Association between NT-proBNP and nocturia among community-dwelling elderly males and females: A cross-sectional analysis of the HEIJO-KYO study.

Aims: To investigate the association between B-type natriuretic peptide (BNP) and nocturia among community-dwelling males and females.

Methods: A total of 1096 participants (mean age 71.9 ± 7.1 years, 518 [47.2%] males) were included in the study. The number of nocturnal voids was recorded in a self-reported urination diary, and nocturia was defined as two or more voids per night. Daytime serum concentration of the N-terminal fragment of BNP precursor (NT-proBNP) was measured. Multivariable logistic regression analysis was performed to determine the association between NT-proBNP and nocturia.

Results: Nocturia was observed in 23.5% of females and 37.1% of males. Higher NT-proBNP (log pg/ml) was associated with nocturia in both gender groups (females: odds ratio [OR]: 1.67, 95% confidence interval [95% CI], 1.21-2.34, p = .002; males: OR: 1.26, 95% CI, 1.01-1.59, p = .046), independent of confounding variables including night-time blood pressure, mean voided volume, and chronic kidney disease. Although the increase in prevalence of nocturia with higher NT-proBNP was equivalent in both genders, some effect of gender on the relationship between NT-proBNP and nocturia was observed (p = .037). Nocturnal urine volume was also significantly and independently associated with NT-proBNP level (females: β = 32.9 ml, 95% CI, 5.63-60.2, p = .018; males: β = 34.6 ml, 95% CI, 9.40-59.9, p = .007).

Conclusions: This study revealed higher serum NT-proBNP is significantly and independently associated with the prevalence of nocturia in both males and females. This is an exploratory cross-sectional study and the analyses are post hoc, so further research works are needed to clarify the causality and clinical value.