The aims of the present study were to investigate the prevalence of lower urinary tract symptoms (LUTS) in Chinese adolescents, including frequency, urgency, urinary incontinence (UI), nocturia, nocturnal enuresis (NE).

A total of 20,287 university students (aged 17-21 year 6,519 boys and 13,768 girls) from 23 provinces and 368 cities in mainland China were included. The survey was conducted using an anonymous questionnaire to collect the information：①gender, date of birth, inhabitation; ②whether exist frequency: the frequency of urination is significantly increased, with more than 8 times of urination during the day; ③whether exist urgency: urgency refers to the sudden and unexpected experience of an immediate and compelling need to void;④whether exist UI(UI was considered to intermittent or persistent involuntary leakage of urine caused by various reasons); ⑤types of UI(definition of UUI: urinary outflow through urethra when there is a strong desire to urinate, stress urinary incontinence (SUI) is defined as involuntary urinary overflow when abdominal pressure such as coughing, sneezing, laughing, etc.) ⑥whether exist nocturia(when get up in the morning after sleep, the nocturia more than two times) ;⑦bedwetting since 5 years old;⑧history of urinary tract infection( UTI).

A total of 22,500 students were investigated, 21,082 questionnaires were collected, 20,345 (90.2%) of which qualified for statistical analysis. The results show that the overall prevalence of frequency is 15.4%, the prevalence was 12.6% in males and 16.7% in females. The overall prevalence of urgency was 20.0%, the prevalence was 17.1% in males and 21.3% in females. The overall prevalence of UI is 4.9%, the prevalence was 3.5% in males and 5.6% in females, and male urgency and stress urinary incontinence account for 53.5% and 46.5% respectively. Female urgency and urinary incontinence accounted for 43.3% and 56.7%. The overall prevalence of nocturia was 12.4%, the prevalence was 13.9% in males and 12.2% in females, respectively, the differences were statistically significant (p <0.05). The overall prevalence of NE was 1.17%; the prevalence was 1.3% in males and 1.1% in females. There was no significant difference between them (p>0.05). There was no significant difference in the prevalence of LUTS between urban and rural areas (P>0.05). The prevalence of LUTS in adolescents with history of UTI was higher than without (p <0.05).

The results of this survey have significant differences in the prevalence pf frequency, urgency, UI between males and females (P<0.05). This is consistent with the literature and the characteristics of LUTS. The prevalence of NE in males and females in this survey was 1.3% and 1.1%, respectively. There was no significant difference between them. This is similar to the research performed in Hong Kong, which showed no significant difference in the NE prevalence between 21- to 25-year-old males and females.[1] In this study, the prevalence of frequency, urgency, UI, nocturia, NE with history of UTI was significantly higher than without. This might due to UTI increased the responsiveness of the bladder to stimulation and increase the risk of LUTS.

The prevalence of LUTS in adolescents is high. More attention should  be paid to their health care, especially the UTI treatment．

Yeung CK, Sihoe JD, Sit FK, Bower W, Sreedhar B, Lau J. Characteristics of primary nocturnal enuresis in adults: an epidemiological study. BJU Int 2004; 93:341–5.