Is Urgency Urinary Incontinence One Disease or Many?

Clinicians routinely manage patients with overactive bladder and urgency leakage using standardized empiric algorithms. However, recent findings regarding urgency urinary incontinence phenotypes suggest that a uniform approach may fail many individuals. Therefore, urinary urgency represents a heterogeneous symptom complex rather than a single uniform disorder. Consequently, identifying underlying pathophysiological variations remains essential for refining clinical therapies. Specifically, researchers in the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN) II cohort evaluated whether physiological measures define distinct subgroups.

Study Design and Physiological Profiling

The investigative team conducted a secondary analysis of 56 symptomatic women alongside 31 asymptomatic controls. In addition, the participants completed comprehensive urethral and vesical motor and sensory testing. Clinicians performed rapid-fill cystometry before and after instilling intravesical lidocaine. Furthermore, investigators analyzed 32 distinct physiological parameters through consensus clustering pipelines. Traditional diagnostics primarily concentrate on detrusor contraction alone. However, this study evaluated bladder compliance, sensory thresholds, and urethral closure pressures concurrently. As a result, the authors could capture the multidimensional nature of lower urinary tract dysfunction.

Identifying Three Urgency Urinary Incontinence Phenotypes

The cluster analysis uncovered three physiologically separate clusters among the affected women. First, Cluster A demonstrated detrusor overactivity during both saline and lidocaine filling cycles. Moreover, these patients showed marked sensory hypersensitivity, reaching sensation volumes at only 39% to 55% of control values. In contrast, their urethral sphincter metrics remained completely intact. Second, Cluster B displayed a prominent lidocaine-dependent capacity gain of 138 milliliters. Additionally, this group exhibited a 30% reduction in maximal urethral closure pressure. Thus, mucosal afferent signals and urethral incompetence prominently characterize this subset. Finally, Cluster C showed minimal volume expansion after lidocaine and lacked detrusor overactivity. Demographic traits and subjective symptom scores appeared comparable across all three groups. Therefore, conventional symptom surveys alone cannot expose these physiological distinctions.

Predictive Markers and Clinical Implications

Multivariable regression models adjusted for participant age, body mass index, and vaginal parity. Consequently, distinct physiological variables strongly predicted cluster membership. Detrusor overactivity accurately differentiated Cluster A, yielding an area under the curve of 0.95. Meanwhile, lidocaine-mediated volume increases predicted Cluster B with an area under the curve of 0.92. For Cluster C, a low normalized first desire to void served as the primary indicator. Currently, clinicians in India and worldwide treat bladder urgency using generic empirical medications. However, antimuscarinics or beta-3 agonists often produce inconsistent therapeutic responses or intolerability. Patients with afferent dysfunction or urethral instability might require alternative therapies. For instance, pelvic floor rehabilitation or targeted neuromodulation may suit specific clusters better. Hence, validating these physiological subsets will help clinicians design targeted, biomarker-driven clinical trials.

Frequently Asked Questions

Q1: Why do symptom questionnaires fail to distinguish urgency urinary incontinence phenotypes?

Patients in different physiological clusters frequently report indistinguishable symptom severity, frequency, and leakage episodes. Therefore, standardized symptom questionnaires cannot capture hidden physiological drivers such as afferent hypersensitivity or urethral closure weakness.

Q2: How does intravesical lidocaine testing clarify incontinence mechanisms?

Intravesical lidocaine temporarily anesthetizes mucosal bladder afferents. Consequently, a marked increase in bladder capacity post-lidocaine points to mucosal sensory hyperactivity rather than isolated detrusor smooth muscle failure.

Q3: How might physiological clustering reshape clinical management in practice?

Currently, clinicians apply one-size-fits-all pharmacological protocols. However, phenotyping could allow physicians to personalize therapy, directing antimuscarinics to motor overactivity and pelvic floor training or neuromodulation to urethral or sensory dysfunction.

References

1. DeLancey JOL et al. Urgency urinary incontinence, one condition, or many? Cluster analysis of physiological variables in the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN) II cohort. Am J Obstet Gynecol. 2026 Nov 05. doi: undefined. PMID: 42988096.
2. Hokanson JA, DeLancey JOL, Kirby AC, et al. Expanded Physiological Testing of the Lower Urinary Tract in Asymptomatic Women and Those With Urgency Urinary Incontinence: Findings From the LURN-Organ Study. Neurourol Urodyn. 2025;44(5):987-996.
3. Lai HH; LURN Study Group. The LURN Study-What Have We "LURN"ed So Far? Neurourol Urodyn. 2026;45(4):654-661.