Absolute Fasting Research Articles

Behavioral changes of transgenic mice carrying Adrb1-A187V mutation with short sleep duration under different dietary conditions

To observe the effects of restricted and high-fat diets on behavioral changes of wild-type (Adrb1+/+) and transgenic mice carrying Adrb1-A187V mutation (Adrb1+/m) with short sleep durations. Adrb1+/+ and Adrb1+/m C57BL/6 mice were randomized into normal chow group (25 Adrb1+/+ and 26 Adrb1+/m mice for behavioral monitoring), odor retention fasting group (17 Adrb1+/+ and 19 Adrb1+/m mice for behavioral monitoring; 6 Adrb1+/+ mice and 6 Adrb1+/m mice for EEG/EMG monitoring), absolute fasting group (6 Adrb1+/+ and 4-5 Adrb1+/m mice for behavioral monitoring; 6 Adrb1+/+ and 6 Adrb1+/m mice for EEG/EMG monitoring), and high-fat diet group (6 Adrb1+/+ and 7 Adrb1+/m mice for behavioral monitoring; 6 Adrb1+/+ and 6 Adrb1+/m mice for EEG/EMG monitoring). Electrodes for EEG and muscle activity monitoring were implanted on the skulls of the mice. After 24 h of odor retention fasting, absolute fasting, or high-fat feeding, the mice were observed for behavioral changes adapted to diet changes. In odor retention fasting experiment, Adrb1+/m mice exhibited more stable fluctuations of activities with mildly reduced movement and prolonged sleep duration, indicating enhanced starvation resistance. In absolute fasting experiment, Adrb1+/m mice showed significantly increased nighttime water intake, improved rhythmicity in water intake (frequent intakes in small amounts), and increased duration of non-rapid eye movement sleep (NREM). In the high-fat diet experiment, Adrb1+/m mice showed higher levels of activity with increased instances of nighttime rearing, longer movement distances, and increased rapid eye movement sleep during daytime. Adrb1+/m mice can quickly respond to environmental changes and under restricted dietary conditions, they can conserve energy by increasing sleep to maintain energy homeostasis but show higher levels of activity under high-fat dietary conditions.

Influence of a proinflammatory state on postprandial outcomes in elderly subjects with a risk phenotype for cardiometabolic diseases

PurposeLow-grade inflammation in obesity is associated with insulin resistance and other metabolic disturbances. In response to high-energy meal intake, blood concentrations of inflammatory markers, glucose and insulin rise. The aim of this study was to examine whether a basal inflammatory state influences postprandial responses.MethodsA randomized crossover trial was performed in 60 participants with a cardiometabolic risk phenotype (age 70 ± 5 years; BMI 30.9 ± 3.1 kg/m2). Each participant consumed three different iso-energetic meals (4300 kJ): a Western diet-like high-fat meal (WDHF), a Western diet-like high-carbohydrate meal (WDHC) and a Mediterranean diet-like meal (MED). Blood samples were collected when fasted and hourly for 5 h postprandially and analyzed for glucose, insulin, interleukin-1β (IL-1β), interleukin-6 (IL-6) and endothelial adhesion molecules. Based on fasting serum C-reactive protein (CRP) concentrations, participants were assigned to a high inflammation (CRP ≥ 2.0 mg/L; n = 30) or low inflammation (CRP < 2.0 mg/L; n = 30) group, and postprandial outcomes were compared.ResultsPlasma IL-6, glucose and serum insulin increased after all meals, while IL-1β and endothelial adhesion molecules were unchanged. The high inflammation group had higher fasting and postprandial IL-6 concentrations than the low inflammation group, although the IL-6 response slope was similar between groups. In response to the WDHC meal, participants in the high inflammation group experienced a higher glycaemic response than those in the low inflammation group.ConclusionA basal proinflammatory state results in higher absolute fasting and postprandial IL-6 concentrations, but the increase in IL-6 relative to basal levels is not different between high and low inflammation groups. Elevated glycaemic response in the high inflammation group may be due to inflammation-induced short-term insulin resistance.The trial was registered at http://www.germanctr.de and http://www.drks.de under identifier DRKS00009861 (registration date, January 22, 2016).

Knowledge of medical students about perioperative nutritional care in Bahia, Brazil: a transversal study

OBJECTIVE: Evaluate the medical students’ knowledge about perioperative nutritional care. These students are from public and private academic institutions in the state of Bahia, Brazil. METHODS: This is a cross-sectional study to analyze medical students based on an online instrument regarding topics related to perioperative care. For data analysis, absolute and relative frequencies were calculated for categorical variables, and mean and standard deviation were calculated for continuous variables. Fisher's Exact Test and G Test were used to analyze the association. Results: 209 responses were obtained. Regarding the learning on nutritional preparation of the patient submitted to a surgery, 25 (64.9%) students of public institutions and 90 (52.3%) students of private ones reported not knowing or not having been exposed to such knowledge. Regarding the importance of addressing topics related to nutritional therapy (NT), 37 (100%) students from public institutions and 168 (97.7%) from private ones recognize the importance of spreading this knowledge. Unnecessary absolute preoperative fasting, shortening techniques of fasting and bronchoaspiration prevention and reintroduction time of a diet in the postoperative period are unknown to most of the population studied. CONCLUSION: Most students included in this study do not have satisfactory knowledge in NT and for preparing the surgical patient.

Use of Mentholated Popsicle in the Management of the Elderly Patient's Thirst in the Immediate Postoperative Period: A Randomized Controlled Trial

PurposeThis study aimed to compare a mentholated popsicle with usual care (absolute fasting) in the change in thirst intensity and discomfort in elderly patients in the immediate postoperative period (IPP). DesignA randomized controlled trial. MethodsThe sample consisted of 50 elderly patients (60 years or older) in the IPP who were randomly assigned to two groups: experimental group (20 mL mentholated popsicle) and control group (usual care). The outcomes, thirst intensity and discomfort, were assessed at baseline and 20 minutes after the intervention. FindingsThe mentholated popsicle presented a statistically significant (P < .001) decrease in thirst intensity and discomfort by 5.0 in the median and a Cohen's r large effect size for both outcomes. There were no adverse events or side effects. ConclusionsThe use of a mentholated popsicle decreased the intensity and discomfort of the elderly patient's thirst in the IPP.

Metabolic and Inflammatory Benefits of Reducing Preoperative Fasting Time in Pediatric Surgery.

To investigate the metabolic/inflammatory impact of reducing the preoperative fasting time in preschool children. Forty children were randomly assigned to a fasting group (absolute fasting after 00:00) and a carbohydrate (CHO) group (allowed to ingest, two hours before surgery, a carbohydrate-rich beverage). Blood samples were collected right before and after surgery to quantify the levels of albumin, interleukin-6, glucose, insulin, C-reactive protein and to calculate insulin resistance by the HOMA-IR index. Preoperative fasting time in the CHO group were shorter than in the fasting group (2.49h vs. 11.24h, p <0.001). Pre- and post-surgical CRP levels were significantly lower in the CHO group (p = 0.05 and p = 0.02, respectively). The preoperative CRP/albumin ratios in the CHO group were lower than in the fasting group (p = 0.03). Four patients (21%) in the fasting group but none in the CHO group were hyperglycemic before surgery (p = 0.04). The two groups had similar levels of albumin, interleukin-6, insulin and HOMA index. There were no adverse events. Reducing the preoperative fasting time with carbohydrate-rich beverages improves the perioperative metabolic and inflammatory responses of preschool children undergoing inguinal hernia surgery.

The use of mentholated popsicle to reduce thirst during preoperative fasting: A randomised controlled trial.

To compare mentholated popsicle with usual care (absolute fasting) in the change of thirst intensity and discomfort of patients in the preoperative fasting. Thirst is defined as the desire to drink water, and it is considered to be a multifactorial symptom. In the preoperative fasting, the patient may experience intense thirst, often for a long time, that can lead to feelings of suffocation, desperation, fear and anxiety. A randomised controlled trial. Forty patients, aged between 18-60years, were randomised to mentholated popsicle group or absolute fasting group (twenty in each). The primary outcomes were thirst intensity, evaluated by a numeric scale ranging from 0 (no thirst)-10 (the worst possible thirst), and discomfort from thirst (evaluated by the Perioperative Thirst Discomfort Scale), both measured twice (baseline and after 20min of intervention). The CONSORT checklist was used to report this study. Mean age was similar in both groups (38years in the mentholated popsicle group and 39 in the absolute fasting group). At baseline, the mentholated popsicle group had higher median for the scales of intensity (6.5) and discomfort (7.5) from thirst than the absolute fasting group (5.0 and 5.0, respectively). At the end of 20min, the popsicle group had a statistically significant decrease in intensity and discomfort from thirst (median decreases of 5.0 and 7.0 points, respectively) when compared to the absolute fasting group (median increases of 0.5 and 1.0 points, respectively). The use of mentholated popsicle decreased the intensity and discomfort from thirst, and it is a viable strategy for the management of thirst in the preoperative fasting. In the preoperative fasting, making mentholated popsicles available to patients is an easy strategy to manage thirst, which might lead to better care.

The role of intermittent fasting and meal timing in weight management and metabolic health.

Obesity remains a major public health concern and intermittent fasting is a popular strategy for weight loss, which may present independent health benefits. However, the number of diet books advising how fasting can be incorporated into our daily lives is several orders of magnitude greater than the number of trials examining whether fasting should be encouraged at all. This review will consider the state of current understanding regarding various forms of intermittent fasting (e.g. 5:2, time-restricted feeding and alternate-day fasting). The efficacy of these temporally defined approaches appears broadly equivalent to that of standard daily energy restriction, although many of these models of intermittent fasting do not involve fed-fasted cycles every other 24 h sleep-wake cycle and/or permit some limited energy intake outside of prescribed feeding times. Accordingly, the intervention period therefore may not regularly alternate, may not span all or even most of any given day, and may not even involve absolute fasting. This is important because potentially advantageous physiological mechanisms may only be initiated if a post-absorptive state is sustained by uninterrupted fasting for a more prolonged duration than applied in many trials. Indeed, promising effects on fat mass and insulin sensitivity have been reported when fasting duration is routinely extended beyond sixteen consecutive hours. Further progress will require such models to be tested with appropriate controls to isolate whether any possible health effects of intermittent fasting are primarily attributable to regularly protracted post-absorptive periods, or simply to the net negative energy balance indirectly elicited by any form of dietary restriction.

Practice Guidelines for Intravenous Conscious Sedation in Dentistry (Second Edition, 2017).

Practice Guidelines for Intravenous Conscious Sedation in Dentistry (Second Edition, 2017).

Basal rate tests (24-hour fasts) performed in type-1 diabetic subjects with either absolute fasting or snacks containing negligible carbohydrate amounts result in similar glucose profiles: A randomized controlled prospective trial.

Basal rate tests (24-hour fasting periods) may be necessary to optimize basal insulin replacement in type 1 diabetes. It was the aim of this study to prospectively compare the allowance of negligible carbohydrate snacks vs absolute fasting. A total of 20 patients with type 1 diabetes (age, 48 ± 15 years (9 women, 11 men); BMI, 28.5 ± 4.5 kg/m2 ; HbA1c, 8.8% ± 2.0% (73.0 ± 21.9 mmol/mol); insulin dose, 0.69 ± 0.31 IU/kg body weight and per day) participated in 2 basal rate tests lasting 24 hours in random order with unchanged basal insulin replacement. On 1 occasion, negligible carbohydrate snacks (salads and vegetables, up to 5.1 g carbohydrate and 276.3 kJ per portion) were allowed; during the second test subjects were obliged to fast absolutely. Plasma glucose profiles were determined using an exact laboratory method. Hypoglycaemic episodes (plasma glucose < 70 mg/dL) were compared. Plasma glucose concentrations during fasting periods, with and without negligible carbohydrate snacks, did not differ significantly ( P = .65) and differences were negligible (95% confidence intervals always included a difference of 0 mmol/L). Also, there was no difference in the number of hypoglycaemic plasma glucose values (P = .40) or in compensatory carbohydrate intake. Basal rate testing with negligible carbohydrate snacks was better tolerated (questionnaire, P = .046) and the desire to discontinue the fasting period was significantly reduced (P = .023). Allowing negligible carbohydrate snacks results in unchanged plasma glucose profiles during basal rate testing and is better tolerated by patients with type 1 diabetes.

Effects of absolute fasting on reproduction and survival of the invasive apple snail Pomacea canaliculata in its native range

A South American freshwater gastropod, the apple snail Pomacea canaliculata, has become a driver of ecosystemic changes in wetlands and an important rice pest after its introduction to various parts of the world, mainly Asia. The objective of this study was to study the effect of an abrupt interruption in food availability in the short term (up to 4 weeks) and long term (up to 8 months) on survival and reproductive activity. The main results indicate that short-term fasting mainly affects the survival of males, but only when they are raised together with females, probably due to a greater mate-searching activity that increases mortality in the individuals with lower reserves. The number of copulating snails or egg-laying females shows an abrupt drop when fasting and a rapid recovery after the food supply is restored. The strategy of discontinuing reproductive activity prioritizes energy conservation for the survival of the females. Interpopulation variation in resistance to starvation was observed in adults, which can be explained to some extent by the food availability that they experienced in their natural environment. No interpopulational differences in survival were seen in hatchlings. The mean maximum values of survival under starvation were 52.6 days in hatchlings and the 3.3% of adults survive over than 200 days, which may be a relevant trait in dispersal and establishment in new habitats.

Perioperative care in an animal model for training in abdominal surgery: is it necessary a preoperative fasting?

Demonstrate that the rabbit may be used in the training of surgery, in addition to present its perioperative care. Thirty two animals, with age and weight, respectively, from 3 to 5.5 months old and 3000 to 4200 grams, were undergone different periods of pre-operative fasting, exclusive intramuscular anesthesia (ketamine+xylazine), laparotomy with total gastrectomy and total splenectomy. It was dosed the pre-operative (initial) and post-surgical (end) serum blood glucose, in addition to quantify the gastric content after the resection of the part. The anesthetical-surgical procedure presented a mortality rate of 3.125% (1:32) and a morbidity rate of 6.25% (2:32). It was evidenced an initial mean blood glucose = 199.4 mg/dl and the end = 326.1 mg/dl. In spite of extended fasting (minimum of 2 hours for the absolute fasting and maximum of 8.5 hours for liquids, and 20.5 hours for solids) all animals presented at the end of the surgical procedure any gastric content and a blood glucose increase. Those with fasting for liquids and solids when compared to the quantity of solid gastric content, presented a moderate negative degree of correlation. The rabbit is a good model to be used in training of surgery, with a low morbi-mortality, able to be anesthetized intramuscularly, with no need of pre-operative fasting and does not present hypoglycemia even with the extended fasting period.

Obesity: Problem, Solution, or Both?

Since 1982, the Southern California Permanente Medical Group's Positive Choice Weight Loss Program in San Diego has treated more than 30,000 adults, predominantly middle-aged, for obesity—some successfully, some not. This has been an extraordinary experience and provided us with numerous counterintuitive observations. We now are convinced that obesity is widely misunderstood, and we realize that the unusual program we have operated safely and effectively for more than a quarter century is often misunderstood as well. There is growing interest in our program and in using our approach as a model for other Kaiser Permanente (KP) Regions. We therefore share an overview here of our experience with this specific program. Consequently, most referenced works in this report are publications emanating from our program, sometimes contrasting those findings with conventional views on the subject. The Positive Choice Weight Loss Program has two integrated components: Prolonged absolute fasting, with the use of a supplement to support health and to prevent death from such fasting. A lengthy and complex group program to explore the basis of each participant's unconscious compulsive use of food, as well as to explore the hidden benefits of obesity for that individual. Given that the average weight loss of someone completing our 20-week program is 62 lb (28 kg) and that approximately 5000 patients each have lost more than 100 lb (45 kg), we realize we have challenged the belief systems of some who assume either that such weight loss cannot commonly be achieved or that the process of supplemented absolute fasting must be dangerous. In fact, the process has been notably safe, and major improvements in biomedical outcomes have been the norm. This article addresses four basic issues: The safety of properly supplemented prolonged absolute fasting in obesity The observed origins of obesity, and their implications The components of a relevant treatment program Outcomes of the Program.

Effect of fasting and taking food on hemostasis effect of patients with gastric ulcer and bleeding

Objective To discuss effect of fasting and taking food on hemostasis effect of patients with gastric ulcer and bleeding. Methods 160 patients with gastric ulcer and bleeding were divided in-to the experimental group and the control group, the experimental group was allowed to take lower ho-moiothermy water gruel (liquid), the control group was required absolute fasting (not medication), until bleeding stop. The two groups adopted identical treatment and nursing. The lienable stomach tube was placed respectively, everyday pH value monitor and occult blood test were carried out by taking out gas-tric juice when fasting and 2 hours after meals. Continuous monitoring tests continued till occult blood test of gastric liquid became negative for 3 times. Stool was kept for occult blood test, at the same time the gastrointestinal tract symptom and bleeding condition were observed, routine blood test was carried out one every other day. The data underwent statistical analysis with SPSS13.0 statistics software package, compari-son between two groups used t test. Results The inner stomach pH value of the experimental group in-creased obviously, the average pH value and percentage of pH above 4 was evidently higher than those of the control group. The time of occult blood test of gastric liquid and stool turning to negative in the experi-mental group was shorter than those of the control group. Conclusions Taking food can elevate pH of gastric liquid, reduce damage caused by gastric acid to gastric mucosa, thus hasten hemostasis process and promote healing. Key words: Fasting; Take food; Gastric ulcer; Hemostasis

Fasting and feasting safely during Ramadan in the patient with diabetes

There are more than one billion Muslims in the world and fasting for Ramadan is an obligatory ritual for all adult Muslims. The majority of Muslims observe absolute fasting (no food or water) between dawn and sunset in the holy month of Ramadan. For people with diabetes who take part in such a fast there are potential benefits and possible risks of hypo- and hyperglycaemia. It is therefore important that medical professionals ensure patients and their relatives (if appropriate) have the knowledge and support to undertake fasting safely. This is as important in India, Pakistan and the Sudan, as it is in the UK, The Netherlands and the USA. This article summarises briefly the religious context of Ramadan together with its potential metabolic impact. It then focuses on providing practical guidance on changes in diet, exercise and drug regimen in patients preparing to fast in Ramadan. Copyright © 2005 John Wiley & Sons, Ltd.

Preoperative fasting and administration of regular medications in adult patients presenting for elective surgery. Has new evidence changed clinical practice?

The duration of preoperative fasting from solid food and liquids, a time-honoured anaesthetic practice, has been the subject of extensive clinical investigations [1,2], editorial comment [3] and speciality guidelines [4,5] in the past decade. Dr Pearse and colleagues' study of current UK clinical practice relating to the duration of preoperative fasting of adult patients and compliance with ongoing cardiac drug administration is therefore timely [6]. Historically, preoperative fasting has not always been a prerequisite of safe, prudent anaesthetic practice. Lister, in the late 19th century, advised oral fluid intake up to two hours before anaesthesia [7]. Despite a body of recent evidence in support of Lister's conclusions, clinicians have continued to err on the side of caution and practice the maxim that 'longer is better'. Mendelson described the risk of gastric acid aspiration during obstetric anaesthesia with the consequent development of pneumonitis in his landmark 1946 study [8]. The conventional wisdom was that techniques to minimize the volume and increase the pH of the gastric contents would reduce the risk of Mendelson's syndrome. The concept of 'nil by mouth' (or in North America NPO), encompassing both fluids and food after midnight, was regarded as a logical practice to ensure an empty stomach at the time of surgery. Prolonged preoperative fasting contributes to patient discomforts, including dry mouth and thirst. In addition, the practice may, in some situations, lead to dehydration, hypovolaemia, and nausea and vomiting [9]. If excess gastric acidity was also a consequence, surely the practice should warrant a major review? The most noteworthy data arising from Pearse and colleagues' study involving 153 adult patients were the range of fasting times. For solids, the range was from 4 h and 30 min to 48 h and for fluids the range was from 4 h 30 min up to 20 h. Concerns about preoperative fasting may be a significant factor in the omission of usual concurrent drug treatment as highlighted in this study. Approximately 25% of patients undergoing elective surgery take regular concurrent medication [10]. Wyld and Nimmo [11] reported that analgesic and pre-medication subscriptions are routinely given. However, 38 of 95 drug treatments for cardiovascular disease, 34 of 103 for respiratory disease and 10 of 61 for endocrine disorders were omitted. When clinical studies in adults undertaken at the Foothills Hospital, Calgary, confirmed that an oral intake of 150 mL water [12] and subsequently coffee or fruit juice [13] 2-3 h before scheduled elective surgery had no clinically important effect on residual gastric fluid volume or pH, fasting guidelines for ambulatory patients were amended to prohibit solid food but permit clear fluid intake. The Canadian Anaesthetists' Society subsequently published guidelines stating that fasting for oral fluids for more than 3 h is unnecessary in healthy patients undergoing elective surgery. The American Society of Anesthesiologists Task Force on preoperative guidelines, published in 1999, were unequivocal in their recommendation that it is appropriate to fast for oral fluids for 2 h or more before procedures requiring general/regional anaesthesia or monitored anaesthesia care in adult patients. Clear liquids include, but are not limited to, water, fruit juices, carbonated beverages, clear tea and black coffee. Clinical investigations and the authority of society practice guidelines has an impact on North American clinical practice because the majority of institutions, both university and private practice, revised their fasting policies in recent times [14]. Why is British practice so slow to change? Perhaps anaesthetists fear that, if the absolute fasting rule is relaxed, patients will eat and drink at will, with subsequent delay or cancellation of surgical procedures. A concerted effort to inform surgeons, nurses and patients of the rationale behind current fasting guidelines enabling both ambulatory and in-patient to take, if they wish, clear fluids before surgery will enhance patient comfort and, considering the vagaries of operating theatre schedules, will be a safe, cost-effective practice. Judith Connolly, MRCPI, FFARCSI Anthony J. Cunningham, MD, FRCPC Departments of Anaesthesia and Critical Care Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9

TWO CASES OF OBTURATOR HERNIA

Two cases of obturator hernia which were diagnosed by pelvic CT are described here. Case 1: A 93-year-old woman complaining of an abdominal pain and vomiting was admitted to the hospital with a diagnosis of intestinal obstruction. Pelvic CT scan indicated incarceration of left obturator hernia. An operation was carried out. During the operation, a part of the ileal wall about 30 cm from the ileocecal region was incarcerated into the left obturator hrnia, but no necrosis nor perforation was associated. Case 2: A 73-year-old woman was admitted to the hospital because of a severe right thigh pain, numbness of the right lower extremity, nausea and vomiting. Absolute fasting and transfusion were indicated with a diagnosis of intestinal obstruction, and ileus symptoms disappeared. Pelvic CT scan performed for searching the cause revealed a right obturator hernia. The patient was not operated on, because no incarceration of the intestine was found out. About three months later ileus symptoms recurred and pelvic CT scan confirmed incarcerated right obturator hernia. So an operation was performed. It was found that a portion of the ileal wall about 40 cm from the ileocecal region was incarcerated into the right obturator hernia and a part of the wall necrotized, which demanded an excision of the intestine. These two cases would indicate the usefulness of pelvic CT in diagnosis of obturator hernia.

Proinsulin as a marker for the development of NIDDM in Japanese-American men.

Disproportionate hyperproinsulinemia is one manifestation of the B-cell dysfunction observed in non-insulin-dependent diabetes mellitus (NIDDM), but it is unclear when this abnormality develops and whether it predicts the development of NIDDM. At baseline, measurements of proinsulin (PI) and immunoreactive insulin (IRI) levels were made in 87 second-generation Japanese-American men, a population at high risk for the subsequent development of NIDDM, and, by using World Health Organization criteria, subjects were categorized as having normal glucose tolerance (NGT; n = 49) or impaired glucose tolerance (IGT; n = 38). After a 5-year follow-up period, they were recategorized as NGT, IGT, or NIDDM using the same criteria. After 5 years, 16 subjects had developed NIDDM, while 71 had NGT or IGT. Individuals who developed NIDDM were more obese at baseline, measured as intra-abdominal fat (IAF) area on computed tomography (P = 0.046) but did not differ in age from those who continued to have NGT or IGT. At baseline, subjects who subsequently developed NIDDM had higher fasting glucose (P = 0.0042), 2-h glucose (P = 0.0002), fasting C-peptide (P = 0.0011), and fasting PI levels (P = 0.0033) and disproportionate hyperproinsulinemia (P = 0.056) than those who continued to have NGT or IGT after 5 years of follow-up. NIDDM incidence was positively correlated with the absolute fasting PI level (relative odds = 2.35; P = 0.0025), even after adjustment for fasting IRI, IAF, and body mass index (relative odds = 2.17; P = 0.013).(ABSTRACT TRUNCATED AT 250 WORDS)

Copper Deficiency Shifts Energy Substrate Utilization from Carbohydrate to Fat and Reduces Fat Mass in Rats

The influence of copper deficiency on energy metabolism and body composition was examined in rats. Weanling male Sprague-Dawley rats were assigned to two dietary treatments: copper-adequate (102.2 mumol/kg) and copper-deficient (9.0 mumol/kg). After 4 wk of treatment, rats were individually housed in metabolic cages within indirect calorimetry units for measurements of respiratory quotient to determine substrate utilization. Body composition was measured by total body electrical conductivity. Net energetic efficiency and fasting heat production were determined from regression analysis of metabolizable energy intake and energy retention (metabolizable energy intake-heat production). Rats were given free access to their respective diets for almost the entire study but were restricted to 70% of normal energy intake for 2 d to provide a range of energy intake required for the regression analysis. Energetic evaluations were determined for 12 d at normal intake and 2 d at a modest restriction (30%). Copper deficiency reduced the respiratory quotient values (0.85 to 0.80), carbohydrate utilization (7.9 to 5.2 g/d), energy retention [8.4 to -66.9 kJ/kg0.75.d)] and energy efficiency (97.8 to 87.7%). However, daily metabolizable energy intake and absolute fasting heat production were not altered. Reductions in final body weights (289 to 263 g), absolute fat mass (65.7 to 51.5 g) and proportion of body fat (22.7 to 19.6 g/100 g) were observed in copper-deficient rats compared with controls when all indirect calorimetry measurements were completed after 7 wk of treatment. Thus, copper deficiency increased utilization of fat as substrate for energy and reduced body fat mass in rats.

Increased plasma response of gastric inhibitory polypeptide to oral glucose and a liquid meal after prolonged starvation in healthy man.

24 young, military subjects participated in a ranger training course of 5 days' duration with prolonged, heavy physical exercise and sleep deprivation. The subjects were divided into two groups showing either large calorie deficiency or nearly isocaloric status. An oral glucose tolerance test was performed on the subjects on day 5 on the course and in a control experiment 8 weeks after the course. During the course the subjects with negative calorie balance showed augmented integrated glucose-induced gastric inhibitory polypeptide (GIP) response (p less than 0.05) and the plasma concentration of GIP after glucose stimulation was higher at 90 and 120 min during the course than in the control experiment. On the other hand, the plasma GIP levels of the subjects on isocaloric diet changed similarly during the experimental period and the control period. In another experiment 11 healthy subjects were given a meal after an overnight fast and after 5 days of absolute fasting. The 5-day fast provoked higher postprandial plasma concentration of GIP between 60 and 150 min after meal stimulation, and the integrated meal-stimulated GIP response increased (p less than 0.01) after the prolonged fasting. The subjects in both experiments showed glucose intolerance. The insulinogenic index decreased during the training course, but increased during the prolonged, absolute fasting. The study shows that there is a dietary modulation of the GIP response to nutrient stimulation in healthy man and that the augmented GIP release is not attributable to insulin release.

Clinical Physiology: The Concentration of Ketone Bodies, Free Fatty Acids, and Glycerol in the Blood of Obese Persons after Injection of Insulin and Glucose Studies before and during Absolute Fasting

Clinical Physiology: The Concentration of Ketone Bodies, Free Fatty Acids, and Glycerol in the Blood of Obese Persons after Injection of Insulin and Glucose Studies before and during Absolute Fasting