Nephrogenic diabetes insipidus

Nephrogenic diabetes insipidus is a disorder of water balance. It is not related to the more common diabetes mellitus (sugar diabetes), in which the body does not produce or properly use insulin. Nephrogenic diabetes insipidus is a distinct disorder caused by complete or partial resistance of the kidneys to arginine vasopressin (AVP).

In a healthy person, AVP acts as a signal to the nephrons to reabsorb water into the body. In nephrogenic diabetes insipidus, the nephrons in the kidneys are not able to respond to this signal, leading to excessive water loss in large amounts of urine. The thirst increases to try to balance this loss from the body.

Nephrogenic diabetes insipidus can be either acquired or hereditary. The acquired form is brought on by certain drugs and chronic diseases and can occur at any time during life. Certain drugs, such as lithium or antiviral medications such as foscarnet (Foscavir), also can cause nephrogenic diabetes insipidus. Nephrogenic diabetes insipidus may also be a temporary complication associated with pregnancy.

The most common inherited nephrogenic diabetes insipidus is an X-linked trait with variable penetrance in heterozygous females that affects the arginine vasopressin (AVP) receptor 2 gene. Heterozygous females may have no symptoms or a variable degree of polyuria and polydipsia, or they may be as severely affected as males.

The two main symptoms of nephrogenic diabetes insipidus are chronic excessive thirst (polydipsia) and excessive urine production (polyuria). Excessive urination at night (nocturia) also occurs. Infants with hereditary nephrogenic diabetes insipidus may eat poorly and fail to gain weight and grow at the expected rate (failure to thrive). They may also be irritable and experience fevers, diarrhea, and vomiting.
Nephrogenic diabetes insipidus

Diabetic hypoglycemia

Hypoglycemia is the leading limiting factor in the glycemic management of type 1 and type 2 diabetes. Severe hypoglycemia can have potentially serious consequences for patients with diabetes, especially if it causes falls or other injuries.

Hypoglycemia happened may due to too little food or skipping a meal; too much insulin or diabetes pills; more active than usual.

Iatrogenic hypoglycemia in patients with diabetes can be defined as all episodes of an abnormally low plasma glucose concentration that expose the individual to potential harm.

Symptoms of hypoglycemia including:
Shaky, fast heartbeat, sweeting, dizzy, anxious, hungry, blurry vision, weakness or fatigue, headache or irritable.

Classification of hypoglycemia in diabetes:
* Severe hypoglycemia
* Documented symptomatic hypoglycemia
* Asymptomatic hypoglycemia
* Probable symptomatic hypoglycemia
* Pseudo-hypoglycemia

Hypoglycemic episodes are common in type 1 diabetes, and 30% of individuals with type 1 diabetes mellitus experience 1 to 3 episodes of severe hypoglycemia annually. The prevalence of hypoglycemia is three times lower in type 2 than in type 1 diabetes mellitus.
Diabetic hypoglycemia 

Notes
Iatrogenic: relating to illness caused by medical examination or treatment.

Cranial diabetes insipidus

Diabetes insipidus is an uncommon disorder that causes an imbalance of fluids in the body. This imbalance leads the patient to produce large amounts of urine. There are 2 main types of diabetes insipidus:
*Cranial diabetes insipidus
*Nephrogenic diabetes insipidus

Cranial diabetes insipidus is a condition in which the hypothalamus does not produce enough AVP to regulate urine production and is the most common type of diabetes insipidus. Arginine vasopressin (AVP) is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus.

Cranial diabetes insipidus has a prevalence of fewer than 1 per 25 000 population—up to 25% of these patients have cranial neoplasms or post-pituitary surgery cranial diabetes insipidus.

Cranial diabetes insipidus can be caused by damage to the hypothalamus or pituitary gland – for example, after an infection, operation, brain tumor or head injury. Both cranial and nephrogenic diabetes insipidus can be inherited or acquired. Approximately one in three cases of diabetes insipidus has no clear, definable cause.

Hypothalamus is a small area of the brain, which is located under the thalamus. The pituitary gland is located just below the hypothalamus. The pituitary is a small gland located near the base of the brain that stores several hormones and releases them into the bloodstream as needed by the body. These hormones regulate many bodily functions.

The hypothalamus works with the pituitary gland, which makes and sends other important hormones around the body.
Cranial diabetes insipidus

Mechanisms of diabetes insipidus

Diabetes insipidus (DI) is part of a group of hereditary or acquired polyuria and polydipsia diseases. It is a rare disease that causes frequent urination. The large volume of urine is diluted, mostly water. To make up for lost water, a person with DI may feel the need to drink large amounts and is likely to urinate frequently, even at night, which can disrupt sleep and, on occa­sion, cause bedwetting.

Two very different mechanisms can cause diabetes insipidus:
• Inadequate release of antidiuretic hormone (ADH, also called arginine vasopressin or AVP) from the hypothalamus (central diabetes insipidus) and
• Inadequate response of the kidney to ADH (nephrogenic diabetes insipidus).

DI can occur at any age, but is mostly found in adults. The disease affecting only about 1 in 25,000 people.

DI should not be confused with diabetes mellitus (DM), which results from insulin deficiency or resistance leading to high blood glucose, also called blood sugar. DI and DM are unrelated, although they can have similar signs and symptoms, like exces­sive thirst and excessive urination. DI can be caused by two fundamentally different defects: Inadequate/impaired secretion of AVP from the posterior pituitary gland and impaired/insufficient renal response to ADH. AVP, a neurohypophyseal nonapeptide, regulates body water and osmotic homeostasis.

DM is far more common than DI and receives more news coverage. DM has two main forms, type 1 diabetes and type 2 diabetes.

Arginine vasopressin (AVP) is an antidiuretic hormone (ADH) is a hormone released from the rear most part of the pituitary gland (the posterior pituitary). This gland is located at the base of the brain, and is about 3 to 5 centimeters behind the bridge of the nose. The AVP system maintains water balance based on serum osmolality and arterial blood volume via the vasopressin-2-receptor. AVP circulates in the bloodstream and acts on the kidneys to reduce the amount of water that is passed out in urine.
Mechanisms of diabetes insipidus