13 Nocturia is multifactorial, with causes beyond the urinary tract itself.1,14 Metabolic syndrome (MetS) consists of a clustering of cardiovascular risk factors, such as obesity, high blood pressure, impaired glucose tolerance, and dyslipidemia. Kupelian et al. reported an association of individual urological
symptoms with MetS.15 Thus, we examined the association between components of MetS and nocturia. Tikkinen reported that obesity was associated with increased nocturia, more strongly among women than among men, in Finland.16 The factors underlying an association between find more nocturia and obesity are unclear. Lifestyle-related factors may also be more common among the obese. It is possible that nocturia in some obese persons is related to excessive nighttime eating or drinking, especially consumption of alcohol.16 Moreover, obesity is a multifactorial disease with adverse health consequences, such as cardiovascular disease, type 2 diabetes, hypertension (HT), sleep apnea, and possibly depression, which may result independently in nocturia.17 In previous studies in animals, an association between HT and the development of LUTS was demonstrated. Spontaneously hypertensive rats, which
develop autonomic hyperactivity at an early age, have been found to have pronounced Selleck AZD1208 bladder overactivity.18 These animals void at least three times more frequently than normotensive control rats, and have been shown to have increased noradrenergic bladder innervation.19 The relation between nocturia and HT is not clear. Some authors reported that HT was an independent risk factor for nocturia among patients in Japan (odds ratio [OR], 1.64; 95% confidence interval [95% CI], 1.45–1.87),20 as well as in the USA (Michigan and
Boston) (OR, 1.52; 95% CI, 1.52–1.94 and OR, 2.00; 95% CI 1.24–3.14, respectively).21,15 But other studies reported no association between HT and nocturia among Dutch or Swedish patients.22,23 Treatment of HT with diuretics and calcium channel blockers can increase urine output.24 It has been reported that the mean blood pressure is higher in men with nocturnal polyuria than in controls. McKeigue hypothesized that HT and nocturnal polyuria each reflect the resetting of the normal pressure–natriuresis relationship in the Liothyronine Sodium kidney, resulting in sodium retention and increased blood pressure.25 Diabetes is a common cause of nocturia. Uncontrolled diabetes leads to hyperglycemia and an osmotic diuresis, predisposing patients to nocturia.26 Diabetes also leads to decrease in functional bladder capacity due to large residual urine volume. Ueda studied bladder function in asymptomatic Japanese patients with diabetes using cystometry.27 This study found that patients have increased bladder capacity at first sensation to void and decreased detrusor contractility. Moreover, 25% of diabetic patients had detrusor hyper-reflexia. More than half had no irritable urinary symptoms.