Effect of intravesical glycosaminoglycan substitution therapy on bladder pain syndrome/interstitial cystitis, bladder capacity and potassium sensitivity

Objective. To evaluate changes in bladder capacity and potassium sensitivity after glycosaminoglycan (GAG) substitution therapy. Material and methods. The study population comprised two groups of female patients with bladder pain syndrome/interstitial cystitis (BPS/IC): responders (those with symptom improvement) and non-responders (those without symptom improvement) after a 10-week period of intravesical, episodic, weekly, GAG substitution therapy. A total of 27 volunteers with increased pre-therapeutic potassium sensitivity were enrolled in the study and re-evaluated using the modified comparative potassium test (maximal bladder capacity with a saline solution versus a 0.2 M KCl solution) following intravesical GAG substitution therapy. Results. In the 13 responders, the average maximal bladder capacity increased by 17% with the saline solution and by 101.5% with the 0.2 M KCl solution. In the 14 non-responders, post-therapeutic average maximal bladder capacity was decreased by 35% with the saline solution and remained relatively unchanged after instillation with a 0.2 M KCl solution. Conclusion. These data demonstrate that in patients who respond symptomatically to intravesical GAG substitution therapy, cystometric bladder capacity is increased, whereas non-responders experience a decrease in bladder capacity.