Diabetes insipidus is a condition that results from insufficient production of the antidiuretic hormone (ADH), or vasopressin. ADH helps the kidneys and body conserve the correct amount of water. For this reason, it's also called "water diabetes." Normally, ADH controls the kidneys' concentration of urine. It is secreted by the hypothalamus (a small gland located at the base of the brain), stored in the pituitary gland, and then released into the bloodstream. ADH is secreted to concentrate the urine and decrease the amount of urine output, which helps prevent dehydration. Diabetes insipidus typically increases thirst and causes excessive production of dilute urine.
The disease is categorized into 2 groups:
Central diabetes insipidus. Insufficient production or secretion of ADH, resulting from damage to the hypothalamus or pituitary gland. Typical causes include injuries to the brain and rare genetic disorders.
Nephrogenic diabetes insipidus. Kidneys do not respond normally to ADH resulting from drugs or chronic disorders. In addition to genetic disorders that affect the kidneys from birth, other chronic causes are kidney failure, sickle cell disease, or polycystic kidney disease.
Diabetes insipidus can be caused by several conditions, including the following:
Malfunctioning hypothalamus (that produces too little ADH)
Malfunctioning pituitary gland (that fails to release adequate ADH into the bloodstream)
Damage to hypothalamus or pituitary gland during surgery or radiation therapy
Blockage in the arteries leading to the brain
Encephalitis (inflammation of the brain)
Meningitis (inflammation of the meninges, the membranes that cover the brain and spinal cord)
Sarcoidosis (a rare inflammation of the lymph nodes and other tissues of the body's immune system)
Certain drugs like lithium
Each child may experience symptoms differently. Common symptoms may include:
Excessive urine production
Infants with diabetes insipidus may also exhibit the following symptoms:
Failure to grow
The symptoms of diabetes insipidus may look like other problems or medical conditions, such as diabetes mellitus. Always consult your child's doctor for a diagnosis.
In addition to a complete medical history and physical examination, including the child's daily fluid intake, dietary intake, and voiding (bowel and bladder elimination) patterns, diagnostic procedures for diabetes insipidus may include:
Urine tests. These measure the ability to concentrate urine. Typically, the child will not drink for several hours (or after midnight while asleep), then urinate twice within an hour of waking. The second urinary speciment if often diagnostic.
Water deprivation test. To observe if dehydration occurs during fasting. This test must only be done in the hospital.
Magnetic resonance imaging (MRI). This diagnostic procedure combines large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. MRI of the brain checks for pituitary abnormalities.
If left untreated in children, diabetes insipidus can lead to brain damage, impaired mental function, intellectual disability, hyperactivity, short attention span, poor growth, and/or restlessness. Treatment for diabetes insipidus depends on what is causing the disease. Treating the cause usually treats the diabetes insipidus. Specific treatment for diabetes insipidus will be determined by your child's doctor based on:
Your child's age, overall health, and medical history
Extent of the disease
Your child's tolerance for specific medications, procedures, or therapies
Expectations for the course of the disease
Your opinion or preference
Treatment may include synthetic antidiuretic hormone medications (often taken as a pill, injection, or nasal spray). Other therapies include medications that stimulate the production of the antidiuretic hormone such as NSAIDs or chlorpropamide. In addition, persons with diabetes insipidus must maintain adequate fluid intake to compensate for the excessive urinary output..When a child's thirst mechanism is also affected, care should be taken to monitor fluid intake and urine production.
Diabetes insipidus can be temporary or permanent, depending on what is causing the disease. With proper management, children with central diabetes insipidus can lead full, healthy lives. Children with nephrogenic diabetes insipidus can also lead relatively normal lives with proper medical care and management, especially if the medical care is started early.