Role of urinary PGE and ion excretion in the etiopathogenesis of primary monosemptomatic enuresis nocturna

Objective: Nowadays, studies on thepathogenesis of primary monosymptomatic enuresis nocturna (PMEN) are stil continuing. In this study, was aimed to investigate the role of urine Na, Ca, osmolality and PGE2 on the etiopathogenesis of PMEN. Materials and Methods: The study included 51 patients who were diagnosed PMEN in Adnan Menderes University School of Medicine general pediatrics and pediatric nephrology clinic, who were randomly selected, who did not receive any treatment for at least 6 months, and were between 5-17 years of age. The control group consisted of 40 randomly selected patients with similar sex and age, noother illnesses and no night time urination for the study group. The clinical evaluations of the patient group and the results of the test sperformed for the differential diagnosis were recorded. All children included in the study group were filled with nightly voiding diary for one weekand a two day daytime voidings chedule. Estimated bladder capacity and maximum void volume were calculated from the diary. An informed consent form was signed for the families of 91 children who participated in the study. Patients was admitted to the Adnan Menderes University pediatric nephrology service and diets were adjusted to receive 30 mg/kg/day of fluid and 3 mmol/kg/day of sodium. Two-thirds of the liquid was set before 16:00, one-thirds after 16:00. The urine volume was calculated between 08:00am - 08:00pm as 'daytime urine volume' and the urine volume was calculated between 08:00pm- 08:00am recorded as 'nighttime urine volume'. Thepatient and control group samples osmolality, sodium (ISE method), calcium (spectrophotometrymethod) and pGE2 (ELISA method) were studied by the same investigator in the daytime and nighttime urine separately. Statistical analyzes of the results wereperformed using chi-square test, Mann Whitney U test, paired t test, Wilcoxon and correlation tests. Type I error level was determined as 0.05. Results: İn the study group31.4% had has a nocturnal urinary incontinence for 2 or more nights and nocturnal polyuria wasfound at 23.5%. In the evenings before get bed, excess amount of liquid consumption was found to be 35.3% in the enuresis group. Excess fluid consumption may have a role in etiopathogenesis.The fact that nighturine Na excretion was significantly higher in the PMEN than in the control group, suggests that nighturine Na excretion may play a role in the pathogenesis of PMEN. Urinary calcium excretion was not foundtoplay a role in the pathogenesis of PMEN. In both PMEN and controlgroups daytime Na and Ca excretions were found higher than nighttime urine Na and Ca excretions. This result was attributed to the intake of salt, calcium-containing foods in the daytime diet, and the intake of Na and Ca in the daytime diet was thought to be the effect of etiopathogenesis. The absence of a difference between the PMEN and the control group in terms of urine osmolality suggested that urine osmolality did not play a role in the pathogenesis of PMEN. In children with PMEN, pGE2 excretion in the urine was statistically higher than in the control group, both day and night. Urinary pGE2 excretion was found to play a role in the pathogenesis of PMEN. It has been observed that there is no gender role in the pathogenesis of PMEN due to ion excretion. The statistically significant high levels of Na and Ca excretions in the nocturnal polyuria of night urine suggests that nocturnal polyuria is the effect of Na and Ca in the urine. The significant elevation of pGE2 levels at two or more voids during the night showed that pGE2 secreted from the bladder may play a role in bladder contraction. The presence of pGE2 excretion at night in previously desmopressin-treated patients was statistically significantly lower than those who did not receive any desmopressin treatment, suggesting that urine pGE2 did not play a role in desmopressin response. In PMEN, night and day urinaryexcretion of pGE2 was weaklycorrelated between only with Ca excretion. Outcome: It was concluded that urinary excretion of Na and pGE2 had a role in the formation of PMEN and urinary Ca excretion and osmolality were not. It was concluded that irregular contractions in the bladder smooth muscle, which are thought to play a role in the etiopathogenesis of PMEN, may have been caused by increased pGE2 secretion from renal collecting ducts and / or from the bladder. Nocturnal polyuria wasthought to be the effect of Na and Ca in nighttime urine in the development of nocturnal polyuria in cases with PMEN. To elucidate the etiopathogenesis of PMEN there is a need for more extensive controlled studies. Keywords: Primary monosymptomatic enuresis nocturna , urinary Na, urinary Ca, osmolality, urinary pGE2, nocturnal polyuria