Kidney Disease and Kidney Failure in Anorexia Nervosa
By: Margherita Mascolo, MD
Monday, March 21, 2016
From the ACUTE team: To offer our readers a more comprehensive look into the various aspects of eating disorders and treatment, Medical Mondays will periodically be penned by team physicians at the ACUTE Center for Eating Disorder.
This week’s Medical Monday is written by Margherita Mascolo, MD, Interim Medical Director.
Hi all, I’m thrilled to have the opportunity to write this piece and share a part of my medical knowledge with you! The topic for this week is kidney failure in anorexia nervosa – what it is, what happens to the kidneys when the body is severely starved, the signs and symptoms, and the permanent damage that can occur when going undetected or untreated.
The kidneys are one of the major filtering organs of the body. They are incredible organs and perform lots of activities, the most notable being balancing water and salts (like potassium) in our bodies. When we are dehydrated, either because we are too busy at work to keep up with our water intake, or because of exercise, or the fact that we are traveling and have limited access to water, the kidneys retain salt and water in an effort to combat dehydration. You may notice that on those occasions your body produces less urine. Certain diseases such as high blood pressure or diabetes, when untreated, lead to permanent damage to the kidneys. In some cases, the kidneys completely lose their ability to balance salt and water and dialysis is needed. With dialysis, the blood is filtered by a machine outside of the body. Treatment is typically required three times per week and thus seriously impacts a person’s lifestyle.
What happens to the kidneys as a result of anorexia nervosa? In restricting anorexia, there may be temporary changes to kidney function due to dehydration. When dehydration is severe, through a complex mechanism involving the kidneys, the level of sodium in the body can drop, sometimes to such dangerously low levels that can cause seizures and irreversible brain damage when treated incorrectly. Other than lower sodium levels, there are no associated changes to salt balance in the body. With good nutrition and adequate hydration, the kidneys rebound and usually there is no permanent damage done to them. You may feel weak, have no energy, your mouth and skin may feel very dry, and you may notice less urine production with a change in urine color to dark yellow.
In binge-purge anorexia, there may be permanent damage done to the kidneys. Purging by means of laxatives, diuretics, or vomiting leads to a chronic state of dehydration and impacts the salts in our blood. One of the most important salt changes is a drop in the level of potassium due to vomiting or diuretic abuse. Low potassium can lead to scarring of the kidneys and loss of their filtering ability. In addition, certain laxatives contain high levels of magnesium which can also impact the kidneys and lead to scarring and malfunction. With dehydration and low potassium you may feel weak, dizzy, have heart palpitations, muscle cramping, and when severe, arrhythmias, seizures, and death.
Perhaps the scariest thing about kidney damage is that, in the majority of the cases, there are no warning signs. I mentioned a few symptoms in the above paragraph to caution you, but the truth is that those signs are non-specific and can happen for a number of different reasons; not necessarily as signs of impending kidney failure. The majority of patients with kidney disease have no symptoms. This is why it is so important for you to be followed closely by expert medical providers so if you do in fact have kidney disease, it can be identified early and prevent permanent damage. If caught early, the treatment may be as simple as increasing water intake and rechecking blood work a week or two after detection. To avoid any lasting damage, it is crucial for you to seek good medical care, have a solid nutritional plan in place, and stop all purging behaviors immediately.
Wishing you health and lasting recovery,
Dr. Margherita Mascolo