Is detrusor overactivity with detrusor underactivity limited to the elderly?

Objective: Detrusor overactivity with detrusor underactivity (DO-DU) is classically described in frail institutionalized elderly patients, but we have also observed this diagnosis in younger populations. This research aims to identify the differences between two age groups of DO-DU patients. Materials and Methods: This study included DO-DU patients from a single center from 2012 to 2023. Patients were divided into two groups: the "Younger" group (aged less than 70 years) and the "Older" group (aged 70 years or older). We separately compared demographics, the number of risk factors considered to affect bladder function, clinical presentations, and urodynamic findings between these two groups in each gender. Results: There were 210 patients included in the analysis, with 50.48% in the younger group and 49.52% in the older group. The median ages of males and females in the younger group were 57 and 62 years, whereas the median ages of males and females in the older group were 76.5 and 76 years. Multiple sclerosis exhibited statistically significant prevalence in the younger patients (7.7% vs. 0%, p = 0.03 in males and 19.9% vs. 4.6% in females). While diabetes mellitus (DM) was more prevalent in the older males (20.0% vs. 4.6%, p = 0.01), transabdominal hysterectomy was more common in the younger females (46.3% vs. 25%, p = 0.04). 69.8% of the younger group and 71.2% of the older group have at least one risk factor that impact their bladder function. There was no statistically significant difference between the two groups across various risk factor categories. The older males reported a higher incidence of urgency (78.3% vs. 58.5%, p = 0.02) and urge incontinence (61.7% vs. 32.3%, p < 0.01), while the younger females reported a higher incidence of straining during voiding on history (46.3% vs. 20.5%, p = 0.01). The younger males exhibited a greater volume of strong desire to void (385 vs. 300 mL, p = 0.01), maximal cystometric capacity (410 vs. 300 mL, p < 0.01), and a lower highest detrusor overactivity (DO) pressure (37 vs. 50.5 cmH(2)O, p = 0.02). The younger group had a higher postvoid residual (170 vs. 85 mL in males, p < 0.01 and 180 vs. 120 mL in females, p = 0.02). The voiding efficiency was lower in younger females (40% vs. 60%, p = 0.02). In both ages, the ICS detrusor contraction index and projected isovolumetric pressure 1 were similar. However, without considering risk factors, the older males had the highest DO pressure (57 vs. 29 cmH(2)O, p < 0.01), and the younger males had a higher voiding pressure (PdetQmax) than the older males (28 vs. 20 cmH(2)O, p = 0.02). Conclusion: DO-DU is not exclusive to elderly patients. It can also be diagnosed in individuals with risk factors regardless of age; therefore, clinicians need a high degree of suspicion, especially in patients who have risk factor(s) for DO and DU. A notable clinical differentiation is that older males diagnosed with DO-DU have a higher incidence of urgency and urge urinary incontinence, while younger females have a higher incidence of straining.