Long-term growth of children with nephrogenic diabetes insipidus

Area of Science:

• Pediatrics
• Endocrinology
• Genetics

Background:

• Primary nephrogenic diabetes insipidus (NDI) is a rare genetic disorder affecting the renal tubules' response to antidiuretic hormone.
• NDI leads to polyuria, polydipsia, reduced caloric intake, and potential growth failure in affected children.
• Limited data exists on the long-term physical growth patterns of children with NDI.

Purpose of the Study:

• To describe the long-term physical growth trajectory of children diagnosed with primary NDI.
• To assess the impact of treatment on growth parameters including height, weight, and BMI.
• To identify factors influencing growth outcomes in pediatric NDI patients.

Main Methods:

• Retrospective study of 14 patients from 11 families with primary NDI, followed for 3-16 years.
• Diagnosis confirmed via clinical, laboratory data, and response to pitressin concentration tests.
• Growth parameters (weight, standing height, BMI) measured periodically; treatment included indomethacin, thiazides, and amiloride.

Main Results:

• Most children initially presented with growth below the third centile.
• A majority demonstrated improved weight, height, and BMI over the follow-up period.
• Mean gains in height, weight, and BMI were 1.72, 1.06, and 1.46 standard deviations, respectively; treatment non-adherence correlated with growth delay.

Conclusions:

• Children with primary NDI can achieve significant growth improvements with consistent medical management.
• Early height deficit at diagnosis was inversely related to height gain during the initial follow-up years.
• Further research into adolescent growth and the effects of specific genetic mutations in NDI is warranted.