Urothelial Dysfunction and Chronic Inflammation in Diabetic Patients with Overactive Bladder.

OBJECTIVES

To investigate urothelial dysfunction, suburothelial inflammation, and muscarinic receptor expression in diabetic patients with overactive bladder (OAB).

METHODS

A total 19 patients with OAB and diabetes mellitus (DM), 14 OAB patients without DM, and 10 healthy control subjects were enrolled in the study. Immunofluorescence staining of E-cadherin, zonula occludens-1 (ZO-1), tryptase (mast cell activation), and apoptosis tests on the bladder urothelium and suburothelium were performed. Tissue muscarinic receptor M2, M3, and purinergic receptor P2X3 levels were measured by Western blotting. Video urodynamic studies were analyzed in relation to immunofluorescence and western blotting results.

RESULTS

The mean age of the controls, OAB patients without and with DM were comparable (62.9 ± 6.9, 58.4 ± 21.3, and 68.9 ± 11.3 years, respectively, P = 0.25). E-cadherin and mast cell expression in the bladder urothelium samples of the DM-OAB group and the OAB group without DM differed significantly from those of the control group (all P < 0.05). However, immunofluorescence analyses including E-cadherin, mast cells, apoptotic cell counts, and ZO-1 were comparable between OAB patients with and without DM. In addition, M3 muscarinic protein expression in the bladders of OAB patients with and without DM was significantly higher than that in the control subjects. The video urodynamic parameters did not correlate with the immunofluorescence data, M2 and M3 muscarinic receptor data, or P2X3 protein expression.

CONCLUSION

Urothelial dysfunction and chronic suburothelial inflammation may contribute to the pathogeneses of OAB. However, DM does not aggravate the severity of urothelial inflammation in OAB patients.