Association between Urinary Stone Disease and Perirenal Tissue Thickness

Introduction: Urinary stone disease is an important morbidity. Metabolic factors such as obesity and diabetes mellitus have been associated with stone disease. Because obesity and increased body mass index, which are characterized by thickening of subcutaneous and visceral tissue, are associated with kidney stones, we investigated subcutaneous and perirenal tissue thickness and stone size in patients with kidney stone disease and compared them with healthy subjects. Methods: A total of 209 subjects who had undergone a stone computerized tomography protocol due to urological symptoms between February2010 and March2012 were included. Results: No significant differences in age or sex between patients and control subjects were observed. Similarly, no significant differences between the study and control groups were observed in terms of the thickness, area and density of subcutaneous tissue, density of visceral tissue, urinary pH, or neutrophil and lymphocyte counts. The visceral tissue area was significantly larger (p= 0.014) and the neutrophil/lymphocyte ratio was significantly elevated (p=0.021) in patients with kidney stones compared to those in controls. The perirenal tissue area of the kidney with a stone increased significantly compared to the opposite kidney without stones (p=0.021). Conclusion: The results suggest that an increased surface area of perirenal visceral adipose tissue detected by imaging studies might be a risk factor for the development of kidney stones. However, prospective studies with a larger cohort are needed to translate our results to clinical practice.