Health Consequences of Bulimia Nervosa
Bulimia Nervosa (BN) is an eating disorder in which individuals engage in binge eating and purging. The purging is motivated by prevention of weight gain after the binge and can take the form of self-induced vomiting, laxative abuse, diuretic abuse, fasting, or excessive exercise.¹ Health consequences of BN vary depending on what purge method is primarily used. Chronic self-induced vomiting can result in detrimental dental and gastrointestinal alterations as well as dangerous fluid and electrolyte imbalances.²
By: Sam Wierzbicki
Bulimia Nervosa (BN) is an eating disorder characterized by recurrent episodes of binge eating and inappropriate compensatory behaviors in order to prevent weight gain. Binges occur within a discrete period of time where the individual eats an amount of food that is objectively more than what most people would eat within that period of time. Purging, or inappropriate compensatory behavior, occurs in response to the binge, and can occur via self-induced vomiting, laxative abuse, diuretic abuse, fasting, and/or excessive exercise. Regardless of what purge method is employed, individuals with BN base self-evaluation on their body shape or weight.¹
Fluid and Electrolyte Imbalances Resulting From Vomiting, Laxative, or Diuretic Use
Purging via vomiting, laxatives, or diuretics poses a risk of fluid and electrolyte imbalances.² Electrolytes are minerals that carry an electric charge in the blood. Sodium, potassium, chloride, and bicarbonate in particular, play a large role in nerve and muscle function and also help to regulate acid-base and fluid balance.³ Vomiting, laxatives, or diuretics can cause significant fluid and electrolyte loss, leading to dehydration and rebound water retention as the body tries to compensate for fluid losses by enhancing fluid retention mechanisms. A dire consequence of electrolyte imbalance is hypokalemia and hypomagnesemia, or low blood potassium and low blood magnesium, respectively.² Potassium is essential to the electrical system of heart muscle;⁴ low levels can lead to cardiac arrhythmias or death. Low blood magnesium can worsen cardiac arrthymia.² Signs of severely depleted blood potassium include muscle cramps, weakness, and twitches as well as abnormal heart rhythm.⁵ It is important to note that hypokalemia-related cardiac complications can occur from malnutrition alone (in the absence of purging) if the body is not receiving enough potassium via food intake.²
In addition to hypokalemia, fluid and electrolyte imbalances that occur in BN can lead to metabolic alkalosis, or elevated serum bicarbonate levels.² This is typically seen in individuals with BN who frequently use laxatives or engage in self-induced vomiting.² In metabolic alkalosis, the body’s pH, or acid-base balance, is disturbed. This is because stomach secretions rich in hydrochloric acid are lost through the vomit. For each hydrogen ion lost in the secretions, a bicarbonate ion is gained, resulting in the body’s pH becoming too basic.⁶ While symptoms of mild metabolic alkalosis include lightheadedness, confusion, and muscle twitches, metabolic alkalosis can ultimately lead to loss of consciousness or coma.⁴
Consequences of Self-Induced Vomiting
Self-induced vomiting (SIV) is the most common method of purging in BN.² SIV can cause salivary gland enlargement, which leads to a physical appearance of puffy cheeks and face.² This consequence can take several months to resolve after SIV has been discontinued.
Chronic SIV presents a wide range of issues to the oral cavity including dental erosion, cavities, periodontal disease, and fissuring at the corners of the mouth.² The basis of dental issues lies in the acidity of gastric contents purged - this wears away the enamel of the teeth and can eventually lead to erosion of the dentin, or the bony layer of tooth protected by the enamel.²,⁷ This erosion overtime leads to dull, yellow, and/or painfully sensitive teeth.²
As with most eating disorders, SIV is accompanied by a plethora of gastrointestinal complications. Individuals commonly complain of heartburn, bloating, gas, constipation, abdominal tenderness and indigestion.² Similar to the erosion that occurs in the oral cavity, purged gastric contents can lead to erosion and ulceration of the esophagus.² This may preempt or co-occur with difficulty or pain when swallowing, sore throat or hoarseness, and vomiting up blood, which may indicate the presence of tears in the esophagus or stomach.² If the esophagus is continually exposed to acidic gastric contents, precancerous lesions can form that put the individual at risk for adenocarcinoma.²
Consequences of Laxative Abuse
The most acute health consequences of laxative abuse are the electrolyte and fluid disturbances described above as well as gastrointestinal issues such as vomiting and diarrhea.²
Chronic laxative abuse complications include confusion, convulsions, muscle weakness, urinary tract infections, decreased bone density mass with a potential to develop into osteoporosis, rectal bleeding, swelling, skin hyperpigmentation, pancreatic damage, malabsorption of nutrients, and cathartic colon.²
Under normal functioning, the muscles of the intestine coordinate contract-and-relax type movements to push contents through the GI tract - these movements are referred to as peristalsis. Chronic laxative use interferes with peristalsis, leading to diarrhea and constipation.² Individuals who abuse laxatives are at risk for dependence as tolerance builds up over time. If stimulant laxatives are used more than 3 times per week over the course of a year, individuals are at risk for cathartic colon.⁸ In cathartic colon, the nerves of the colon muscles become damaged; this leads to a flaccid, dilated colon that struggles to carry out normal peristalsis.² Signs of cathartic colon include bloating, a feeling of fullness, abdominal pain, and incomplete fecal evacuation.⁸ The most serious implications for cathartic colon are partial colonic resection, colectomy, or ostomy.²
When laxative use is discontinued, individuals will likely experience constipation and pseudo-Bartter’s syndrome, or rebound swelling typically seen in the legs.² The swelling can be distressing to individuals as it may be perceived as weight gain, but it is likely to resolve within 10 days.²
Consequences of Diuretic Abuse
Diuretic abuse as a purging method is relatively rare. Abuse of over-the-counter diuretics poses very little medical risk, but it may provide an opening for prescription diuretic abuse.² Prescription diuretics are often prescribed for high blood pressure and function by increasing the amount of water and salt excreted from the body through the urine.⁸ Inappropriately using prescription diuretics to purge can put individuals at risk for fluid and electrolyte imbalances. Health complications that accompany diuretic overuse include dehydration, nausea, heart palpitations, excessive urine production, blood and pus in urine, constipation, low blood potassium levels, cardiac electrical impulse issues, nephropathy, and abdominal pain.² Long term abuse can result in kidney impairment. Similar to laxative use, once diuretic use is discontinued, temporary rebound swelling may result.²
While the health consequences of chronic purging are significant, and in some cases, life-threatening, most of these complications are reversible once purging is discontinued.
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This post was written by BALANCE Dietetic Intern, Sam Wierzbicki.
Sam is a Dietetic Intern and graduate student at New York University, where she is pursuing her Master’s Degree in Clinical Nutrition. Before beginning her graduate degree in nutrition, Sam worked in the educational field as a private academic tutor to children and adolescents. She completed her undergraduate education at Princeton University, majoring in English literature. After completing her dietetic internship, Sam plans to work in the disordered eating space as a HAES and Intuitive Eating aligned Registered Dietitian.
References
American Psychiatric Association, American Psychiatric Association, eds. Diagnostic and Statistical Manual of Mental Disorders: DSM-5. 5th ed. American Psychiatric Association; 2013.
Herrin M, Larkin M. Nutrition Counseling in the Treatment of Eating Disorders. 2nd ed. Brunner-Routledge; 2013.
Overview of electrolytes - hormonal and metabolic disorders. Merck Manuals Consumer Version. Accessed June 22, 2021. https://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/electrolyte-balance/overview-of-electrolytes
Hyperkalemia (High potassium). www.heart.org. Accessed June 22, 2021. https://www.heart.org/en/health-topics/heart-failure/treatment-options-for-heart-failure/hyperkalemia-high-potassium
Low potassium levels(Hypokalemia). Cleveland Clinic. Accessed June 22, 2021. https://my.clevelandclinic.org/health/diseases/17740-low-potassium-levels-in-your-blood-hypokalemia
Metabolic alkalosis: practice essentials, pathophysiology, etiology. Published online April 3, 2021. Accessed June 22, 2021. https://emedicine.medscape.com/article/243160-overview#:~:text=Vomiting%20or%20nasogastric%20(NG)%20suction,gained%20in%20the%20extracellular%20space.
Goldberg M, Kulkarni AB, Young M, Boskey A. Dentin: structure, composition and mineralization. Front Biosci (Elite Ed). 2011;3:711-735.
Diuretics: types, uses, risks, and more. Healthline. Published February 27, 2019. Accessed June 22, 2021. https://www.healthline.com/health/diuretics