidism (2%) and nonthyroidal illness (9%) were estimated in HIV-infected patients. The values of thyroid autoantibodies were almost normal in HIV-infected patients, except the three cases presented with elevated ATBG, indicating that thyroid abnormalities were not due to elevated ATBG and ATPO.

CONCLUSIONS

Thyroid hormones are of great importance and due to high prevalence of thyroid function abnormality, it is recommended that thyroid function tests should be monitored in all HIV-infected patients before starting the treatment.

Racial/ethnic disparities in HIV diagnoses among persons aged 50 years and older in 37 US States, 2005-2008

OBJECTIVES

We examined racial/ethnic disparities in HIV diagnosis rates for persons aged 50 years and older.

METHODS

We analyzed surveillance data from the Centers for Disease Control and Prevention regarding HIV diagnoses during 2005 through 2008 in 37 states. Average annual rates of diagnoses were calculated for persons aged 50 years and older and compared with rates for persons aged 13 to 49 years.

RESULTS

The average annual rate of diagnosis (per 100,000 persons) for older persons was 9.8. Rates among older Blacks (49.2) and Hispanics/Latinos (19.5) were 12.6 and 5.0 times, respectively, the rate among older Whites (3.9); rates among younger Blacks (102.5) and Hispanics/Latinos (39.0) were 7.7 and 2.9 times, respectively, the rate among younger Whites (13.3). Older persons were more likely than younger persons to receive a late HIV diagnosis (prevalence ratio=1.5, P<.001).

CONCLUSIONS

Racial/ethnic disparities in HIV diagnosis rates are greater among persons aged 50 years and older than among younger persons. The greater HIV diagnosis rates in Blacks and later diagnosis among older persons of all races/ethnicities indicate a need to increase their awareness of risk factors for HIV infection.

Substance Abuse, Hepatitis C, and Aging in HIV: Common Cofactors that Contribute to Neurobehavioral Disturbances

Although the prevalence of neurocognitive disturbances among individuals with HIV has decreased in recent years, rates of impairment still remain high. This review presents findings from comorbid conditions that may contribute to further neurocognitive impairments in this already vulnerable population. We will focus on three co-factors that have received substantial attention in the neuroAIDS literature: drug use, hepatitis C co-infection (HCV), and aging. All three conditions commonly co-occur with HIV and likely interact with HIV in complex ways. Collectively, the extant literature suggests that drug use, HCV, and aging serve to worsen the neurocognitive profile of HIV through several overlapping mechanisms. A better understanding of how specific comorbidities interact with HIV may reveal specific phenotypes of HIV-associated neurocognitive disorder that may aid in the development of more targeted behavioral and pharmacological treatment efforts.

Neurocognitive consequences of HIV infection in older adults: an evaluation of the "cortical" hypothesis

The incidence and prevalence of older adults living with HIV infection is increasing. Recent reports of increased neuropathologic and metabolic alterations in older HIV+ samples, including increased cortical beta-amyloid, have led some researchers to suggest that aging with HIV may produce a neuropsychological profile akin to that which is observed in “cortical” dementias (e.g., impairment in memory consolidation). To evaluate this possibility, we examined four groups classified by HIV serostatus and age (i.e., younger ≤40 years and older ≥50 years): (1) Younger HIV− (n = 24); (2) Younger HIV+ (n = 24); (3) Older HIV− (n = 20); and (4) Older HIV+ (n = 48). Main effects of aging were observed on episodic learning and memory, executive functions, and visuoconstruction, and main effects of HIV were observed on measures of verbal learning and memory. The interaction of age and HIV was observed on a measure of verbal recognition memory, which post hoc analyses showed to be exclusively attributed to the superior performance of the younger HIV seronegative group. Thus, in this sample of older HIV-infected individuals, the combined effects of HIV and aging do not appear to result in a “cortical” pattern of cognitive deficits.

Sex and race effects on risk for selected outcomes among elderly HIV-infected patients

The HIV-infected population in the United States is aging. A retrospective study of 132 patients (26 women, 106 men) ≥59 years of age was undertaken to evaluate the effect of race and sex on selected outcomes. With the exception of women being more likely to have diagnosis of depression compared with men, sex had little influence on risk for other conditions among elderly patients with HIV. In contrast, African American race was significantly associated with the risk for several selected disorders and outcomes. These results can assist in future prevention efforts among senior individuals with HIV infection.

Aging and HIV infection

INTRODUCTION

Population aging has become a global phenomenon, and HIV infection among older individuals is also increasing. Because age can affect the progression of HIV infection, we aimed to evaluate the present knowledge on HIV infection in older patients.

METHODS

Literature review of the last 20 years.

RESULTS

Older HIV-infected patients have lower CD4(+) T cell counts, higher viral load and are more frequently symptomatic at diagnosis. The infection progresses more rapidly, with higher morbidity and lethality rates. However, older patients are more compliant to antiretroviral treatment; they experience a better virologic response, and treatment represents a positive clinical impact. Aging affects the complex interaction between HIV infection and the immune system. Both conditions contribute to the dysfunction of immune cells, including a decrease in the phagocytes' microbicidal capability, natural killer cells' cytolytic function, expression of toll-like receptors and production of interleukin-12. Chronic immune activation responsible for the depletion of CD4(+) and CD8(+) T cells in HIV infection appears to worsen with senescence. Older patients also exhibit a less robust humoral response, with the production of less avid and specific antibodies.

CONCLUSION

Both HIV and aging contribute to immune dysfunction, morbidity and mortality. However, highly active antiretroviral therapy (HAART) is beneficial for older patients, and treatment of older patients should not be discouraged.

Prevalence of chronic renal failure stage 3 or more in HIV-infected patients in Antwerp: an observational study

The introduction of Highly Active Antiretroviral Therapy has transformed HIV-infection from an inevitably lethal disease to a chronic condition with a life expectancy comparable to that of people with diabetes mellitus. In recent years it has become evident that people living with HIV/AIDS have an increased risk of developing cardiovascular disease and it is expected that the prevalence of chronic kidney disease will rise accordingly. To investigate the prevalence of chronic kidney disease in patients with HIV, we conducted a retrospective observational analysis using the clinical database of a large centre (Institute of Tropical Medicine) in the urban area of Antwerp, Belgium. The prevalence of chronic kidney disease among HIV infected subjects was found to be 3.0%. The development of chronic kidney disease was associated with age above 50 years, lower CD4 cell counts and Caucasian origin. Screening for chronic renal disorders and prevention of evolution toward chronic renal failure is a crucial challenge in the management of people living with HIV/AIDS.

HIV transmission and high rates of late diagnoses among adults aged 50 years and over

OBJECTIVES

Describe the epidemiology and impact of late diagnosis among older adults living with HIV and estimate age at infection.

METHODS

Comparative national analyses between individuals diagnosed when aged 50 years and over with individuals diagnosed prior to 50 years. Age at infection was estimated using CD4 cell count at diagnosis.

RESULTS

A total of 8255 older adults accessed HIV care in England, Wales and Northern Ireland in 2007, a 3.5-fold increase compared to 2000; with one in 10 individuals newly diagnosed in 2007. When compared with younger adults at diagnosis, older adults were significantly more likely to be men (74 vs. 58%; P < 0.001), infected through sex between men (40 vs. 34%; P < 0.001) and of white ethnicity (60 vs. 38%; P < 0.001). Older heterosexual adults were more likely to be infected within the UK (16 vs. 12%; P < 0.001), with evidence of travel abroad among white heterosexual men. Almost half (48%) of older adults were late presenters vs. a third (33%) of younger adults. Older late presenters were 14 times more likely to die within a year of diagnosis compared with older adults who were not diagnosed late (14 vs. 1%; P < 0.001) and had 2.4 times the risk of dying than younger late presenters. We estimate that nearly half (48%) of older adults diagnosed between 2000 and 2007 acquired their infection at age 50 and over.

CONCLUSION

Our study provides evidence of HIV transmission, high rates of late presentation and an increased risk of short-term mortality among older adults. These findings highlight the need for increased targeted prevention efforts and strategies to increase HIV testing among older adults at risk of HIV.

Aging and HIV infection: a comparison between older HIV-infected persons and the general population

BACKGROUND

As HIV-infected persons age, the relative contribution of HIV infection, combination antiretroviral therapy (cART), and the normal aging process to the frequent comorbidities is unknown.

METHODS

We prospectively evaluated comorbidities, cardiovascular risk, cognitive function, and anthropomorphic and laboratory parameters of HIV-infected persons aged 50 years and over in two US urban clinics. Results were compared to controls from the National Health and Nutrition Examination Survey (NHANES) matched 1:1 by age, race, gender, smoking status, and body mass index (BMI).

RESULTS

We enrolled 122 HIV-infected persons; median age 55 years, 83% male, 57% Caucasian, 39% current smokers, mean BMI 26 kg/m2, and 92% on cART. Compared to controls, HIV-infected persons had a higher prevalence of hypertension (54% vs 38%), hypertriglyceridemia (51% vs 33%), low bone mineral density (BMD) (39% vs 0%), and lipodystrophy and greater receipt of antihypertensive and lipid-lowering medications (all Ps < .05). Groups were similar in prevalence of coronary heart disease, diabetes mellitus, chronic viral hepatitis, non-AIDS-defining malignancies and Framingham Risk and cognitive function scores.

CONCLUSIONS

Older HIV-infected persons have a higher prevalence of hypertension, hypertriglyceridemia, low BMD, and lipodystrophy than matched controls, suggesting that HIV and treatment-related factors exceed "normal" aging in the development of those problems.

Aging with HIV: a cross-sectional study of comorbidity prevalence and clinical characteristics across decades of life

Nurses and nurse practitioners require information on the health problems faced by aging HIV-infected adults. In this descriptive, cross-sectional study, we reviewed the electronic medical records of 1,478 adult patients seen in an HIV clinic between May 2006 and August 2007 to examine patterns of comorbidities, and immunological and clinical characteristics across each decade of life. With increasing age, patients were found to have lower HIV viral loads, more prescribed medications, and a higher prevalence of comorbid conditions, including coronary artery disease, hypertension, hypercholesterolemia, hypogonadism, erectile dysfunction, diabetes, peripheral neuropathy, hepatitis C, esophageal gastric reflux disease, and renal disease. Fortunately, with increasing age, patients were also more likely to have public or private health insurance and tended to be more compliant to medical appointments. With growing interest in aging with HIV, this study highlights the vastly different comorbidity profiles across decades of life, calling into question what constitutes "older" with HIV.

Factors associated with preclinical disability and frailty among HIV-infected and HIV-uninfected women in the era of cART

BACKGROUND

HIV-associated immune injury is hypothesized to increase the risk of preclinical disability and frailty via inflammatory pathways. We investigated the role of CD4+ T cell depletion and clinical AIDS on preclinical disability and frailty in HIV-positive women with a history of combination antiretroviral therapy (cART) and HIV-negative women.

METHODS

This was a cross-sectional study nested within the Women's Interagency HIV Study (WIHS), a prospective cohort study initiated in 1994 across five U.S. cities. Questionnaires and tests were performed by 573 HIV-negative and 1206 HIV-positive women. Prevalence ratios were computed using regression models.

RESULTS

Severe CD4+ cell depletion was an independent predictor of slowness, weakness, and frailty in HIV-positive women compared with HIV-negative women. Women with CD4+ counts<100 cells/mm3 were 0.13 seconds slower to complete 4 meters (95% CI 0.06-0.21), 1.25 kg weaker (95% CI -2.31--0.19), and had 2.7 times higher prevalence of frailty (95% CI 1.46-5.01).

CONCLUSIONS

This study is one of the largest studies to administer performance-based tests to investigate disability and frailty in HIV-positive women. HIV-positive women with intact immune systems and without a history of clinical AIDS were no different from HIV-negative women on tests of slowness, weakness, and frailty phenotype.

Inpatient health services utilization among HIV-infected adult patients in care 2002-2007

OBJECTIVE

This study examines the frequency of inpatient hospitalization, the number of inpatient days, and factors associated with inpatient utilization in a multistate HIV cohort between 2002 and 2007.

DESIGN

A prospective cohort study of HIV-infected adults in care at 11 US HIV primary and specialty care sites located in different geographic regions.

METHODS

Demographic, clinical, and resource utilization data were collected from medical records for the years 2002-2007. Rates of resource use were calculated for number of hospital admissions, total inpatient days, and mean length of stay per admission.

RESULTS

Annual inpatient hospitalization rates significantly decreased from 35 to 27 per 100 persons from 2002 to 2007. The number of inpatient days per year significantly decreased over time, whereas mean length of stay per admission was stable. Women, patients 50 years or older, blacks, injection drug users, and patients without private insurance had higher hospitalization rates than their counterparts. Admission rates were lower for patients with high CD4 counts and low HIV-1 RNA levels.

CONCLUSIONS

Inpatient hospitalization rates and number of inpatient days decreased for HIV patients in this multistate cohort between 2002 and 2007. Sociodemographic disparities in inpatient utilization persist.

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.

Non-AIDS-defining deaths and immunodeficiency in the era of combination antiretroviral therapy

OBJECTIVE

To assess whether immunodeficiency is associated with the most frequent non-AIDS-defining causes of death in the era of combination antiretroviral therapy (cART).

DESIGN

Observational multicentre cohorts.

METHODS

Twenty-three cohorts of adults with estimated dates of human immunodeficiency virus (HIV) seroconversion were considered. Patients were seroconverters followed within the cART era. Measurements were latest CD4, nadir CD4 and time spent with CD4 cell count less than 350 cells/microl. Outcomes were specific causes of death using a standardized classification.

RESULTS

Among 9858 patients (71 230 person-years follow-up), 597 died, 333 (55.7%) from non-AIDS-defining causes. Non-AIDS-defining infection, liver disease, non-AIDS-defining malignancy and cardiovascular disease accounted for 53% of non-AIDS deaths. For each 100 cells/microl increment in the latest CD4 cell count, we found a 64% (95% confidence interval 58-69%) reduction in risk of death from AIDS-defining causes and significant reductions in death from non-AIDS infections (32, 18-44%), end-stage liver disease (33, 18-46%) and non-AIDS malignancies (34, 21-45%). Non-AIDS-defining causes of death were also associated with nadir CD4 while being cART-naive or duration of exposure to immunosuppression. No relationship between risk of death from cardiovascular disease and CD4 cell count was found though there was a raised risk associated with elevated HIV RNA.

CONCLUSION

In the cART era, the most frequent non-AIDS-defining causes of death are associated with immunodeficiency, only cardiovascular disease was associated with high viral replication. Avoiding profound and mild immunodeficiency, through earlier initiation of cART, may impact on morbidity and mortality of HIV-infected patients.

Temporal changes in causes of death among HIV-infected patients in the HAART era in Rio de Janeiro, Brazil

BACKGROUND

The widespread use of highly active antiretroviral therapy (HAART) has led to marked decreases in death rates in Brazil in HIV-infected individuals. Nonetheless, there are scarce data on specific causes of death.

METHODS

Death rates from a cohort of HIV-infected patients in Rio de Janeiro, Brazil, were analyzed in 2-year periods, from 1997 to 2006. Poisson models and survival models accounting for competing risks were used to assess association of covariables. A standardized validated algorithm was used to ascertain specific causes of death.

RESULTS

Of the 1538 eligible patients, 226 (14.7%) died during the study period, corresponding to a mortality rate of 3.2 per 100 person-years. The median follow-up time was 4.61 years (interquartile range = 5.63 years) and the loss to follow-up rate was 2.4 per 100 person-years. Overall, 98 (43.4%) were classified as non-AIDS-related causes. Although opportunistic infections were the leading causes of death (37.6%), deaths due to AIDS-related causes declined significantly over time (P < 0.01). In the most recent period (2005-2006), the rate of non-AIDS-related causes of deaths was higher than that of AIDS-related causes of death.

CONCLUSIONS

In the HAART era, there has been a significant change in causes of death among HIV-infected patients in Rio de Janeiro. As access to HAART improves, integration with other public programs will become critically important for the long-term success of HIV/AIDS programs in developing countries.

Vulnerabilities and caregiving in an ethnically diverse HIV-infected population

The current study aimed to identify the primary informal caregivers of a group of urban HIV+ adults (n = 250) and to determine relationships between demographic, medical, and substance use characteristics and caregivers types. Reported caregiver types included 36.8% familial, 22.4% significant other, and 22.8% institutional or other caregiver relationships. The remaining 18% of the sample reported having no individual that rendered informal care. Factors associated with the absence of an informal caregiver included African American race and low education. Hispanic participants reported the highest frequency of family caregivers while participants with a history of substance disorder were less likely to identify a significant other as a caregiver. This study demonstrates the evolving nature of informal caregiving in HIV, race- and education-related disparities in the absence of primary caregivers, and the importance of sociocultural and demographic factors in the study of HIV caregiving.

Immunosenescence Modulation by Vaccination

A decline in immune function is a hallmark of aging that leads to complicated illness from a variety of infectious diseases, cancer and other immune-mediated disorders, and may limit the ability to appropriately respond to vaccination. How vaccines might alter the senescent immune response and what are the immune correlates of protection will be addressed from the perspective of 1) stimulating a previously primed response as in the case of vaccines for seasonal influenza and herpes zoster, 2) priming the response to novel antigens such as pandemic influenza or other viruses, 3) vaccination against bacterial pathogens such as pneumococcus, and 4) altering the immune response to an endogenous protein as in the case of a vaccine against Alzheimer’s disease. In spite of the often limited efficacy of vaccines for older adults, influenza vaccination remains the only cost-saving medical intervention in this population. Thus, considerable opportunity exists to improve current vaccines and develop new vaccines as a preventive approach to a variety of diseases in older adults. Strategies for selecting appropriate immunologic targets for new vaccine development and evaluating how vaccines may alter the senescent immune response in terms of potential benefits and risks in the preclinical and clinical trial phases of vaccine development will be discussed.

Epidemiology of HIV and response to antiretroviral therapy in the middle aged and elderly

HIV is increasing in prevalence in the middle aged and older population owing to both increased longevity, and new infections in these populations. Highly active antiretrorival therapy (HAART) therapy may be less effective at restoring immune function in older patients compared with younger patients. There are significant toxicities associated with HAART therapy that, combined with decreased renal and liver function in older patients, may be more problematic in older HIV-infected patients. Comorbid disease is becoming an increasing problem with coadministration of multiple drugs and significant drug-drug interactions. Psychosocial issues in the older patient are often different than those in younger HIV-infected patients and providers should try to address these issues early. Finally, future research should work to identify the ideal timing and type of HAART regimens for older HIV-infected individuals.

Ageing with HIV: newly diagnosed older adults in Italy

The prevalence of HIV/AIDS among people in midlife and late adulthood has been increasing in Western countries over the last decade. We analyzed data from a prospective, observational multi-centre study on individuals newly diagnosed with HIV between January 2004 and March 2007 in 10 public counselling and testing sites in Latium, Italy. At diagnosis, routine demographic, epidemiological, clinical and laboratory data are recorded, and patients are asked to complete a questionnaire investigating socio-demographic and psycho-behavioural aspects. To analyze the association of individual characteristics with age, we compared older adults (> or = 50 years) with their younger counterpart (18-49 years). To adjust for potential confounding effect of the epidemiological, clinical and behavioural characteristics, to identify factors associated with older age at HIV diagnosis, multivariate logistic regression analysis was performed. Overall, 1073 individuals were identified, 125 of whom (11.6%) were aged 50 years or above. The questionnaire was completed by 41% (440/1073). Compared with their younger counterparts, a higher proportion of older patients were males, born in Italy, reported heterosexual or unknown HIV risk exposure, were never tested for HIV before and were in a more advanced stage of HIV infection at diagnosis. In addition, older adults had a lower educational level and were more frequently living with their partners or children. With respect to psycho-behavioural characteristics, older patients were more likely to have paid money for sex and have never used recreational drugs. Interestingly, no differences were found regarding condom use, which was poor in both age groups. These findings may have important implications for the management of older adults with HIV, who should be targeted by appropriate public health actions, such as opportunistic screening and easier access to healthcare. Moreover, strategies including information on HIV and prevention of risk behaviours are needed.

HIV-induced immunodeficiency and mortality from AIDS-defining and non-AIDS-defining malignancies

OBJECTIVE

To evaluate deaths from AIDS-defining malignancies (ADM) and non-AIDS-defining malignancies (nADM) in the D:A:D Study and to investigate the relationship between these deaths and immunodeficiency.

DESIGN

Observational cohort study.

METHODS

Patients (23 437) were followed prospectively for 104 921 person-years. We used Poisson regression models to identify factors independently associated with deaths from ADM and nADM. Analyses of factors associated with mortality due to nADM were repeated after excluding nADM known to be associated with a specific risk factor.

RESULTS

Three hundred five patients died due to a malignancy, 298 prior to the cutoff for this analysis (ADM: n = 110; nADM: n = 188). The mortality rate due to ADM decreased from 20.1/1000 person-years of follow-up [95% confidence interval (CI) 14.4, 25.9] when the most recent CD4 cell count was <50 cells/microl to 0.1 (0.03, 0.3)/1000 person-years of follow-up when the CD4 cell count was more than 500 cells/microl; the mortality rate from nADM decreased from 6.0 (95% CI 3.3, 10.1) to 0.6 (0.4, 0.8) per 1000 person-years of follow-up between these two CD4 cell count strata. In multivariable regression analyses, a two-fold higher latest CD4 cell count was associated with a halving of the risk of ADM mortality. Other predictors of an increased risk of ADM mortality were homosexual risk group, older age, a previous (non-malignancy) AIDS diagnosis and earlier calendar years. Predictors of an increased risk of nADM mortality included lower CD4 cell count, older age, current/ex-smoking status, longer cumulative exposure to combination antiretroviral therapy, active hepatitis B infection and earlier calendar year.

CONCLUSION

The severity of immunosuppression is predictive of death from both ADM and nADM in HIV-infected populations.

Abnormal thyroid function in older men with or at risk for HIV infection

OBJECTIVES

The aim of the study was to evaluate the prevalence of and factors associated with abnormal thyroid function in older men with or at risk for HIV infection.

METHODS

A cross-sectional analysis of 636 men > or =49 years old was carried out using data obtained from interviews, from measurements of body mass index (BMI), HIV-1 serology and viral load, CD4 cell count, hepatitis C virus (HCV) assays, thyroid-stimulating hormone (TSH) and free thyroid hormone levels.

RESULTS

Participants were 54% black, 57% overweight/obese, 57% HIV seropositive, and 72% HCV seropositive; 38% reported recent cocaine or heroin use. Decreased TSH was found in 56 men (8.8%) and raised TSH in 23 men (3.6%). Only three men had abnormal free thyroxine levels.

CONCLUSIONS

Abnormal TSH levels were noted in 12.4% of older men with or at risk for HIV infection, but nearly all reflected subclinical hyperthyroidism or subclinical hypothyroidism.

Increasing proportion of AIDS diagnoses among older adults in Italy

We evaluated the impact of AIDS among older persons in Italy and compared these cases with cases among younger persons. The data source was Italy's National AIDS Registry. We considered adults diagnosed with AIDS between 1982 and 2005. Older adults were defined as those aged 50 years or older at diagnosis. Of the total adult cases, 8.8% were among older adults. This proportion increased over time, from 4.9% in 1982-1990 to 15.9% in 2000-2005. Among older adults, the most represented exposure category (80.8%) was sexual intercourse (heterosexual and homosexual). At AIDS diagnosis, older adults, compared to younger adults, had a higher risk of developing AIDS dementia complex or wasting syndrome, and of presenting multiple AIDS-defining illnesses. A significantly lower proportion of older adults were undergoing antiretroviral therapy, compared to younger adults. Among older adults, 67.2% were late testers, compared to 32.8% of younger adults. Most of the older adults acquired the infection through sexual contact; approximately two thirds of them were diagnosed late (i.e., first HIV-positive test 6 months or less before AIDS diagnosis); and only one fourth were undergoing antiretroviral therapy at diagnosis. These observations stress the need to more seriously consider the possibility of HIV infection among older individuals and to collect more detailed information on their sexual behavior.

Immunologic and clinical responses to highly active antiretroviral therapy in patients with HIV infection aged >50 years

We analyzed the effect of age on highly active antiretroviral therapy efficacy and tolerance in 639 patients with human immunodeficiency virus (HIV) infection (99 of whom were aged >50 years, and 540 of whom were aged <50 years). Late testing, which was more frequent in the older age group, was the only independent factor associated with immunologic and clinical evolution of infection. Age >50 years was associated with earlier treatment discontinuation.

Subthreshold and superthreshold coexistence of pathogen variants: the impact of host age-structure

It is well known that in the most general epidemic models with multiple pathogen variants a competitive exclusion principle is valid, such that the variant with the highest reproduction number eliminates the rest. Mechanisms such as super-infection, coinfection, and cross-immunity can lead to pathogen polymorphism where multiple strains coexist. It is also known that variability of infectivity with host age can destabilize the endemic equilibrium and cause oscillations. In this article we show that the hosts' chronological age can itself lead to coexistence of microparasites in the most basic model where competitive exclusion will occur without the age structure. Moreover, the host age-structure leads to multiple subthreshold dominance equilibria, and both weakly and strongly subthreshold coexistence. We find that the two pathogens cannot cooperate to persist subthreshold if neither one of them can persist subthreshold by itself. If, however, one of them can persist subthreshold by itself, it can cause the two pathogens to coexist in a strongly subthreshold equilibrium. The second strain that persists subthreshold through the mediation of the first always has a lower virulence. Our results show that age structure in infectivity can permit the coexistence of competing pathogens when the incidence is of proportionate mixing type (frequency-dependent transmission) and at least one of the strains is virulent.

HIV and Aging

Between 2001 and 2004, the percentage of all HIV cases in patients aged >or=50 years increased from 17% to 23%. This concerning increase is expected to continue over the next decade. The increasing prevalence of HIV in these patients is a result of increased longevity in patients treated with highly active antiretroviral therapy (HAART) as well as new primary infections in older patients. While older patients may achieve virological suppression at the same rate as younger patients, the immunological benefit of HAART in older patients may be reduced compared with younger patients. In addition, the toxicities associated with HAART may be worse in older HIV patients, particularly those with underlying renal or hepatic insufficiency. All previous studies evaluating the virological and immunological benefits of HAART in older patients have had relatively small sample sizes and none has compared efficacy or rates of toxicity by HAART treatment class. Co-morbidities are more common in older than in younger patients and can impact on the management of HIV in these patients. Providers must be cognisant of drug-drug interactions and potential adverse effects of HAART regimens when selecting an ideal antiretroviral regimen for older HIV patients. Given the increased longevity and rates of malignancies in HIV-infected patients, providers should also be particularly vigilant in maintaining routine health screening in older HIV patients. Controlled trials on HIV epidemiology, pathogenesis, and therapeutic and clinical outcomes are also needed in older patients. As the HIV-infected population ages, there is a growing need to better determine the effectiveness of HAART in older patients, and to investigate factors associated with a more rapid course of HIV infection in patients aged >50 years.

Aging and HIV infection

With the advent of highly active antiretroviral therapy (HAART) in mid-1995, the prognosis for HIV-infected individuals has brightened dramatically. However, the conjunction of potent antiviral therapy and longer life expectancy may engender a variety of health risks that, heretofore, HIV specialists have not had to confront. The long-term effects of HIV infection itself and exposure to antiretroviral agents is unknown. Several aspects of aging, including psychiatric disease, neurocognitive impairment, and metabolic and hormonal disorders, may be influenced by chronic exposure to HIV and/or HIV therapeutics. In this paper, we discuss the health issues confronting HIV-infected older adults and areas for future research.