Analysis of unexplained electrolyte Abnormalities a window to detect "Eating Disorders": JAMA.

Canada: An original publication of JAMA Network Open under Psychiatry has concluded that individuals with an eating disorder are tied to preceding outpatient electrolyte abnormality. The study highlighted how unexplained electrolyte abnormalities are clinically crucial in future screening for eating disorder diagnosis.

Eating disorders refer to disturbed eating behaviours that adversely impact health and compromise the body's normal functioning.

The prevalence rate is approximately 2%, with women and adolescents predilection.

This condition is challenging for both physician and patient as there is a lack of treatment options. The situation is complicated further due to a lack of self-awareness, shame, and social stigma, which causes delayed Diagnosis and treatment. There is an urgent need for screening and early detection.

Acute cases of eating disorders may present with electrolyte abnormalities. This causes imbalances in ions like potassium, sodium, magnesium, and phosphate. Acid-base disturbances are also prompt.

One of the previous studies has mentioned that among 1026 adults with an eating disorder have hypokalemia (25.8 %), hyponatremia (14%), and metabolic alkalosis (16.6 %). However, the data on the prevalence of electrolyte abnormalities remains limited and non-understood in the outpatient setting among such individuals.

The consequences of electrolyte abnormalities are fatal and predispose to cardiac arrhythmias, weakness of muscles, and mental status changes.

The question that arises here is:

Is there any association between electrolyte abnormalities in outpatient labs and Diagnosis of eating disorder in the future?

Screening tools to identify such individuals are the SCOFF questionnaire. If electrolyte imbalance is related to an eating disorder diagnosis, the clinician can make decisions for more intensive screening.

Based on the above background, Dr Gregory Hundermen, MD, from the Division of Nephrology at the Department of Medicine, University of Ottawa, Ottawa, led a team of researchers to conduct a large population-level case-control study to evaluate whether there is an association between electrolyte abnormalities and eating disorder future Diagnosis.

The key points of the study are:

• Provincial administrative health data was used in the study. The study individuals were from Ontario.
• The study participants were 13 years or older ( 2008 to 2020).
• Controls (without eating disorders) were matched 4:1 to Cases (with an eating disorder) based on age and sex.
• The outpatient electrolyte measurements were done before the index (between 3 years and 30 days).
• Controls were assigned a pseudo-index date.
• The Exposures in the study were hypomagnesemia , hypernatremia , hypokalemia , hyperkalemi, hyponatremia (serum sodium, 130 mmol/L or lower), metabolic acidosis or metabolic alkalosis.
• A total of 6970 individuals had an eating disorder.
• The individuals with an eating disorder had a mean age of 28 years, with 87.2% females and 12.8% males.
• Twenty-seven thousand eight hundred seventy-eight individuals were without an eating disorder diagnosis with a mean age of 28 years; 87.2% female and 12.8% male.
• The preceding electrolyte abnormality was recorded in 18.4% of individuals with an eating disorder compared to individuals without an eating disorder ( 7.5 %). The adjusted odds ratio was 2.12.
• Three hundred eighty-six days was the median time calculated from the earliest electrolyte abnormality to the Diagnosis of an eating disorder.
• Specifically interpreting, electrolyte abnormalities related to the higher risk of an eating disorder were hypokalemia, hyperkalemia, hyponatremia, hypernatremia, hypophosphatasia and metabolic acidosis with an aOR of 1.98; 1.97; 5.26; 3.09; 2.83 and 2.60 respectively.
• The hospitalisation rate was higher in individuals with an eating disorder (26.7% vs 11.2%).
• Those with an eating disorder had higher psychiatric comorbidities compared to the controls, including anxiety (19.7% vs 4.7%), depression (19.3% vs 3.4%), personality disorder (4.3% vs 0.4%), and substance abuse (8.1% vs 1.9%).
• The comparative details of electrolyte imbalances in an individual with an eating disorder vs those without were recorded as hypokalemia (12.1% vs 4.6%), hyperkalemia (2.8% vs 1.3%), hyponatremia (2.5% vs 0.4%), hypernatremia (0.3% vs 0.1%), hypomagnesemia (0.2% vs 0.1%), hypophosphatemia (11.9% vs 0.4%]), metabolic acidosis (2.3% vs 1.2%), and metabolic alkalosis (1.4% vs 0.4%). The P value was  < .001.

The researchers said we incorporated a much more severe definition for each electrolyte abnormality for additional analysis, including hypernatremia (serum sodium, 155 mmol/L or higher), hyponatremia (serum sodium, 128 mmol/L or lower), hypokalemia (serum potassium levels of 3.0 mmol/L or below), hyperkalemia (serum potassium, 6.0 mmol/L or higher), hypophosphatemia (serum phosphate, 0.60 mmol/L or lower) and hypomagnesemia (serum magnesium, 0.40 mmol/L or lower).

They concluded that individuals with electrolyte abnormalities had a higher risk of a subsequent eating disorder diagnosis.

The researchers finally explained that Diagnosis of eating disorders is challenging, so readily available tests will enable healthcare providers to screen the individuals. Our results are clinically useful. The most common electrolyte abnormality was hypokalemia. Our findings highlight that severe hypokalemia and severe hyponatremia are tied to 7-fold and 5-fold higher odds for eating disorder diagnosis, respectively.

ICES supported the study, they acknowledged.

Further reading:

Hundemer GL et al. Analysis of Electrolyte Abnormalities in Adolescents and Adults and Subsequent Diagnosis of an Eating Disorder. JAMA Netw Open. 2022;5(11):e2240809.