Central Diabetes Insipidus
Also written as NDI, DI.
A patient with central diabetes insipidus is started on desmopressin.
What our notes say
- A patient with central diabetes insipidus is started on desmopressin. (Pituitary disorders)
- Clinical Relevance: Deficiency of ADH leads to central Diabetes Insipidus, characterized by polyuria (excessive urination) and polydipsia (excessive thirst). (Hypothalamic Hormones: Endocrine Regulation and Functions — Notes)
- Central Diabetes Insipidus results from insufficient ADH production by the hypothalamus or release from the posterior pituitary. (Hypothalamic Hormones: Endocrine Regulation and Functions — Notes)
- Desmopressin for central diabetes insipidus. — Mimic normal pituitary output; avoid over‑replacement which can cause osteoporosis, hypertension or fluid overload. (Pituitary disorders)
- True volume depletion, or hypovolemia, generally refers include central diabetes insipidus (CDI) and nephrogenic diato a state of combined salt and water loss exceeding betes insipidus (NDI). (Harrisons Pulmonary and Critical Care Medicine)
- For example, inadvertent administration of hypertonic NaCl or NaHCO3 or replacing Central diabetes insipidus Nephrogenic diabetes insipidus (Harrisons Pulmonary and Critical Care Medicine)
Study material on Central Diabetes Insipidus
- Harrisons Pulmonary and Critical Care Medicine
- Devendra K. Gupta, Krishna M. Goel - Hutchison’s Paediatrics. chdhe-Jaypee Brothers (2012)
Practice questions on Central Diabetes Insipidus
Central diabetes insipidus is confirmed by which pattern?
- Low urine osmolality (<300) + high serum osmolality/Na → corrects with DDAVP
- Concentrated urine corrected by water deprivation only
- Normal serum osmolality with dilute urine
- High urine osmolality, low plasma Na
Answer: A. Central DI is due to ADH deficiency, leading to the inability to concentrate urine despite high serum osmolality. Water deprivation fails to increase urine osmolality, but administration of DDAVP (a synthetic ADH analog) causes significant urine concentration. This distinguishes it from nephrogenic DI.
Central diabetes insipidus is distinguished from nephrogenic DI by
- Severity of polyuria
- Urine specific gravity alone
- Serum osmolality
- Response to desmopressin (ADH analogue)
Answer: D. Water deprivation then desmopressin: central DI responds (urine concentrates). Nephrogenic DI = no response (renal resistance to ADH).