Matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases-1 levels in severely obese patients: what is the effect of weight loss?

Introduction: There is increased evidence that circulating levels of matrix metalloproteinases and their tissue inhibitors are altered in obesity and may be implicated in its pathogenesis. This study aimed to compare the serum concentrations of pro-matrix metalloproteinase-1 (pro-MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in severely obese patients with or without metabolic syndrome, and to investigate the potential effect of weight loss on their circulating levels.

Methods: A total of 102 severely obese subjects were included in our study. Of these, 61 had no other features of metabolic syndrome, while the rest were 41 age- and sex-matched subjects with severe obesity and metabolic syndrome according to the NCEP-ATP criteria. Fourty-two age and sex-matched healthy lean individuals were used as controls.

Results: Severely obese subjects had higher circulating levels of TIMP-1 than the lean ones (120.6 ± 50.6 vs. 89.0 ± 35.2 ng/ml) and obese patients with metabolic syndrome had higher TIMP-1 levels than their metabolically healthy counterparts (134.8 ± 38.4 vs. 111.0 ± 55.62 ng/ml). A positive association was also found between TIMP-1 levels and various anthropometric and metabolic parameters in the obese subjects. Moreover, weight loss of more than 5% resulted in a significant reduction of the TIMP-1 levels in obese subjects, irrespective of the presence or not of metabolic syndrome. No significant differences in pro-MMP-1 concentrations were found between the obese (2.8 ± 2.4 ng/ml) and lean individuals (2.8 ± 0.8 ng/ml).

Conclusions: In conclusion, we demonstrated that increased TIMP-1 serum levels are found in severely obese patients and particularly in these with metabolic syndrome, while weight loss of more than 5% resulted in reduction of TIMP-1 levels.