Various factors are involved in the development of overactive bladder (OAB). Among them, metabolic syndrome and lifestyle-related diseases were closely related to the onset of OAB. 
Earlobe creases (EC) are associated with metabolic syndromes, such as hypertension, diabetes, and dyslipidemia, which cause angiopathic changes in the arterioles. Previous studies have identified the presence of EC as a risk factor for ischemic heart disease, and EC was a biomarker for chronic systemic inflammation and increased oxidative stress.
Thus, the presence of an EC was closely related to the risk factors for developing OAB. However, no studies have examined the relationship between the presence or absence of EC and OAB. 
The objective of this study was to examine the relationship between the presence or absence of EC and OAB morbidity.

This was a single-center, cross-sectional study involving patients who were examined at our facility and provided consent. Patients who were already being treated for OAB, had a neurogenic bladder, or had malignant tumors in the pelvic organs, were excluded. The patients' earlobes were macroscopically examined, and a patient was deemed "positive" if a crease was observed. Lower urinary tract symptoms were evaluated using the overactive bladder symptom score (OABSS) for subjective symptoms and uroflowmetry for objective findings. A score of ≥ 2 points in OABSS question 3 (urinary urgency) with a total score of ≥ 3 points indicated OAB. Differences were considered statistically significant at p <0.05.

A total of 190 subjects (89 men) were included in the analysis. The group of subjects with EC (EC group) had 72 patients (37.9%), while the group without EC (N-EC group) had 118 patients (62.1%). The total OABSS score was significantly higher in the EC group than in the N-EC group (EC group: 7.7 ± 2.6, N-EC group: 4.6 ± 3.4, P<0.001). In addition, the EC group had significantly higher scores on OABSS question 3 (urinary urgency). The EC and N-EC groups scored 3.0 ± 1.1 and 1.8 ± 1.6, respectively (P<0.001). 
Furthermore, 67 patients (93.1%) from the EC group and 66 patients (55.9%) from the N-EC group met the diagnostic criteria for OAB. The number of OAB patients was significantly higher in the EC group (P<0.001).
Regarding the objective findings, the EC group had a significantly smaller voided volume than the N-EC group (EC group: 155.2±54.5 mL, N-EC group: 200.7±73.5 mL, P<0.001). Moreover, the maximum flow rate was significantly worse in the EC group (15.4 ± 17.4 ml/s) than in the N-EC group (20.8 ± 8.9 ml/s).
The presence of an EC was an independent risk factor for OAB on both univariate and multivariate analyses (odds ratio, 8.152; 95% confidence interval, 2.84-27.75; P<0.001).

The EC group had more OAB patients than the N-EC group. Their subjective and objective findings were also worse.

The presence of an EC was a strong indication that a patient may have lower urinary tract symptoms, such as OAB.