Banca de DEFESA: JASON AZEVEDO DE MEDEIROS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JASON AZEVEDO DE MEDEIROS
DATE: 14/11/2025
TIME: 09:00
LOCAL: REMOTA
TITLE:

TRANSCUTANEOUS AURICULAR VAGUS NERVE STIMULATION AND PHYSICAL EXERCISE AS STRATEGIES FOR MODULATING CARDIAC AUTONOMIC FUNCTION IN PEOPLE LIVING WITH HIV/AIDS

KEY WORDS:

Vagus nerve stimulation, HIV, Autonomic Nervous System, Physical Exercise, Therapy.

PAGES: 25
BIG AREA: Ciências da Saúde
AREA: Educação Física
SUMMARY:

People living with HIV/AIDS (PLWHA) may present with cardiac autonomic dysfunction resulting from the direct action of HIV on the central and autonomic nervous systems. Antiretroviral therapy (ART) remains the most effective strategy for controlling HIV viral replication. However, cardiovascular complications have been associated with the side effects of ART. Non-pharmacological strategies, such as transcutaneous auricular vagus nerve stimulation (taVNS) and physical exercise, may serve as important alternative therapies for modulating cardiac autonomic function. The aim of this thesis was to investigate, through two experimental studies and a rapid review, the effects of taVNS and the available evidence on physical exercise in the cardiac autonomic function of PLWHA. Two experimental studies were conducted: a proof-of-concept clinical trial to evaluate the acute effect of taVNS on cardiac vagal activity, and a pilot chronic study to analyze the effect of taVNS on post-exercise heart rate recovery. The rapid review sought to synthesize the acute and chronic effects of physical exercise on the cardiac autonomic function of PLWHA. The experimental studies included men living with HIV/AIDS who underwent a 30-minute taVNS protocol per session, with an intensity set at 200% of the sensory threshold, a frequency of 10 Hz, and a pulse width of 500 µs. Data collection included anamnesis, physical activity level assessment (IPAQ), anthropometric evaluation (weight and height), body composition by DEXA, sensory threshold determination, and pain perception using a visual analogue scale (VAS). In the acute study, cardiac vagal activity was assessed through vagally mediated heart rate variability (vmHRV) indices, including the root mean square of successive differences (rMSSD) and the percentage of differences between adjacent normal intervals greater than 50 ms (pNN50). In the chronic study, heart rate recovery (HRR) was assessed at 60-, 120-, and 300-seconds post-exercise. Peak oxygen consumption during the cardiopulmonary exercise test and the rate of perceived exertion (RPE) were also evaluated. In the acute study, no significant changes were observed in HRV parameters over time or between conditions, indicating that a single taVNS session was not sufficient to modulate cardiac vagal activity in PLWHA. Similarly, in the chronic study, no significant effects of time or group × time interaction were found for HRR at 60-, 120-, or 300-second post-exercise, suggesting that four weeks of taVNS did not induce relevant changes in cardiac autonomic modulation in this population. The rapid review indicated that PLWHA tend to exhibit slower vagal reactivation after acute exercise, whereas chronic interventions particularly aerobic exercise tends to enhance parasympathetic modulation, reflected by higher SDNN and improved HRR values. Taken together, the results do not confirm the effect of taVNS on cardiac vagal activity or post-exercise HRR in PLWHA. Meanwhile, the review reinforces that chronic physical exercise, especially aerobic training, remains the most effective non-pharmacological strategy to improve autonomic modulation in this population.

COMMITTEE MEMBERS:
Interno - 2627140 - BRENO GUILHERME DE ARAUJO TINOCO CABRAL
Externo à Instituição - JASON R JAGGERS
Presidente - 2626634 - PAULO MOREIRA SILVA DANTAS
Externo à Instituição - RONALDO VAGNER THOMATIELI DOS SANTOS - UNIFESP
Externo à Instituição - UIRASSU BORGES