Hypokalemia in patients with anorexia nervosa during refeeding is associated with binge–purge behavior, lower body mass index, and hypoalbuminemia

Abstract

Background Hypokalemia is frequently found in patients with anorexia nervosa and sometimes leads to life-threatening conditions. Although their serum potassium levels are considered to further decrease during refeeding, no previous studies have addressed actual changes in the serum potassium levels and potential mechanisms underlying hypokalemia during the refeeding period of patients with anorexia nervosa. In this study, we investigated factors associated with hypokalemia during refeeding of patients with anorexia nervosa. Methods We recruited 52 independent patients from 89 admissions with anorexia nervosa (body mass index, 13.0 ± 3.3) from the psychiatry unit in Ashikaga Red Cross Hospital during the period from April 2003 to March 2018 and analyzed serum potassium levels at admission. Of the 89 admissions, 66 admissions with > 1-week hospitalization were recruited to determine the lowest potassium levels during the refeeding period. We analyzed these levels with multiple linear regression analysis with explanatory variables, including data upon admission and treatment-related indicators. Results The initial serum potassium level of 3.6 ± 0.9 mg/dl decreased to 3.1 ± 0.7 mg/dl at nadir hypophosphatemia, which was observed an average of 2.5 days after admission. A lower serum potassium level at admission and a lower nadir potassium level during refeeding were associated with a lower body mass index, hypoalbuminemia, and binge–purge behavior. Similar results were obtained when the analysis included restrictive or binge–purge types as well as the independent patient group. Conclusions Lower body mass index, hypoalbuminemia, and binge–purge behavior might be used as indicators to guide clinical approaches for controlling serum potassium levels in patients with anorexia nervosa during refeeding. Plain English summary Hypokalemia, low levels of serum potassium, in patients with anorexia nervosa sometimes leads to life-threatening conditions. Thus, it is of great importance to predict the risk of hypokalemia in patients with anorexia nervosa during the refeeding period. Our study found that hypokalemia in patients with anorexia nervosa during refeeding is associated with a lower body mass index and hypoalbuminemia (low levels of serum albumin), in addition to binge–purge behavior.

The Restrictive Type, Infectious Complications, a Long Duration of Illness Might Predict Nadir Hematological Values Among Individuals With Anorexia Nervosa During the Refeeding Period: A Retrospective Study

“…Indeed, our previous study revealed that the restrictive type independently is associated with the development of refeeding hypophosphatemia, a hallmark of refeeding syndrome, among anorexic patients with severe malnutrition, and this association was independent of a low body mass index [20]. Similarly, we also previously found that the extent of the decrease in potassium during the refeeding period is greater for the restrictive type than for the bingepurge type of anorexia nervosa [29]. Given these ndings, it is reasonable to consider that the restrictive type itself poses a risk of organ dysfunction and electrolyte depletion.…”

“…As a treatment-related indicator, the caloric intake was measured because it frequently affects laboratory data during the refeeding period [20,28,29]. Caloric intake (in kilocalories) refers to the average total caloric intake from day 1 through day 7 [20,28,29], including both oral intake and intravenous infusion therapy. If the patient ate only half the provided 1200kcal meal, the actual amount of total caloric intake was recorded as 600 kcal.…”

“…If the patient ate only half the provided 1200kcal meal, the actual amount of total caloric intake was recorded as 600 kcal. To accurately investigate the effect of energy intake on an individual patient depending on his or her weight, we used the total caloric intake per body weight at admission for this analysis [20,29]; this measure is widely used for diet therapy for diabetes mellitus [30].…”

The restrictive type and infectious complications might predict nadir hematological values among individuals with anorexia nervosa during the refeeding period: a retrospective study

“…For hematological values during the refeeding period (the nadir hematological values and the rate of decrease in the values), the presence of infectious diseases during the hospital stay (both at admission and during the refeeding period) was counted. As a treatment-related indicator, the caloric intake was measured because it frequently affects laboratory data during the refeeding period [20,28,29]. Caloric intake (in kilocalories) refers to the average total caloric intake from day 1 through day 7 [20,28,29], including both oral intake and intravenous infusion therapy.…”

“…As a treatment-related indicator, the caloric intake was measured because it frequently affects laboratory data during the refeeding period [20,28,29]. Caloric intake (in kilocalories) refers to the average total caloric intake from day 1 through day 7 [20,28,29], including both oral intake and intravenous infusion therapy. If the patient ate only half the provided 1200-kcal meal, the actual amount of total caloric intake was recorded as 600 kcal.…”