While heart disease, diabetes, hypertension, obesity, and smoking have been identified as risk factors for lower urinary tract symptoms (LUTS), the impact of seasons on LUTS is not well understood. Previous epidemiological surveys indicated that storage symptoms were worse in winter compared to summer. However, these studies surveyed different populations in summer and winter, leaving the precise relationship between seasons and LUTS unclear. In this study, we tracked the seasonal changes of LUTS within the same population for over two years to elucidate the impact of seasons on LUTS.

From September 2019 to February 2024, patients who visited our hospital for LUTS treatment and had complete tri-monthly LUTS questionnaire data for over two years were included. LUTS were evaluated using the Overactive Bladder Symptom Score (OABSS) and the International Prostate Symptom Score (IPSS). The baseline was established during the summer of the first year (June to August), with subsequent evaluations in the winter of the first year (December to February), and in the summer and winter of the second year. Our region experiences four distinct seasons, with average temperatures ranging from 24.9°C to 30.7°C in summer 2020 and 6.2°C to 8.7°C in winter 2021. Statistical analysis was conducted by one-way analysis of variance with post-hoc Dunnett test.

The study included 122 participants, with 87 males and 35 females. The median age was 77 years (IQR 72-82), median height was 163 cm (IQR 157-168), median weight was 59.5 kg (IQR 53-67), and median BMI was 22.5 kg/m^2 (IQR 20.7-24.7). The chief complaints were urgency in 57 cases (47%), weak stream in 33 cases (27%), and nocturia in 32 cases (26%). Comorbidities included hypertension in 56 cases (46%) and diabetes in 33 cases (27%). The OABSS total scores for the first summer, winter, second summer, and winter were 5.64 ± 0.25, 7.25 ± 0.30, 5.85 ± 0.29, and 7.32 ± 0.34, respectively. Significant seasonal changes were observed, with OABSS total scores increasing in winter and decreasing in summer (Figure 1A). Notably, urgency (Q3) and urge urinary incontinence (Q4) of the OABSS showed significant seasonal changes (Figure 1B, C). The IPSS voiding symptom scores for the first summer, winter, second summer, and winter were 6.32 ± 0.46, 7.57 ± 0.47, 6.59 ± 0.47, and 7.48 ± 0.49, respectively, and seasonal changes were not statistically significant (Figure 2A). On the other hand, the IPSS storage symptom scores were 5.51 ± 0.27, 6.60 ± 0.31, 5.63 ± 0.27, and 6.5 ± 0.31, respectively, and it was found that these scores increase in winter and decrease in summer (Figure 2B).

The results indicated a worsening of urgency and urge urinary incontinence during winter compared to summer. These symptoms significantly affect the quality of life (QOL) in patients with LUTS, suggesting that seasonal changes of LUTS could have a substantial impact on QOL of patients.

This longitudinal study has revealed that LUTS, specifically urgency and urge urinary incontinence which affect the QOL of patients, worsen during colder seasons and improve during warmer seasons.

Continence 12S (2024) 101566
DOI: 10.1016/j.cont.2024.101566