JMIR Publications

ABSTRACT

Background:

With the advent of antiretrovirals, older people living with HIV (PLWH) are living near-normal lifespans. However, older PLWH are at greater risk to experience cognitive impairment and reduced brain integrity despite well-controlled viremia. A robust literature supports exercise interventions as a method of improving cognition and structural brain integrity in older individuals without HIV (PWoH). The effects of exercise on cardiometabolic, neurocognitive and neural structures in older PLWH are less well-known, with few prospective studies examining these measures.

Objective:

This prospective, randomized clinical trial will examine the effects of a six-month exercise training intervention compared to a six-month stretching intervention (control) on cardiorespiratory fitness, physical function and strength, cognition and neuroimaging measures of brain volumes and cerebral blood flow in older PLWH.

Methods:

Sedentary, older PLWH (ages ≥40; n=150) with undetectable HIV viral load (<20 copies/mL) will be enrolled into the study. At the baseline and final visit, fasting plasma lipid, insulin, glucose and brain neurotrophic factor concentrations, cardiorespiratory fitness, cognitive performance, brain volumes and cerebral blood flow via a magnetic resonance imaging (MRI) scan will be measured and participants will be randomized in a 2:1 ratio to either the exercise or control stretching intervention All participants will complete their assigned programs at a community fitness center three times a week for 6 months. A professional fitness trainer will provide personal training guidance at all sessions for individuals enrolled in both arms. Individuals randomized to the exercise intervention will perform endurance and strength training exercises, while those randomized to the control intervention will perform stretches to increase flexibility. A mid-point visit (at 3 months) will assess cognitive performance, and at the end-point visit subjects will undergo cardiorespiratory fitness and cognition testing, and an MRI scan. Physical activity throughout the duration of the trial will be recorded using an actigraph.

Results:

Recruitment and data collection are complete as of December 2020. Data processing, cleaning and organization are complete as of December 2021. Data analysis began in January 2022, with publication of study results for primary aims 1 and 2 expected by late 2022.

Conclusions:

This study will investigate the effects of a 6-month aerobic and resistance exercise training intervention to improve cardiometabolic risk factors, cognitive performance and cerebral structure and blood flow in sedentary, older PLWH. Results will inform clinicians and patients of the potential benefits of structured aerobic exercise training program on cognitive, functional and cardiometabolic health status of older PLWH. Assessment of compliance will inform the development and implementation of future exercise programs for older PLWH. Clinical Trial: This clinical trial has been registered to ClinicalTrials.gov (NCT02663934).