Matrix Metalloproteinases/Tissue Inhibitors of Metalloproteinases Ratio: A Biomarker of Bone Resorption in Geriatric Osteoporosis?

BACKGROUND: Matrix metalloproteinases (MMPs) play an important role in bone resorption and are regulated by tissue inhibitors of metalloproteinases (TIMPs). We investigated the use of MMP2/TIMP2 and MMP9/TIMP1 ratios as biomarkers of bone resorption in geriatric osteoporosis and evaluated the relationship between osteoporosis and geriatric syndromes. METHODS: This analytical cross-sectional study involved 87 patients (41 with osteoporosis) treated at the geriatric outpatient clinic of a university hospital. The demographic characteristics, comprehensive geriatric assessment scores, laboratory findings, and bone mineral density of the patients were recorded. Serum MMP9, TIMP1, MMP2, and TIMP2 levels were analyzed by enzyme-linked immunosorbent assay (ELISA). RESULTS: We enrolled 41 and 46 patients with and without osteoporosis, respectively. The groups showed no significant differences in MMP2/TIMP2 and MMP9/TIMP1 ratios (p=0.569 and p=0125, respectively). While the basic activities of daily life (BADL) scores in the osteoporosis group were higher than those in the group without osteoporosis, the instrumental activities of daily life (IADL) scores were significantly lower (p=0.001 and p=0.007, respectively). No significant differences were observed in Mini-Nutritional Assessment, Mini-Mental State Examination, and Geriatric Depression Scale scores (p=0.598, p=0.898, and p=0.287, respectively). CONCLUSION: This is the first study to examine the relationship between osteoporosis and several geriatric syndromes, as well as the relationship between osteoporosis and serum MMP, TIMP values, and MMP/TIMP ratios in geriatric patients. Our results showed that osteoporosis causes dependency in both BADLs and IADLs, and that the MMP2/TIMP2 and MMP9/TIMP1 ratios provided no additional benefit in demonstrating bone resorption in geriatric osteoporosis.