Massive obesity: complications and treatment.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
R L Atkinson
Publications and source records attributed to R L Atkinson.
Effects of ileal transposition on food intake, dietary preference, and weight gain in Zucker obese rats.
This study evaluated the effects of ileal transposition (IT) surgery on food intake, body weight, and dietary preferences in Zucker obese rats. Eight rats had a 10-cm segment of terminal ileum transposed to the upper jejunum. Eight rats underwent sham IT (SIT) and six rats had no surgery (CON). During weeks 1-10 and 21-24, rats were fed a selection diet of protein (casein), carbohydrate (corn starch), and fat (lard) in three separate dishes. Rat chow was fed from weeks 11 to 20. IT rats had a lower weight and a lower change in weight from base line throughout most of the study. Energy intake was less in IT vs. SIT rats during the selection periods (weeks 1-10 and 21-24), but did not differ on the chow diet (weeks 11-20). Digestible energy, measured at weeks 10, 20, and 24, was lower in IT rats only at week 10. IT rats had no malabsorption by fecal calorie measurements. IT rats ate fewer fat calories at both selection periods. We conclude that IT causes long-term reduction in body weight, no malabsorption or long-term changes in digestible energy, and a persistent decrease in preference for dietary fat. Further studies are needed to determine whether increased energy expenditure is a mechanism for the long-term difference in body weight after IT.
Animals↗
Ileal transposition surgery attenuates the increased efficiency of weight gain on a high-fat diet.
High-fat diets enhance weight gain in rats and humans. Ileal transposition surgery (IT) causes long-term weight loss on ad libitum food intake. This study was designed to study the effect of high-fat diets on weight loss following ileal transposition surgery. We weight matched 40 rats, performed IT or sham IT, and fed defined high-carbohydrate (12 percent kcal as fat) or high-fat (45 percent kcal as fat) diets for 15 weeks postsurgery (N = 10/group, data are means +/- s.e.m.). Overall, IT rats ate less than sham IT rats, 9587 +/- 304 v. 10,615 +/- 356 kcal (39.6 +/- 1.2 v. 43.8 +/- 1.5 MJ) (P less than 0.01), and gained less weight (-14 +/- 7.8 v. 46 +/- 13.7 g) (P less than 0.01). Sham IT rats had similar food intakes on the two diets, but body weights were increased on the high-fat diet. However, the IT rats on the high-fat diet did not gain more weight or have higher efficiency of weight gain than did the IT rats on the high-carbohydrate diet. We conclude that ileal transposition attenuates the increased efficiency of weight gain usually associated with consumption of a high-fat diet. The mechanisms of this decreased metabolic efficiency are unclear.
Animals↗
Low and very low calorie diets.
Low and very low calorie diets may be useful for the initial treatment of obesity, but long-term weight loss requires life-style changes in eating and activity patterns. Very low calorie diets cause rapid weight loss and improvement of complications of obesity, but the possibility of severe complications mandates careful selection and close supervision by a health professional team.
Diet, Reducing↗
Effects of cardiac stress during a very-low-calorie diet and exercise program in obese women.
To assess the safety of very-low-calorie diets (VLCDs), stress tests known to induce arrhythmias in susceptible patients were performed in 24 obese women on a VLCD (660-720 kcal/d) for 6 wk. Half of the subjects had diet only (DO) and half underwent supervised exercise (DE) four times weekly. Five control subjects ate a balanced, moderately low-calorie diet (approximately 1400 kcal/d). Stress tests included maximal and submaximal (85%) exercise, psychological stress, and isometric handgrip tests, all with constant electrocardiogram (ECG) monitoring. Twenty-four-hour Holter monitors at weeks 0 and 6 and weekly resting ECGs were obtained. DO and DE lost similar amounts of weight. There were no changes in QT intervals or in voltage or width of the QRS complex on resting ECG and no arrhythmias on Holter monitoring. These data support the safety of VLCDs containing greater than or equal to 650 kcal/d and adequate amounts of high-quality protein, vitamins, and minerals for use for periods of at least 6 wk in normal, healthy obese women.
Adult↗
The future direction of nutrition research: science, public health, public policy.
Explore the source record for details and available documents.
Forecasting↗
Management of solitary melanoma metastasis of the brain.
A retrospective analysis of 31 patients operated upon for cerebral secondary melanoma was conducted. There was no operative mortality and no operative complications in 76% of cases. Significant and life-threatening complications occurred in five patients (17%). The major benefit from surgical excision is relief of symptoms: 64% had complete remission of symptoms while a further 20% were substantially improved. A few patients' lives were prolonged by surgery and there are a number of long-term survivors. Surgical excision should be performed when a patient has an accessible solitary cerebral secondary without evidence of melanoma elsewhere.
Adult↗
Short-bowel syndrome: a case report.
A 32-year-old woman suffered massive infarction of the small bowel and after surgical resection was left with only 40 cm of postduodenal small bowel. She was maintained initially on total parenteral nutrition (TPN), but because of poor compliance with her dietary regimen she had a stormy course when given enteral feedings. With intensive counseling her compliance improved and she was able to maintain good nutritional status with oral feeding. This case report illustrates the need for intensive nutritional support for patients with short bowel. Although initial survival depends on TPN, it should be followed by an aggressive attempt to use enteral feedings alone. The program should be individualized, and caregivers must be aware of the many potential complications, since early diagnosis and treatment of complications may be critical for survival.
Adult↗
Opioids in the regulation of food intake and energy expenditure.
This paper and the following four papers summarize a symposium on the role of opioids in regulation of feeding, body weight, and energy expenditure. The central sites of opioid action are discussed, as is opioid activity in invertebrates, large animals, and humans. This paper provides a historical review of developments in the field from the early concepts of an endogenous opioid system to the current understanding of multiple receptor types and their interaction in regulating ingestive behavior. Opioids from all three opioid families may stimulate food intake, and some evidence exists that opioids may stimulate energy expenditure. Eating and drinking behavior is very complex and involves a number of components. Our understanding of the role of opioids in this process is shallow, and future research must be designed carefully to evaluate individual components of ingestive behavior.
Animals↗
Opioid regulation of food intake and body weight in humans.
Relatively few studies of humans have evaluated the effects of opioids on food intake and body weight. Most have focused on the potential role of opioids in the etiology of obesity. Measurements of endogenous opioids in plasma or spinal fluid of humans reveal higher levels, particularly of beta-endorphin, in obese subjects. Opioid agonists such as methadone and butorphanol tartrate stimulate food intake, and all studies with naloxone, an opioid antagonist, demonstrate a reduction of short-term food intake in obese or lean humans. Long-term studies with naltrexone, an antagonist similar to naloxone, show no effect on food intake or body weight. Opioid agonists or antagonists have little effect on nutrient selection in humans. The effects on feeding-related hormones is equivocal. Further studies with more specific opioid receptor activities are needed.
Animals↗
Very low calorie diets: getting sick or remaining healthy on a handful of calories.
Explore the source record for details and available documents.
Body Weight↗
Naltrexone hydrochloride (Trexan): a review of serum transaminase elevations at high dosage.
In summary, evidence is presented associating typically asymptomatic and reversible elevations of serum transaminase values with high daily dosages of naltrexone. Statistical significance was found only between placebo and the 300 mg dosage. Subjects aged 40 years and over were significantly more likely to develop this finding than younger subjects. All subjects with significant elevations of transaminase values in these studies took daily naltrexone dosages higher than recommended for opioid addiction. The daily dosage of naltrexone recommended for opioid addiction did not cause abnormalities of serum transaminase values in these studies.
Adult↗
Effects of long-term therapy with naltrexone on body weight in obesity.
The endogenous opiate system is thought to be associated with the regulation of food intake and body weight. Opiate antagonists decrease food intake in animals, but there are no controlled studies in obese man to evaluate body weight response to naltrexone. Sixty obese people were randomized into three groups and given 0, 50, or 100 mg of the opiate antagonist naltrexone for 8 weeks in an outpatient, double-blind study. Weight loss was not significant in either the 50 or 100 mg groups as compared with placebo. However, when broken down by sex, women had a significant (P less than 0.05) weight loss of 1.7 kg, while men did not lose weight. Side effects were modest, but six subjects had one or more abnormal liver function test results; in one subject these abnormalities appeared to be clinically significant. The effects of naltrexone on weight loss were less than expected in light of prior animal studies, but further studies with a wider dose range of naltrexone may be indicated.
Administration, Oral↗
Effects of calorie restriction and weight loss on glucose and insulin levels in obese humans.
The relative contributions of weight loss vs calorie restriction in the improvement of glucose tolerance in obese subjects has not been well studied. We measured fasting and stimulated glucose and insulin levels in seven obese subjects at 4 time periods: on a regular diet before weight loss, on a very low calorie ketogenic diet (VLCKD) after 4 days and after 6 weeks, and after 4 days back on a regular diet. Fasting glucose and insulin levels fell significantly after only 4 days of calorie restriction and did not change after 6 weeks. With return to a regular diet, these levels rose toward baseline even through body weight remained well below baseline. Stimulated glucose and insulin levels during an insulin tolerance test, intravenous glucose tolerance test, and standard meal demonstrated a similar pattern, although the changes due to either diet or weight loss were minimal. We conclude that calorie restriction has a greater effect on glucose and insulin levels than does weight loss in obese subjects who are losing weight.
Adult↗
Naloxone improves sleep apnea in obese humans.
To test the hypothesis that endogenous opiates play a role in the etiology of the sleep apnea syndrome, we administered naloxone, an opiate antagonist, to ten obese humans with sleep apnea. On two separate nights we measured the frequency and severity of sleep apnea during naloxone infusion vs saline control infusion. The number of oxyhemoglobin desaturation episodes was not significantly lowered but the average maximal oxyhemoglobin desaturation fell significantly (P less than 0.01) with naloxone. The desaturation index (average maximal oxyhemoglobin desaturation times desaturations per hour) fell by 21 percent (P less than 0.05) on the night of naloxone infusion. Nine of the ten patients had a lower desaturation index with naloxone. REM sleep decreased by 80 percent (P less than 0.05) in the subjects in whom it was measured. We conclude that opiate antagonists hold promise in the treatment of sleep apnea and that the endogenous opiate system may be involved in the production of sleep apnea.
Endorphins↗
Compliance of chest wall in obese subjects.
Whereas studies in awake subjects have demonstrated that chest wall compliance (Ccw) is low in obese subjects, the one study performed on paralyzed obese subject found Ccw to be normal. The purpose of this study was to measure Ccw in awake obese subjects with the pulse-flow technique, a method which appears to detect respiratory muscle relaxation. Seven normal males, 14 obese males, and 8 obese females [body mass index (BMI) varied from 20 to 83 kg/m2] were studied in the seated position. Ccw was measured by blowing air at a constant flow into the mouth and lungs for approximately 2 s and calculated by dividing airflow in liters per second by the change in esophageal minus body surface pressure in centimeters of water per second. In normal and obese subjects we found no correlation between BMI and Ccw. We conclude that obesity does not decrease Ccw.
Adult↗
Endocrine and metabolic effects of opiate antagonists.
The endogenous opiate system is involved in the regulation of numerous bodily functions, but the literature suggests that the effects of endogenous opioids differ among species and between animals and man. Naltrexone, a relatively pure opiate antagonist, appears to have significant effects on the secretion of the gonadotropins (luteinizing hormone and follicle-stimulating hormone), adrenocorticotropin (ACTH), cortisol, and probably catecholamines. Naltrexone appears to have minor or no effects on prolactin, the pituitary-thyroid axis, growth hormone, insulin, glucagon, vasopressin, and the gut hormones. Naltrexone also seems to reduce food intake and cause weight loss in humans. The dosages of opiate antagonist and the presence of other variables play a major role in the responses seen in various studies.
Adrenocorticotropic Hormone↗
A comprehensive outpatient weight reduction program: dietary patterns, psychological considerations, and treatment principles.
A comprehensive outpatient approach to weight reduction has the best chance of long-term success. This article outlines the dietitian's role and summarizes dietary patterns and psychological problems encountered in such a program at the University of Virginia Clinical Nutrition Center. Patients were assisted in making gradual changes in eating patterns through nutrition education and the use of behavior modification techniques. Initial food diaries often reflected a low intake of fruits, vegetables, whole grains, and legumes; increased consumption of these high-fiber foods is advocated as an aid to weight loss. Psychological support is an important component of the weight reduction process. The dietitian must be adequately prepared to provide this therapy but also must be able to recognize when patients should be referred for further psychological counseling. Two case studies are presented to illustrate the sabotage which must be dealt with by patients as they lose weight and struggle to maintain that weight loss.
Adult↗