Electrolyte Disturbances a Harbinger of Eating Disorders? Electrolyte Disturbances a Harbinger of Eating Disorders?

Electrolyte abnormalities may serve as a precursor to a future eating disorder diagnosis, a finding that may help pinpoint candidates for screening.

Researchers found that adolescents and adults with electrolyte abnormalities on routine outpatient lab work were twice as likely as those without these disturbances to be subsequently diagnosed with an eating disorder.

“These electrolyte abnormalities were in fact seen well ahead (> 1 year on average) of the time when patients were diagnosed with eating disorders,” study investigator Gregory Hundemer, MD, Department of Nephrology, University of Ottawa in Ontario, told Medscape Medical News.

“Incidentally discovered outpatient electrolyte abnormalities may help to identify individuals who may benefit from more targeted screening into an underlying eating disorder. This, in turn, may allow for earlier diagnosis and therapeutic intervention,” Hundemer said.

The study was published online November 8 in JAMA Network Open.

Tailored Screening?

Electrolyte abnormalities are often found when an individual is diagnosed with an eating disorder, but it’s largely unknown whether electrolyte abnormalities prior to the acute presentation of an eating disorder are associated with the future diagnosis of an eating disorder.

To investigate, the researchers used administrative health data to match 6970 individuals (mean age, 28 years; 13% male) with an eating disorder diagnosis to 27,878 controls without an eating disorder diagnosis.

They found that individuals with an eating disorder were more likely to have a preceding electrolyte abnormality compared with peers without an eating disorder (18.4% vs 7.5%).

An outpatient electrolyte abnormality present 3 years to 30 days prior to diagnosis was associated with about a twofold higher odds for subsequent eating disorder diagnosis (adjusted odds ratio, 2.12; 95% CI, 1.86 – 2.41).

The median time from the earliest electrolyte abnormality to eating disorder diagnosis was 386 days (range, 157 to 716 days).

Hypokalemia was the most common electrolyte abnormality (present in 12% of cases vs 5% of controls), while hyponatremia, hypernatremia, hypophosphatemia, and metabolic alkalosis were the most specific for a subsequent eating disorder diagnosis.

Severe hypokalemia (serum potassium levels of 3.0 mmol/L or lower) and severe hyponatremia (serum sodium, 128 mmol/L or lower) were associated with over sevenfold and fivefold higher odds for the diagnosis of an eating disorder, respectively.

As previously reported by Medscape Medical News, the US Preventive Services Task Force (USPSTF) issued its first-ever statement on screening for eating disorders earlier this year.

The task force concluded that there is insufficient evidence to weigh the balance of benefits and harms of screening for eating disorders in adolescents and adults with no signs or symptoms of an eating disorder or concerns about their eating and who have not previously been diagnosed with an eating disorder.

Hundemer and colleagues believe an incidental electrolyte abnormality may identify candidates at high risk for an underlying eating disorder who many benefit from screening.

Several screening tools of varying complexity have been developed that are validated and accurate in identifying individuals with a potential eating disorder.

They include the SCOFF questionnaire, the Eating Disorder Screen for Primary Care, the Eating Attitudes Test, and the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire.

Underdiagnosed, Undertreated

Offering perspective on the findings, Kamryn T. Eddy, PhD, co-director, Eating Disorders Clinical and Research Program, Massachusetts General Hospital, Boston, said the notion “that a physical sign may help to promote eating disorder assessment is important particularly given that early detection can improve outcomes.”

“But this finding appears in the current context of eating disorders going largely underdetected, underdiagnosed, and undertreated across medical and psychiatric settings,” said Eddy, associate professor, Department of Psychiatry, Harvard Medical School.

“Indeed, eating disorders are prevalent and cut across age, sex, gender, weight, race, ethnicity, and socioeconomic strata and still, many providers do not routinely assess for eating disorders,” Eddy said.

“I might suggest that perhaps in addition to letting electrolyte abnormalities be a cue to screen for eating disorders, an even more powerful shift toward routine screening and assessment of eating disorders by medical providers be made,” Eddy told Medscape Medical News.

This study was supported by ICES, which is funded by an annual grant from the Ontario Ministry of Health and the Ministry of Health and Long-Term Care (MOHLTC). Hundemer and Eddy have disclosed no relevant financial relationships.

JAMA Netw Open. 2022;5(11):e2240809. Full text

For more Medscape Psychiatry news, join us on Twitter and Facebook.