Background
Considering the critical need to identify people with HIV (PWH) at risk of frailty and sarcopenia, we present the results of the Functional substudy of the IMAGING study, a study aimed to identify image aging markers by whole-body magnetic resonance imaging (WB-MRI) in 50 PWH aged 50 years or older and 25 matched controls.
Methods
The Functional substudy is an exploratory study that evaluates WB-MRI muscle markers (intramuscular fat content in glutes, psoas, iliac, and total muscle) and specific muscular (irisin and myostatin) and mitochondrial (coenzyme Q10) plasma biomarkers for diagnosing pre-frailty/frailty or sarcopenia in PWH. Imaging, from the WB-MRI data collected in a Vantage Galan 3T (Canon Medical Systems, Japan) at the CMCiB, and muscle biomarkers were compared between PWH and controls, and correlated with functional evaluations (Barber, Barthel, Lawton, Fried phenotype, SPPB and grip strength) and DXA scan. Statistical analyses were performed using R software (https://www.r-project.org/). The protocol was approved by the Ethics Committee [Reference no. PI-20-035].
Results
Median duration of HIV infection was 29 years; all had undetectable viral loads. PWH had more comorbidities (median 5 vs. 3); 50% of PWH and 28% of controls had over 5 comorbidities. Malnutrition risk was higher in PWH (31% vs. 13.6%). A higher prevalence of dependency, prefrailty/frailty and low bone mineral density (BMD) were observed among PWH, as well as higher plasma levels of myostatin and lower levels of irisin (Table 1). Higher Coenzyme Q10 levels were associated with poorer health (dependency, frailty, osteopenia/osteoporosis); high irisin levels with frailty and dependency; and lower myostatin levels with poorer health, though some contradictory data were noted. Lower intramuscular fat fractions were observed in malnutrition and less so in conditions like dependency. Associations were found between higher intramuscular fat content and time of infection, time on antiretroviral therapy and time until therapy; while a better immunological status was associated with lower fat content.
Conclusions
In summary, PWH showed overall more dependency and frailty compared to controls with more unfavorable accompanying plasma markers. Thus, specifically irisin and Coenzyme Q10, might be potential diagnostic markers for dependency and frailty, if larger studies support their clinical utility potential. These results encourage us to continue assessing these markers for their predictive and diagnostic potential.
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