Results
A total of 379 patients from eight centers were included in study and the mean age of patients was 56.6±12.5 (18-94) years old. Of these patients 340 (89.7%) were male and 39 (10.3%) were female. The mean BMI was 28.5±5.0 (18.7-49) kg/m2 and the most common co-morbidity was hypertension (27.2%). The demographic characteristics of patients were given in Table 1. Nocturnal polyuria was the most common subtype (68.1%); the other subtypes were reduced bladder capacity (64.1%), mixed nocturia (combinations of nocturnal polyuria, reduced bladder capacity and global polyuria) (42.7%) and global polyuria (8.7%). However, 6.1% of the patients did not comply with the afore-mentioned subtypes and this was defined as isolated nocturia which probably reflects the patients with sleep disorders. The distribution of etiological factors is given in Figure 1.
Regarding the severity of nocturia; 155 (41%) patients had mild, 167 (45%) patients had moderate and 57 (15%) patients had severe nocturia. Increased nocturia severity was associated with higher age, comorbidities and beta-blocker medication rates (p=0.005, p<0.001 and p=0.002 respectively); however the body mass index (BMI) values, smoking status and gender were similar between the nocturia severity groups (Table 2). All of the urinary symptom questionnaires’ scores used in our study including ICIQ-FLUTS, ICIQ-MLUTS and OAB were significantly rising with the increase in nocturia severity (Table 2). Increased nocturia severity was found to be associated with higher daytime urinary frequency, night-time urine volume, total daily urine volume and evening liquid consumption according to 3-day frequency-volume chart results (Table 3). However there were no significant differences between the nocturia severity groups in terms of maximal flow rates (Qmax) in uroflowmetry and post-voiding residual volumes (p=0.070 and p= 0.267). Rate of all pathophysiological mechanisms of nocturia were rising with the increase of nocturia severity, especially for mild nocturia compared to moderate-severe nocturia (Table 3).