Serum and salivary inflammatory biomarkers in juvenile idiopathic arthritis—an explorative cross-sectional study

Table 1 Characteristics of the study groups

Characteristics	JIA (N = 42)	Controls (N = 30)
Age at study visit, median years (IQR)	13.9 (11.3–15.1)	14.3 (12.2–16.4)
Sex, females, n (%)	29 (69.0)	22 (73.3)
Iso-BMI > 25^a, n (%)	10 (23.8)	6 (20.0)
Parental education^b, high level, n (%)	19 (50.0)	17 (65.4)
CRP ≥ 5 mg/L^c, n (%)	3 (7.1)	3 (10.3)
ESR > 10 mm/h^d, n (%)	16 (38.1)	4 (13.8)
Salivary flow rate^e, mL/min, mean (SD)	0.4 (± 0.5)	0.6 (± 0.6)

JIA Juvenile idiopathic arthritis, IQR Interquartile range, CRP C-reactive protein in milligram per liter plasma or serum, SD standard deviation, ESR Erythrocyte sedimentation rate measured in millimeter per hour
^aiso-BMI = body mass index adjusted for age and sex, corresponding to adult BMI groups according to The International Obesity Task Force for overweight/obesity: iso-BMI ≥ 25 kg/m2
^bParental education level, mother and father, the parent with the highest level determined the grouping: Low = primary and high school (≤ 13 years of education), High = university-level education
^cCRP ≥ 5 indicates active inflammation, CRP missing in 1 in the control group
^dESR > 10 mm/h indicates active inflammation, ESR missing in n = 1 in the control group
^eUnstimulated salivation: Saliva collected by drooling and spitting into a collection tube. Participants were instructed not to eat, drink, brush their teeth, or take any other than prescribed medication before collecting saliva, n = 4 saliva samples from the JIA group are missing

ISSN: 1546-0096