Fig. 4

Comparison of MMP-3 concentrations in serum between post-urban and post-forest walking in RA patients and HG volunteers. Experiments were performed in September （A） and in October （B）. Total data of each group are shown in column （C）. （A） RA patients （N＝5）, HG volunteers （N＝5）. （B） RA patients （N＝7）, HG volunteers （N＝6）. White and black bars indicate relative MMP-3 levels in serum after urban and forest walking, respectively.