Case Report
DOI:
A woman with polyuria and polydipsia
Rahman MA 1* , Kibria MG 2
1 Dr. Md. Azizur Rahman , Associate Professor of Endocrinology, TMSS Medical College and RCH, Thengamra,Bogura, Bangladesh
2 Dr. Md. Golam Kibria , Intern, TMSS Medical College and RCH, Thengamra,Bogura, Bangladesh

* Corresponding Author: Dr. Md. Azizur Rahman , Associate Professor of Endocrinology, TMSS Medical College and RCH, Thengamra,Bogura, Bangladesh
Abstract
Diabetes insipidus (DI) is characterized by polyurea and polydipsia which occurs due to inappropriate secretion or action of antidiuretic hormone (ADH). DI usually are of four types viz. Central diabetes insipidus, Nephrogenic diabetes insipidus, Dipsogenic diabetes insipidus and Gestational diabetes insipudus. Among them CDI is most importent and is caused by damage to hypothalamus or pituitary gland. Mrs Morium, a 35 years house wife, hailing from village Darial, Noongola of Bogra sador upazilla, admitted to TMSS Medical college (TMC) and Rofatullah Community Hospital (RCH) on 16.08.2016 with complaints of intense thirst (water intake ~ 21 L / 24 h) and large volume of urination (~ 18 L/24 h). Her urine osmolality was 72 mosmol/Kg, Serum osmolality was 292 mosmol/Kg, MRI of brain (pituitary gland) was normal, Radio immuno assay of plasma AVP was 2.99 pmol/L. With single dose of Desmopressin per nasally improved her complaints and two dose daily completely ceased her problems.
Keywords
Diabetes insipidus, polyuria, polydipsia
Introduction
Inappropriate secretion or action of serum antidiuretic hormone (ADH) is termed diabetes insipidus (DI), characterized by polyurea (defined as 24 hour urine output in excess of 40 ml/kg) and polydipsia'. The hypothalamus, a small gland located at the base of the brain, produces vasopressin also called antidiuretic hormone (ADH), controls the fluid removal rate through urination’. A decrease of 75% or more in the secretion or action of ADH usually results Diabetes insipidus (DI). The patients may pass 5-20 L or more of urine in 24 hours’. The types of diabetes insipidus include—Central, Nephrogenic, Dipsogenic and Gestational’. Among them central diabetes insipidus (CDI) is most important. CDI happens when damage to a person's hypothalamus or pituitary gland causes disruption in the normal production, storage and release of ADH? Damage can result from surgery, infection, inflammation, a tumor, head injury, inherited defect in the gene that produces ADH and in some cases cause is unknown®. CDI is characterized by poly urea, polydipsia, urinary frequency and nocturia®. Nephrogenic Diabetes Insipidus (NDI) occurs when kidneys do not respond to ADH?. In adults, NDI is opposed to CDI, tends to present more gradually than CDI; as sensitivity to ADH decreases, polyuria increases’. NDI can result from gene mutation, chronic kidney disease, certain drugs, lower potassium level in blood, high calcium level in blood and some cases cause is unknown. Lithium, widely used in therapy of bipolar disorder, is the commonest of acquired NDI®. Other cause of NDI are bilateral urinary tract obstruction” and polycystic kidney diseases®. In cases, where polyuria is due to vast amount of ingested fluid driven primarily by behavioral or thirst disorders, it is called primary polydipsia or Dipsogenic diabetes insipidus occurs due to defect in thirst mechanism. Primary polydipsia is characterize by the ingestion of vast amount of fluid, most frequently water, causes hypotonic polyuria’. During pregnancy, the placenta produces cystine aminopeptidases (vasopressinase) which metabolizes both oxytocin and ADH. When cysteine aminopeptidase levels are greatly elevated ADH is degraded beyond the capacity of the hypothalamic/pituitary axis to secrete it sufficiently to maintain a proper urinary concentration; This results in GDI, also known as ‘transient DI of pregnancy’. The relationship between plasma osmolality and urine osmolality is helpful in establishes a diagnosis’. In order to diagnosis of DI, urine osmolality should < 300 mosmol/kg. The gold standard is a dehydration test followed by plasma ADH levels can be indirect measurement of urine concentration is usually used first’. An MRI imaging appearance as a bright spot in the sella turcica which represents stored ADH; the absence of a bright spot is not necessarily diagnostic of CDI".