To investigate the prevalence of nocturia and its risk factors in Chinese young adults.Questionnaires were used to analyze the risk factors that may affect the nocturia of young people. The relative controllable factors were selected from many factors, and appropriate interventions were taken for the controllable factors.It has positive significance to reduce the incidence of nocturia and its prevention and treatment.Providing a theoretical basis for coping with nocturia in clinical work.

From September 2018 to December 2018, we investigated the prevalence of  nocturia  in Chinese adolescent by distribute an anonymous questionnaire in 13,874 university students [20.0±1.5 years old (17-23 years old)]who come from all over the country from 2017 to 2018.The following information was collected: gender, age, height, weight, birthplace, household classification (rural, urban), as well as the number of urination during the day, the number of void at night, whether there is urgency, urinary incontinence, enuresis, urinary tract infection, sleep conditions, etc. Nocturia is currently defined by the International Continence Society（ICS） as the complaint that the individual has to wake at night one or more times to void, each void being preceded and followed by sleep. We define nocturia as ≥2 voids per night; based on the observation that 1 void per night is common in young people and is usually not a complaint. Univariate analysis and multivariate logistic regression analysis was used to determine the risk factors of nocturia (P <0.05 is statistically significant).

A total of 13,416 were qualified for statistical analysis and 1624 (12.1%) was found to have nocturia, including 577 (13.7%) males and 1047 females (11.8%) (male:female=1:1.8); The prevalence nocturia of the 18,19,20,21,22 and 23 age groups were 8.3%, 11.5%, 13.1%, 15.7%, 15.0%, 14.5% and 12.4%.The prevalence of nocturia increased with age and difference between groups are significant( χ 2 = 71.923, P < 0.001).The average number of nocturia in all respondents was 0.87 times. Univariate analysis using the total respondents revealed that age, gender, born in rural areas, urinary ≥6 times during the day, urinary urgency, enuresis, previous urinary system infection and deeper sleep had an significant impacts on the prevalence of nocturia(P<0.05). Multivariate logistic regression analysis of the univariate analysis of meaningful indicators found that gender (OR: 0.793, 95% CI: 0.702~0.896, P<0.001); born in rural areas (OR: 1.152, 95% CI) : 1.022~1.298, P=0.021); urinary urgency (OR: 1.493 and 1.261, 95% CI: 1.181~1.887 and 1.068~1.488, P<0.001); previous urinary tract infections (OR: 3.970 and 1.315, 95% CI: 1.591 to 9.906 and 0.968 to 1.786, P=0.004); deeper sleep (OR: 0.846, 95% CI: 0.754~ 0.950, P=0.005) were significantly associated with nocturia.

This study found that the prevalence of nocturia increased with age in young people with a small age span, which is consistent with the findings of Coyne KS et al [1].Women's protective factors for nocturia may be related to estrogen. Studies have shown that estrogen receptors are widely distributed in urethral smooth muscle and detrusor cells, which are important for the maintenance of urethral smooth muscle tension and length [2].Deeper sleep depth as a protective factor is consistent with the results of Hvistendahl GM et al [3]. However, whether the quality of sleep caused by nocturia is declining, or the nocturia caused by the decline in sleep quality needs further study. The prevalence of nocturia in rural areas is higher than that in cities, which may be related to rural medical conditions and poor health concept. These people with symptoms of both urgency and nocturia can be identified as suspected overactive bladder (OAB) with symptoms of nocturia.

The prevalence of nocturia in Chinese adolescents is 12.1% and increased with age,and its risk factors of nocturia are gender, born in rural areas, urinary urgency, deeper sleep,and previous urinary system infection in Chinese adolescent.

Coyne KS, Zhou Z, Bhattacharyya SK, Thompson CL, Dhawan R, Versi E. The prevalence of nocturia and its effect on health-related quality of life and sleep in a community sample in the USA. BJU Int 2003;92: 948–54.
Thom DH, Rortveit G: Prevalence of postpartum urinary incontinence: a systematic review. Acta Obstet Gynecol Scand 2010, 89(12):1511-1522
Hvistendahl GM, Frokiaer J, Nielsen S, Djurhuus JC: Gender differences in nighttime plasma arginine vasopressin and delayed compensatory urine output in the elderly population after desmopressin. J Urol 2007, 178(6):2671-2676.