Endocrine Abstracts

Objective: Human immunodeficiency virus (HIV)-infected patients demonstrate an increased risk of osteoporosis and fractures. The pathophysiology of HIV-induced bone loss is complex and remains largely unknown. Recent studies have identified a molecular signature of small non-coding RNAs (microRNAS) in patients with osteoporosis, but data are lacking in HIV-infected patients. The aim of the present study was to investigate the expression profile of microRNAs related to bone metabolism in HIV infected (HIV+) patients with osteoporosis.

Methods: This was a cross-sectional study of one single centre. Thirty HIV+ male patients on anti-retroviral treatment (ART) with low bone mass and 30 male HIV+ patients matched for age and ADT duration with normal bone mass were included in the analysis. Twenty matched for age not −HIV infected (HIV-) and otherwise healthy individuals, from whom 10 had low bone mass and were drug-naive at the time of enrollement were also included as controls. All participants had measurements of bone mineral density, vertebral fracture assessment and complete biochemical work up. In our study cohort we evaluated changes in the serum relative expression of selected miRs linked to bone metabolism.

Results: Mean age of the enrolled HIV + patients and mean duration of ART were 55 ± 8 years and 11 ± 7 years, respectively. None of the participants had a prior history of a fragility fracture. Three miRs were significantly deregulated in HIV+ patients with osteoporosis compared to HIV+patients with normal bone mass. In particular miR-24 was significantly increased (fold change 2.34, P = 0.03), and miR21 and miR-23a were significanlty decreased (fold changes 0.49, P < 0.001 and fold change 0.75, P = 0.04, respectively). The relative expression of miR-124 was significantly decreased (fold change 0.432, P = 0.02) in the serum of HIV+patients compared to controls. In a subgroup analysis between osteoporotic patients with and without HIV--infection, the relative expression of miR-124 and miR-29a were also significantly decreased in the serum of HIV+ patients compared to HIV- individuals (fold regulation 0.12, P = 0.01 and fold regulation 0.07, P = 0.02)

Conclusion: The serum expression profile of miRs linked to bone metabolism is significantly deregulated in HIV+ osteoporotic males compared to HIV+ patients with normal bone mass, in line with what has been shown in non HIV infected osteoporotic patients.