Serum Serotonin Levels as a Potential Risk Factor for Overactive Bladder in a Community-Dwelling Population: A Four-Year Longitudinal Study.

PURPOSE

This study aims to investigate the potential influence of serum serotonin (5-HT) levels on the development of overactive bladder (OAB) in a community-dwelling population.

METHODS

A four-year longitudinal study was conducted involving 615 subjects who participated in the Iwaki Health Promotion Project in Hirosaki, Japan, in both 2015 and 2019. OAB was defined as experiencing urinary urgency at least once a week with an Overactive Bladder Symptom Score (OABSS) of ≥ 3. Baseline data from 2015, including serum 5-HT levels, other laboratory data, and comorbidity information, were used for the analysis. The association between serum 5-HT levels and incident OAB in 2019 (OAB-2019) was examined using multivariate logistic regression analyses.

RESULTS

The study included 250 men and 365 women, of whom 74 individuals (29 men and 45 women) met the diagnostic criteria for OAB in 2019. Significant differences were observed between the OAB-2019 and non-OAB-2019 groups, including age, chronic kidney disease, irritable bowel syndrome, hypertension, glycemic status, mental status, and OAB in 2015. Participants in the OAB-2019 group had significantly lower serum 5-HT levels compared to the non-OAB-2019 group (100 vs. 129 ng/mL, p < 0.001). After adjusting for confounders, multivariable analysis revealed that serum 5-HT levels < 134 ng/mL (odds ratio: 2.48, 95% confidence interval: 1.39-5.83, p = 0.004), age, mental status, and OAB in 2015 independently served as risk factors for OAB-2019.

CONCLUSIONS

Low serum 5-HT levels may be associated with an increased risk of OAB. Further research is needed to elucidate the underlying mechanisms responsible for this association.