Relationship between capillaroscopic alterations and bone ultrasound parameters in patients with raynaud phenomenon

The aim of this study was to evaluate phalangeal bone quantitative ultrasound (QUS) parameters in patients with Raynaud phenomenon (RP) and relate it with nailfold capillaroscopy findings. Patients referring to our Rheumatology Unit with RP were enrolled and studied for capillaroscopy alterations; bone quality profile was measured by QUS of the phalanxes: AD-SoS (Amplitude Dependent Speed of Sound) UBPI (Ultrasound Bone Profile Index), UBI (ultrasound Bone Index), Z score and T score were collected. One hundred thirty six females with RP had investigated for age, height, weight, Body Mass Index, previous diseases and therapies, menopausal age were enrolled. Nailfold capillaroscopy revealed minor alterations (borderline capillary dilatation, no capillary loss) in 36.8% (Group I), major alterations (capillaries definitely dilated, avascular areas, microbleeding) in 37.5% (Group II) and no significative alterations in 25.7% of patients (Group 0). A higher frequency of low QUS parameters in phalanxes was observed in group II when compared to group I or 0 (72.5% vs 54% vs 18%; p<0.01). With an ANOVA analysis we found a significant difference between the three groups in terms of Ad-SOS (Group II 1750±140; Group I 1890±132; Group 0 1990±167, p<0.001), UBPI (Group II 0.21±0.17; Group I 0.36±0.21; Group 0 0.51±0.24, p<0.001), UBI (Group II 1.2±0.43; Group I 1.4±0.32; Group 0 1.5±0.41, p<0.001), Z-scores (Group II -2.8±1.45; Group I -1.85±1.27; Group 0 -1.1±1.39, p<0.001) and T-scores (Group II -4.8±2.1; Group I -3.2±1.8; Group 0 -1.8±2.4, p<0.001). A standard linear regression analysis revealed an association between the capillaroscopy findings and QUS (R 0.47±0.8, p<0.01). In our study patients with capillaroscopy alterations showed reduced phalangeal quantitative ultrasound parameters, more markedly in patients with scleroderma pattern or other major capillaroscopy alterations, independently from confounding variables.