Visceral adipose tissue in granulomatosis with polyangiitis: association with disease activity parameters.

Objective: To assess the body composition (BC) of patients with granulomatosis with polyangiitis (GPA) compared to healthy controls, emphasizing visceral adipose tissue (VAT) and associated BC parameters with disease activity, the damage index, and inflammatory parameters in patients with GPA.

Methods: This study was conducted in 43 patients with GPA and 43 healthy controls matched by sex, age, and body mass index (BMI). BC was analyzed using dual-energy X-ray absorptiometry (DXA). The fat mass parameters evaluated were total fat mass (FM), adiposity (%), the fat mass index (FMI: fat mass/ht), and VAT (g, cm, cm). Disease activity was assessed by the Birmingham Vasculitis Activity Score (BVAS). Damage was assessed by the Vasculitis Damage Index (VDI). C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) were measured.

Results: Comparing patients with GPA with healthy controls, patients had a significantly greater VAT (VAT in g: 685.81 ± 306.10 vs. 581.21 ± 235.57, p = 0.04; VAT in cm: 142.23 ± 63.48 vs. 119.84 ± 49.54, p = 0.03; VAT in cm: 741.33 ± 330.97 vs. 628.44 ± 254.66, p = 0.04). Patients with higher VAT (≥ 768 g) had an increased value of ESR (22.77 ± 26.79 vs. 11.57 ± 11.30 mm/1st hour, p = 0.04) and an increased value of BVAS (3.18 ± 4.15 vs. 0.90 ± 1.70, p = 0.01) when compared to patients with less VAT (< 768 g).

Conclusion: Patients with GPA have altered BC compared to healthy controls. Moreover, higher VAT was associated with disease activity and higher inflammatory markers, suggesting a relationship between GPA activity and adiposity parameters. Key points • Granulomatosis with polyangiitis patients have increased visceral adipose tissue when compared to health controls; • Granulomatosis with polyangiitis patients with higher values of visceral adipose tissue have worse disease activity and higher inflammatory markers; • This paper represents important contribution to the well-studied association between vasculitis and inflammatory markers, adding the role of adipose visceral tissue in the disease physiopathology.