DIABETES INSIPIDUS

MADE BY:-UMMEY AIMAN

MBBS 1ST YR

IIMS&R

DIABETES INSIPIDUS Antidiuretic hormone is a hypothalamic hormone,

synthesized in the cells of supraoptic nucleus

and stored in posterior pituitary gland.

Diabetes insipidus is a posterior pituitary disorder.

It is caused due to hyposecreation of antidiuretic hormone. Or caused due to renal disorder.most common type in humans is the neurological form.

The incidence of diabetes insipidus in the general population is 3 in 100,000.

Difference between diabetes mellitus and diabetes insipidus.

Although they have a common name, diabetes mellitus and diabetes insipidus are two entirely separate conditions with unrelated mechanisms. Both cause large amounts of urine to be produced (polyuria), and the term "diabetes" is derived from the Greek word meaning siphon. However, diabetes insipidus is either a problem with the production of antidiuretic hormone (central diabetes insipidus) or kidney's response to antidiuretic hormone (nephrogenic diabetes insipidus), whereas diabetes mellitus causes polyuria via a process called osmotic diuresis, due to the high blood sugar leaking into the urine and taking excess water along with it.

Types of diabetes insipidus

Central (neurogenic) diabetes insipidus.

Nephrogenic diabetes insipidus.

CENTRAL DIABETES INSIPIDUS

Complete or partial failure of ADH secretion.

In this distal tubular segments cannot reabsorb water in the absence of ADH,this condition is called “central”diabetes insipidus.

Results in formation of large volume of dilute urine that can exceed 15L/day.

CAUSES

It may be cause due to lesion of Supraoptic and Paraventricular nuclei of hypothalamus.

Lesion in hypothalamo-hypophyseal tract. Head injuries Infection Congenital causes

SIGN AND SYMPTOM

The primary abnormality abserved clinically is – Polyuria Polydipsia due to activated thirst center Dehydration that is excessive loss of water In children ,DI can interfere with apetite ,

weight ,and growth. They may present with fever , vomitting , or diarrhea.

TEST Water deprivation test This test confirm the diagnosis and help determine the

cause of diabetes insipidus . you will be asked to stop dinking water for several hour before test ,then we measure the changes in urine output and its body weight.

Vasopressin or Desmopressin test This test is helpful to distinguished between central and

nephrogenic diabetes insipidus. Reduction of urine output and increases urine osmolarity

, then ADH is deficient. But in renal pathology, there is no such changes like

above.

TREATMENT Treatment for central diabetes insipidus is

administration of a synthetic analog of ADH ,DESMOPRESSIN.

DESMOPRESSIN

act on

V2 RECEPTER(vasopressin) It increases water permeability in late DCT and

collecting duct. Desmopressin can be given by injection , nasal spray or

orally . It restore urine output toward normal.

NEPHROGENIC DIABETES INSIPIDUS

in this normal or elevated levels of ADH are present but renal tubular segments cannot respond appropriately, This condition is known as “Nephrogenic” diabetes insipidus because abnormality resides in kidney.

It is caused due to mutation of gene in v2 receptor or aquaporin.

Causes- Failure of DCT and collecting duct. Impairments of function of loop of Henle due to diuretics. Some drugs like lithium and tetracycline can impair the ability of

DCT to respond to ADH.

FEATURE

It result in formation of large volume of dilute urine which

result in dehydration .

TREATMENT To correct the underlying renal disorder. Hereditary type of diabetes insipidus account for less

than 10 % of the cases.