Obesity Trends and Body Mass Index Changes After Starting Antiretroviral Treatment: The Swiss HIV Cohort Study

Metabolically Healthy or Metabolically Unhealthy Obese HIV-Infected Patients: Mostly a Matter of Age?

Background: Life expectancy of HIV-infected patients has increased with antiretroviral treatment (ART). Chronic diseases associated with aging, including metabolic and cardiovascular diseases are becoming more prevalent in this population. We aimed to evaluate the association of obesity and aging with cardiometabolic comorbidities and metabolic health status among patients with HIV infection. Methods: We evaluated 580 HIV-1 infected patients (71.7% male, mean age of 47.7 ± 11.5 years). We analyzed the association of age and obesity (defined by and by central obesity) with gender, duration of HIV infection, and ART, anthropometric parameters, cardiometabolic comorbidities, Framingham risk score (FRS), blood pressure, lipid profile, uric acid, liver biochemical tests, and glycemic profile. Furthermore, we analyzed the above-mentioned associations according to the category and central obesity into the metabolically healthy (MH) and unhealthy (MUH) categories. To evaluate the association of anthropometric parameters with cardiometabolic comorbidities, we performed unadjusted and adjusted logistic regression models. Results: The prevalence of excessive weight and cardiometabolic comorbidities increased with age. Patients with normal weight were younger and there was a higher proportion of female patients in the obesity group. The prevalence of hypertension and metabolic syndrome were higher among patients who were overweight or with obesity. The FRS was higher among patients with obesity. The proportion of MUH patients was higher among patients with excessive weight and central obesity. MUH patients had more cardiometabolic comorbidities and a higher FRS. In the normal weight group, MUH patients were older, and in the obesity group they were more likely to be male. The anthropometric parameter most associated with metabolic syndrome was waist circumference and that most associated with hypertension was waist-to-height ratio. The anthropometric parameter most associated with diabetes and FRS was waist-to-hip ratio. Conclusion: Patients with HIV present a high prevalence of obesity and related comorbidities. Ageing significantly contributes to metabolic dysfunction in this population. The proportion of MUH patients is higher among groups with excessive weight and central obesity, with those patients presenting a higher cardiovascular risk. Our results highlight the importance of evaluating and addressing obesity in patients with HIV, as well as metabolic comorbidities and cardiovascular risk.

Adipose Tissue in HIV Infection

HIV infection and antiretroviral therapy (ART) treatment exert diverse effects on adipocytes and stromal-vascular fraction cells, leading to changes in adipose tissue quantity, distribution, and energy storage. A HIV-associated lipodystrophic condition was recognized early in the epidemic, characterized by clinically apparent changes in subcutaneous, visceral, and dorsocervical adipose depots. Underlying these changes is altered adipose tissue morphology and expression of genes central to adipocyte maturation, regulation, metabolism, and cytokine signaling. HIV viral proteins persist in circulation and locally within adipose tissue despite suppression of plasma viremia on ART, and exposure to these proteins impairs preadipocyte maturation and reduces adipocyte expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) and other genes involved in cell regulation. Several early nucleoside reverse transcriptase inhibitor and protease inhibitor antiretroviral drugs demonstrated substantial adipocyte toxicity, including reduced mitochondrial DNA content and respiratory chain enzymes, reduced PPAR-γ and other regulatory gene expression, and increased proinflammatory cytokine production. Newer-generation agents, such as integrase inhibitors, appear to have fewer adverse effects. HIV infection also alters the balance of CD4+ and CD8+ T cells in adipose tissue, with effects on macrophage activation and local inflammation, while the presence of latently infected CD4+ T cells in adipose tissue may constitute a protected viral reservoir. This review provides a synthesis of the literature on how HIV virus, ART treatment, and host characteristics interact to affect adipose tissue distribution, immunology, and contribution to metabolic health, and adipocyte maturation, cellular regulation, and energy storage. © 2017 American Physiological Society. Compr Physiol 7:1339-1357, 2017.

HIV and ageing: improving quantity and quality of life

PURPOSE OF REVIEW

Evidence-based strategies are needed to address the growing complexity of care of those ageing with HIV so that as life expectancy is extended, quality of life is also enhanced.

RECENT FINDINGS

Modifiable contributing factors to the quantity and quality of life in adults ageing with HIV include: burden of harmful health behaviours, injury from HIV infection, HIV treatment toxicity and general burden of age-associated comorbidities. In turn, these factors contribute to geriatric syndromes including multimorbidity and polypharmacy, physiologic frailty, falls and fragility fractures and cognitive dysfunction, which further compromise the quality of life long before they lead to mortality.

SUMMARY

Viral suppression of HIV with combination antiviral therapy has led to increasing longevity but has not enabled a complete return to health among ageing HIV-infected individuals (HIV+). As adults age with HIV, the role of HIV itself and associated inflammation, effects of exposure to antiretroviral agents, the high prevalence of modifiable risk factors for age-associated conditions (e.g. smoking), and the effects of other viral coinfections are all influencing the health trajectory of persons ageing with HIV. We must move from the simplistic notion of HIV becoming a 'chronic controllable illness' to understanding the continually evolving 'treated' history of HIV infection with the burden of age-associated conditions and geriatric syndromes in the context of an altered and ageing immune system.

Higher Time-Updated Body Mass Index: Association With Improved CD4+ Cell Recovery on HIV Treatment

BACKGROUND

Prior studies found overweight or obese HIV-infected individuals had greater early CD4 cell recovery on antiretroviral therapy (ART), but the results have been inconsistent. We assessed the longitudinal relationship between body mass index (BMI) and CD4 cell recovery on ART in a large, multisite cohort to identify potential physiologic links between adiposity and CD4 cell expansion.

METHODS

We modeled the relationship of time-updated BMI with CD4 count in patients starting ART from 17 North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) cohorts. The primary analysis used a linear mixed effects model incorporating up to 13 years of data per patient and adjusted for age, sex, race, ART regimen, baseline CD4 count and other covariates. Sensitivity analyses limited the cohort to patients with sustained viral suppression or censored at virologic failure.

RESULTS

Fourteen thousand eighty-four HIV-infected individuals initiating ART contributed data between 1998 and 2010. Time-updated BMI was significantly associated with CD4 cell recovery over time (P < 0.001). After 5 years of ART, the mean CD4 count at a BMI of 30 kg/m was 22% higher than at a BMI of 22 kg/m (606 vs. 498 cells per microliter) and 34% higher at a BMI of 40 kg/m (665 vs. 498 cells per microliter). Results were similar in the sensitivity analyses.

DISCUSSION

Higher BMI is associated with long-term advantages in immune recovery on ART. Although it is unclear if this impacts health outcomes, including balancing the negative health effects of obesity, elucidating the underlying mechanism could identify therapies for patients with suboptimal immune reconstitution.

From Wasting to Obesity: The Contribution of Nutritional Status to Immune Activation in HIV Infection

The impact of human immunodeficiency virus (HIV) infection on innate and adaptive immune activation occurs in the context of host factors, which serve to augment or dampen the physiologic response to the virus. Independent of HIV infection, nutritional status, particularly body composition, affects innate immune activation through a variety of conditions, including reduced mucosal barrier defenses and microbiome dysbiosis in malnutrition and the proinflammatory contribution of adipocytes and stromal vascular cells in obesity. Similarly, T-cell activation, proliferation, and cytokine expression are reduced in the setting of malnutrition and increased in obesity, potentially due to adipokine regulatory mechanisms restraining energy-avid adaptive immunity in times of starvation and exerting a paradoxical effect in overnutrition. The response to HIV infection is situated within these complex interactions between host nutritional health and immunologic function, which contribute to the varied phenotypes of immune activation among HIV-infected patients across a spectrum from malnutrition to obesity.

Cerebral blood flow and cognitive function in HIV-infected men with sustained suppressed viremia on combination antiretroviral therapy

OBJECTIVE

To assess if HIV-infected patients on long-term successful combination antiretroviral therapy show cerebral blood flow (CBF) alterations in comparison with HIV-uninfected, otherwise similar controls. To explore whether such alterations are associated with HIV-associated cognitive impairment and to explore potential determinants of CBF alterations in HIV.

DESIGN

Cross-sectional comparison of CBF in an observational cohort study.

METHODS

Clinical, cognitive and MRI data of 100 middle-aged aviremic HIV-infected men on combination antiretroviral therapy and 69 HIV-uninfected controls were collected and compared. From pseudocontinuous arterial spin labeling MRI data, CBF-maps were calculated. The associations of mean gray matter CBF with clinical and cognitive parameters were explored in regression models, followed by a spatial delineation in a voxel-based analysis.

RESULTS

CBF was decreased in HIV-infected patients compared with HIV-uninfected controls (P = 0.02), adjusted for age, ecstasy use and waist circumference. Spatially distinct and independent effects of total gray matter volume and HIV-serostatus on CBF were found. Within the HIV-infected group, decreased CBF was associated with increased triglyceride levels (P = 0.005) and prior clinical AIDS (P = 0.03). No association between CBF and cognitive impairment was found.

CONCLUSION

Decreased CBF was observed among HIV-infected patients, which was associated with both vascular risk factors as well as with measures of past immune deficiency. These results provide support for increased vascular disease in HIV-infected patients as represented by hemodynamic alteration, but without overt cognitive consequences within the current cohort of patients on long-term successful treatment.

Aging metabolism: intervention strategies

Human beings are subjected to aging and age-associated diseases. Life expectancy has improved impressively in the last century due to social and economic development, but despite increasing improvement is still more limited than average in those ones with chronic diseases such as treated HIV infection. There has been a substantial research on the underlying factors responsible for aging both in the general and the HIV-infected populations. Several specific targets for potential intervention have been identified but studies so far have been limited to small experiments in cultured cells or living beings other than humans such as mice or flies. Time has come for designing and developing human studies with those candidate therapies showing most promising benefits and least potential toxicities to treat age-related diseases.

Changes in weight and weight distribution across the lifespan among HIV-infected and -uninfected men and women

Examine body composition changes across the lifespan of HIV-infected compared to uninfected adults. Longitudinal study of antiretroviral therapy (ART)-treated HIV-infected and uninfected participants from the Multicenter AIDS Cohort Study and Women's Interagency HIV Study. Body mass index (BMI), waist (WC), hip circumference (HC), and waist-to-height ratio (WHtR) measured at semiannual visits from 1999 to 2014. The age effect on outcomes over time was investigated using multivariate, piecewise, linear mixed-effect regression models adjusted for demographics, substance use, and comorbidities. Person-visits from 2363 men (1059 HIV-infected/1304 HIV-uninfected) and 2200 women (1455 HIV-infected/745 HIV-uninfected), median ages 45 [IQR 39,51] and 40 [32,46], respectively, were included. BMI gains were slower among HIV-infected participants of 40 years or less (P < 0.001), similar between HIV-infected and uninfected persons 40 to 60 years of age, and plateaued after age 60 in both groups. WC and WHtR increased across the age spectrum (P < 0.001) regardless of HIV serostatus, with significantly greater gains in HIV-infected men more than 60. Black race and Hispanic ethnicity were associated with greater BMI and WC. Lower BMI, WC, hip circumference, and WHtR were associated with hepatitis C infection among women only, and with substance use among all participants, and with lower CD4 cell count and shorter ART duration among HIV-infected participants. Slower BMI gain among younger HIV-infected adults may be partly explained by substance use and hepatitis C infection, and suggests that lower BMI does not represent improved health. Further analysis of muscle and fat abundance and quality will advance understanding of metabolic risk over the lifespan, a key to reducing morbidity in an aging population.

Obesity in patients with HIV infection: epidemiology, consequences and treatment options

Even though wasting used to characterize patients with HIV infection prior to the antiretroviral therapy (ART) era, obesity is becoming increasingly prevalent in this population. Areas covered: In the present review, we discuss the epidemiology, consequences and treatment options for obesity in patients with HIV infection. Expert commentary: Obesity exerts a multitude of detrimental cardiometabolic effects and appears to contribute to the increasing cardiovascular mortality of this population. However, there are very limited data on the optimal management of obesity in patients with HIV infection. Given the potential for interactions between antiobesity agents and ART that might compromise viral control, lifestyle changes should represent the cornerstone for the prevention and management of obesity in HIV infection.

Obesity prevalence and related risk of comorbidities among HIV+ patients attending a New England ambulatory centre

Background

Human immunodeficiency virus infection and obesity are pro‐inflammatory conditions that, when occurring together, may pose a synergistic risk for diabetes and cardiovascular disease.

Purpose

The aim of the current study was (i) to document the prevalence of obesity in HIV+ patients treated at the Miriam Hospital Immunology Center (Providence, RI) and (ii) to investigate the relationship between obesity and comorbidities.

Methods

The study population consisted of 1,489 HIV+ adults (70% men; average age 48 ± 11 years) treated between 01/01/2012 and 06/30/2014. Separate logistic regressions tested the associations between overweight and obesity and comorbid diagnoses (diabetes, hypertension and cardiovascular disease), as compared with normal weight. Covariates included age, gender and smoking status.

Results

Approximately 37% of patients were overweight (body mass index 25.0–29.9), and an additional 28% were obese (body mass index ≥30.0). Obesity was associated with higher odds of comorbid diabetes (OR = 3.26, CI = 1.98–5.39) and hypertension (OR = 2.11, CI = 1.49–2.98). There was no significant association between obesity and the presence of cardiovascular disease (OR = 1.12, CI = 0.66–1.90). Overweight was associated only with higher odds of comorbid diabetes (OR = 1.72; CI = 1.02–2.88).

Conclusion

Our findings demonstrate a heightened risk of comorbidities in overweight and obese HIV+ patients. Future studies should investigate whether weight loss interventions for this population can reduce cardiovascular and metabolic risk factors as they do in other populations.

The metabolic and cardiovascular consequences of obesity in persons with HIV on long-term antiretroviral therapy

OBJECTIVE

This study assessed the effect of obesity on metabolic and cardiovascular disease risk factors in HIV-infected adults on antiretroviral therapy with sustained virologic suppression.

DESIGN

Observational, comparative cohort study with three group-matched arms: 35 nonobese and 35 obese HIV-infected persons on efavirenz, tenofovir and emtricitabine with plasma HIV-1 RNA  less than  50  copies/ml for more than 2 years, and 30 obese HIV-uninfected controls. Patients did not have diabetes or known cardiovascular disease.

METHODS

We compared glucose tolerance, serum lipids, brachial artery flow-mediated dilation, carotid intima-media thickness, and soluble inflammatory and vascular adhesion markers between nonobese and obese HIV-infected patients, and between obese HIV-infected and HIV-uninfected patients, using Wilcoxon rank-sum tests and multivariate linear regression.

RESULTS

The cohort was 52% men and 48% nonwhite. Nonobese and obese HIV-infected patients did not differ by clinical or demographic characteristics. Obese HIV-uninfected controls were younger than obese HIV-infected patients and less likely to smoke (P < 0.03 for both). Among HIV-infected patients, obesity was associated with greater insulin release, lower insulin sensitivity, and higher serum high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-α receptor 1 levels (P < 0.001), but similar lipid profiles, sCD14, sCD163, intercellular adhesion molecule 1 and vascular cell adhesion molecule 1, and carotid intima-media thickness and flow mediated dilation. In contrast, Obese HIV-infected patients had adverse lipid changes, and greater circulating intercellular adhesion molecule 1, vascular cell adhesion molecule 1 and sCD14, compared with obese HIV-uninfected controls after adjusting for age and other factors.

CONCLUSION

Obesity impairs glucose metabolism and contributes to circulating high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-α receptor 1 levels, but has few additive effects on dyslipidemia and endothelial activation, in Obese HIV-infected adults on long-term antiretroviral therapy.

Perspectives on pharmacogenomics of antiretroviral medications and HIV-associated comorbidities

PURPOSE OF REVIEW

To summarize current knowledge and provide perspective on relationships between human genetic variants, antiretroviral medications, and aging-related complications of HIV-1 infection.

RECENT FINDINGS

Human genetic variants have been convincingly associated with interindividual variability in antiretroviral toxicities, drug disposition, and aging-associated complications in HIV-1 infection. Screening for HLA-B5701 to avoid abacavir hypersensitivity reactions has become a routine part of clinical care, and has markedly improved drug safety. There are well established pharmacogenetic associations with other agents (efavirenz, nevirapine, atazanavir, dolutegravir, and others), but this knowledge has yet to have substantial impact on HIV-1 clinical care. As metabolic complications including diabetes mellitus, dyslipidemia, osteoporosis, and cardiovascular disease are becoming an increasing concern among individuals who are aging with well controlled HIV-1 infection, human genetic variants that predispose to these complications also become more relevant in this population.

SUMMARY

Pharmacogenetic knowledge has already had considerable impact on antiretroviral prescribing. With continued advances in the field of human genomics, the impact of pharmacogenomics on HIV-1 clinical care and research is likely to continue to grow in importance and scope.

Short-term weight gain after antiretroviral therapy initiation and subsequent risk of cardiovascular disease and diabetes: the D:A:D study

OBJECTIVES

The aim of the study was to assess the impact of the gain in body mass index (BMI) observed immediately after antiretroviral therapy (ART) initiation on the subsequent risk of cardiovascular disease (CVD) and diabetes.

METHODS

We analysed data from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) cohort study. Outcomes were development of (i) CVD (composite of myocardial infarction/stroke/coronary procedure) and (ii) diabetes. The main exposure variable was change in BMI from ART initiation (pre-ART) to 1 year after initiation (continuous variable) in treatment-naïve individuals initiating ART with no history of CVD or diabetes (for respective outcomes). BMI [weight (kg)/(height (m))(2)] was categorized as underweight (< 18.5), normal (18.5-25), overweight (25-30) and obese (> 30). Poisson regression models were fitted stratified for each pre-ART BMI category to allow for category-specific estimates of incidence rate ratio (IRR). Models were adjusted for pre-ART BMI and CD4 count, key known risk factors (time-updated where possible) and calendar year.

RESULTS

A total of 97 CVD events occurred in 43,982 person-years (n = 9321) and 125 diabetes events in 43,278 person-years (n = 9193). In fully adjusted analyses for CVD, the IRR/unit gain in BMI (95% confidence interval) in the first year of ART, by pre-ART BMI category, was: underweight, 0.90 (0.60-1.37); normal, 1.18 (1.05-1.33); overweight, 0.87 (0.70-1.10), and obese, 0.95 (0.71-1.28) (P for interaction = 0.04). For diabetes, the IRR/unit gain in BMI was 1.11 (95% confidence interval 1.03 to 1.21), regardless of pre-ART BMI (P for interaction > 0.05).

CONCLUSIONS

Short-term gain in BMI following ART initiation appeared to increase the longer term risk of CVD, but only in those with pre-ART BMI in the normal range. It was also associated with increased risk of diabetes regardless of pre-ART BMI.

Human immunodeficiency virus and acquired immunodeficiency syndrome: recent developments and their implications for pediatric surgeons

Advances in medical management have enhanced both the quality and the quantity of life currently enjoyed by HIV-infected infants and children. Advances in surgical treatment have complemented these advances and contributed to the improving prognosis of HIV disease in the pediatric population. The resultant "aging" of the pediatric HIV population means that pediatric surgeons can expect to encounter HIV-infected patients on an ever-increasing basis. This article reviews the new advances in diagnosis and treatment of pediatric HIV disease most relevant to pediatric surgical practice.