Hypothesis / aims of study
Background: Nocturia is defined by the International Continence Society as “the complaint that the individual has to wake at night one or more times to void”.[1] Nocturia has become a commom clinical symptom among the elderly.[2]The prevalence of nocturia in men increase with age.[3] Nowadays, clinicians treat nocturia mainly as same as Benign Prostate Hyperplasia / Lower urinary tract symptoms in elderly men. It is less nocticed that nocturia of adults in especial elderly patients is primarily caused by nocturnal polyuria.[4,5] In our country, it is rarely to treat nocturia in elderly men with desmopressin. Abstract Objectives: To explore the effects and safeties of desmopressin on elderly men with nocturia.
Study design, materials and methods
We used random number table to divide elderly men with nocturia into 2 groups, treatment group and control group. The patients in treatment group took Desmopressin Acetate Tablets 0.2 mg and those in control group took Tamsulosin Hydrochloride Sustained Release Capsule 0.2 mg orally before going to bed in the night for 4 weeks. The patient recorded 24 hours voiding diaries for 3 days and worked out mean number of nocturnal voids, hours of undisturbed sleep (HUS) before treatment and before every subsequent visit. Before treatment and weekly after treatment, mean number of nocturnal voids, HUS, Night Quality of Life (NQoL), Quality of Life(QoL), adverse events were recorded. Before treatment and both 1 week and 4 weeks after treatment, the patients in treatment group had to be checked blood serum sodium.
Results
42 men had been diagnosised with nocturia in outpatient department of the investigator from December 2014 to March 2016, 34 of them were recruited in our study and randomly enter either treatment group or control group. Each group consisted of 17 cases. There was no statistical difference in the baseline data between two groups (all P＞0.05). The average ages of treatment group and the control group were 65.17 ± 11.24 and 63.88 ± 9.27 years old, the courses of disease were 3.02 ± 4.98 and 2.26 ± 2.62 years, respectively. Before treatment, mean numbers of nocturnal voids were 3. 82 ± 1.16 and 3.21 ± 1.40 times, HUS were 1.79± 1.71 and 1.75 ± 0.61h, NQoL were 51.76 ± 13.80 and 41.18 ± 13.64, QoL were 4.00 ± 1.00 and 3.94 ± 0.90, respectively. 4 weeks after treatment, mean numbers of nocturnal voids decreased to 1.63 ± 0.98 and 2.00 ± 0.88 times, HUS increased to 4.00 ± 0.66 and 2.59 ± 0.69h, NQoL decreased to 20.88 ± 12.02 and 30.59 ± 12.36, QoL decreased to 1.35 ± 1.06 and 2.85 ± 0.95 in treatment group and control group, individually. The improvements in mean number of nocturnal voids, QoL and NQoL in treatment group were all superiored to the control group ( all P＜0.05). Two patients in treatment group appeared dizzy during the follow-up period. In one of both, the symptom disappeared after the Desmopressin dose decreased from 0.2 mg to 0.1 mg per night. The symptom sustained and the dose was not changed in the other one. In treatment group, other two patients suffered from dyspepsia, one palpitation and one thirst. Those symptoms could be tolerated and the dose was not changed. In control group, 2 patients suffered from thirst, one nasal congestion, one dizzy and one short of breath. All those symptoms could be tolerated and the dose was not changed. There was no statistical difference between the occurrence rate of adverse events in the 2 groups (P=0.714).
Interpretation of results
Nocturia of adults, in especial elderly, patients is primarily caused by nocturnal polyuria. Arginine vasopressin(AVP) increases water permeability by distal convoluted tubule and collecting tubes.It can promote water absorption and reduce urine production. Serum level of AVP is increased and the amount of urine production is decreased during night. A significant proportion of elderly patients with nocturia lack this physiologic increase of the AVP during nighttime.Desmopressin is synthetic analogues of AVP.It is selective vasopressin type 2 receptor(V2 receptor) agonist.It simulates AVP combines with V2 receptor on the collecting tubule. Desmopressin increases the reabsorption of water,concentrate urine and decrease the total urine volume,thus alleviates nocturia.