Critical analysis of bariatric procedures in Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is a complex genetic disorder localized to chromosome 15 and is considered the most common genetic cause of the development of life-threatening obesity. Although some morbidities associated with PWS, including respiratory disturbance/hypoventilation, diabetes, and stroke, are commonly seen in obesity, others such as osteoporosis, growth hormone deficiency, and hypogonadism, and also altered pain threshold and inability to vomit, pose unique issues. Various bariatric procedures have been used to cause gastric stasis, decrease gastric volume, and induce malabsorption, with poor results in PWS patients in comparison with normal obese individuals.

Energy metabolism, nitrogen balance, and substrate utilization in critically ill children.

BACKGROUND: Critically ill patients are characterized by a hypermetabolic state, a catabolic response, higher nutritional needs, and a decreased capacity for utilization of parenteral substrate. OBJECTIVE: We sought to analyze the relation between a patient's metabolic state and their nutritional intake, substrate utilization, and nitrogen balance (NB) in mechanically ventilated, critically ill children receiving parenteral nutrition. DESIGN: This was a cross-sectional study in which resting energy expenditure (REE) and NB were measured and substrate utilization and the metabolic index (MI) ratio (REE/expected energy requirements) were calculated. RESULTS: Thirty-three children (mean age: 5 y) participated. Their average REE was 0.23 +/- 0.10 MJ x kg(-1) x d(-1) and their average MI was 1.2 +/- 0.5. Mean energy intake, protein intake, and NB were 0.25 +/- 0.14 MJ x kg(-1) x d(-1), 2.1 +/- 1 g x kg(-1) x d(-1), and -89 +/- 166 mg x kg(-1) x d(-1), respectively. Patients with an MI >1.1 (n = 19) had a higher fat oxidation than did patients with an MI <1.1 (n = 14; P < 0.05). Patients with lipogenesis (n = 13) had a higher carbohydrate intake than did patients without lipogenesis (n = 20; P < 0.05). Patients with a positive NB (n = 12) had a higher protein intake than did patients with a negative NB (n = 21; P < 0.001) and lower protein oxidation (P < 0.01). CONCLUSIONS: Critically ill children are hypermetabolic and in negative NB. In this population, fat is used preferentially for oxidation and carbohydrate is utilized poorly. A high carbohydrate intake was associated with lipogenesis and less fat oxidation, a negative NB was associated with high oxidation rates for protein, and a high protein intake was associated with a positive NB.

Hepatic veno-occlusive disease in ataxia-telangiectasia.

Existing descriptions of liver abnormalities in ataxia-telangiectasia have been associated with co-existent hepatitis virus infection. Here we report veno-occlusive disease of the liver in 2 patients with ataxia telangiectasia that is not attributable to bone marrow transplantation or coincidental hepatitis infection.

Resting energy expenditure and nitrogen balance in critically ill pediatric patients on mechanical ventilation.

Nutritional support is important in critically ill patients, with variable energy and nitrogen requirements (e.g., sepsis, trauma, postsurgical state) in this population. This study investigates how age, severity of illness, and mechanical ventilation are related to resting energy expenditure (REE) and nitrogen balance. Nineteen critically ill children (mean age, 8 +/- 6 [SD] y and range 0.4-17.0 y) receiving total parenteral nutrition (TPN) were enrolled. We used indirect calorimetry to measure REE. Expected energy requirements (EER) were obtained from Talbot tables. Pediatric Risk of Mortality (PRISM) and Therapeutic Intervention Scoring System (TISS) score were calculated. Total urinary nitrogen was measured using the Kjeldahl method. PRISM and TISS scores were 9 +/- 5 and 31 +/- 6 points, respectively. REE was 62 +/- 25 kcal.kg-1.d-1, EER was 42 +/- 11 kcal.kg-1. d-1, and caloric intake was 49 +/- 22 kcal.kg-1.d-1. Nitrogen intake was 279 +/- 125 mg.kg-1.d-1, total urinary nitrogen was 324 +/- 133 mg.kg-1.d-1, and nitrogen balance was -120 +/- 153 mg.kg-1.d-1. The protein requirement in this population was approximately 2.8 g.kg-1.d-1. These critically ill children were hypermetabolic, with REE 48% higher (20 kcal.kg-1.d-1) than expected. Nitrogen balance significantly correlated with caloric and protein intake, urinary nitrogen, and age, but not with severity of illness scores or ventilatory parameters.

A position paper of the North American Society for Pediatric Gastroenterology and Nutrition. Pediatric gastroenterology Workforce Survey and future supply and demand.

BACKGROUND: The North American Society for Pediatric Gastroenterology and Nutrition (NASPGN) performed a Workforce Survey to determine the current number and distribution of pediatric gastroenterologists in the United States and Canada and to estimate the supply and demand in the future in the United States. METHODS: The response rate was more than 90%. There were 624 pediatric gastroenterologists in the United States, and 48 in Canada. RESULTS: There were 2.4 pediatric gastroenterologists per million population in the United States, ranging from 3.1 per million in the Northeast to 1.9 per million in the West, and 1.6 per million in Canada. In the United States, fewer than 5 pediatric gastroenterologists retire each year, but more than 40 fellows per year complete training. In the United States, 30% of pediatric gastroenterologists believe there is already an excess supply; only 12% believe there is a shortage (p < 0.001). CONCLUSIONS: If the number of fellows who complete training each year remains unchanged, in 10 years there will be more than 950 pediatric gastroenterologists in the United States (3.3 per million population). At the same time, if the demand for pediatric gastroenterologists remains 2.4 per million population, there will be a demand for only 675. If these assumptions are correct, it is necessary to reduce the number of fellows to be trained. Although it is difficult to predict future workforce needs reliably, we recommend that the number of fellowship positions in training programs in the United States be reduced by 50% to 75%. Changes in health care in the coming years will be challenging, and effective planning is necessary for pediatric gastroenterologists to achieve their clinical, research, and educational missions.

Resting energy expenditure in children in a pediatric intensive care unit: comparison of Harris-Benedict and Talbot predictions with indirect calorimetry values.

The use of prediction equations has been recommended for calculating energy expenditure. We evaluated two equations that predict energy expenditure, each of which were corrected for two different stress factors, and compared the values obtained with those calculated by indirect calorimetry. The subjects were 55 critically ill children on mechanical ventilation. Basal metabolic rates were calculated with the Harris-Benedict and Talbot methods. Measured resting energy expenditure was 4.72 +/- 2.53 MJ/d. The average difference between measured resting energy expenditure and the Harris-Benedict prediction with a stress factor of 1.5 was -0.98 MJ/d, with an SD delta of 1.56 MJ/d and limits of agreement from -4.12 to 2.15; for a stress factor of 1.3 the average difference was -0.22 MJ/d, with an SD delta of 1.57 MJ/d and limits of agreement from -3.37 to 2.93. The average difference between measured resting energy expenditure and the Talbot prediction with a stress factor of 1.5 was -0.23 MJ/d, with an SD delta of 1.36 MJ/d and limits of agreement from -2.95 to 2.48; for a stress factor of 1.3, it was 0.42 MJ/d, with an SD delta of 1.24 MJ/d and limits of agreement from -2.04 to 2.92. These limits of agreement indicate large differences in energy expenditure between the measured value and the prediction estimated for some patients. Therefore, neither the Harris-Benedict nor the Talbot method will predict resting energy expenditure with acceptable precision for clinical use. Indirect calorimetry appears to be the only useful way of determining resting energy expenditure in these patients.

Bone mineral changes in young women with hypothalamic amenorrhea treated with oral contraceptives, medroxyprogesterone, or placebo over 12 months.

OBJECTIVES: The objectives of this study were to assess (1) whether treatment with oral contraceptives, in comparison with medroxyprogesterone and placebo, improved bone mineral in women with hypothalamic amenorrhea and (2) whether treatment with medroxyprogesterone, in comparison with placebo, improved bone mineral in women with hypothalamic oligomenorrhea. STUDY DESIGN: The study was a randomized, controlled clinical trial. Twenty-four white women, aged 14 to 28 years, with hypothalamic amenorrhea or oligomenorrhea were prospectively enrolled for a 12-month intervention period. Amenorrheic subjects were randomized to receive oral contraceptives, medroxyprogesterone, or placebo. Oligomenorrheic subjects were randomized to receive medroxyprogesterone or placebo. Bone mineral was measured by dual-energy x-ray absorptiometry at baseline and at 6 and 12 months. RESULTS: In amenorrheic subjects spine and total body bone mineral measurements at 12 months were greater in the oral contraceptive group than in the medroxyprogesterone and placebo groups when baseline bone mineral measurements, body weight, and age were controlled for (p < or = 0.05). There were no differences in hip bone mineral calcium and bone mineral density measurements at 12 months among the three groups. In oligomenorrheic subjects there was no detectable improvement in bone mineral associated with medroxyprogesterone use. CONCLUSIONS: This study supports the hypothesis that oral contraceptive use in women with hypothalamic amenorrhea will improve lumbar spine and total body bone mineral.

PIP: The objectives of this study were to assess 1) whether treatment with oral contraceptives (OCs), in comparison with medroxyprogesterone and placebo, improved bone mineral content and density in women with hypothalamic amenorrhea and 2) whether treatment with medroxyprogesterone, in comparison with placebo, improved bone mineral content and density in women with hypothalamic oligomenorrhea. The study was a randomized, controlled clinical trial. 24 White women, aged 14-28 years, with hypothalamic amenorrhea or oligomenorrhea were prospectively enrolled for a 12-month intervention period. Amenorrheic subjects were randomized to receive OCs, medroxyprogesterone, or placebo. Oligomenorrheic subjects were randomized to receive medroxyprogesterone or placebo. Bone mineral content and density were measured by dual-energy x-ray absorptiometry at baseline and at 6 and 12 months. In amenorrheic subjects spine and total body bone mineral measurements at 12 months were greater in the OC group than in the medroxyprogesterone and placebo groups when baseline bone mineral measurements, body weight, and age were controlled for (p or= 0.05). There were no differences in hip bone mineral calcium and bone mineral density measurements at 12 months among the three groups. In oligomenorrheic subjects there was no detectable improvement in bone mineral content and density associated with medroxyprogesterone use. This study supports the hypothesis that OC use in women with hypothalamic amenorrhea will improve lumbar spine and total body bone mineral content and density.

Nutrition requirements in patients with toxic epidermal necrolysis.

Patients with toxic epidermal necrolysis, a severe, exfoliative skin disorder, have clinical features similar to those of partial-thickness burn patients. The literature suggests that they also have similar nutritional requirements. We report two patients diagnosed with toxic epidermal necrolysis on mechanical ventilation, in whom resting energy expenditure and respiratory quotient were measured by indirect calorimetry. The patients were treated using standard burn protocols. Nitrogen balance was calculated by measuring total urinary nitrogen in urine samples obtained over 24 hours. These measurements were done while the patients were on mechanical ventilation and receiving total parenteral nutrition. As in burn patients, early in their course the two patients had resting energy expenditure values twice that predicted. After 12 days of hospitalization, nitrogen balance was negative in patient 1 and positive in patient 2. Energy and protein requirements appear to have been related to the amount of body surface affected.

Survival after aberrant right subclavian artery-esophageal fistula: case report and literature review.

Development of a fistula between an aberrant right subclavian artery and the esophagus is a rare cause of heretofore fatal hematemesis. We report the first known survivor of this devastating complication of the most common aortic arch anomaly. Intraoperative esophagogastroduodenoscopy, intraesophageal balloon tamponade, and arteriography were the keys to successful management. This lesion should be suspected in the setting of bright red, "arterial" hematemesis. Prolonged nasogastric and/or endotracheal intubation should be avoided in patients with a known aberrant right subclavian artery or other aortic arch anomaly.

Dietary guidelines for children: U.S. recommendations.

The primary goal for pediatric dietary guidelines is to provide nutrients to support optimal growth and development at different ages from infancy through the end of adolescence. Over the past 15 years increasing attention has been directed toward developing nutrition recommendations that may lower the risk of chronic illness later in life. Recent evidence supports earlier studies that demonstrate that atherogenesis begins in childhood, is an evolving process and is influenced by environmental factors. As a result, in part, because of nutritional recommendations to lower the fat content of the diet, total fat and saturated fat as a percentage of total energy intake have declined in the diet of children and adolescents over the past 20 years. At the same time there has been no increase in the prevalence of growth failure; children, in fact, are heavier than their counterparts of 15 years ago. With a decrease in dietary fat, the mean serum cholesterol of the population as a whole has decreased steadily over the past 20 years. Children can safely eat a lower fat diet in which fat contributes 30% of total energy and saturated fat < 10% of total energy.

Childhood obesity: pathophysiology and treatment.

Childhood obesity is among the most difficult problems which pediatricians treat. It is frequently ignored by the pediatrician or viewed as a form of social deviancy, and blame for treatment failure placed on the patients or their families. The definition of obesity is difficult. Using total body electrical conductivity (TOBEC) technology, total body fat ranges between 12% and 30% of total body weight in normal children and adolescents. This is influenced not only by age, but also by physical fitness. Anthropometry is the easiest way to define obesity. Children whose weight exceeds 120% of that expected for their height are considered overweight. Skinfold thickness and body mass index are indices of obesity that are more difficult to apply to the child. Childhood obesity is associated with obese parents, a higher socioeconomic status, increased parental education, small family size and a sedentary lifestyle. Genetics also clearly plays a role. Studies have demonstrated that obese and non-obese individuals have similar energy intakes implying that obesity results from very small imbalances of energy intake and expenditure. An excess intake of only 418 kJ per day can result in about 4.5 kg of excess weight gain per year. Small differences in basal metabolic rate or the thermic effects of food may also account for the difference in energy balance between the obese and non-obese. In the Prader Willi Syndrome, there appears to be a link between appetite and body fatness. When placed on growth hormone, lean body mass increases, body fat decreases, sometimes to normal, and appetite becomes more normal.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of fat-free mass estimates in men infected with the human immunodeficiency virus.

BACKGROUND: Loss of lean-body mass has been found to be predictive of death from wasting in HIV-infected individuals. Several clinically applicable, noninvasive methods for estimating body wasting are available, but the comparability of these methods is not known. The objective of this study was to assess the agreement between estimates of lean-body mass in HIV-infected men. METHODS: Lean-body mass was measured by bioelectrical impedance assessment, by prediction equations that used anthropometric measurements, and by total body electrical conductivity as the comparison method in 27 outpatient HIV-infected men seen at the Houston Veterans Affairs Special Medicine Clinic. Agreement was assessed by comparing the difference between two methods (the bias) with the mean of those two methods. This statistical approach evaluates whether two methods are similar enough that measurements from one might accurately replace those of the other. RESULTS: The mean +/- SE for lean-body mass were 55.98 +/- 1.96 kg for total body electrical conductivity and 55.18 +/- 1.27 kg for bioelectrical impedance assessment; they ranged from 55.18 +/- 1.27 to 63.71 +/- 1.89 kg for the prediction equations. CONCLUSIONS: In individual subjects, no alternate method gave estimates of lean-body mass that were the same as estimates from total body electrical conductivity. One prediction equation (Brozek) gave estimates that might be useful for following changes in fat-free mass over time because the bias did not change substantially for increasing values of lean-body mass. On the other hand, because there were no statistically significant differences between the mean lean-body mass estimates by total body electrical conductivity and those measured by bioelectrical impedance assessment or a prediction equation on the basis of body mass index, the latter two methods might be useful in assessing lean-body mass in groups.

Body composition of sedentary and physically active spinal cord injured individuals estimated from total body electrical conductivity.

Reliability and evidence of construct validity of Total Body Electrical Conductivity (TOBEC) for estimating body composition in spinal cord injured subjects was evaluated using 17 males with C6-L2 spinal cord transections. Subjects reporting regular exercise were categorized as active (n = 12); nonexercisers were considered sedentary (n = 5). Measures included body weight, length, circumferences, skinfolds, and three TOBEC readings. Reliability for percent fat of both single and multiple TOBEC trials (t = 3) ranged from .994 to .999. Average percent fat values were significantly (p < .009) higher in sedentary subjects. Sum of seven skinfolds was significantly correlated (r[15] = 0.73, p < .01) with percent fat measured by TOBEC. Results suggest TOBEC is reliable (rtt > 0.99) in estimating body composition in spinal cord injured individuals. High reliability estimates for single and multiple trials indicate use of a single trial will provide reliable body fat estimates. Construct validity evidence infers that TOBEC measured body composition discriminates between active and sedentary paraplegics.

Anthropometric measurements and estimating body composition in ballet dancers.

The purpose of this study was to develop and cross-validate an equation for estimating fat-free mass (FFM) in female ballet dancers. One hundred twelve, 11- to 25-yr old, female dancers had FFM measured by total body electrical conductivity (TOBEC) and anthropometrics, including skinfold and circumference measurements. The regression equation that best estimated FFM in the dancers was FFM = 0.73 x body weight (kg) + 3.0, (R2 = 88%, SEE = 1.5 kg, P < 0.001). This equation was then cross-validated on a separate group of 23 female dancers who also had FFM measured by TOBEC. FFM estimated by this equation correlated with FFM measured by TOBEC (r = 0.94, SEE = 0.9 kg), and the difference in the FFM values using the two methods (the equation and TOBEC) did not change with the size of the FFM of the dancers. FFM in accomplished female ballet dancers can be best estimated from body weight alone. This is related to the homogeneity of body size and body composition in female ballet dancers at this level.