INTRODUCTION/OBJECTIVES This study aims to evaluate the role of fat free mass index (FFMI) and phase angle (PhA) as markers to predict occurrence of new digital ulcers in systemic sclerosis (SSc) patients. METHODS Body composition evaluation from bioelectrical impedance and clinical assessment were performed in SSc patients at enrollment and after 12 months follow-up. RESULTS Seventy-nine SSc patients (67 female) with a mean age of 53 ± 13 years were enrolled. In SSc patients with a digital ulcers history, FFMI value is lower (p < 0.05) and phase angle (PhA) value is higher (p < 0.01) than SSc patients without a digital ulcers history. After 12 months of follow-up, 30 patients (38%) presented at least one new episode of digital ulcers. Patients with reduced FFMI had a relative risk of 6.7 for new digital ulcers (CI 2.1-21.8, p < 0.001). Patients with reduced PhA had a relative risk of 10.1 for new digital ulcers (CI 3.5-29.5, p < 0.0001). In multivariate analysis, FFMI and PhA were associated with major vascular complication (digital ulcers, pulmonary arterial hypertension, and scleroderma renal crisis). FFMI loss, assessed as delta between follow-up and baseline, is higher in SSc with short duration (≤ 3 years) than SSc patients with long duration [0.4 (0-0.50) vs - 0.10 (- 0.2-0)]. CONCLUSION In SSc patients, reduction of the FFMI and PhA represents after 12 months a risk factor for development of new digital ulcers and major vascular complication.Key Points• Fat free mass index represents a risk factor for development of digital ulcers• Phase angle represents a risk factor for development of digital ulcers• Body compositions in systemic sclerosis are a marker of activity disease.

中文翻译：

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减少无脂脂肪质量指数和相角是系统性硬化症患者发展为数字性溃疡的危险因素。

引言/目的本研究旨在评估无脂肪质量指数（FFMI）和相角（PhA）作为预测系统性硬化症（SSc）患者新发数字溃疡发生的标志物的作用。方法在入选时以及随访12个月后，对SSc患者进行生物电阻抗评估身体成分并进行临床评估。结果纳入平均年龄为53±13岁的79名SSc患者（67名女性）。与没有数字溃疡病史的SSc患者相比，具有数字病史的SSc患者的FFMI值较低（p <0.05），相角（PhA）值较高（p <0.01）。随访12个月后，有30名患者（38％）出现了至少一发新发的数字性溃疡。FFMI降低的患者发生新的数字溃疡的相对风险为6.7（CI 2.1-21.8，p <0.001）。PhA降低的患者发生新的数字溃疡的相对风险为10.1（CI 3.5-29.5，p <0.0001）。在多变量分析中，FFMI和PhA与主要血管并发症（数字溃疡，肺动脉高压和硬皮病肾病）相关。FFMI丢失（以随访与基线之间的差值评估）在短期（≤3年）的SSc中比持续时间较长的SSc更高[0.4（0-0.50）对-0.10（-0.2-0）]。结论在SSc患者中，FFMI和PhA降低是12个月后发展为新的数字溃疡和主要血管并发症的危险因素。