Research Article Effectsof12-WeekExerciseProgramonEnzymeActivityofSerum Matrix Metalloproteinase-9 and Tissue Inhibitor of Metalloproteinase-1 in Female Patients with Postmenopausal Osteoporosis: A Randomized Control Study Tamara Filipovi´ c , 1 Kristina Gopˇ cevi´ c , 2 Sanja Dimitrijevi´ c , 3 Marija Hrkovi´ c, 1 Ana Backovi´ c, 4 and Milica Lazovi´ c 1 1 Institute for Rehabilitation, School of Medicine, University of Belgrade, Belgrade, Serbia 2 Institute for Chemistry in Medicine, School of Medicine, University of Belgrade, Belgrade, Serbia 3 Special Hospital for Cerebral Palsy and Developmental Neurology, School of Medicine, University of Belgrade, Belgrade, Serbia 4 Turval Laboratory Srl, Udine, Italy Correspondence should be addressed to Tamara Filipovi´ c; tamarabackovic@gmail.com Received 26 August 2019; Revised 27 December 2019; Accepted 3 January 2020; Published 30 January 2020 Guest Editor: Borja Sañudo Copyright © 2020 Tamara Filipovi´ c et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Osteoporosis is a disease characterized by decreased bone density and destruction of bone microarchitecture. Indicators for altered bone homeostasis are changes in the serum level of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). e purpose of the current study was to evaluate the effect of a 12-week exercise program on enzyme activity of serum MMP-9 and TIMP-1 in postmenopausal osteoporotic patients. Materials and methods. Participants were randomized in two groups: exercise (EG) (N � 37) and control (CG) (N � 31). e exercise group completed a 12-week supervised exercise program, while the control group did not take part in any physical activity. Enzyme activities of serum MMP-9 and TIMP-1 were detected by gelatin zymography and ELISA in both groups, respectively. Results. Significant differences between pretreatment and posttreatment enzyme activities of serum MMP-9 (p � 0.009), TIMP-1 (p ≤ 0.001), and MMP-9/TIMP-1 ratio (p ≤ 0.001) were detected in the exercise group. Exercises decreased the activity of serum MMP-9 and increased the activity of TIMP-1, while the enzyme activities of MMP-9 (0.583) and TIMP-1 (0.210) have not been significantly changed in CG. Patients from the exercise group had better treatment. Conclusion. Our results suggest that a 12-week exercise program has an influence on enzyme activity of serum MMP-9, revealing a possible role of MMPs in initiating training-specific adaptation. Although measurements of circulating MMP-9 and TIMP-1 allowed us to detect effects of exercise, as of today, they have no real role in the diagnosis of osteoporosis and/or follow-up of osteoporotic patient’s response to treatment. MMP-9 might be used as an important prognostic marker for the evaluation of patient’s response to exercise. Larger-randomized controlled studies need to be performed to expand this area of knowledge. is trial is registered with trial registration number: NCT03816449). 1.Introduction Osteoporosis is a chronic, progressive, and systemic meta- bolic bone disease characterized by low bone mineral density and microarchitectural changes of bone tissue leading to an increased tendency to fractures [1, 2]. Because of its mul- tifactorial dimension, identifying the factors that are involved in osteoclast and osteoclast differentiation is as important as their dynamic changes, depending on the use of appropriate therapy [1]. Matrix metalloproteinases (MMPs) are a family of zinc dependent, proteolytic enzymes, responsible for extracel- lular matrix (ECM) degradation and cleavage of its struc- tural components such as collagen and gelatin, thus having a Hindawi BioMed Research International Volume 2020, Article ID 9758289, 9 pages https://doi.org/10.1155/2020/9758289