Thymus Imaging Detection and Size Is Inversely Associated With Metabolic Syndrome and Frailty in People With HIV

Background: People with HIV (PWH) may experience accentuating aging in relation to immuno-activation. Little is known regarding thymus (THY) involution in this process. We sought to investigate the relationship between THY imaging detection/size and clinically relevant aging outcomes such as metabolic syndrome (MetS), multimorbidity (MM), and frailty in PWH.

Methods: This was a cross-sectional observational study including 665 HIV patients (81% males; median age, 53 years) attending Modena HIV Metabolic Clinic from 2014 to 2017. They underwent thoracic computed tomography scan as part of the medical assessment for cardiovascular disease, in which THY detection and size were reported using a semiquantitative score. Outcome measures were MetS, MM, and frailty.

Results: THY was detected in 27.0% of subjects; 71.1% showed THY size of grade 1-2, and 28.9% exhibited grade ≥3. Covariates that inversely correlated with THY detection were age, male gender, body mass index (BMI), and HIV duration. Covariates that inversely correlated with MetS were age, HIV duration, BMI, and THY grade 1-2. Covariates that inversely correlated with MM were age, HIV duration, and CD4 nadir. Covariates that inversely correlated with frailty were age, HIV duration, CD4 nadir, BMI, and THY detection.

Conclusions: THY is inversely associated with MetS and frailty in PWH.