Seasonal variance of serum biomarker levels in osteoarthritis patients : a cross-sectional study of 104 patients

Objective: Prior studies have noted the importance of serum biomarkers in the pathogenesis of diseases. However, few studies have demonstrated the variance of inflammatory factors, bone metabolism factors, and hormones in OA (osteoarthritis) patients recruited from different seasons. This cross-sectional study was aimed to explore the seasonal influential factors of OA in patients recruited from different seasons. Methods: We retrospected 182 OA patients (from Feb 2014 to Jan 2015) hospitalized in the Department of Sports Medicine & Adult Reconstructive Surgery at Nanjing Drum Tower Hospital (the Affiliated Hospital of Nanjing University Medical School) and tested their preoperative blood samples for serum IL-6 (Interleukin-6), IL-1β, Tumor necrosis factor-α (TNF-α), Dickkopf1 (DKK1), Sclerostin (SOST), Osteopontin (OPN), Osteoprotegerin (OPG), Osteocalcin (OC), leptin, and Parathyroid hormone (PTH). Results: A total of 104 patients were included in this study (81 females, 23 males). The number of patients in each group was 24 in winter, 30 in spring, 26 in summer, and 24 in fall, respectively. Levels of serum TNF-α and IL-6 in the winter group were significantly higher than the other groups. IL-1β, however, showed the highest level in the fall group. Serum DKK1 topped in the winter group, while SOST peaked in the fall group. OPN level was higher in the spring and the summer group, which was the opposite of OPG. The fall group also presented higher levels of OC and PTH. Leptin level, on the other hand, topped in the summer group. Conclusions: Our findings showed that inflammatory factor (TNF-α), bone metabolism factors (DKK1, SOST, OPN, OPG), and bone metabolism hormones (OCN, PTH, leptin) in OA patients were associated with seasonal changes, which might provide a new perspective for identifying the pathogenesis of OA.