Table 1 Baseline characteristics of our study population.

Study population at first visit	933 (100%)
Age (years)	43.4±14.4
Gender	♀ 856/933 (91.7%)
	♂ 77/933 (8.3%)
BMI (kg/m 2 )	25.9±5.7
Age of disease onset (years)	35.5±13.8
Disease duration (years)	4.9±5.5
Patients with immigration background	268/933 (28.7%)

BMI: Body mass index.