Urine electrolytes as markers of bulimia nervosa

Electrolyte and acid-base abnormalities associated with purging behaviors

OBJECTIVE

Eating disorders that are associated with purging behaviors are complicated by frequent blood electrolyte and acid-base abnormalities. Herein, we review the major electrolyte and acid-base abnormalities and their treatment methods. The body of rigorous, eating disorder-specific literature on this topical area is not robust enough to perform a systematic review as defined by PRISMA guidelines. Therefore, a qualitative review of mostly medical literature was conducted.

RESULTS

Hypokalemia, hyponatremia, and sodium chloride-responsive metabolic alkalosis are the most common serum changes that occur as a result of purging behaviors. They vary depending on the mode and frequency of purging behaviors. They can all potentially cause dangerous medical complications and are in need of definitive medical treatment.

DISCUSSION

Eating disorders that are associated with purging behaviors are associated with a number of electrolyte and acid-base changes which are complex in their origin, documented to be medically dangerous and this definitive treatment is necessary to help achieve a successful treatment outcome, and in need of definitive treatment as described herein.

Hypomagnesemia in adolescents with eating disorders hospitalized for medical instability

BACKGROUND

Hypomagnesemia in patients with eating disorders is poorly characterized, particularly among adolescents.

METHODS

To determine the prevalence of hypomagnesemia (Mg ≤ 1.7 mg/dL) and clinical characteristics of adolescents hospitalized with a DSM-IV-diagnosed eating disorder who developed hypomagnesemia, a retrospective chart review was conducted on all adolescents aged 10-21 years with an eating disorder were hospitalized at a tertiary care children's hospital from 2007 to 2010. Patients were refed orally with standard nutrition and high-energy liquid supplements. Serum magnesium and phosphorus were obtained on admission, every 24-48 hours for the first week, and thereafter as clinically indicated. Clinical characteristics of patients with hypomagnesemia were compared with those of individuals with normal magnesium levels and those with hypophosphatemia.

RESULTS

Eighty-six of 541 eligible participants (15.9%) developed hypomagnesemia. Forty (47%) with hypomagnesemia admitted to purging in the year before admission, with 88% purging during the prior month. Compared with those with normal serum magnesium levels, patients with hypomagnesemia were older (P = .0001), ill longer (P = .001), more likely to be purging (P = .04), and more likely to have an alkaline urine (P = .01). They did not differ in eating disorder diagnosis, BMI, or other electrolyte disturbances. Hypomagnesemia developed 4.9 ± 5.5 days after refeeding was initiated, significantly later than the onset of hypophosphatemia, 0.95 ± 2.6 days (P < .001).

CONCLUSIONS

Hypomagnesemia is prevalent in adolescents hospitalized for an eating disorder and is associated with purging and alkaline urine. Hypomagnesemia develops later in the course of refeeding than hypophosphatemia. Magnesium levels should continue to be monitored after the more immediate risk of hypophosphatemia has passed, especially in those with alkaline urine.

Toward the optimal clinical use of the fraction excretion of solutes in oliguric azotemia

While the fractional excretion of solutes have long been considered excellent research tools to investigate tubular physiology, their clinical use has become common over the last 40 years in the diagnoses of many disorders; however, none have reached the clinical utility of the fractional excretion of sodium in the ability to distinguish pre-renal azotemia from acute tubular necrosis. Nevertheless, there are many drugs and medical conditions that interfere with that utility and recently other solutes, including urea, uric acid and lithium, have been recently investigated to improve the diagnostic ability in clinical situations where the fractional excretion of sodium is known to be unreliable. We review the tubular physiology of these solutes and show how the differences in tubular physiology might be exploited to develop a strategy for their optimal clinical use.

Medical complications of bulimia nervosa and their treatments

OBJECTIVE

To present a cogent and practical review of the medical complications and their treatment in patients with bulimia nervosa.

METHOD

Thorough review of the medical literature from 1990 to current in regards to the medical complications of bulimia nervosa and the therapeutic intervention that are effective to treat them.

RESULTS

Extensive and detailed review of the medical complications of bulimia nervosa.

Towards a physiologically based diagnosis of anorexia nervosa and bulimia nervosa

Diagnosis of anorexia nervosa (AN) and bulimia nervosa (BN), while including such physiological data as weight and the reproductive status of the individual, are primarily based on questionnaires and interviews that rely on self-report of both body-related concerns and eating-related behaviors. While some key components of eating disorders are psychological and thus introspective in nature, reliance on self-report for the assessment of eating-related behaviors and nutritional status lacks the objectivity that a physiologically based measure could provide. The development of a more physiologically informed diagnosis for AN and BN would provide a more objective means of diagnosing these disorders, provide a sound physiological basis for diagnosing subclinical disorders and could also aid in monitoring the effectiveness of treatments for these disorders. Empirically supported, physiologically based methods for diagnosing AN and BN are reviewed herein as well as promising physiological measures that may potentially be used in the diagnosis of AN and BN.

Insulinogenic index at 15 min as a marker of stable eating behavior in bulimia nervosa

BACKGROUND & AIMS

The aim of this study was to determine the relationship between insulinogenic index at 15 min (II15 min), body weight maintenance, and the presence of vomiting in patients with bulimia nervosa.

METHODS

Forty-eight bulimic inpatients and 14 controls underwent an oral glucose tolerance test on the seventh hospital day. We calculated II15 min and other biological markers, including serum amylase concentrations. During the first week after admission, we monitored the frequency of vomiting and calculated changes in body weight. Patients were divided into 4 subgroups according to the presence of vomiting and weight loss.

RESULTS

Two-factor analysis of variance of the II15 min value revealed significant main effects of vomiting and body weight change (P < 0.001 for both). The II15 min values for controls and bulimic patients with weight loss and no vomiting were lower than those of other bulimic groups. The II15 min values were positively correlated with serum amylase concentrations (r = 0.37, P < 0.01), body weight change (r = 0.35, P < 0.05), and frequencies of vomiting (r = 0.49, P < 0.05).

CONCLUSIONS

These findings suggest that II15 min values may be a useful marker for assessing the stability of eating behavior in patients with bulimia nervosa.

Bulimia Nervosa: A Primary Care Review

Bulimia nervosa is a psychiatric condition that affects many adolescent and young adult women. The disorder is characterized by bingeing and purging behavior and can lead to medical complications. Thus, patients with bulimia nervosa commonly present in the primary care setting. Physical and laboratory examinations reveal markers of bulimia nervosa that are useful in making the diagnosis. Treatment is beneficial, and outcomes of early intervention are good. This article discusses the history, presentation, and tools needed for recognizing and treating bulimia nervosa in primary care.