## 3 Results  
### Baseline Characteristics of Systemic Sclerosis Patients and Healthy Controls  
Twenty healthy participants were examined. The median age was 26 years (range 19-56), and 13 (65%) were female. All were Caucasian; 19 (95%) participants were right-handed. All healthy individuals were nonsmokers. Two had arterial hypertension (10%) and were taking antihypertensive medication. Twenty female SSc patients were included. The median age was 60 years (range 24-79). Nineteen patients (95%) were Caucasian, and one patient was of Asian descent (5%). All SSc patients were right-handed (100%). Figure 3 shows the disposition of patients and HCs. SSc patients were significantly older than HCs (\(p\) < 0.0001) and included more female participants (\(p\) = 0.0083). Some of the recruited SSc patients were past (\(n\) = 4, 20%) or current (\(n\) = 2, 10%) smokers, while all HCs were non-smokers (\(p\) = 0.0293). No differences were  
Figure 3: CONSORT flowchart of screened and included patients. \(n\), number. found regarding ethnicity or dexterity (_p_ > 0.9999). Four (20%) SSc patients had type 2 diabetes mellitus, and three (15%) had chronic kidney disease. Thirteen SSc patients were categorized as having limited cutaneous SSc (lcSSC) and five with diffuse cutaneous SSc (dcSSC); one patient was diagnosed with Very Early Diagnosis of Systemic Sclerosis (VEDOSS). At the same time, one exhibited no skin involvement (sine scleroderma). Eighteen patients (90%) reported the presence of RP. Nailfold video capillaroscopy was available in 15 patients. Here, an \"early pattern\" was present in three patients, while ten patients demonstrated an \"active pattern\" and two patients a \"late pattern.\" Fourteen patients (70%) took vasoactive medication: ten used calcium-channel blockers (CCB) and seven patients received intravenous iloprost. In addition, a phosphodiesterase-inhibitor (PDE5-i) was prescribed in two SSc patients, and one patient was taking an endothelin receptor antagonist (ERA). All patient characteristics are shown in Table 1. \begin{table}
\begin{tabular}{l c c c} \hline  & **Systemic Sclerosis** & **Healthy Controls** & **\(p\)-Value** \\  & **\(n\) = 20** & **\(n\) = 20** & **\(p\)-Value** \\ \hline Demographic Data & & & \\ \hline Age; years, median (range) & 60 (24–79) & 26 (19–56) & **\(<\)0.0001** \\ Female Sex, \(n\) (\%) & 20 (100\%) & 13 (65\%) & **0.0083** \\ Right-handed & 20 (100\%) & 19 (95\%) & \\ Disease duration; months, median (range) & 50 (1–288) & - & \(>\)0.9999 \\ Ethnicity & & & - \\  & - Caucasian, \(n\) (\%) & 19 (100\%) & 20 (100\%) & \\  & - Asian, \(n\) (\%) & 1 (5\%) & 0 (0\%) & \(>\)0.9999 \\  & - Smoking status & & & \\  & - Current, \(n\) (\%) & 2 (10\%) & 0 (0\%) & **0.0293** \\  & - Past, \(n\) (\%) & 4 (20\%) & 0 (0\%) & \\  & - Never, \(n\) (\%) & 14 (70\%) & 20 (100\%) & \\ Comorbidities & & & & \\  & - Diabetes mellitus & 4 (20\%) & 0 (0\%) & **0.083** \\  & - Chronic kidney disease & 3 (15\%) & 0 (0\%) & \\ \hline Systemic Sclerosis-related characteristics & & & \\ \hline SSc type & & & \\ - VEDOSS, \(n\) (\%) & 1 (6.3\%) & - & \\ - Limited, \(n\) (\%) & 13 (68.8\%) & - & \\ - Diffuse, \(n\) (\%) & 5(18.8\%) & - & \\ - Sine scleroderma, \(n\) (\%) & 1 (6.3\%) & - & \\ \hline Antibody status & & & \\ \hline - Anti-Scl70., \(n\) (\%) & 2/19 (10.5\%) & - & \\ - Anti-CENP-B, \(n\) (\%) & 12/19 (63.2\%) & - & \\ - Anti-RNA PoI III, \(n\) (\%) & 3/15 (20\%) & - & \\ - Anti-Fibrillarin pos., \(n\) (\%) & 2/17 (11.8\%\%) & - & \\ \hline \multicolumn{4}{c}{Organ manifestations} \\ \hline - Raynaud’s phenomenon, \(n\) (\%) & 18 (90\%) & - \\ - ILD, \(n\) (\%) & 6 (30\%) & - \\ - PAH, \(n\) (\%) & 3 (15\%) & - \\ - Gastrointestinal, \(n\) (\%) & 15 (75\%) & - \\ - Musculoskeletal, \(n\) (\%) & 19 (95\%) & - \\ - Renal, \(n\) (\%) & 4 (20\%) & - \\ - Digital ulcers, \(n\) (\%) & 0 (0\%) & - \\ \hline \end{tabular}
\end{table} 
Table 1: Baseline characteristics of the study population.