Metabolic and hormonal changes during the refeeding period of prolonged fasting

Acute Cardiomyopathy in a Prisoner on a Hunger Strike

Chronic starvation and its associated metabolic derangements are known to have dangerous cardiovascular implications in the long term, but less is known about the cardiovascular consequences of acute starvation, such as in the context of a hunger strike. This case describes a patient who presented with signs and symptoms of acute coronary syndrome which began two weeks into a hunger strike and was ultimately found to have stress cardiomyopathy with complete resolution on subsequent imaging.

Review: The amazing gain-to-feed ratio of newly weaned piglets: sign of efficiency or deficiency?

Shortly after weaning, piglets generally eat dry feed poorly; but nevertheless, a phenomenal gain-to-feed ratio is achieved as they gain about as much weight as they eat (150-200 g/d). The high gain-to-feed ratio, though, cannot be explained by their nutrient intake or nutrient repartitioning. Analyses based on tissue composition and bio-electrical impedance data showed that newly weaned piglets lose fat, maintain protein, and gain large amounts of water because of edema. This edema, which may well contribute up to one kg of BW, seems to be triggered by refeeding syndrome. Refeeding syndrome in adult humans occurs when subjects fast for an extended period of time (weeks) that results in downshifts in metabolic activity and concomitant shedding of phosphate (PO4), magnesium (Mg), and potassium (K) in urine. If food is abruptly reintroduced, thus, resulting in strong insulin spikes, metabolism is triggered but hampered by a lack of PO4, Mg, K, and thiamine, causing hypophosphatemia, metabolic stress, and edema. In piglets, the same process appears to happen immediately after weaning but in hours rather than weeks, possibly linked to their high metabolic rate. Refeeding syndrome can be lethal in humans but does not appear to be directly lethal in piglets. Our attempts to prevent it through altered diet composition and/or controlled feeding programs have not resulted in better performance at the end of the nursery phase. A practical ramification of weaning-induced edema is that growth and gain-to-feed ratio data immediately after weaning should be interpreted with caution. In addition, diets arguably should be formulated to not strongly trigger insulin release, while high lysine levels are not needed as the gain is not based on protein accretion.

A novel fasting regimen revealed protein reservation and complement C3 down-regulation after 14-day's continual dietary deprivation

Objectives

The aim is to evaluate the effect of a novel 14-day fasting regimen on the balance between skeletal muscle and adipose tissue composition which might associate with inflammatory factors. Our analysis includes basic physical examinations, clinical laboratory analysis, bioelectrical impedance and biochemical analytic assessments of healthy volunteers.

Methods

Eight healthy subjects were randomly selected from a pool of volunteers to undergo a continual dietary deprivation (CDD) regimen. Individuals were assigned to take Flexible Abrosia (FA, prebiotic combination) plus appropriate mineral supplement of potassium and magnesium at 3 mealtime every day to prevent potential injury from starved intestinal flora and avoid spasms of smooth muscle due to hunger. Physical and medical examinations were conducted and blood samples were collected at following timepoints: before CDD as self-control (0D), day 7 and day 14 during fasting, and 7-21days and/or 2~3mo after refeeding.

Results

The combination of FA and mineral supplements significantly decreased self-reported physical response of starvation, with tolerable hunger-mediated sensations experienced during CDD. Bioelectrical and biochemical results indicated significant reduction in both muscle lean and fat mass on day 7. Meanwhile, markers related to fat composition consistently decreased during and after CDD. In addition, most biochemical marker levels, including serum proteins, reached their inflection points at the 7th day of CDD as compared to the control measurements. Levels of these factors started to show a relative plateau, or reversed direction upon the 14th day of CDD. The exceptions of above factors were myostatin and complement protein C3, which remained at lower concentrations in the blood throughout CDD, and were unable to fully recover toward baseline levels even after 3 months' refeeding.

Conclusion

Our results indicated that human subjects undergoing prolonged dietary restriction were well protected by FA and mineral ions from gut injury or physical discomfort of starvation. Most factors showed a relative plateau response at the end of 14D-CDD. The muscle tissues were well preserved during prolonged fasting, and an improved protein/lipid ratio was observed. Upon refeeding, constant lower levels of myostatin and complement C3 were maintained after CDD implies a long-term beneficial effect in dealing with anti-aging and inflammation.

Prolonged Fasting as a Cause of Deep Vein Thrombosis: A Case Report

Background  Intermittent fasting is becoming more popular as health benefits are described in recent literature. Various forms of fasting exist, one of them involving a zero-calorie diet and drinking only water. However, the safety of water-only fasting is still not well established. We report a case of a man who developed a lower limb deep vein thrombosis at the end of a 2-week water-only fasting and characterized by an initial period of 5 days of no food and no water intake. We reviewed literature regarding potential links between fasting and venous thromboembolism (VTE). Clinical Approach  We believe that fasting can induce important dehydration, leading to hypercoagulability and then contribute to the development of a venous thrombosis. The patient was treated with apixaban for 3 months as is recommended in patients with a provoked event caused by a transient risk factor. No thrombotic recurrence was observed during the 6-month follow-up. Conclusion  The public needs to be aware of the potential life-threatening complications associated with important dehydration in the setting of medically unsupervised fasting, and these might include VTE. Whether a VTE with dehydration as the only identified risk factor should be approached as a low recurrence risk situation or not still needs to be clarified.

Mechanisms of ageing: growth hormone, dietary restriction, and metformin

Tackling the mechanisms underlying ageing is desirable to help to extend the duration and improve the quality of life. Life extension has been achieved in animal models by suppressing the growth hormone-insulin-like growth factor 1 (IGF-1) axis and also via dietary restriction. Metformin has become the focus of increased interest as a possible anti-ageing drug. There is some overlap in the postulated mechanisms of how these three approaches could produce anti-ageing effects, with convergence on common downstream pathways. In this Review, we draw on evidence from both animal models and human studies to assess the effects of suppression of the growth hormone-IGF-1 axis, dietary restriction, and metformin on ageing.

Traditional and Medical Applications of Fasting

Fasting has been practiced for millennia, for religious, ethical, or health reasons. It is also commonplace among different species, from humans, to animals, to lower eukaryotes. Research on fasting is gaining traction based on recent studies that show its role in many adaptive cellular responses such as the reduction of oxidative damage and inflammation, increase of energy metabolism, and in boosting cellular protection. In this expert review, we recount the historical evolution of fasting and we critically analyze its current medical applications, including benefits and caveats. Based on the available data, we conclude that the manipulation of dietary intake, in the form of calorie restriction, intermittent fasting, dietary restriction with the exclusion of some nutrients, prolonged fasting, and so forth, is anthropologically engraved in human culture possibly because of its positive health effects. Indeed, many studies show that fasting ameliorates many biochemical parameters related to cardiovascular and cancer risk, and neurodegeneration. Mechanistic studies are plentiful, but largely limited to cell cultures or laboratory animals. Understandably, there are no controlled trials of any form of fasting that gauge the effects on [any cause] mortality. Physicians should be aware that misinformation is pervasive and that their patients often adopt dietary regimens that are far from being clinically validated. Moreover, doctors are often unaware of their patients’ religious or traditional fasting and of its potential health effects. Based on current evidence, no long-term fasting should be undertaken without medical supervision until future research will hopefully help shed further light on fasting and its effects on human health.

LRG1 is an adipokine that mediates obesity-induced hepatosteatosis and insulin resistance

Dysregulation in adipokine biosynthesis and function contributes to obesity-induced metabolic diseases. However, the identities and functions of many of the obesity-induced secretory molecules remain unknown. Here, we report the identification of leucine-rich alpha-2-glycoprotein 1 (LRG1) as an obesity-associated adipokine that exacerbates high fat diet-induced hepatosteatosis and insulin resistance. Serum levels of LRG1 were markedly elevated in obese humans and mice compared to their respective controls. LRG1 deficiency in mice greatly alleviated diet-induced hepatosteatosis, obesity, and insulin resistance. Mechanistically, LRG1 bound with high selectivity to the liver and promoted hepatosteatosis by increasing de novo lipogenesis and suppressing fatty acid β-oxidation. LRG1 also inhibited hepatic insulin signaling by down-regulating insulin receptor substrates 1 and 2. Our study identified LRG1 as a key molecule that mediates the crosstalk between adipocytes and hepatocytes in diet-induced hepatosteatosis and insulin resistance. Suppressing LRG1 expression and function may be a promising strategy for the treatment of obesity-related metabolic diseases.

Leptin treatment prevents impaired hypoglycemic counterregulation induced by exposure to severe caloric restriction or exposure to recurrent hypoglycemia

Hypoglycemia-associated autonomic failure (HAAF) is a maladaptive failure in glucose counterregulation in persons with diabetes (PWD) that is caused by recurrent exposure to hypoglycemia. The adipokine leptin is known to regulate glucose homeostasis, and leptin levels fall following exposure to recurrent hypoglycemia. Yet, little is known regarding how reduced leptin levels influence glucose counterregulation, or if low leptin levels are involved in the development of HAAF. The purpose of this study was to determine the effect of hypoleptinemia on the neuroendocrine responses to hypoglycemia. We utilized two separate experimental paradigms known to induce a hypoleptinemic state: 60% caloric restriction (CR) in mice and three days of recurrent hypoglycemia (3dRH) in rats. A sub-set of animals were also treated with leptin (0.5-1.0 μg/g) during the CR or 3dRH periods. Neuroendocrine responses to hypoglycemia were assessed 60 min following an IP insulin injection on the terminal day of the paradigms. CR mice displayed defects in hypoglycemic counterregulation, indicated by significantly lower glucagon levels relative to controls, 13.5 pmol/L (SD 10.7) versus 64.7 pmol/L (SD 45) (p = 0.002). 3dRH rats displayed reduced epinephrine levels relative to controls, 1900 pg/mL (SD 1052) versus 3670 pg/mL (SD 780) (p = 0.030). Remarkably, leptin treatment during either paradigm completely reversed this effect by normalizing glucagon levels in CR mice, 78.0 pmol/L (SD 47.3) (p = 0.764), and epinephrine levels in 3dRH rats, 2910 pg/mL (SD 1680) (p = 0.522). These findings suggest that hypoleptinemia may be a key signaling event driving the development of HAAF and that leptin treatment may prevent the development of HAAF in PWD.

Hepatic ballooning degeneration: a new feature of the refeeding syndrome in rats

AIM OF THE STUDY

Hepatic changes have been described during the refeeding syndrome due to increase in enzymes and hepatomegaly; however, they have not been properly described. Thus, the objective of this study was to investigate the hepatic histological characteristics and biochemical markers of hepatic steatosis in Wistar rats with refeeding syndrome.

MATERIAL AND METHODS

Thirty male Wistar rats were allocated to one of three groups: C, F or R. The animals from group C received an AIN-93 diet for 96 hours, and were then sacrificed. Animals allocated to group F were fasted for 48 hours and sacrificed. Animals from group R were also fasted for 48 hours, but were refed for another 48 hours, with AIN-93. The liver, blood and epididymal and retroperitoneal fats were collected.

RESULTS

Data obtained in groups F and R show the changes observed in refeeding syndrome, during starvation and refeeding. The serum glucose, magnesium, potassium and phosphorus, in group F, decreased. There was no evidence of hepatic steatosis. Hypophosphatemia, hypomagnesemia and hypokalemia were also observed in group R, confirming refeeding syndrome. The main histological characteristic, in this group, was the extensive presence of ballooning degeneration. This is the first article that has detected such change in liver structure, due to refeeding syndrome. The possible causes are: retention of sodium, causing whole body edema; and/or dysfunction of the sodium/potassium pump of the hepatocytes, as a result of hypophosphatemia.

CONCLUSIONS

This is the first description of an animal model of hepatic severe ballooning degeneration induced due to refeeding syndrome.

Glucose mediates insulin sensitivity via a hepatoportal mechanism in high-fat-fed rats

Poor nutrition plays a fundamental role in the development of insulin resistance, an underlying characteristic of type 2 diabetes. We have previously shown that high-fat diet-induced insulin resistance in rats can be ameliorated by a single glucose meal, but the mechanisms for this observation remain unresolved. To determine if this phenomenon is mediated by gut or hepatoportal factors, male Wistar rats were fed a high-fat diet for 3 weeks before receiving one of five interventions: high-fat meal, glucose gavage, high-glucose meal, systemic glucose infusion or portal glucose infusion. Insulin sensitivity was assessed the following day in conscious animals by a hyperinsulinaemic-euglycaemic clamp. An oral glucose load consistently improved insulin sensitivity in high-fat-fed rats, establishing the reproducibility of this model. A systemic infusion of a glucose load did not affect insulin sensitivity, indicating that the physiological response to oral glucose was not due solely to increased glucose turnover or withdrawal of dietary lipid. A portal infusion of glucose produced the largest improvement in insulin sensitivity, implicating a role for the hepatoportal region rather than the gastrointestinal tract in mediating the effect of glucose to improve lipid-induced insulin resistance. These results further deepen our understanding of the mechanism of glucose-mediated regulation of insulin sensitivity and provide new insight into the role of nutrition in whole body metabolism.

Energy Metabolism and Intermittent Fasting: The Ramadan Perspective

Intermittent fasting (IF) has been gaining popularity as a means of losing weight. The Ramadan fast (RF) is a form of IF practiced by millions of adult Muslims globally for a whole lunar month every year. It entails a major shift from normal eating patterns to exclusive nocturnal eating. RF is a state of intermittent liver glycogen depletion and repletion. The earlier (morning) part of the fasting day is marked by dominance of carbohydrate as the main fuel, but lipid becomes more important towards the afternoon and as the time for breaking the fast at sunset (iftar) gets closer. The practice of observing Ramadan fasting is accompanied by changes in sleeping and activity patterns, as well as circadian rhythms of hormones including cortisol, insulin, leptin, ghrelin, growth hormone, prolactin, sex hormones, and adiponectin. Few studies have investigated energy expenditure in the context of RF including resting metabolic rate (RMR) and total energy expenditure (TEE) and found no significant changes with RF. Changes in activity and sleeping patterns however do occur and are different from non-Ramadan days. Weight changes in the context of Ramadan fast are variable and typically modest with wise inter-individual variation. As well as its direct relevance to many religious observers, understanding intermittent fasting may have implications on weight loss strategies with even broader potential implications. This review examines current knowledge on different aspects of energy balance in RF, as a common model to learn from and also map out strategies for healthier outcomes in such settings.

Starvation-induced Liver Enzyme Elevation after Initiation of Feeding

Exacerbation of liver enzymes after the initiation of feeding in malnourished patients is caused by refeeding syndrome or persistent starvation. There are no definite clinical markers for distinguishing between the two conditions. We herein report a 63-year-old woman with starvation-induced liver enzyme elevation. Her body weight was inversely associated with the liver enzyme levels after refeeding, which was a different course from refeeding syndrome. Normalization of liver enzymes ensued as the caloric intake increased and weight gain progressed. Daily changes in body weight can be a useful clinical marker for distinguishing between refeeding syndrome and starvation-induced liver enzyme elevation.

A Suitable Diet for Recovery from Starvation Is a High-Fat Diet, but Not a High-Protein Diet, in Rats

The present study aims to determine the most suitable dietary balance of energy-producing nutrients for recovery from starvation. Rats were fed their standard high- carbohydrate diet (HCD, carbohydrate energy : protein energy : fat energy=71 : 18 : 11) for 7 d and then deprived of food for 3 d (short-term starvation) or 8 d (long-term starvation). The starved rats were then fed the HCD, a high-protein diet (HPD, 31 : 57 : 12), or a high-fat diet (HFD, 34 : 14 : 52) for 8 d. Rats had ad libitum access to drinking water throughout the experimental period, including the starvation period. The reference group was allowed free access to the HCD throughout the experimental period. Characteristically, increased drinking, increased urea nitrogen in the plasma and urine, and hypertrophy of the kidneys, were observed in the HPD group. Furthermore, the recovery of plasma glucose level was insufficient in this group. Therefore, administration of a HPD was contraindicated in recovery from starvation. The recovery of body weight after starvation was excellent in the HFD group. No effect on the metabolism of B-group vitamins involved in energy metabolism was found with the administration of any diet. The effects of HCD and HFD administration on recovery from starvation were investigated in further detail. No adverse effects were observed on the tissue to body weight mass ratios or biochemical parameters in blood in the HFD group. From the above findings, it is hypothesized that a HFD is most suitable for quickly reversing the influence of starvation.

Expanding the differential diagnosis for transaminitis in patients with anorexia nervosa

Aminotransferase elevations have been described in patients with anorexia nervosa. Hypothesized etiologies have included ischemic hepatitis, refeeding-induced transaminitis, and the process of autophagy. Supervised enteral nutrition is the mainstay of treatment for severe anorexia, but an increase in aminotransferase levels after initiation of enteral feeding presents clinicians with a diagnostic dilemma. We present a 31-year-old woman with anorexia nervosa (body mass index [BMI] of 13.5 kg/m²) who experienced a worsening of aminotransferase elevations even after the initiation of enteral feeding. Despite nutritional supplementation, the patient's weight continued to fall for 6 days. Peak aminotransferase concentrations correlated with the patient's lowest weight and improved only after an increase in BMI was eventually achieved. Secondary causes of severe transaminitis were investigated, and after no cause was found, a liver biopsy was performed. Pathology was consistent with liver injury secondary to severe malnutrition rather than from refeeding syndrome. This case highlights malnutrition as an important cause of aminotransferase elevations and underscores the need for judicious early weight restoration in patients with anorexia and abnormal liver chemistry.

Abnormal Liver Function Tests in an Anorexia Nervosa Patient and an Atypical Manifestation of Refeeding Syndrome

Refeeding syndrome is defined as electrolyte and fluid abnormalities that occur in significantly malnourished patients when they are refed orally, enterally, or parenterally. The principal manifestations include hypophosphatemia, hypokalemia, vitamin deficiencies, volume overload and edema. This can affect multiple organ systems, such as the cardiovascular, pulmonary, or neurological systems, secondary to the above-mentioned abnormalities. Rarely, patients may develop gastrointestinal symptoms and show abnormal liver function test results. We report the case of a 52-year-old woman with anorexia nervosa who developed refeeding syndrome and simultaneous elevations of liver function test results, which normalized upon the resolution of the refeeding syndrome.

Nutritional and other types of oedema, albumin, complex carbohydrates and the interstitium - a response to Malcolm Coulthard's hypothesis: Oedema in kwashiorkor is caused by hypo-albuminaemia

The various types of oedema in man are considered in relation to Starling's hypothesis of fluid movement from capillaries, with the main emphasis on nutritional oedema and the nephrotic syndrome in children. It is concluded that each condition has sufficient anomalous findings to render Starling's hypothesis untenable. The finding that the endothelial glycocalyx is key to control of fluid movement from and into the capillaries calls for complete revision of our understanding of oedema formation. The factors so far known to affect the function of the glycocalyx are reviewed. As these depend upon sulphated proteoglycans and other glycosaminoglycans, the argument is advanced that the same abnormalities will extend to the interstitial space and that kwashiorkor is fundamentally related to a defect in sulphur metabolism which can explain all the clinical features of the condition, including the formation of oedema.

Ghrelin

BACKGROUND

The gastrointestinal peptide hormone ghrelin was discovered in 1999 as the endogenous ligand of the growth hormone secretagogue receptor. Increasing evidence supports more complicated and nuanced roles for the hormone, which go beyond the regulation of systemic energy metabolism.

SCOPE OF REVIEW

In this review, we discuss the diverse biological functions of ghrelin, the regulation of its secretion, and address questions that still remain 15 years after its discovery.

MAJOR CONCLUSIONS

In recent years, ghrelin has been found to have a plethora of central and peripheral actions in distinct areas including learning and memory, gut motility and gastric acid secretion, sleep/wake rhythm, reward seeking behavior, taste sensation and glucose metabolism.

Neglect: failure to thrive and obesity

Medical providers need to monitor growth at every visit. Weight status is influenced by genetics, medical conditions, socioeconomic status, and family environment. Screening for food security and psychosocial risk factors is an integral tool to identify families at risk for nutritional deficits and child maltreatment. Nutritional rehabilitation is best accomplished in an outpatient, multidisciplinary setting. Medical neglect should be considered in failure to thrive and obesity when there is a serious risk of harm from identified medical complications, additional or worsening medical complications occurring despite a multidisciplinary approach, and/or non-adherence with the treatment plan.

Refeeding syndrome in Southeastern Taiwan: Our experience with 11 cases

AIM: To present our experience with refeeding syndrome in southeastern Taiwan.

METHODS: We conducted a retrospective study during a 2-year period at the Mackay Memorial Hospital, Taitung Branch. We enrolled patients with very little or no nutrition intake for more than 10 d, a high risk group of refeeding syndrome, including those suffering from alcohol abuse, cancerous cachexia, chronic malnutrition, and prolonged starvation.

RESULTS: A total of 11 patients (7 males, 4 females) with nasogastric feeding were included as having refeeding syndrome. Most of them had the symptoms of diarrhea, lethargy, and leg edema. The initial nutritional supplement was found to be relatively high in calories (1355.1 ± 296.2 kcal/d), high in protein (47.3 ± 10.4 gm/d), low in vitamin B1 (2.0 ± 0.5 mg/d), low in potassium (1260.4 ± 297.7 mg/d), and low in phosphorus (660.1 ± 151.8 mg/d). Furthermore, hypophosphatemia (2.4 ± 0.9 mg/dL) was noted during follow-up. Based on the suggestions of a dietician and a gastroenterologist, the clinical disorders of diarrhea, malaise and leg edema were significantly improved. The level of phosphate was also increased (3.3 ± 0.6 mg/dL).

CONCLUSION: Refeeding syndrome is an overlooked and risky disorder that has some potentially fatal complications. Nasogastric feeding in nursing homes is an important risk factor for patients and deserves greater attention based on the initial results of this study.

Refractory hypoglycemia and subsequent cardiogenic shock in starvation and refeeding: report of three cases

OBJECTIVE

Although starvation is associated with high in-hospital mortality, its related cardiac complications are not sufficiently understood. The aim of this study was to determine the clinical course and pathogenesis of cardiac complications in malnourished patients.

METHODS

We reviewed three cases of hypoglycemia and hypotriglyceridemia with cardiac complications in starvation.

RESULTS

This report concerns three patients, respectively suffering from anorexia nervosa, esophageal carcinoma, and Parkinson's disease. Their ages ranged from 18 to 70 y, body mass index was 11.5 ± 1.5 kg/m2 (mean ± SD), and the main symptom was coma. The average blood glucose level was 15.7 ± 7.8 mg/dL without any history of insulin use or diabetes mellitus. In all cases, hypoglycemia was refractory and repetitive so that continuous glucose administration was required to maintain euglycemia. Serum triglyceride and non-esterified fatty acid levels were also very low (7 ± 4 mg/dL and 10 ± 9.1 μEq/L, respectively). Levels of serum potassium, phosphate, and magnesium were almost normal at admission. The main cardiac complications included Takotsubo cardiomyopathy and cardiac arrest. All patients survived as a result of intensive treatment.

CONCLUSIONS

Repetitive severe hypoglycemia without known background causes should be viewed as an important sign. Once this occurs, the administration of a much higher caloric input than usual accompanied by intensive monitoring will be required to maintain appropriate glucose levels. The early identification of such patients seems to be essential to reduce the high risk for cardiac complications during starvation and refeeding.

Refeeding syndrome: screening, incidence, and treatment during parenteral nutrition

The possible deleterious effects of feeding after a period of prolonged starvation have been known for over 60 years. The resultant biochemical disturbance, symptoms, and signs have been termed the refeeding syndrome (RS). The key to the pathophysiology is the stimulation of insulin release resulting in anabolic activity. Depleted electrolyte and micronutrient stores are overwhelmed and cellular function disrupted. A concise definition of RS is not agreed and hampers interpretation of clinical data. Hypophosphatemia and appearance of tissue edema/pathological fluid shifts are the most often agreed diagnostic criteria. The characteristics of particular patient groups at risk have been recognized for some time, and there are guidelines from the National Institute for Clinical Excellence in the UK to aid recognition of individuals at high risk along with protocols for initiating nutrition. Using loose diagnostic criteria, RS appears to occur in 4% of cases of parenteral nutrition (PN) when case records were reviewed by experts in a large study into PN care in the UK. Disappointingly, prescribers recognized only 50% of at risk cases. Early data from a similar study in New Zealand appear to show a similar pattern. Prospective series looking at patients receiving nutrition support in institutions with Nutrition Support Teams have found an incidence of 1-5%. RS is still underrecognized. Patients receiving PN should be counted as being in a high-risk category and feeding protocols to avoid RS applied. Low rates of RS then occur and death from this cause be avoided.

Distinctions between the islets of mice and men: implications for new therapies for type 1 and 2 diabetes

OBJECTIVE

To elucidate why diabetes is so difficult to treat despite the present tools and pharmacologic armamentarium and to provide insights into emerging therapies by describing human and rodent data that demonstrates the ability to transform progenitor cells within the adult pancreas into new islets.

METHODS

A literature review focused on the distinctions between human and rodent islets.

RESULTS

We are beginning to elucidate important differences between the architecture and composition of the islets of Langerhans in humans and rodents. In contrast to rodent islets, human islets are more heterogeneous in cellular composition and have more prominent intra-islet vascularity, with smooth muscle-containing blood vessels that are not present in rodent islets. Some studies report that more than 70% of human beta cells have direct physical contact with other cell types, whereas others describe that smaller human islets possess features more typical of rodents, while larger islets exhibit greater vascularity and a cellular distribution distinct from centrally clustered beta cells surrounded by a mantle of alpha and delta cells found in rodents.

CONCLUSIONS

The differences between the islets of mice and men may influence why treatments hailed as reversing diabetes among rodents have not been successfully translated into humans. Increased understanding of the complexities within the human islet may yield unique insights into reversing diabetes in humans.

A 40-day water-only fast by a Pentecostal woman: clinical and religious observations

A 57-year-old woman presented to the hospital after a 40-day acaloric (water-only) fast, which was motivated by her Christian beliefs and Pentecostal affiliation. She exhibited hyponatremia on admission, and developed hypokalemia, hypophosphatemia and hypomagnesemia during refeeding. The authors are unaware of other published case reports describing medical and religious aspects of prolonged fasting by Christians for spiritual reasons. Nevertheless, this practice is advocated by some Pentecostal and non-Pentecostal sources, and may be more common than is widely recognized.

Subjective experience of sensation in anorexia nervosa

The nature of disturbance in body experience in anorexia nervosa (AN) remains poorly operationalized despite its prognostic significance. We examined the relationship of subjective reports of sensitivity to and behavioral avoidance of sensory experience (e.g., to touch, motion) to body image disturbance and temperament in adult women currently diagnosed with AN (n = 20), women with a prior history of AN who were weight restored (n = 15), and healthy controls with no eating disorder history (n = 24). Levels of sensitivity to sensation and attempts to avoid sensory experience were significantly higher in both clinical groups relative to healthy controls. Sensory sensitivity was associated with body image disturbance (r(56) = .51, p < .0001), indicating that body image disturbance increased with increased global sensitivity to sensation. Sensory sensitivity was also negatively and significantly correlated with lowest BMI (r(2) = -.32, p < .001), but not current BMI (r(2) = .03, p = .18), and to the temperament feature of harm avoidance in both clinical groups. We discuss how intervention strategies that address sensitization and habituation to somatic experience via conditioning exercises may provide a new manner in which to address body image disturbance in AN.

Occurrence of refeeding syndrome in adults started on artificial nutrition support: prospective cohort study

BACKGROUND

Refeeding syndrome is a potentially life-threatening condition characterised by severe intracellular electrolyte shifts, acute circulatory fluid overload and organ failure. The initial symptoms are non-specific but early clinical features are severely low-serum electrolyte concentrations of potassium, phosphate or magnesium. Risk factors for the syndrome include starvation, chronic alcoholism, anorexia nervosa and surgical interventions that require lengthy periods of fasting. The causes of the refeeding syndrome are excess or unbalanced enteral, parenteral or oral nutritional intake. Prevention of the syndrome includes identification of individuals at risk, controlled hypocaloric nutritional intake and supplementary electrolyte replacement.

OBJECTIVE

To determine the occurrence of refeeding syndrome in adults commenced on artificial nutrition support.

DESIGN

Prospective cohort study.

SETTING

Large, single site university teaching hospital. Recruitment period 2007-2009.

PARTICIPANTS

243 adults started on artificial nutrition support for the first time during that admission recruited from wards and intensive care.

MAIN OUTCOME MEASURES

PRIMARY OUTCOME

occurrence of the refeeding syndrome. Secondary outcome: analysis of the risk factors which predict the refeeding syndrome. Tertiary outcome: mortality due to refeeding syndrome and all-cause mortality.

RESULTS

133 participants had one or more of the following risk factors: body mass index <16-18.5≥(kg/m(2)), unintentional weight loss >15% in the preceding 3-6 months, very little or no nutritional intake >10 days, history of alcohol or drug abuse and low baseline levels of serum potassium, phosphate or magnesium prior to recruitment. Poor nutritional intake for more than 10 days, weight loss >15% prior to recruitment and low-serum magnesium level at baseline predicted the refeeding syndrome with a sensitivity of 66.7%: specificity was >80% apart from weight loss of >15% which was 59.1%. Baseline low-serum magnesium was an independent predictor of the refeeding syndrome (p=0.021). Three participants (2% 3/243) developed severe electrolyte shifts, acute circulatory fluid overload and disturbance to organ function following artificial nutrition support and were diagnosed with refeeding syndrome. There were no deaths attributable to the refeeding syndrome, but (5.3% 13/243) participants died during the feeding period and (28% 68/243) died during hospital admission. Death of these participants was due to cerebrovascular accident, traumatic injury, respiratory failure, organ failure or end-of-life causes.

CONCLUSIONS

Refeeding syndrome was a rare, survivable phenomenon that occurred during hypocaloric nutrition support in participants identified at risk. Independent predictors for refeeding syndrome were starvation and baseline low-serum magnesium concentration. Intravenous carbohydrate infusion prior to artificial nutrition support may have precipitated the onset of the syndrome.

Ghrelin- and serotonin-producing gastric carcinoid

We report the case of a 57-year-old woman with gastric carcinoid. The tumor was surgically removed and immunohistochemical investigation demonstrated a rare combination: ghrelin and serotonin in the cytoplasm of the tumor cells. The functional significance of simultaneous production of ghrelin and serotonin is not clear. It may be that an autocrine/paracrine interaction exists between these two different hormones.

A mathematical model of weight loss under total starvation: evidence against the thrifty-gene hypothesis

The thrifty-gene hypothesis (TGH) posits that the modern genetic predisposition to obesity stems from a historical past where famine selected for genes that promote efficient fat deposition. It has been previously argued that such a scenario is unfeasible because under such strong selection any gene favouring fat deposition would rapidly move to fixation. Hence, we should all be predisposed to obesity: which we are not. The genetic architecture of obesity that has been revealed by genome-wide association studies (GWAS), however, calls into question such an argument. Obesity is caused by mutations in many hundreds (maybe thousands) of genes, each with a very minor, independent and additive impact. Selection on such genes would probably be very weak because the individual advantages they would confer would be very small. Hence, the genetic architecture of the epidemic may indeed be compatible with, and hence support, the TGH. To evaluate whether this is correct, it is necessary to know the likely effects of the identified GWAS alleles on survival during starvation. This would allow definition of their advantage in famine conditions, and hence the likely selection pressure for such alleles to have spread over the time course of human evolution. We constructed a mathematical model of weight loss under total starvation using the established principles of energy balance. Using the model, we found that fatter individuals would indeed survive longer and, at a given body weight, females would survive longer than males, when totally starved. An allele causing deposition of an extra 80 g of fat would result in an extension of life under total starvation by about 1.1-1.6% in an individual with 10 kg of fat and by 0.25-0.27% in an individual carrying 32 kg of fat. A mutation causing a per allele effect of 0.25% would become completely fixed in a population with an effective size of 5 million individuals in 6000 selection events. Because there have probably been about 24,000 famine events since the evolution of hominins 4 million years ago, there has been ample time even for genes with only very minor impacts on adiposity to move to fixation. The observed polymorphic variation in the genes causing the predisposition to obesity is incompatible with the TGH, unless all these single nucleotide polymorphisms (SNPs) arose in the last 900,000 years, a requirement we know is incorrect. The TGH is further weakened by the observation of no link between the effect size of these SNPs and their prevalence, which would be anticipated under the TGH model of selection if all the SNPs had arisen in the last 900,000 years.

Influence of a regular, standardized meal on clinical chemistry analytes

Background

Preanalytical variability, including biological variability and patient preparation, is an important source of variability in laboratory testing. In this study, we assessed whether a regular light meal might bias the results of routine clinical chemistry testing.

Methods

We studied 17 healthy volunteers who consumed light meals containing a standardized amount of carbohydrates, proteins, and lipids. We collected blood for routine clinical chemistry tests before the meal and 1, 2, and 4 hr thereafter.

Results

One hour after the meal, triglycerides (TG), albumin (ALB), uric acid (UA), phosphatase (ALP), Ca, Fe, and Na levels significantly increased, whereas blood urea nitrogen (BUN) and P levels decreased. TG, ALB, Ca, Na, P, and total protein (TP) levels varied significantly. Two hours after the meal, TG, ALB, Ca, Fe, and Na levels remained significantly high, whereas BUN, P, UA, and total bilirubin (BT) levels decreased. Clinically significant variations were recorded for TG, ALB, ALT, Ca, Fe, Na, P, BT, and direct bilirubin (BD) levels. Four hours after the meal, TG, ALB, Ca, Fe, Na, lactate dehydrogenase (LDH), P, Mg, and K levels significantly increased, whereas UA and BT levels decreased. Clinically significant variations were observed for TG, ALB, ALT, Ca, Na, Mg, K, C-reactive protein (CRP), AST, UA, and BT levels.

Conclusions

A significant variation in the clinical chemistry parameters after a regular meal shows that fasting time needs to be carefully considered when performing tests to prevent spurious results and reduce laboratory errors, especially in an emergency setting.

Laparoscopic reconversion of Roux-en-Y gastric bypass to original anatomy: technique and preliminary outcomes

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (RYGB) is one of the most common bariatric procedures performed. Dumping syndrome, intolerance to RYGB-induced restriction, and weight loss issues are possible problems bariatric surgeons are confronted with. This study reports the feasibility, safety, and outcomes of laparoscopic reconversion of RYGB to original anatomy (OA) as treatment of these complications.

METHODS

Between January 2005 and April 2008, eight patients benefited from laparoscopic reconversion of RYGB to OA. Reason was dumping syndrome without postprandial hypoglycemia (three), intolerance to RYGB-induced restriction (three), too much (one) and too little weight loss (one). Mean weight and body mass index (BMI) at RYGB were 104.7±19.3 kg and 38.7±6 kg/m(2), respectively. Four patients suffered of obesity co-morbidities. Mean time between RYGB and reconversion was 21±18.8 months. Mean weight, BMI, and % excess weight loss at reconversion was 66.8±21.7 kg, 20.1±7 kg/m(2), and 23.7±55%, respectively. The procedure involved dismantling both gastrojejunostomy and jejunojejunostomy, reanastomosing gastric pouch to gastric remnant, and proximal alimentary limb end to distal biliary limb end.

RESULTS

Mean operative time was 132.2±29.5 min. There were no conversions to open surgery and no early complications. Gastrogastrostomy was performed manually (four) and by linear stapler (four), and jejunojejunostomy by linear stapler (eight). Mean hospital stay was 7.7±3.5 days. After a mean follow-up of 18.3±9.2 months, two patients continued to further lose weight, two patients maintained the same weight, and four patients presented weight regain. Gastroesophageal reflux disease appeared in three patients.

CONCLUSIONS

Laparoscopic reconversion of RYGB to OA is feasible and safe. Dumping syndrome and intolerance to RYGB-induced restriction are resolved. The anatomy remains one of the aspects besides nutritional and psychological factors in cases of reconversion for weight issues.

Physiological roles of preproghrelin-derived peptides in GH secretion and feeding

Among the factors playing a crucial role in the regulation of energy metabolism, gastro-intestinal peptides are essential signals to maintain energy homeostasis as they relay to the central nervous system the informations about the nutritional status of the body. Among these factors, preproghrelin is a unique prohormone as it encodes ghrelin, a powerful GH secretagogue and the only orexigenic signal from the gastrointestinal tract and obestatin, a proposed functional ghrelin antagonist. These preproghrelin-derived peptides may contribute to balance energy intake, metabolism and body composition by regulating the activity of the GH/IGF-1 axis and appetite. Whereas the contribution of ghrelin has been well characterized, the role of the more recently identified obestatin, in this regulatory process is still controversial. In this chapter, we describe the contribution of these different preproghrelin-derived peptides and their receptors in the regulation of GH secretion and feeding. Data obtained from pharmacological approaches, mutant models and evaluation of the hormones in animal and human models are discussed.

Refeeding with a high-protein diet after a 48 h fast causes acute hepatocellular injury in mice

Elucidating the effects of refeeding a high-protein diet after fasting on disease development is of interest in relation to excessive protein ingestion and irregular eating habits in developed countries. The objective of the present study was to address the hepatic effects of refeeding a high-protein diet after fasting. Mice were fasted for 48 h and then refed with a test diet containing 3, 15, 35, 40, 45 or 50 % casein. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and liver immediate-early gene expression levels were sequentially measured for the first 24 h after initiation of refeeding. Refeeding with a 50 % casein diet after 48 h of fasting led to a rapid (within 2-3 h) and abnormal elevation in serum ALT (P = 0·006) and AST (P = 0·001) activities and a marked increase in liver Finkel-Biskis-Jinkins (FBJ) osteosarcoma oncogene (P = 0·007) and nuclear receptor subfamily 4, group A, member 1 (P = 0·002) mRNA levels. In contrast, refeeding of the 3, 15 or 35 % casein diets produced no substantial increases in serum ALT and AST activities in mice. Refeeding of 40, 45 or 50 % casein increased serum ALT and AST activities in proportion to this dietary casein content. In mice refed the 3, 15 or 35, but not 50 %, casein diets, liver heat shock protein 72 transcript levels greatly increased. We conclude from these data that the consumption of a high-protein diet after fasting causes acute hepatocellular injury in healthy animals, and propose that careful attention should be paid to the use of such diets.

Role of the evolutionarily conserved starvation response in anorexia nervosa

This review will summarize recent findings concerning the biological regulation of starvation as it relates to anorexia nervosa (AN), a serious eating disorder that mainly affects female adolescents and young adults. AN is generally viewed as a psychosomatic disorder mediated by obsessive concerns about weight, perfectionism and an overwhelming desire to be thin. By contrast, the thesis that will be developed here is that, AN is primarily a metabolic disorder caused by defective regulation of the starvation response, which leads to ambivalence towards food, decreased food consumption and characteristic psychopathology. We will trace the starvation response from yeast to man and describe the central role of insulin (and insulin-like growth factor-1 (IGF-1))/Akt/ F-box transcription factor (FOXO) signaling in this response. Akt is a serine/threonine kinase downstream of the insulin and IGF-1 receptors, whereas FOXO refers to the subfamily of Forkhead box O transcription factors, which are regulated by Akt. We will also discuss how initial bouts of caloric restriction may alter the production of neurotransmitters that regulate appetite and food-seeking behavior and thus, set in motion a vicious cycle. Finally, an integrated approach to treatment will be outlined that addresses the biological aspects of AN.

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

Refeeding syndrome is difficult to diagnose since the guidelines for identifying those at risk are largely based on subjective clinical parameters and there are no predictive biochemical markers. We examined the suitability of insulin-like growth factor 1 (IGF1) and leptin as markers to identify patients at risk of the refeeding syndrome before initiation of parenteral nutrition (PN). A total of thirty-five consecutive patients referred for commencement of PN were included. Serum leptin and IGF1 were measured before starting PN. Electrolytes, liver and renal function tests were conducted before and daily for 1 week after initiating PN. The primary outcome was a decrease in phosphate 12–36 h after initiating PN. ‘Refeeding index’ (RI) was defined as leptin × IGF1 divided by 2800 to produce a ratio of 1·0 in patients who are well nourished. RI had better sensitivity (78 %; 95 % CI 40, 97 %) and specificity (78 %; 95 % CI 40, 97 %) with a likelihood ratio of 3·4, at a cut-off value of 0·19 for predicting a ≥ 30 % decrease in phosphate concentration within 12–36 h after starting PN, compared with IGF1 or leptin alone. However, IGF1 was a better predictor of mortality than either leptin or the RI. The present study is the first to derive and test the ‘RI’, and find that it is a sensitive and specific predictor of the refeeding syndrome in hospitalised patients before starting PN.

Ghrelin neutralization during fasting-refeeding cycle impairs the recuperation of body weight and alters hepatic energy metabolism

Ghrelin, a hormone whose levels increase during food deprivation, plays a pivotal role in the regulation of food intake, energy metabolism and storage, as well as in insulin sensitivity. Here, we investigated the effects of acyl-ghrelin neutralization with the acyl-ghrelin-binding compound NOX-B11(2) during the fasting-refeeding cycle. Our data demonstrate that ghrelin neutralization with NOX-B11(2) impairs recuperation of lost body weight after food deprivation. Analysis of enzymes involved in glucose and lipid metabolism in liver of fed, fasted and refed rats revealed that neutralization of acyl-ghrelin resulted in minor decreases in the enzymes of glycolytic and lipogenic pathways during fasting. However, during refeeding these enzymes as well as glycogen levels recovered more slowly when acyl-ghrelin was blocked. The high levels of ghrelin in response to food deprivation may contribute to an adequate decrease in hepatic glycolytic and lipogenic enzymes and aid in the recovery of body weight and energetic reserves once food becomes available after the fasting period.

Important aspects of nutrition in children with cancer

Adequate nutrition during cancer plays a decisive role in several clinical outcome measures, such as treatment response, quality of life, and cost of care. However, the importance of nutrition in children and young adults with malignancies is still an underestimated topic within pediatric oncology. The importance of our work is to reinforce and indicate that malnutrition in children with cancer should not be accepted at any stage of the disease or tolerated as an inevitable process. Unique to our manuscript is the close collaboration, the exchange of knowledge and expertise between pediatric oncologists and a nutritional specialist, as well as the comprehension of the mechanisms during cancer cachexia and malnutrition. We provide a critical review of the current state of research and new knowledge related to nutritional management in childhood cancer.

Influence of a light meal on routine haematological tests

INTRODUCTION

Patient-related variables, such as physical exercise, stress and fasting status are important sources of variability in laboratory testing. However, no clear indications about fasting requirements exist for routine haematological tests, nor has the influence of meals been assessed.

METHODS

We studied 17 healthy volunteers who consumed a light meal containing a standardized amount of carbohydrates, protein and lipids. Blood was taken for routine haematological tests before the meal and 1, 2 and 4 hours thereafter.

RESULTS

One hour after the meal, neutrophil count and mean corpuscular haemoglobin (MHC) increased significantly, whereas lymphocyte and monocyte counts, red blood cell distribution width, haematocrit, and mean corpuscular volume decreased significantly. A clinically significant variation was only observed for lymphocytes. Two hours after the meal, a significant increase was observed for neutrophils and MCH, whereas lymphocytes, eosinophils, haemoglobin and haematocrit decreased significantly. Clinically significant variations were recorded for lymphocytes, red blood cells (RBC), haemoglobin, haematocrit and MCH. Four hours after the meal MCH was significantly increased, while lymphocytes, eosinophils, RBC, haemoglobin and haematocrit were significantly decreased. Clinically significant variations were recorded for neutrophils, eosinophils, RBC, hematocrit and MCH.

CONCLUSION

The significant variation of several haematological parameters after a light meal demonstrates that the fasting time needs to be carefully considered in order to interpret the results of haematological tests correctly.