Study the relevance between inflammatory factors and estradiol and their association with knee osteoarthritis in postmenopausal women.

OBJECTIVE: To investigate whether serum levels of inflammatory factors and estradiol (E2) are involved in the pathogenesis of postmenopausal women with knee osteoarthritis (OA).

PATIENTS AND METHODS: 58 randomly patients diagnosed with postmenopausal knee OA that underwent orthopedic surgery from October 2013 to October 2016 in our hospital were selected. These patients, considered as the experimental group, according to the degree of cartilage damage, were divided into light, medium and heavy groups. 58 patients with menstrual disorders without knee OA were in the control group. 35 cases without osteoarthritis were included in the normal control group. Serum levels of interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), erythrocyte sedimentation rate (ESR), high sensitive C- reactive protein (CRP), estradiol (E2) and IL-1, IL-6 and TNF-α levels in the synovial fluid of the experimental group were measured.

RESULTS: The serum levels of IL-1, IL-6, TNF-α, and CRP in the normal control group, the control group and the experimental group were gradually increasing, the difference was statistically significant (p<0.05). The level of serum E2 was gradually decreasing (p<0.05); the difference of ESR between normal control group and control group had no significant difference (p>0.05), but the level of ESR in experimental group was higher than the normal control group and the control group (p<0.05). The serum levels of IL-1, TNF-α in experimental group of mild, moderate and severe sub-group were gradually increasing, the difference was statistically significant (p<0.05); while the level of IL-6 in the early, middle stage of OA increased significantly, and the late was reduced (p<0.05). The level of E2 was gradually decreased in the mild, moderate and severe sub-group of the experimental group, which had statistically significant difference (p<0.05). The level of serum E2 in the experimental group was positively correlated with the levels of IL-1, IL-6 and TNF-α in synovial fluid (p<0.05).

CONCLUSIONS: The lack of estradiol is associated with the pathogenesis of OA in postmenopausal women, the inflammatory factors of IL-1, IL-6, TNF-α in postmenopausal increased in serum and synovial fluid may promote and aggravate the OA.