Associations of Changes in Serum Inflammatory Factors, MMP-3, 25(OH)D and Intestinal Flora with Osteoporosis and Disease Activity in Rheumatoid Arthritis Patients

Background: To explore the associations of changes in serum inflammatory factors, matrix metalloproteinase-3 (MMP-3), 25-hydroxy vitamin D [25(OH)D], and intestinal flora with osteoporosis and disease activity in rheumatoid arthritis (RA) patients, so as to provide references for clinical diagnosis and treatment. Methods: A total of 98 RA patients were selected as the objects of study (RA group), and divided into active-stage group (n = 56) and remission-stage group (n = 42) according to the disease activity score (DAS28). Another 50 healthy people receiving physical examination in our hospital during the same period were selected as the control group. The changes in serum inflammatory factors, MMP-3, 25(OH)D, and intestinal flora were compared among the three groups, and the osteoporosis of the subjects was analyzed in each group. Moreover, the associations of changes in serum inflammatory factors, MMP-3, 25(OH)D, and intestinal flora with osteoporosis and disease activity in RA patients were analyzed using the Pearson's method. Results: Compared with those in the control group, the levels of serum MMP-3, interleukin-6 (IL-6), IL-10, and Creactive protein (CRP). The Escherichia coli count were significantly increased, while the level of serum 25(OH)D, bone mineral density (BMD), and Lactobacillus and Bifidobacterium counts were significantly decreased in the active-stage group and remission-stage group, more obviously in active-stage group (p < 0.05). The osteoporosis and disease activity in RA patients were positively correlated with serum IL-6, IL-10, CRP, MMP-3, Escherichia coli and BMD, but negatively correlated with 25(OH)D, Lactobacillus and Bifidobacterium (p < 0.05), and not correlated with the sharp score (p > 0.05). Conclusions: There are certain associations of changes in serum inflammatory factors, MMP-3, 25(OH)D, and intestinal flora with osteoporosis and disease activity in RA patients, showing certain value in clinical application.