Bladder dysfunction has one of the highest prevalences as a comorbidity of obesity in industrialized countries. The aetiopathogenesis of obesity-associated bladder dysfunction is still obscure, but there is growing evidence that general metabolic changes in obese patients may be in part responsible. As demonstrated recently, high fat diet (HFD) significantly alters the protein expression in the urinary bladder, activates multiple signalling pathways associated with cell survival and inflammation and ultimately provokes bladder fibrosis in an obese rat model. The study aimed to elucidate the role of matrix metalloproteases (MMPs) and their specific tissue inhibitors of metalloproteases (TIMPs) in obesity-related bladder extracellular matrix (ECM) remodelling and the effect of weight loss surgery via sleeve gastrectomy (SG) on phenotype and molecular parameters.