Though the name has ‘diabetes’ in it, nephrogenic diabetic insipidus has not much in common with the condition, except a few signs and symptoms. Nephrogenic diabetes insipidus is a very rare kidney disorder characterized by excessive urination and thirst. Unlike diabetes mellitus, nephrogenic diabetes insipidus is present at birth, and mostly affects men. However, very rarely, the condition can develop later in life, either as a result of certain drug use, or by underlying conditions like hypokalemia and hypercalcemia, kidney disease, obstruction of the ureters, and as a short-term complication of pregnancy. The kidney uses an antidiuretic hormone called vasopressin for balancing water in the body. When it fails to do so, results in a large volume of dilute urine production. People with the condition are more exposed to severe dehydration, as they throw out the water content frequently through excessive urination. The condition can result in severe complications if left untreated.
A bit of history behind nephrogenic diabetes insipidus:
The medical world first introduced the term nephrogenic diabetes insipidus in 1947, which until then, was termed as diabetes insipidus renalis. One of the interesting historical facts revolves around the word ‘insipidus’ in diabetes insipidus. Insipid refers to something dull, lacking flavor. The condition is known so, not for the affected people being flavorless, but their urine! It might seem unacceptable for you, but, trust me, doctors that time used to taste urine to spot a condition. When tested that way, doctors found that the urine of people with the condition tastes flavorless and watery.
Signs and Symptoms:
As explained earlier, nephrogenic diabetes insipidus is mainly characterized by symptoms like excessive urination and thirst. However, the symptoms may vary in people according to the severity of the condition. Acquired nephrogenic diabetes insipidus is usually less severe when compared to the hereditary forms of the condition. Children born with the condition tend to show the symptoms early and get diagnosed before they turn 1-year old. Acquired NDI show symptoms later during adulthood. Most people suffer from excessive urination at night. Infants with the condition may even experience symptoms like lethargy, unexplained fevers, vomiting, irritability, retching, and vomiting. One may even experience diarrhea, constipation, and poor feeding. Some infants with the condition might show poor growth or weight gain than usual.
People with extreme dehydration might experience lethargy, irritability, muscle pain, and unexplained weakness. In adults, very rare yet fatal symptoms like hypovolemic shock and hyponatremic seizures are also seen. The hypovolemic shock caused by severe dehydration results in a lack of blood for the heart to pump. Lack of water in the body reduces the sodium levels in the blood resulting in a condition called hyponatremia seizures. Both the conditions need to get immediate medical attention, otherwise may lead to death.
What causes NDI?
Vasopressin or the antidiuretic hormone controls the balance of fluid intake and fluid discharge. When there is less fluid consumption, the antidiuretic hormone signals the kidneys to produce less urine. In the same way, high fluid intake leads to lower ADH levels and more urine production. Irregularities in the antidiuretic level due to any medical condition, genetics, or medications can cause the inability to distill urine, resulting in increased urination. Many factors may affect the regulation of antidiuretic hormones, resulting in nephrogenic diabetes insipidus.
Types of nephrogenic diabetes insipidus explained:
Referring to the previous points discussed, nephrogenic diabetes insipidus has two main classifications- acquired and genetic. Let us look into the details:
The main cause of an acquired NDI is the use of certain medications and underlying medical conditions. Among them, the majority of cases are caused by medication use. Medications used to treat bipolar disorder and some of the medical conditions, like lithium, can cause NDI. Long-term use of various other medications like orlistat, rifampin, ofloxacin, foscarnet, ifosfamide, didanosine, cidofovir, and demeclocycline can also lead to the condition. Medications that affect the minerals in the body or causing organ damage are also linked to NDI. Acquired NDI is directly linked to conditions like chronic kidney disease, hypercalcemia, hypokalemia, and polycystic kidney disease. Pregnancy is also considered a potential cause to develop acquired NDI. The type of condition is more prevalent among adults than children.
Genetic NDI stems from genetic mutations run in families. A mutation refers to damages or mistakes that result in a change of genes in a person. The mutation causes genetic nephrogenic diabetes insipidus. These types of NDI are mostly diagnosed in children.
As explained in an earlier section, nephrogenic diabetes can cause serious complications if left untreated. It can even develop life-threatening symptoms that require immediate medical attention. If you experience frequent urges to urinate, especially at night along with excessive thirst all the time, you should visit your nearest physician for the first-line diagnosis. If you find any symptoms as mentioned before, in your child, take the child for a doctor visit to confirm if he/she is suffering from nephrogenic diabetes insipidus. Though it is impractical to expect diagnosis merely from the symptoms, it could save life at times. The symptoms of nephrogenic diabetes insipidus can be identical to other medical conditions, especially in young children. If you see your child facing difficulties in potty training, frequently bedwetting, dehydration, and abnormal growth take him/her to the doctor for further diagnosis.
Diagnosis procedures mainly focus on finding whether kidneys are functioning the right way, sustaining the required amount of fluid in your body, and controlling the quantity of urine. Doctors usually use blood tests and urine tests in children as their diagnosis can be difficult compared to the adults. Commonly recommended urine tests for children include a polyuria test, first monitoring tests, and measurement tests. A polyuria test is used to evaluate the quantity of urine excreted within 24-hour time. The test is done by directly collecting the urine. First monitoring tests are prescribed to analyze the density of urine and chemicals present in it if any. The other test called measurement tests evaluates the pH level, potassium, creatinine protein, sodium, chloride, and potassium, along with the urine concentration.
In older children and adults, doctors may recommend other tests like MRI, renal sonography, or blood tests. An MRI helps in analyzing the size of the kidney and find structural anomalies if any. Renal sonography can be relatively new terminology for you. It is an ultrasound test that helps in pointing out abnormalities in the kidney. It can even rule out severe damages to the kidney. Blood tests are recommended to analyze the levels of creatine, sodium, urea, chloride, and potassium in your blood.
A water deprivation test is a very rare diagnostic procedure held by expert medical professionals. If not done the right way, it can be life-threatening. The test is all about withholding water intake to analyze the amount of urine produced and released by the kidneys. If you have severe dehydration from nephrogenic diabetes insipidus or any other medical conditions, you must inform the doctor before appealing for this kind of diagnostic procedure.
Is nephrogenic diabetes insipidus treatable?
Treatments might focus on specific symptoms that can vary from person to person. You might need the help of a team of experts from different medical departments to coordinate the treatment for nephrogenic diabetes insipidus. In the case of children with the condition, a team of experts including pediatricians, nephrologists, nutritionists, endocrinologists, and other specialists can be involved in planning and executing the treatment. The cornerstone of any treatment is to ensure the right amount of fluid intake and to reduce excessive urination.
If your doctor finds any medication to be causing the condition, an alternate medicine or discontinuing the medication would be recommended. If caused by any underlying diseases, treatment will primarily focus on reversing the same. The treatment plan, duration, and results may vary depending on the severity of the condition. If you have a mild case of NDI, the doctor might recommend a few diet changes like reducing the intake of sodium and protein. This could help you in reducing the urine volume. When medications can’t help you in taming the condition, doctors may prescribe a few medicines along with the diet changes. Medications used to treat NDI can include desmopressin, NSAIDs, and diuretics.
Treating children with NDI requires utmost care and focus. Minimal treatments like diet modifications and multivitamins are mostly suggested for children with nephrogenic diabetes insipidus. During treatment, you must monitor infants for the right fluid intake to prevent severe dehydration, as they do not have much fluid in their bodies to cope with the condition.
Do check out act1diabetes to find more about diseases related to diabetes and other information.
Though the condition is characterized by very common symptoms like dehydration and excessive urination, it can put you at the risk of death. However, getting treated on time can help you stay healthy. Do not ignore symptoms like excessive thirst and urination, for it could be an indication of such kinds of rare conditions. If you are diagnosed with nephrogenic diabetes insipidus, it is recommended to get genetic counseling along with your families.