To investigate the levels of serum CXC chemokine ligand 1 (CXCL1), CC chemokine (CCL) 4 and CCL11 in patients with knee osteoarthritis (KOA) complicated with osteoporosis (OP), and to analyze their relationship with bone density, bone metabolism indexes and inflammatory factors.

A prospective collection of 181 KOA patients admitted to our hospital from September 2021 to August 2023 were selected as research objects, patients were divided into combined OP group (n=108) and non-combined OP group (n=73) according to whether they were combined with OP. The general data of two groups were collected, and the levels of serum CXCL1, CCL4 and CCL11 were detected. The bone mineral density (BMD) of total hip, femoral neck and lumbar L1-L4, serum bone metabolism indexes and inflammatory factors were detected. The correlation between serum CXCL1, CCL4 and CCL11 levels and bone mineral density, serum bone metabolism indexes and inflammatory factors were analyzed by Pearson correlation analysis. Multivariable binary Logistic regression analysis was used to analyze the independent influencing factors of KOA combined with OP, and the diagnostic value of serum CXCL1, CCL4 and CCL11 in KOA combined with OP were analyzed by receiver operating characteristic (ROC) curve.

The levels of serum CXCL1, CCL4, CCL11, bone metabolism indexs type I collagen carboxy terminal cross-linked peptide (s-CTX), type I collagen amino terminal propeptide (PINP), osteocalcin (BGP), bone alkaline phosphatase (BAP), interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) in OP group were higher than those in non-combined OP group (P<0.05), and the BMD of total hip, femoral neck and lumbar L1-L4 were lower than those in non-combined OP group (P<0.05). Pearson Correlation Analysis showed that, the levels of CXCL1, CCL4 and CCL11 in serum of KOA patients with OP were positively correlated with bone metabolism indexes s-CTX, PINP, BGP, BAP and inflammatory factors IL-1β, IL-6 and TNF-α, and negatively correlated with total hip, femoral neck and lumbar L1-L4 BMD (P<0.05). ROC curve analysis showed that: the area under the ROC curve (AUC) of the combined diagnosis of KOA combined with OP was 0.853, which was better than the single diagnostic efficacy of serum CXCL1, CCL4 and CCL11 levels (0.789, 0.693, 0.741).

The levels of CXCL1, CCL4 and CCL11 are abnormally elevated in the serum of patients with KOA combined with OP, multivariate analysis confirms that the three are independent influencing factors of KOA combined with OP, and they have certain diagnostic efficacy for KOA combined with OP, and the levels of CXCL1, CCL4 and CCL11 are negatively correlated with bone mineral density, and positively correlated with bone metabolism indexes and inflammatory factors.