Abnormal Trabecular and Cortical Bone Microarchitecture in Chronic Hepatitis C Infection and Associations With Select Inflammatory Cytokines.

BACKGROUND

Hepatitis C virus (HCV) infection is associated with reduced bone mineral density (BMD) and increased fracture risk. The structural underpinnings for skeletal fragility with HCV and contributions of inflammatory cytokines remain unknown. We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to compare skeletal parameters by chronic HCV.

METHODS

We conducted a cross-sectional study among 58 participants with chronic HCV and 58 participants without HCV. Volumetric BMD and cortical dimensions of the radius and tibia were determined by HR-pQCT; visceral fat area and appendicular lean mass were assessed by whole body dual-energy x-ray absorptiometry; serum levels of tumor necrosis factor α (TNF-α), interleukin 6, and interleukin 18 were measured. Multivariable linear regression was used to estimate group differences in bone measurements and cytokines.

RESULTS

Participants with chronic HCV had lower radius trabecular volumetric BMD (-24.2 mg hydroxyapatite [HA]/cm3) and lower tibia trabecular volumetric BMD (-20.5 mg HA/cm3), cortical area (-20.9 mm2), and cortical thickness (-0.47 mm) than participants without HCV (all P < .05), independent of age, sex, visceral fat area, appendicular lean mass, and smoking. Mean log TNF-α was higher with chronic HCV (+0.1-log pg/mL; P < .001), but no differences in mean log interleukin 6 or interleukin 18 were observed. Higher log TNF-α was associated with lower radius trabecular volumetric BMD (-99.7 mg HA/cm3), lower tibia cortical volumetric BMD (-91.6 mg HA/cm3), and higher tibia cortical porosity (+1.39%) by HR-pQCT (all P < .05).

CONCLUSIONS

Patients with chronic HCV had decreased trabecular volumetric BMD and cortical dimensions and higher TNF-α than individuals without infection, suggesting that HCV-associated inflammation might contribute to bone deficits.