Lower serum serotonin levels linked to overactive bladder: Study

Japan: A new study by Teppei Okamoto and the team reported that lower serum 5-HT levels could independently be associated with the presence of overactive bladder (OAB). The study is published in the World Journal of Urology.

OAB is a multifactorial condition. Some types of 5-HT receptors are expressed in the urothelium and may be involved in the visceral sensation of the bladder. Dr. Okamoto from Hirosaki University Graduate School of Medicine, Hirosaki, Japan, and colleagues aimed to investigate the association between serum serotonin (5-HT) levels and overactive bladder in a community-dwelling population. 

The study was designed as a cross-sectional study that analyzed 1024 subjects who participated in the Iwaki Health Promotion Project in 2015 in Hirosaki, Japan. OAB was assessed using the Overactive Bladder Symptom Score (OABSS). OAB was defined as an occurrence of urinary urgency at least once a week and an OABSS of ≥ 3.

They assessed serum 5-HT levels, laboratory data, and comorbidities of each participant. Participants' mental health status was evaluated using the Center for Epidemiologic Studies Depression (CES-D) scale. The association of serum 5-HT levels and OAB was analyzed by multivariable logistic regression analysis.

This study included 394 men and 630 women. Of those, 118 (44 male and 74 female) were OAB sufferers

The results of the study were found to be

• A total of 394 men and 630 women were included in the study. Of those, 118 (44 male and 74 female) were OAB sufferers. A significant group difference in age, history of cardiovascular disease, chronic kidney disease, hypertension, diabetes mellitus, and CES-D score was observed.

• Participant's serum 5-HT levels in the OAB group were significantly lower than those in the non-OAB group (100 vs. 127 ng/mL).

• Multivariable analysis showed that age (odds ratio [OR]; 1.06) and log serum 5-HT level (OR; 0.25) were independently associated with OAB.

Okamoto and the team concluded that "Lower serum 5-HT levels could independently be associated with the presence of OAB. Further study is necessary to elucidate a possible causal relationship between serum 5-HT levels and OAB."

Reference:

Okamoto, T., Hatakeyama, S., Imai, A. et al. The association between serum serotonin levels and overactive bladder: results from a community-based cross-sectional study in Japan. World J Urol 39, 169–175 (2021). https://doi.org/10.1007/s00345-020-03167-2