Assessment of Serum sRANKL, sRANKL/OPG Ratio, and Other Bone Turnover Markers with the Estimated 10-Year Risk of Major and Hip Osteoporotic Fractures in Rheumatoid Arthritis: A Cross-Sectional Study

Table 1

Comparison of selected patient characteristics between the groups with rheumatoid arthritis with osteoporosis vs. without osteoporosis.

Clinical features	RA+ osteoporosis	RA without osteoporosis
Females, (%)	77 (100)	79 (100)	—
Age (yr),			<0.001
Body mass index (kg/m^2),			<0.001
Disease characteristics
Disease duration (yr),			0.058
Menopausal duration (yr),			<0.001
DAS28 score,			0.086
HAQ-Di score,			0.173
ESR (mm/hr),			0.006
Rheumatoid factor (UI/mL),			0.186
Tumor necrosis factor-α (pg/mL),			0.711
ACPAs (+), (%)	59 (76.6)	53 (67.1)	0.215
Anti-CCP2 (+), (%)	45 (58.4)	47 (59.5)	1.000
Anti-CCP2 (RU/mL),			0.867
Anti-MCV (+), (%)	51 (66.2)	40 (50.6)	0.053
Anti-MCV (U/mL),			0.356
Treatment characteristics
cs-DMARD use, (%)	62 (80.5)	63 (79.7)	1.000
Monotherapy (1 cs-DMARD), (%)	27 (43.5)	30 (47.6)	0.721
Politherapy (2 cs-DMARD or more), (%)	33 (52.4)	35 (56.5)	0.721
Glucocorticoid use, (%)	64 (83.1)	62 (78.5)	0.544
Glucocorticoid dose (mg/day),			0.241
Biomarker serum levels
sRANKL (pmol/L),			0.005
OPG (pg/mL),			0.670
sRANKL/OPG ratio			0.017
DKK-1 (pg/mL),			0.028
SOST (pg/mL),			<0.001
OC (ng/mL),			0.190
CTSK (pg/mL),			0.494

DAS28: Disease Activity Score for 28 joints; HAQ-DI: Health Assessment Questionnaire Disability Index; BMD: bone mineral density; ESR: erythrocyte sedimentation rate; ACPAs: antibodies against cyclic-citrullinated peptides/proteins included anti-CCP2 or anti-MCV; cs-DMARD: conventional synthetic-disease-modifying antirheumatic drugs; sRANKL: Soluble Receptor Activator for Nuclear Factor kappa B Ligand; OPG: osteoprotegerin; DKK-1: Dickkopf-1; SOST: sclerostin; OC: osteocalcin; CTSK: cathepsin k. Qualitative variables were expressed in frequencies (%) and quantitative variables in (SD). Statistical tests: Chi-square test (or Fisher exact test if applicable) for comparisons between proportions. Independent sample Student -tests were conducted for comparisons between means, and values were obtained comparing RA patients with osteoporosis vs. RA patients without osteoporosis. The group of patients without osteoporosis included patients with osteopenia or with normal BMD ().