Assessment of vascular function in HIV-infected patients

Muscle mass, strength, bone mineral density and vascular function in middle-aged people living with HIV vs. age-matched and older controls

Introduction

Combination antiretroviral therapy (cART) substantially extended the life of people living with HIV (PLHIV). However, prolonged HIV infection and cART increase the risk of comorbidities accelerating age-related muscle, bone, and vascular disorders. This cross-sectional study compared muscle mass and strength, bone mineral density (BMD), and vascular function in middle-aged PLHIV treated with cART vs. non-infected age-matched and older controls.

Methods

After careful screening for secondary diseases and medications, body composition, muscular and vascular function were assessed in 12 PLHIV (43.9±8.7 yrs old; HIV-infection for 16.2±8.6 yrs; on cART for 11.6±9.2 yrs), 12 age-matched (CONT, 43.2±8.5 yrs old), and 12 older (OLDER, 74.4±8.3 yrs old) controls through dual x-ray absorptiometry, isokinetic dynamometry, and venous occlusion plethysmography, respectively.

Results

PLHIV and CONT showed similar relative muscle mass (65.3±8.0 vs. 66.9±7.3%, respectively; P= 0.88) and strength (160.7±53.9 vs. 152.0±52.9 N.m⁻¹, respectively; P= 0.90), which were greater than OLDER (80.6±18.8 N.m^−1; P= 0.001). Total BMD was similar in PLHIV (1.04±0.13 g.cm⁻²) and OLDER (1.00±0.15 g.cm⁻², P= 0.86), and both groups presented lower values than CONT (1.20±0.13 g.cm⁻², P< 0.01). No significant difference across groups was detected for macrovascular reactivity (P= 0.32).

Conclusion

Age-related osteopenia might be accelerated in middle-aged PLHIV on prolonged cART, as their BMD approached values found in older adults. On the other hand, muscle mass, isokinetic strength, and vasodilation capacity were similar in PLHIV and age-matched uninfected controls.

Association of HIV Infection and Antiretroviral Therapy With Arterial Stiffness: A Systematic Review and Meta-Analysis

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Influence of Physical Exercise on Advanced Glycation End Products Levels in Patients Living With the Human Immunodeficiency Virus

Introduction: Combined antiretroviral therapy (cART) used to treat acquired immunodeficiency virus (HIV) induces a number of adverse effects, such as insulin resistance and dyslipidemia, which ultimately increases the cardiovascular risk. Advanced glycation end products (AGEs) have been implicated in the etiology of cardiovascular diseases, diabetes and other chronic diseases. It is known that physical exercise improves the lipid profile, insulin resistance and reduces the risk of cardiovascular diseases. However, the impact of physical exercise on AGE levels in HIV-infected patients has not been so far investigated. Therefore, this study compared AGEs levels in people with and without HIV and verified the effect of physical training on serum AGE levels.

Methods: Participants were initially assigned into three groups: healthy control (CTL, n = 35), physically inactive HIV-infected (In-HIV, n = 33) and physically active HIV-infected (Ac-HIV, n = 19). The In-HIV group underwent physical training for 3 months, consisting of 60-min sessions of multimodal supervised exercise (aerobic, resistance and flexibility) with moderate intensity (50–80% heart rate reserve), performed 3 times/week. AGEs were measured in serum by fluorescence spectrometry.

Results: At baseline, serum AGEs fluorescence level was significantly higher in inactive HIV-patients when compared to controls or active HIV-patients (In-HIV: 0.93 ± 0.08 vs. controls: 0.68 ± 0.13 and Ac-HIV: 0.59 ± 0.04 A.U.; P < 0.001). Triglycerides were also higher in In-HIV than CTL (182.8 ± 102 vs. 132.8 ± 52.3 mg/dL; P < 0.05). Waist circumference was lower in Ac-HIV, compared to In-HIV and controls (83.9 ± 10.4 vs. 92.9 ± 13.5 and 98.3 ± 12.4, respectively; P < 0.05). Body mass, fasting blood glucose, LDL, HDL, and total cholesterol were similar between groups. After training, AGE levels decreased (Baseline: 0.93 ± 0.08 vs. 3 months follow-up: 0.59 ± 0.04 AU; P < 0.001), no further difference being detected vs. CTL or Ac-HIV. Conclusion: HIV-infected patients under cART exhibited elevated AGEs levels compared to healthy individuals and physically active patients. Short-term aerobic training of moderate intensity counteracted this condition.

Increased vascular function and superoxide dismutase activity in physically active vs inactive adults living with HIV

This study compared macro- and microvascular endothelial function and redox status in active vs inactive HIV-infected patients (HIVP) under antiretroviral therapy. Using a cross-sectional design, macro- and microvascular reactivity, systemic microvascular density, and oxidative stress were compared between 19 HIVP (53.1 ± 6.1 year) enrolled in a multimodal training program (aerobic, strength and flexibility exercises) for at least 12 months (60-minutes sessions performed 3 times/wk with moderate intensity) vs 25 sedentary HIVP (51.2 ± 6.3 year). Forearm blood flow during reactive hyperemia (521.7 ± 241.9 vs 361.4% ± 125.0%; P = 0.04) and systemic microvascular density (120.8 ± 21.1 vs 105.6 ± 25.0 capillaries/mm² ; P = 0.03) was greater in active than inactive patients. No significant difference between groups was detected for endothelium-dependent and independent skin microvascular vasodilation (P > 0.05). As for redox status, carbonyl groups (P = 0.22), lipid peroxidation (P = 0.86), catalase activity (P = 0.99), and nitric oxide levels (P = 0.72) were similar across groups. However, superoxide dismutase activity was greater in active vs inactive HIVP (0.118 ± 0.013 vs 0.111 ± 0.007 U/mL; P = 0.05). Immune function reflected by total T CD4 and T CD8 counts (cell/mm³ ) did not differ between active and inactive groups (P > 0.82). In conclusion, physically active HIVP exhibited similar immune function, but greater macrovascular reactivity, systemic microvascular density, and superoxide dismutase activity than inactive patients of similar age.

Microvascular Function in Aging Among Women Living with HIV

Combined antiretroviral therapy (CART) has turned HIV-infection to a treatable chronic disease during which many patients survive to middle and older age. However, they prematurely develop non-AIDS comorbidities such as cardiovascular disease, metabolic syndrome, diabetes, and HIV-associated neurocognitive disorders (HAND). Microcirculatory changes and endothelial dysfunction occur early both in HIV-infected and in aging patients, in whom they usually precede cardiovascular and neurocognitive impairments. Also, mild cognitive involvement has been reported in women during the menopausal transition. Disruption of the blood-brain barrier, as well as microvascular and cerebral blood flow changes, has been reported in HIV patients with HAND, including postmenopausal women. However, most studies addressing this issue included women aged less than 50 years. Whether HIV-infected women growing older with CART would be subsequently exposed to an increased progression of cognitive impairment overtime remains unknown.

Immunodominance: a pivotal principle in host response to viral infections

We encounter pathogens on a daily basis and our immune system has evolved to mount an immune response following an infection. An interesting phenomenon that has evolved in response to clearing bacterial and viral infections is called immunodominance. Immunodominance refers to the phenomenon that, despite co-expression of multiple major histocompatibility complex class I alleles by host cells and the potential generation of hundreds of distinct antigenic peptides for recognition following an infection, a large portion of the anti-viral cytotoxic T lymphocyte population targets only some peptide/MHC class I complexes. Here we review the main factors contributing to immunodominance in relation to influenza A and HIV infection. Of special interest are the factors contributing to immunodominance in humans and rodents following influenza A infection. By critically reviewing these findings, we hope to improve understanding of the challenges facing the discovery of new factors enabling better anti-viral vaccine strategies in the future.