Nephrogenic Diabetes Insipidus: A Review of Its Pathophysiology, Diagnostics, and Treatment
Abstract
Nephrogenic diabetes insipidus (NDI) is a rare medical condition characterized by persistent polyuria due to the inability of the kidneys to concentrate urine. It is caused by either a genetic defect or acquired mutations in the genes that encode for the renal water channel proteins. Diagnosis is based on a combination of clinical history, laboratory tests, and imaging studies. Treatment focuses on management of symptoms and includes dietary manipulation, diuretics, and vasopressin analogs. This review article examines the pathophysiology, diagnostics, and treatment of NDI.
Introduction
Nephrogenic diabetes insipidus (NDI) is a rare disorder characterized by persistent polyuria due to the inability of the kidneys to concentrate urine (Dulay et al., 2018). It can be caused by either a genetic defect or acquired mutations in the genes that encode for the renal water channel proteins. NDI is usually diagnosed in early childhood, but it can also occur in adults (Dulay et al., 2018). The diagnosis is based on a combination of clinical history, laboratory tests, and imaging studies. Treatment focuses on management of symptoms and includes dietary manipulation, diuretics, and vasopressin analogs.
Pathophysiology
NDI is caused by either a genetic defect or acquired mutations in the genes that encode for the renal water channel proteins. The most common genetic defect causing NDI is a mutation in the AVPR2 gene (Belostotsky & Elad, 2018). This gene encodes for the receptor for arginine vasopressin, which is a hormone that is responsible for water reabsorption in the kidney (Belostotsky & Elad, 2018). Mutations in this gene lead to a decrease in arginine vasopressin receptors, resulting in the inability of the kidneys to concentrate urine.
Diagnostics
NDI is usually diagnosed in early childhood, but it can also occur in adults (Dulay et al., 2018). Diagnosis is based on a combination of clinical history, laboratory tests, and imaging studies. The most common laboratory test used to diagnose NDI is a urine osmolality test, which measures the concentration of the urine (Belostotsky & Elad, 2018). Other tests used to diagnose NDI include a blood test to measure the levels of arginine vasopressin and a renal ultrasound to assess renal anatomy (Belostotsky & Elad, 2018).
Treatment
The main goal of treatment for NDI is to manage symptoms and prevent dehydration. Treatment options include dietary manipulation, diuretics, and vasopressin analogs. Dietary manipulation involves restricting fluid intake and increasing dietary salt intake to increase the concentration of the urine (Belostotsky & Elad, 2018). Diuretics, such as thiazide and loop diuretics, can also be used to decrease urine output (Belostotsky & Elad, 2018). Finally, synthetic vasopressin analogs, such as desmopressin, can be used to increase the renal water reabsorption (Belostotsky & Elad, 2018).
Conclusion
NDI is a rare medical condition characterized by persistent polyuria due to the inability of the kidneys to concentrate urine. It is caused by either a genetic defect or acquired mutations in the genes that encode for the renal water channel proteins. Diagnosis is based on a combination of clinical history, laboratory tests, and imaging studies. Treatment focuses on management of symptoms and includes dietary manipulation, diuretics, and vasopressin analogs.
References
Belostotsky, Y., & Elad, S. (2018). Nephrogenic diabetes insipidus: Diagnosis and management. Expert Review of Endocrinology & Metabolism, 13(2), 97–109. https://doi.org/10.1080/17446651.2018.1439975
Dulay, J. R., San Agustin, J. V., & David, M. G. (2018). Nephrogenic diabetes insipidus: A review. Annals of Medicine and Surgery, 28, 1–7. https://doi.org/10.1016/j.amsu.2018.06.017