# Fatigue, monocyte activation, and degree centrality of the thalamus in post-menopausal women living with HIV

## TL;DR

This study explores how brain connectivity and monocyte activation relate to fatigue in post-menopausal women with and without HIV.

## Contribution

The study investigates whether thalamic degree centrality mediates the effect of monocyte activation on fatigue in post-menopausal women with HIV.

## Key findings

- HIV-positive women had higher sCD14 levels and lower thalamic degree centrality compared to HIV-negative women.
- Higher sCD14 levels were associated with lower thalamic degree centrality.
- Thalamic degree centrality was linked to increased fatigue.

## Abstract

Post-menopause is associated with chronic fatigue, inflammation, and aberrant brain connectivity, however there is a dearth of studies comparing these effects as a function of HIV. The current study investigated whether degree centrality of the thalamus mediates the effect of sCD14, a marker of monocyte activation, on fatigue and whether those parameters vary as a function of HIV-status. Resting-state functional connectivity MRI data, blood plasma, and self-report data were collected from 16 HIV + and 25 HIV- post-menopausal women. Analyses tested whether degree centrality of the thalamus, caudate, and right putamen mediated the relationship between sCD14 and fatigue. HIV-serostatus was then tested as a moderator. Compared to HIV-negative, HIV + women had higher levels of sCD14, t(34) = -3.85, p <.001, and lower thalamic degree centrality, t(33) = 2.17, p =.038. SCD14 predicted lower thalamic DC, b = -1.16, p =.035. Degree centrality predicted fatigue, b = -4.50, p =.03. Indirect and moderation effects were not significant. Monocyte activation is feature of chronic HIV-infection that impacts the number of thalamic connections to whole brain. The reduced thalamic degree centrality is associated with greater neurobiological vulnerability for fatigue after menopause.