Prevalence, risk factors, and symptom bother of nocturia: a population-based survey in China.

Purpose: To evaluate the prevalence, risk factors, and symptom bother of nocturia in Chinese adults.

Methods: A population-based, cross-sectional survey was conducted among individuals aged ≥18 years in five geographical regions of China, via a stratified sampling approach. A structured questionnaire was used to obtain information on sociodemographic characteristics, general health, and past disease, and the International Consultation on Incontinence Questionnaire-Male/Female Lower Urinary Tract Symptoms Long Form was administered to estimate the prevalence of nocturia and rate their symptom bother. The current International Continence Society definition of nocturia (≥1 void/night) was used, and a secondary analysis was conducted with the threshold of two or more voids per night.

Results: Of the 4,723 subjects contacted, 3,023 completed the interviews (64% response rate). After being weighted by age and genders, 57.5% participants reported voiding once or more per night and 24.7% twice or more per night. Advanced age, higher body mass index, smoking, hypertension, and diabetes mellitus were associated risk factors in both genders. Lower urinary tract symptoms suggestive of benign prostatic enlargement increased the occurrence of nocturia in men, and higher parity and vaginal delivery were correlated with nocturia in women. Degree of bother increased with the higher frequency of nocturia, but was not affected by genders.

Conclusions: The prevalence of nocturia is quite high in China and increases with advancing age. Nocturia bothers sufferers greatly, and many known risk factors are associated with this bothersome condition. Experiencing two or more nightly voids is more clinically relevant.