Cortical and Trabecular Bone Deficit in Middle-Aged Men Living with HIV

Area of Science:

• Bone Metabolism and HIV Research
• Medical Imaging and Diagnostics

Background:

• Middle-aged men living with HIV (MLWH) face an elevated risk of hip fracture, occurring nearly a decade earlier than in uninfected individuals.
• Limited data exists on specific hip bone deficits (cortical and trabecular) in MLWH, crucial for understanding bone strength.
• Human immunodeficiency virus (HIV) infection and its treatments can impact bone health.

Purpose of the Study:

• To compare hip bone density and structural parameters between MLWH and healthy controls.
• To investigate the association between antiretroviral therapy (ART) regimens, CD4 counts, and bone health in MLWH.
• To identify specific regions of cortical and trabecular bone deficit in MLWH.

Main Methods:

• Quantitative CT scans were performed on 83 MLWH and 166 age- and BMI-matched controls.
• Hip volumetric bone mineral density (vBMD) and cortical bone mapping parameters (cortical thickness [CTh], cortical bone vBMD [CBMD], cortical mass surface density [CMSD], endocortical trabecular density [ECTD]) were analyzed.
• Statistical analyses adjusted for covariates including age, BMI, smoking, alcohol use, HCV co-infection, tenofovir exposure, and CT scanner types.

Main Results:

• MLWH demonstrated significantly lower total hip vBMD, CMSD, and ECTD compared to controls, even after covariate adjustment.
• Cortical bone mapping revealed localized deficits in CTh, CBMD, and CMSD in the anterolateral trochanteric region and femoral neck of MLWH.
• Lower CD4 T-cell counts and protease inhibitor (PI)-based ART regimens at ART initiation were independently associated with lower total hip vBMD and CMSD in MLWH.

Conclusions:

• MLWH exhibit reduced hip bone density characterized by cortical and trabecular bone deficits compared to community-dwelling controls.
• Specific regions of the hip, including the femoral neck, show localized bone structural abnormalities in MLWH.
• Lower CD4 T-cell counts and PI-based ART regimens are significant factors associated with poorer bone density in MLWH, highlighting potential targets for intervention.