**2. Urodynamic Finding in Patients with DM-Associated OAB**

Traditionally, diabetic cystopathy is considered as a triad of decreased bladder sensation, increased bladder capacity, and impaired emptying function [7]. Recent clinical and experimental evidence suggests that storage problems such as OAB and detrusor overactivity are common manifestations in early DM. Table 1 summarizes the urodynamic findings of patients with diabetic bladder dysfunction [8–12]. These studies showed that patients (both sexes) with DM had progressive, diverse bladder dysfunction depending on the stage of DM. In addition, diabetic bladder dysfunction is highly associated with other diabetic complications. Majima et al. analyzed the impact of DM on bladder function and found that the presence of both diabetic retinopathy and nephropathy was correlated with the presence of detrusor underactivity [9]. Patients with only diabetic retinopathy had the highest percentage of detrusor hyperactivity and impaired contractility (DHIC). Interestingly, a sub-population of patients reported in our literature search has normal detrusor contractility patterns, but develop detrusor overactivity, which was seen only in cases with neither retinopathy nor diabetic nephropathy. Furthermore, Lee et al. studied urodynamic characteristics and sensory bladder function in type 2 DM women at a mean age of 66.9 years [11]. The electrophysiological evidence indicated an association between impaired A-delta as well as C-fiber bladder afferent pathways and poor emptying function in the women with detrusor underactivity. However, patients with detrusor overactivity had similar current perception threshold values as those in the normal detrusor function group. Ho et al. compared the urodynamic finding in women with DM with and without OAB [13]. Compared to DM without OAB, the women with DM and OAB were more likely to have increased bladder sensation, detrusor overactivity, impaired voiding dysfunction, and a higher percentage of bladder outlet obstruction (BOO). Because of the very different presentations of diabetic bladder dysfunction, we suggest patients with DM-associated OAB undergo a comprehensive evaluation for possible diabetic complications and urodynamic studies before treatment of refractory DM-associated OAB.


**Table 1.** Summary of urodynamic findings in patients with diabetes.

DO: detrusor overactivity; DHIC: detrusor hyperactivity and impaired contractility; DU: detrusor underactivity; SUI: stress urinary incontinence; NA: not available.
