Leptin and insulin growth factor 1: diagnostic markers of the refeeding syndrome and mortality

Association between energy delivery from parenteral nutrition and refeeding syndrome in hospitalized adults: A retrospective cohort study

BACKGROUND

Patients receiving parenteral nutrition (PN) may develop refeeding syndrome (RFS). This study determined RFS prevalence in hospitalized adults on PN and evaluated whether higher energy delivered by PN on day 1 of PN initiation was associated with RFS development.

METHODS

We reviewed the medical records of adult patients receiving PN at a Thai quaternary hospital from June 2019 to May 2022. RFS was defined based on the Nutrition Management Clinical Practice Recommendation by the Society of Parenteral and Enteral Nutrition of Thailand. The association between PN energy delivery and RFS development was determined using a generalized estimating equation for multiple logistic regression analysis adjusted for NICE guideline risk factors.

RESULTS

A total of 547 patients was included (mean age 59.8 ± 17.2 years, mean body mass index 20.7 ± 4.8 ). The prevalence of RFS was 45%. Factors associated with RFS included energy from PN on the first day of PN initiation (adjusted odds ratio [aOR] 1.17; 95% CI 1.04-1.33; for every 5 kcal/kg/day increase), starvation >5 days prior to PN (aOR 1.54; 95% CI 1.04-2.26), concomitant diuretic use (aOR 1.81; 95% CI 1.25-2.64), low baseline potassium level (aOR 1.79; 95% CI 1.19-2.70), and individual compounding PN (aOR 1.61; 95% CI 1.04-2.51).

CONCLUSION

RFS was common among hospitalized patients receiving PN. The amount of energy delivered on the first day of PN was independently associated with RFS, raising a concern regarding initiation of PN with higher energy.

Impact of Refeeding Syndrome on Short- and Medium-Term All-Cause Mortality: A Systematic Review and Meta-Analysis

BACKGROUND

The refeeding syndrome has been described as a potentially life-threatening complication of renutrition. However, moving from single reports to larger population studies, the real impact of refeeding syndrome on all-cause mortality is still unknown.

METHODS

PubMed/Medline, EMBASE, Cochrane library, and CINAHL databases were systematically searched until September 2020 for studies reporting mortality rates in patients who developed the syndrome at renutrition compared with those who did not develop it. Effect sizes were pooled through a random-effect model.

RESULTS

Thirteen studies were finally considered in the meta-analysis, for a total of 3846 patients (mean age 64.5 years; 58% males). Pooled data showed a nonsignificant trend toward an increased short-term (≤1 month) mortality in patients developing the refeeding syndrome (odds ratio = 1.27, 95% confidence interval 0.93-1.72), mostly driven by studies in which renutrition was not prescribed and supervised by a nutritional support team (P = .01 at subgroup analysis) and by studies published in previous years (P = .04 at meta-regression). When examining medium-term (≤6 month) mortality, an overall statistical significance toward higher risk was observed (odds ratio = 1.54, 95% confidence interval 1.04-2.28).

CONCLUSION

This was the first meta-analysis that specifically assessed the impact of refeeding syndrome on mortality. Our results suggested a nonsignificant trend toward increased mortality in the short term but a significantly increased mortality in the medium term. The supervision/management of the refeeding process by a nutrition specialist might be a key factor for the limitation of this mortality excess.

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.

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.

Mortality associated with new risk classification of developing refeeding syndrome in critically ill patients: A cohort study

BACKGROUND & AIMS

Although refeeding syndrome (RFS) has been recognized as a potentially fatal metabolic complication, the definition of RFS has remained unclear. Recently, European researchers suggested an evidence-based and consensus-supported algorithm that consisted of a new RFS risk classification and treatment strategies for medical inpatients. The classification was based on the National Institute for Health and Clinical Excellence (NICE) criteria for patients at risk of developing RFS. In this study, we aimed to investigate the frequency of each applied new risk group and the association between the new classification and mortality in critically ill patients.

METHODS

This cohort study was conducted at a Japanese metropolitan tertiary-care university hospital from December 2016 to December 2018. We included critically ill adult patients who were admitted to the intensive care unit (ICU) via the emergency department and who stayed in the ICU for 24 h or longer. We applied the new risk classification based on the NICE RFS risk factors on ICU admission. The main exposure was risk classification of RFS: no risk, low risk, high risk, or very high risk. The primary outcome was in-hospital mortality censored at day 30 after ICU admission. We performed a multivariable analysis using Cox proportional hazard regression.

RESULTS

We analyzed 542 patients who met the eligibility criteria. The prevalence of the four RFS risk classification groups was 25.8% for no risk, 25.7% for low risk, 46.5% for high risk, and 2.0% for very high risk. The 30-day mortality was 5.0%, 7.2%, 16.3%, and 27.3%, respectively (log-rank trend test: p < 0.001). In the multivariable Cox regression, adjusted hazard ratios with no risk group as a reference were 1.28 (95% CI 0.48-3.38) for low risk, 2.81 (95% CI 1.24-6.35) for high risk, and 3.17 (95% CI 0.78-12.91) for very high risk.

CONCLUSIONS

Approximately half the critically ill patients were categorized as high or very high risk based on the new risk classification. Furthermore, as the risk categories progressed, the 30-day in-hospital mortality increased. Early recognition of patients at risk of developing RFS may improve patient outcomes through timely and optimal nutritional treatment.

Refeeding syndrome : physiological background and practical management

Refeeding problems have been recognised since the the liberation of starved communities under siege. The main clinical problems may relate to hypophosphataemia, hypomagnesaemia and hypokalaemia with a risk of sudden death; thiamine deficiency with the risk of Wernike's encephalopathy/Korsakoff psychosis and sodium/water retention. The problems are greatest with oral/enteral feeding and especially with carbohydrate due to it increasing plasma insulin and thus glucose entry into cells. It is difficult to predict patients at risk of refeeding problems so there must be a high clinical suspicion on refeeding any malnourished patient (including any who have had no or very little nutrition for over 5 days). Generous vitamin and electrolyte supplementation may be given while monitoring closely and increasing the calorie intake reasonably rapidly from 10 to 20 kcal/kg/24 hours. Often patients in this category are not hungry, but over the course of a few days, the restoration of their appetite is an indication that the risks of refeeding have been managed and it is now safe to increase the feed aiming for repletion. If problems do occur, the feed should be slowed to the previous day's amount, reduced further or rarely stopped while fluid and electrolyte issues are corrected.

Management of Refeeding Syndrome in Medical Inpatients

Refeeding syndrome (RFS) is the metabolic response to the switch from starvation to a fed state in the initial phase of nutritional therapy in patients who are severely malnourished or metabolically stressed due to severe illness. It is characterized by increased serum glucose, electrolyte disturbances (particularly hypophosphatemia, hypokalemia, and hypomagnesemia), vitamin depletion (especially vitamin B1 thiamine), fluid imbalance, and salt retention, with resulting impaired organ function and cardiac arrhythmias. The awareness of the medical and nursing staff is often too low in clinical practice, leading to under-diagnosis of this complication, which often has an unspecific clinical presentation. This review provides important insights into the RFS, practical recommendations for the management of RFS in the medical inpatient population (excluding eating disorders) based on consensus opinion and on current evidence from clinical studies, including risk stratification, prevention, diagnosis, and management and monitoring of nutritional and fluid therapy.

Management and prevention of refeeding syndrome in medical inpatients: An evidence-based and consensus-supported algorithm

OBJECTIVES

Refeeding syndrome (RFS) can be a life-threatening metabolic condition after nutritional replenishment if not recognized early and treated adequately. There is a lack of evidence-based treatment and monitoring algorithm for daily clinical practice. The aim of the study was to propose an expert consensus guideline for RFS for the medical inpatient (not including anorexic patients) regarding risk factors, diagnostic criteria, and preventive and therapeutic measures based on a previous systematic literature search.

METHODS

Based on a recent qualitative systematic review on the topic, we developed clinically relevant recommendations as well as a treatment and monitoring algorithm for the clinical management of inpatients regarding RFS. With international experts, these recommendations were discussed and agreement with the recommendation was rated.

RESULTS

Upon hospital admission, we recommend the use of specific screening criteria (i.e., low body mass index, large unintentional weight loss, little or no nutritional intake, history of alcohol or drug abuse) for risk assessment regarding the occurrence of RFS. According to the patient's individual risk for RFS, a careful start of nutritional therapy with a stepwise increase in energy and fluids goals and supplementation of electrolyte and vitamins, as well as close clinical monitoring, is recommended. We also propose criteria for the diagnosis of imminent and manifest RFS with practical treatment recommendations with adoption of the nutritional therapy.

CONCLUSION

Based on the available evidence, we developed a practical algorithm for risk assessment, treatment, and monitoring of RFS in medical inpatients. In daily routine clinical care, this may help to optimize and standardize the management of this vulnerable patient population. We encourage future quality studies to further refine these recommendations.

Nutritional status and metabolic profile in neurologically impaired pediatric surgical patients

BACKGROUND

Malnutrition is reported in pediatric neuromotor disability and impacts the child's health. We described the nutritional and metabolic status in neurologically impaired (NI) children undergoing surgery.

METHODS

Anthropometry, body composition, hormonal and nutritional evaluations were performed in 44 NI subjects (13.7±8.0 years). Energy needs were calculated by Krick's formula. Metabolic syndrome (MS) was defined applying the following criteria (≥3 defined MS): fasting blood glucose >100 mg/dL and/or homeostasis model assessment for insulin resistance (HOMA-IR) >97.5th percentile, trygliceride level >95th percentile, high-density lipoprotein (HDL)-cholesterol level <5th percentile, systolic/diastolic pressure >95th percentile; whilebody mass index - standard deviation score (BMI-SDS) <2 and biochemical malnutrition markers (≥2) defined undernutrition.

RESULTS

Energy intake was not adequate in 73.8% of the patients; no correlation between energy intake and BMI was noted. Undernutrition was noted in 34.1% of patients and MS in 11.36% of subjects. Fifty percent of the patients presented with insulin resistance, which was not related to BMI, body composition or other MS components.

CONCLUSIONS

Nutritional and metabolic monitoring of disabled children and young adults is recommended to prevent adverse outcomes associated with malnutrition.

Incidence and Risk Factors of Refeeding Syndrome in Head and Neck Cancer Patients-An Observational Study

This study aimed to determine the incidence rates of refeeding phenomena (defined as a decline in p-phosphate) and refeeding syndrome (RFS; defined as development of clinical symptoms in addition to a decline in p-phosphate) in head and neck cancer patients, and to identify risk factors. Fifty-four head and neck cancer patients referred for surgery were included. Forty-six potential risk factors were registered at the baseline, and p-phosphate was measured at Days 2, 4, and 7. Eleven patients (20%) developed RFS, and twenty-eight (52%) developed refeeding phenomena. At baseline, these patients presented a higher prevalence of head and neck pain, eating difficulties, higher p-phosphate levels, lower p-transferrin levels, and, in men, lower b-hemoglobin levels. Patients who developed symptoms had a decline in p-phosphate ≥0.22 mmol/l. At baseline, these patients had higher p-phosphate levels, higher alcohol consumption, and lower p-transferrin and p-sodium levels, as well as a higher prevalence of eating difficulties, low handgrip strength (HGS), and a history of radiation therapy. The risk factors most strongly associated with the development of refeeding phenomena and RFS were pain, eating difficulties, low HGS, high alcohol intake, and previous radiation therapy.

Predicting refeeding hypophosphataemia: insulin growth factor 1 (IGF-1) as a diagnostic biochemical marker for clinical practice

Background

Refeeding syndrome (RS) is a potentially fatal condition that can occur following the re-introduction of nutrition after a period of starvation. Hypophosphataemia following the reintroduction of nutrition is often the only reliable biochemical marker of RS. Refeeding index (RI) generated from baseline insulin-like growth factor-1 (IGF-1) and leptin has been proposed as a useful biochemical marker for the identification of patients at risk of developing refeeding hypophosphataemia (RH).

Methods

A prospective study included 52 patients referred for parenteral nutrition (PN). The sensitivity and specificity of IGF-1 measured using a sensitive assay was compared to the RI in predicting the development of RH (a ≥30% drop in PO4 during the first 36-h of PN administration). Leptin and IGF-1 were analysed on baseline samples using a quantitative enzyme-linked immunoassay. Daily blood samples were collected from all patients for routine biochemistry for the full duration of PN administration.

Results

High sensitivity IGF-1 measurement alone was comparable with the RI, using receiver–operating characteristic (ROC) curve analysis, with areas under the curve being 0.79 and 0.80, respectively, and superior to leptin alone (0.72) for predicting ≥30% drop in PO4. The cut-off value for IGF-1 that gave best sensitivity (91% [95% CI 75–98%]) and specificity (65% [95% CI 41–85%]) was 63.7 µg/L, with a likelihood ratio of 2.59.

Conclusion

Baseline IGF-1 is an objective, sensitive and specific biochemical marker in identifying patients who are at high risk of developing RH prior to PN administration and therefore may have a role in clinical practice.

Insulin-like growth factor-I (IGF-I) and clinical nutrition

IGF-I (insulin-like growth factor-I) is a peptide hormone, produced predominantly by the liver in response to pituitary GH (growth hormone), which is involved in a wide variety of physiological processes. It acts in an endocrine, paracrine and autocrine manner to promote growth. The production of IGF-I signals the availability of nutrients needed for its anabolic actions. Recently, there has been growing interest in its role in health and disease. IGF-I has long been known to be regulated by nutrition and dysregulated in states of under- and over-nutrition, its serum concentrations falling in malnutrition and responding promptly to refeeding. This has led to interest in its utility as a nutritional biomarker. A considerable evidence base supports utility for measurement of IGF-I in nutritional contexts. Its concentration may be valuable in providing information on nutritional status, prognosis and in monitoring nutritional support. However, it is insufficiently specific for use as a screening test for under nutrition as its serum concentration is influenced by many factors other than nutritional status, notably the APR (acute-phase response) and endocrine conditions. Concentrations should be interpreted along with clinical findings and the results of other investigations such as CRP (C-reactive protein). More recently, there has been interest in free IGF-I which holds promise as a nutritional marker. The present review covers nutritional regulation of IGF-I and its dysregulation in disease, then goes on to review recent studies supporting its utility as a nutritional marker in clinical contexts. Although not currently recommended by clinical guidelines, it is likely that, in time, measurement of IGF-I will become a routine part of nutritional assessment in a number of these contexts.

The insulin-like growth factor system and nutritional assessment

Over recent years there has been considerable interest in the role of the insulin-like growth factor (IGF) system in health and disease. It has long been known to be dysregulated in states of under- and overnutrition, serum IGF-I levels falling in malnourished patients and responding promptly to nutritional support. More recently, other proteins in this system have been observed to be dysregulated in both malnutrition and obesity. Currently no biochemical marker is sufficiently specific for use in screening for malnutrition, but levels may be valuable in providing information on nutritional status and in monitoring of nutritional support. All have limitations as nutritional markers in that their serum levels are influenced by factors other than nutritional status, most importantly the acute phase response (APR). Levels should be interpreted along with clinical findings and the results of other investigations such as C-reactive protein (CRP). This paper reviews data supporting the use of proteins of the IGF system as nutritional markers.