A Comparative Study of Vitamin D Serum Levels in Monosymptomatic Enuretic Children and Non-Enuretic Children.

Background: Enuresis refers to urinary incontinence during sleep in children over 5 years of age. The pathogenesis of enuresis is complex. It is related to low functional bladder capacity, nocturnal bladder overactivity, and high arousal threshold, and it is also related to the immaturity of the central nervous system. Also, it was related to nocturnal polyuria and decreased nocturnal urine osmolality. There are many clinical observations that link nocturnal enuresis with developmental delay in language and physical growth. Vitamin D is important for the critical biological actions involving neural function and development. It is involved in the regulation of nerve growth factor synthesis. It also has a neuroprotective effect. It not only plays a vital role in skeletal growth but also has other critical biological actions in neural development and function. Furthermore, Vitamin D deficiency was linked to increased urinary output, which raised the question of whether Vitamin D levels are linked to nocturnal polyuria and decreased nocturnal urine osmolality. It was observed in the mice model study that Vitamin D is a negative regulator of the renin-angiotensin system, and its deficiency leads to abnormal thirst and increased water intake by mice with Vitamin D deficiency and as much as twice urinary output than normal mice.

Aim of the study: To evaluate the relationship between Vitamin D deficiency and nocturnal enuresis and to study the correlation between Vitamin D deficiency and urine osmolality, which is an indirect indicator of ADH deficiency.

Patients and methods: This is a case-control study that started in February 2020 and ended in August 2020 in our tertiary hospital. The study included 60 children with primary monosymptomatic nocturnal enuresis selected randomly and 60 healthy children as a control group. We compared Vitamin D levels, nocturnal polyuria, and nocturnal urine osmolality among both groups.

Results: In our study, there was a statistically significant difference between both groups regarding serum Vitamin D values. The results of the serum Vitamin D level showed that 63.3% of cases with nocturnal enuresis had low Vitamin D levels with a mean range (18.8 ± 7.1) compared with 41.7% in the control group with a higher mean range (23.7 ± 9.6), and a p value of 0.002.

Conclusion: Our study indicates that there is a significant relationship between primary monosymptomatic nocturnal enuresis and serum Vitamin D deficiency in children. We also proved that Vitamin D level is correlated positively with nocturnal urine osmolality.

Trial registration: Clinical trials registration number: NCT06243042.