Beer potomania is a syndrome of binge drinking, poor nutritional intake, and profound hyponatremia.
Hyponatremia is due to a large consumption of beer (which has a poor salt content) together with a minimal intake of ordinary food. Three facts contribute to beer potomania:
- Beer contains a lot of free water with very little salt and protein (one liter of beer contains only 30 mg of sodium).
- The amount of free water we excrete depends upon number of osmoles that need to be excreted.
- The kidneys can dilute urine to a maximum of 50 mosm/L
- An excessive intake of beer without intake of solutes can cause hyponatremia because beer does not contain electrolytes but does contain excessive carbohydrates. This is a type of polydipsia, exceeding the kidney’s ability to dilute urine and the subsequent loss of electrolytes, combined with suppression of intake of food or other solutes.
- Ingestion of excess fluids (free water) than the kidney can excrete under normal conditions and the decreased ingestion of solute necessary to excrete adequate amounts of diluted urine in beer potomania have a combined effect to cause hyponatremia. An article published in JASN by T. Berle stated: “It is classically taught that when renal function is normal and the secretion of antidiuretic hormone is fully suppressed, the kidney has the capacity to excrete large volumes of dilute urine, allowing for a broad range of water intake. This flexibility protects against the development of hyponatremia even in the face of water intake that can approach 20 L/d. What is not as widely recognized is the impact that alterations in solute intake, and therefore excretion, have on this process. A decrement in solute intake markedly reduces the above-mentioned flexibility and puts the individual at risk for the unexpected development of hyponatremia. In contrast, an increment in solute intake can be used therapeutically to treat this electrolyte disorder and allow those prone to it to liberalize their water intake.”
Electrolyte and Biomarker Studies
A value of Uosm <; 100 mOsm/kg is indicative of a complete and appropriate suppression of antidiuretic hormone (ADH) secretion, a finding seen with either primary polydipsia (including ‘beer potomania’) or reset osmostat. Criteria used to diagnose the ‘beer potomania’ syndrome include
- A history of binge beer drinking
- Poor dietary intake
- Decreased serum sodium levels
- Absence of other known causes of hyponatremia