Are the clinical phenotypes of systemic sclerosis determinant for osteoporosis and fragility fractures?

Abstract

Aim: Systemic sclerosis (SSc) is associated with an increased risk of osteoporosis and fractures. The aim of this single-center cross-sectional study was to evaluate whether clinical phenotype and nailfold videocapillaroscopy (NVC) pattern could influence bone mineral density (BMD) values and fragility fractures in patients with SSc.

Methods: A cohort of 84 consecutive outpatients (age 63.7 ± 13.7 years) diagnosed with SSc, 43 classified as diffuse cutaneus SSc (dSSc) and 41 as limited cutaneus SSc (lSSc), were enrolled in the study. All patients underwent BMD by Dual Energy X-ray Absorptiometry (DX, pulmonary function tests for diffusing capacity of carbon monoxide (DLCO), and NVC to be assigned to an "early," "active," or "late" pattern.

Results: Patients with dSSc exhibited significantly lower BMD values compared to those with lSSc; moreover, the prevalence of osteoporosis and major osteoporotic fractures were higher in dSSc than in lcSSc (39,6% and 41,9% vs. 29,2% and 34,1%, respectively). Patients with a "late" or "active" NVC pattern had a more marked reduction in BMD with respect to those with a "early" pattern (p < 0.05). Moreover, patients with dSSc showed a greater reduction in DLCO values compared to those with lSSc in all three capillaroscopic patterns (p < 0.05). DLCO reduction and history of previous fracture were independent predictors of total hip BMD in dSSc patients.

Conclusion: Patients with SSc, and particularly those with a "diffuse" phenotype, have a high prevalence of osteoporosis and major osteoporotic fractures. Furthermore, in both SSc phenotypes, the presence of an "active" or "late" capillaroscopic pattern was associated with reduced BMD and DLCO values.