Metabolic syndrome (MetS) has been implicated in the aetiology of lower urinary symptoms. The objective of this study was to investigate the relationship between urgency and the components of MetS, including obesity, hyperglycemia, hypertension, and dyslipidemia, in a residential population who had nocturia.

A cross-sectional questionnaire survey assessing the role of components of MetS on nocturia with urgency was conducted. 
We collected data on participants who participated in a multiphasic health screening, from April 2015 to March 2016, with written informed consent. 
All participants were asked to answer a validated self-reported questionnaire for OAB screening [1]. One of the screening questions we used was “It is difficult to hold on when I have the sudden compelling desire to urinate” with a choice of the following two responses: yes or no. Participants who answered ‘yes’ were identified as having urgency. Nocturia was defined as 2 or more voids per night.
Participants underwent a detailed health evaluation, including age, waist circumference, blood pressure (BP), fasting plasma glucose, triglyceride, and HDL cholesterol levels and provided a list of current medications, including those for diabetes, hypertension, and dyslipidemia.
Subjects were stratified into 5 age groups (≤49, 50-59, 60-69, 70-79, 80 years). The prevalence of nocturia was determined for each age group.
We analyzed the relationship between urgency and age, gender, obesity, hyperglycemia, hypertension, and dyslipidemia among participants who had nocturia. Obesity was defined as high waist circumference (≥85 cm in men and ≥90 cm in women). Hyperglycemia was defined as fasting glucose concentration ≥110 mg/dL and/or current use of antidiabetic medication. Hypertension was defined as systolic BP ≥130 mmHg, diastolic BP ≥85 mmHg, or current use of antihypertensive medication. Dyslipidemia was defined as triglyceride concentrations ≥150 mg/dL and/or HDL-cholesterol levels <40 mg/dL, or treatment for dyslipidemia. These definitions are consistent with the Japanese definition of metabolic syndrome [2].  MetS was diagnosed when obesity plus two or more of the following cardio-metabolic risks according to Japanese criteria: high blood pressure, hyperglycemia, and lipid abnormality [2].
The chi-square test and logistic regression modeling were used for statistical analyses. Values of p<0.05 were considered statistically significant. All statistical analyses were conducted using IBM SPSS Statistics version 22 (IBM Corp., Armonk, New York).

A total of 14,194 individuals aged 18-95 years participated in a multiphasic health screening in Fukui, Japan. We excluded 1,716 participants (12.0%) with incomplete responses on the questionnaire, leaving a sample of 12,478 participants (5,313 men, 7,165 women).
Participants’ median age was 69 years (range 18-95), and 3,570 (28.6%) participants had nocturia including 1,987 men (37.4%) and 1,583 women (22.1%). The prevalence of nocturia both with and without urgency was increased with age (Figure).
Participants who had nocturia with urgency had a significantly higher prevalence of obesity (37.3% vs 32.3%, p=0.020), hyperglycemia (37.5% vs 32.5%, p=0.012), dyslipidemia (42.0% vs 37.9%, p=0.046), and MetS (24.0% vs 18.8%, p=0.002), compared with those without urgency.
In univariate analysis, age, female sex (Odds ratio (OR) 1.47, 95%CI 1.21-1.68), obesity (OR 1.22, 95%CI 1.03-1.45), hyperglycemia (OR 1.24, 95%CI 1.05-1.47), and dyslipidemia (OR 1.19, 1.01-1.40) (Table) were all significantly associated with the combination of urgency with nocturia, compared to nocturia alone. 
In multivariate analysis, a significant association was found between urgency and the following: age, female (OR 1.58, 95%CI 1.33-1.88), obesity (OR 1.34, 95%CI 1.11-1.60), and hyperglycemia (OR 1.20, 95%CI 1.01-1.20) among participants with nocturia (Table).
A significant association was found between nocturia with urgency and MetS. The age and sex-adjusted odds ratio (95%CI) was 1.49 (1.22-1.82).

The results from our epidemiological study indicate nocturia with urgency can be a marker of increasing in MetS components, compared with nocturia without urgency.
This study had several limitations. This study was a cross-sectional; therefore, we cannot conclude that there is a causal relationship between nocturia with urgency and obesity or hyperglycemia. Longitudinal studies are necessary to confirm the relationship.

Our study confirmed that individuals who report nocturia with urgency are more at risk of obesity, hyperglycemia, and MetS than those with nocturia without urgency. The combination of symptoms should prompt closer attention to cardiovascular health among primary care providers.

Yamaguchi O et al: Neurogenic Bladder Society. Clinical guidelines for overactive bladder. Int J Urol 2009, 16: 126.
Committee to Evaluate Diagnostic Standards for Metabolic Syndrome: Definition and the diagnostic standard for metabolic syndrome. Nippon Naika Gakkai Zasshi 2005, 94: 794.