Body mass index cut-off point associated with refeeding hypophosphatemia in adults with eating disorders

Risk factors for the development of refeeding syndrome in adults: A systematic review

Identifying patients with a particularly high risk of refeeding syndrome (RFS) is essential for taking preventive measures. To guide the development of clinical decision-making and risk prediction models or other screening tools for RFS, increased knowledge of risk factors is needed. Therefore, we conducted a systematic review to identify risk factors for the development of RFS. PubMed, EMBASE, Cochrane Library, and Web of Science were searched from January 1990 until March 2023. Studies investigating demographic, clinical, drug use, laboratory, and/or nutrition factors for RFS were considered. The Newcastle-Ottawa Scale was used to appraise the methodological quality of included studies. Of 1589 identified records, 30 studies were included. Thirty-three factors associated with increased risk of RFS after multivariable adjustments were identified. The following factors were reported by two or more studies, with 0-1 study reporting null findings: a previous history of alcohol misuse, cancer, comorbid hypertension, high Acute Physiology and Chronic Health Evaluation II score, high Sequential Organ Failure Assessment score, low Glasgow coma scale score, the use of diuretics before refeeding, low baseline serum prealbumin level, high baseline level of creatinine, and enteral nutrition. The majority of the studies (20, 66.7%) were of high methodological quality. In conclusion, this systematic review informs on several risk factors for RFS in patients. To improve risk stratification and guide development of risk prediction models or other screening tools, further confirmation is needed because there were a small number of studies and a low number of high-quality studies on each factor.

Predicting extremely low body weight from 12-lead electrocardiograms using a deep neural network

Previous studies have successfully predicted overweight status by applying deep learning to 12-lead electrocardiogram (ECG); however, models for predicting underweight status remain unexplored. Here, we assessed the feasibility of deep learning in predicting extremely low body weight using 12-lead ECGs, thereby investigating the prediction rationale for highlighting the parts of ECGs that are associated with extremely low body weight. Using records of inpatients predominantly with anorexia nervosa, we trained a convolutional neural network (CNN) that inputs a 12-lead ECG and outputs a binary prediction of whether body mass index is ≤ 12.6 kg/m2. This threshold was identified in a previous study as the optimal cutoff point for predicting the onset of refeeding syndrome. The CNN model achieved an area under the receiver operating characteristic curve of 0.807 (95% confidence interval, 0.745-0.869) on the test dataset. The gradient-weighted class activation map showed that the model focused on QRS waves. A negative correlation with the prediction scores was observed for QRS voltage. These results suggest that deep learning is feasible for predicting extremely low body weight using 12-lead ECGs, and several ECG features, such as lower QRS voltage, may be associated with extremely low body weight in patients with anorexia nervosa.

The incidence of the refeeding syndrome. A systematic review and meta-analyses of literature

BACKGROUND & AIMS

The refeeding syndrome (RFS) has been recognized as a potentially life-threatening metabolic complication of re-nutrition, but the definition widely varies and, its incidence is unknown. The aim of this systematic review and meta-analyses was to estimate the incidence of RFS in adults by considering the definition used by the authors as well as the recent criteria proposed by the American Society of Parenteral and Enteral Nutrition (ASPEN) consensus. Furthermore, the incidence of refeeding hypophosphatemia (RH) was also assessed.

METHODS

Four databases were systematically searched until September 2020 for retrieving trials and observational studies. The incidences of RFS and RH were expressed as percentage and reported with 95% confidence intervals (CI).

RESULTS

Thirty-five observational studies were included in the analysis. The risk of bias was serious in 16 studies and moderate in the remaining 19. The incidence of RFS varied from 0% to 62% across the studies. No substantial change in the originally reported incidence of RFS was found by applying the ASPEN criteria. Similarly, the incidence of RH ranged between 7% and 62%. In the subgroup analyses, inpatients from Intensive Care Units (ICUs) and those initially fed with >20 kcal/kg/day seemed to have a higher incidence of both RFS (pooled incidence = 44%; 95% CI 36%-52%) and RH (pooled incidence = 27%; 95% CI 21%-34%). However, due to the high heterogeneity of data, summary incidence measures are meaningless.

CONCLUSION

The incidence rate of both RFS and RH greatly varied according to the definition used and the population analyzed, being higher in ICU inpatients and in those with increased initial caloric supply. Therefore, a universally accepted definition for RFS, taking different clinical contexts and groups of patients into account, is still needed to better characterize the syndrome and its approach.

Diets with high carbohydrate contents were associated with refeeding hypophosphatemia: A retrospective study in Japanese inpatients with anorexia nervosa

OBJECTIVE

Refeeding hypophosphatemia (RH) is a potentially fatal complication in patients with anorexia nervosa (AN), and its dietary preventive strategy is not well established. We aimed to examine the association between carbohydrate content in the diet and the occurrence of RH in inpatients with AN via retrospective medical chart review.

METHOD

We performed a chart review to collect data of patients with AN hospitalized at the Department of Psychosomatic Medicine of the University of Tokyo Hospital between April 1, 2012, and February 29, 2020. Receiver operating characteristic (ROC) analysis was performed to determine the cutoff point of the percentage of carbohydrate content in the diet for the occurrence of RH. Multivariate logistic regression analysis was performed with occurrence of RH as the dependent variable and the carbohydrate content of more than the identified cutoff point as the independent variable adjusting for the risk factors for RH.

RESULTS

The percentage of carbohydrate content that is higher than the cutoff point obtained from the ROC analysis (58.4%) was significantly associated with the occurrence of RH, even after adjusting for variables associated with RH in univariate logistic regression analysis (age and body mass index) as well as the average daily calorie intake (odds ratio, 5.37; 95% confidence interval, 1.60-18.1; p = .0066).

DISCUSSION

We identified that diets with higher carbohydrate contents were associated with RH in inpatients with AN, even after adjusting for known risk factors. Our findings may promote the development of dietary preventive strategies against RH in inpatients with AN.

Outcomes of a higher calorie inpatient refeeding protocol in Asian adolescents with anorexia nervosa

OBJECTIVE

This study aims to compare the outcomes of higher calorie refeeding (HCR) and a lower calorie refeeding (LCR) methods among a diverse sample of young Asian adolescents admitted to a tertiary institution in Asia for management of anorexia nervosa (AN).

METHOD

This is a retrospective case control study of Asian adolescents who were managed using an inpatient HCR protocol (2016-2017) and an LCR protocol (2010-2014). Baseline characteristics, daily change in percent median body mass index (%mBMI), and rates of refeeding hypophosphatemia were analyzed between groups.

RESULTS

A total of 125 adolescents with AN were analyzed with 61 (52%) patients in the HCR group. Mean age was 14.0 years (SD =1.5) and mean presenting %mBMI was 73.2 (SD =6.9) with mean length of stay of 11.9 days (SD = 6.6). Patients in the HCR group had significantly increased rate of change of %mBMI (M = 0.39, SD = 0.31) than patients in the LCR group (M = 0.12, SD = 0.43) (p < .001). There was an increased rate of mild hypophosphatemia in the HCR group (HCR: 46%, LCR: 22%, p = .007) but no difference in rates of moderate hypophosphatemia and no cases of severe hypophosphataemia. Lower presenting %mBMI significantly predicted the phosphate levels (p = .004).

DISCUSSION

In a sample of Asian adolescents with AN, use of an HCR protocol was associated with improved rate of inpatient weight gain. There was increased risk of mild hypophosphataemia, but not moderate to severe hypophosphataemia, suggesting that an HCR protocol can be used safely with close monitoring of phosphate levels.

Anorexia nervosa restricting type has increased in severity over three decades: Japanese clinical samples from 1988 to 2018

OBJECTIVE

Although eating disorders (EDs) surged in the late 1900s and are now recognized worldwide, the time trend of ED characteristics remains unknown. This study aimed to clarify changes in characteristics of anorexia nervosa restricting type (AN-R) over 30 years.

METHODS

We conducted a cross-sectional study and examined 996 female treatment-seeking patients with AN-R in Japan from 1988 to 2018. Demographics, body mass index (BMI), and Eating Disorder Inventory scores were compared among three groups in accordance with the time of initial consultation: Group 1 (1988-1998), Group 2 (1998-2008), Group 3 (2008-2018).

RESULTS

The mean BMI at the initial consultation significantly decreased by 0.6 kg/m² (from 14.0 kg/m² in Group 1 to 13.4 kg/m² in Group 3). Groups 2 and 3 scored significantly higher in drive for thinness, interpersonal distrust, and interoceptive awareness than those in Group 1. The range of onset age is wider and the number of late-onset AN-R with prolonged delay in treatment has increased over time.

DISCUSSION

This study shows that AN-R has increased in physical and psychopathological severity over the past 30 years in Japan. Interdisciplinary research is needed to clarify the relationship between AN-R and time trend.

The Refeeding Syndrome: a neglected but potentially serious condition for inpatients. A narrative review

The Refeeding Syndrome (RFS) is a potentially serious, but still overlooked condition, occurring in individuals who are rapidly fed after a period of severe undernourishment. RFS derives from an abnormal electrolyte and fluid shifts leading to many organ dysfunctions. Symptoms generally appear within 2-5 days of re-feeding and may be absent/mild or severe and life threating, depending on the pre-existing degree of malnutrition and comorbidities. The lack of a standard definition and the nonspecificity of the symptoms make both incidence estimate and diagnosis difficult. In 2020, the American Society for Parenteral and Enteral Nutrition (ASPEN) proposed a unifying definition for the RFS and its severity classification. The awareness of the condition is crucial for identifying patients at risk, preventing its occurrence, and improving the management. The objectives of this narrative review were to summarize the current knowledge and recommendations about the RFS and to provide useful tips to help physicians to recognize and prevent the syndrome.

Retrospective analysis of hypophosphatemia rates and other clinical parameters in patients with eating disorders

OBJECTIVE

To retrospectively assess medical services of a specialist inpatient eating disorders (EDs) unit.

METHOD

We retrospectively evaluated clinical parameters of 288 inpatients classified as 'moderately' or 'significantly' medically compromised between 1 January 2016 and 30 June 2019.

RESULTS

We analysed 288 patients (mean age 32.5 [SD = 11.4] years, 96% women, 76% with anorexia nervosa). Average length of stay was 38.4 (SD = 28.4) days. Average admission body mass index (BMI) was 14.8 (SD = 1.8) kg/m² , and 16.1 (SD = 1.9) kg/m² at 4 weeks. At admission, 82% of patients were considered significantly medically compromised, while 6% were deemed moderately compromised. Only 5% of patients required transfer to intensive care unit. Prevalence of hypophosphatemia was 17.7%; rates did not increase significantly between years despite more assertive re-feeding processes. There was no association between risk classification at admission and change in BMI at 4 weeks (F_(2,166) = 0.588, p = 0.557). BMI at admission was found to be significantly associated with clinical outcome (β = 0.92, p < 0.001).

DISCUSSION

Hypophosphatemia rates did not increase despite more assertive re-feeding over 3 years. Our results provide support for a model of treatment that simultaneously addresses the medical and psychiatric sequelae of patients with severe EDs.