Exploring the correlations of BMP and PPARγ with fat metaplasia associated in spondyloarthritis
Objective To investigate the serum levels of bone morphogenetic proteins(BMPs)and peroxisome proliferator-activated receptor gamma(PPARγ)at various stages of fat metaplasia in axial spondyloarthritis(axSpA),aiming at assessing the severity of fat metaplasia and predict early structural progression in axSpA.Methods Thirty axSpA patients and 34 healthy controls were included.The serum levels of BMP2,BMP4,BMP9 and PPARγ were analyzed.The study employed the Logistic regression analysis for predictive value assessment.Results The serum levels of BMP4,BMP9,PPARγ in the case group were significantly higher than those in the healthy group,with all differences being statistically significant(all P<0.001).The degree of fat metaplasia in patients with axSpA was positively correlated with serum BMP4(r = 0.581,P<0.001)and PPARγ(r = 0.507,P = 0.004).The serum BMP4 levels in the severe fat metaplasia group(17.290±7.880 pg/mL)were significantly higher than those in the no or mild fat metaplasia group[(9.131±4.087)pg/mL],with a significant difference(P = 0.002).Similarly,PPARγ levels in the severe fat metaplasia group[(104.561±49.764)pg/mL]were also significantly higher than those in the no or mild fat metaplasia group[(64.392±27.007)pg/mL],with a significant difference(P = 0.045).Elevated levels of BMP4 might be a risk factor for severe fat metaplasia in axSpA(OR = 1.367,95%CI:[1.026,1.822],P = 0.033).Conclusion Serum BMP4 and PPARγ levels are crucial for assessing fat metaplasia in axSpA patients.