Obesity is a major contributor to deterioration of physical function toward sarcopenia in knee osteoarthritis (OA) due to its effect mediated through adipokines-derived molecules that have pro-/anti-inflammatory properties. This study aimed to investigate relationships of serum adiponectin, 25-hydroxyvitamin D (25(OH)D), interleukin (IL)-6, and physical performance in knee OA patients. A total of 175 knee OA patients and 52 healthy controls were recruited. Serum adiponectin, 25(OH)D, IL-6, biochemical markers, knee pain and functional scores, muscle strength, physical performance, metabolic parameters, and body composition were evaluated. Serum adiponectin levels were significantly higher in knee OA patients than that in controls, while its serum levels were significantly decreased in obese patients, especially those with sarcopenia. Furthermore, there were independent relationships of serum adiponectin with body composition parameters, knee pain scores, physical function tests, and metabolic parameters in knee OA patients. Besides, serum adiponectin levels were positively associated with 25(OH)D levels, and negatively correlated with C-reactive protein and IL-6 levels in knee OA. Additionally, low serum adiponectin could be used to distinguish knee OA patients with sarcopenic obesity from those without sarcopenic obesity. Circulating adiponectin levels may serve as a possible surrogate biomarker for exacerbated physical function in knee OA patients-particularly sarcopenic obesity.

中文翻译：

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血清脂联素减少反映了膝部骨关节炎的低维生素D，高白介素6和较差的身体表现。

肥胖是导致膝关节骨关节炎（OA）的肌肉减少症的身体机能下降的主要因素，这是由于其通过具有促炎/抗炎特性的脂肪因子衍生的分子介导的。这项研究旨在调查膝OA患者的血清脂联素，25-羟基维生素D（25（OH）D），白介素（IL）-6与身体机能的关系。总共招募了175名膝OA患者和52名健康对照。评估血清脂联素，25（OH）D，IL-6，生化指标，膝盖疼痛和功能评分，肌肉力量，身体机能，代谢参数和身体成分。膝骨关节炎患者的血清脂联素水平显着高于对照组，而肥胖患者尤其是肌肉减少症患者的血清脂联素水平显着降低。此外，膝骨关节炎患者血清脂联素与身体成分参数，膝关节疼痛评分，身体功能测试和代谢参数之间存在独立关系。此外，血清脂联素水平与25（OH）D水平呈正相关，与膝OA中的C反应蛋白和IL-6水平呈负相关。另外，低血清脂联素可用于区分患有肌肉减少症的膝OA患者和没有肌肉减少症的膝OA患者。循环脂联素水平可能是膝OA患者特别是少肌症肥胖患者身体机能增强的可能替代生物标志物。血清脂联素水平与25（OH）D水平呈正相关，与膝OA中C反应蛋白和IL-6水平呈负相关。另外，低血清脂联素可用于区分患有肌肉减少症的膝OA患者和没有肌肉减少症的膝OA患者。循环脂联素水平可能是膝OA患者尤其是少肌症肥胖患者身体机能增强的替代生物标志物。血清脂联素水平与25（OH）D水平呈正相关，与膝OA中C反应蛋白和IL-6水平呈负相关。另外，低血清脂联素可用于区分患有肌肉减少症的膝OA患者和没有肌肉减少症的膝OA患者。循环脂联素水平可能是膝OA患者尤其是少肌症肥胖患者身体机能增强的替代生物标志物。