We evaluated the relationship between body mass index (BMI), including low BMI, and nocturia in Japanese women.

We collected data on 18 952 women who participated in a multiphasic health screening in Fukui, Japan, in 2006. The participants were asked to report any current or previous disease. Self-reported current body weight and height were used to calculate the BMI. We analyzed the relationship between nocturia, as assessed by a questionnaire, and other variables including age, BMI, and comorbidities.

The participants’ mean age was 60.6 years. Overall, the prevalence of nocturia (two or more voids/night) was 4.3% and increased in an age-dependent manner. BMI did not affect nocturia in the young participants. The prevalence of nocturia was higher in the high-BMI women (>25.0 kg/m 2 ) in their fifth and sixth decades, but the prevalence was higher in the low-BMI (<18.5 kg/m 2 ) in the women more than 80-years old. A multivariate analysis revealed a significant association between nocturia and the following: age, BMI, sleep disturbance, arteriosclerosis, cerebrovascular disease, chronic pulmonary disease, diabetes mellitus, and hypertension. Not only high BMI (which is already reported as a risk of nocturia) but also low BMI was a factor related to nocturia.

Our findings indicate that in addition to obesity, low BMI is a factor of nocturia in women.

Neurourology and urodynamics. 2019 Jul 23 [Epub ahead of print]

Hideaki Ito, Yoshitaka Aoki, Hideki Oe, Minekatsu Taga, Katsuki Tsuchiyama, Osamu Yokoyama

Department of Urology, Faculty of Medical Science, University of Fukui, Eiheiji-cho, Fukui, Japan.