Increased Urinary Concentration of C-Terminal Telopeptide of Type II Collagen and Pain by Radiographic Grade in Women with Knee Osteoarthritis in Northeastern Mexico: A Cross-Sectional Study

Osteoarthritis (OA) of the knee causes disability, pain, and progressive destruction of cartilage in adult women. The objective of the study was to evaluate the concentrations of the urinary biomarker C-terminal telopeptide of type II collagen (CTX-II) and pain by radiographic grade in women with knee OA in northeastern Mexico: Cross-sectional study of 155 women with knee OA. Concentrations of biochemical parameters were evaluated and urine samples were collected to measure biomarker levels (uCTX-II) ng/mmol by competitive enzyme-linked immunoabsorbent assay (ELISA) technique and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale was used for pain classification; median age of 49 years and 29.1 kg/m(2) of body mass index (BMI). uCTX-II biomarker levels were grade 2 (210.7 ng/mmol), grade 3 (314.8 ng/mmol), and grade 4 (478.8 ng/mmol) relative to Kellgren and Lawrence, uCTX-II levels were compared with WOMAC scale and presented significant statistical difference (p = 0.0001). An association of the biomarker CTX-II and an increase in BMI was found in female patients with knee OA (odds ratio = 1.01; 95% confidence interval 1.001-1.005; p = 0.047).This study demonstrates an increase in the levels of the biomarker uCTX-II, the degree of pain, and radiographic grade in women with knee OA in northeastern Mexico.