Evidence for bone mineral density and bone resorption in middle and elderly women with knee osteoarthritis in Shanghai: a cross sectional study

Abstract

Purpose: To explore the cross-sectional association between knee Osteoarthritis (OA) and bone metabolism in adults. Methods: A cross-sectional sample of 2812 female residents living in Lujiazui and Longhua distincts of Shanghai (range 45–80 years old) was included from July of 2015 to February of 2016. Data collection including basic characteristic, disease history and other information was performed by physicians from Longhua Hospital via a face-to-face interview. Lumbar Bone Mineral Density (BMD) was measured by using dual-energy X-ray absorptiometry by a qualified technician. Fasting blood was collected and bone metabolic biochemical markers were detected by third-party medical laboratory company. A multivariable logistic analysis model was applied to test the relationship between lumbar BMD and knee OA. Results: One thousand and ninety-five knee OA patients were analyzed in total. Four hundred and fifty-six (41.6%) patients suffered osteopenia and 346 (31.6%) also had osteoporosis (OP) in knee OA group. Age, Body Mass Index (BMI), chronic diarrhea and vitamin D were determined as potential confounders by data mining. After adjustment for them, lumbar BMD [OR (95%CI):0.43(0.26, 0.72), P = 0.0013] and lumbar BMD T-scores [OR (95%CI): 0.90(0.85, 0.95), P = 0.0002] were negatively associated with knee OA. In contrast, the prevalence of knee OA was significantly higher in the osteopenia group [OR (95%CI):1.12 (0.93, 1.35), P = 0.2356] and the OP group [OR (95%CI):1.28(1.05, 1.57), P = 0.0157] than in the normal group. The OR (95%CI) for trend was 1.13(1.02, 1.25), P = 0.0157. After adjusted the potential confounders, people who expressed higher B-CTX held greater risk to suffer KOA by 66% [OR (95%CI) P: 1.66 (1.07, 2.57) 0.0237]. There were two kinds tendency appeared in fitted curve. KOA increased with B-CTX augment before and decreased after turning point (B-CTX = 0.3 ng/mL),[ BCTX<0.3 ng/mL OR (95%CI) P: 1.34 (1.17, 1.54) <0.0001, B-CTX>0.3 ng/mL OR (95%CI) P: 0.96 (0.90, 1.03) 0.2317. Data was the effect size of B-CTX on KOA with per 0.1 ng/mL (100 pg/mL) change.]. Conclusions: It was the first time for us to conclude that a higher lumbar BMD was independent protective factor for knee OA in Chinese population, and we firstly found that B-CTX played different roles in KOA progression. When the concentration of serum B-CTX was less than 0.3 ng/mL, it was a risk factor to KOA, but when it was higher than 0.3 ng/mL, it was on the contrary. The study providing an unambiguous evidence for knee OA research and clinical treatment.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)