Browsing by Subject "Body Weight"
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Item Anorexia nervosa(1965-09-30) UnknownItem Control of appetite in mouse and man by the hormone ghrelin(2013-04-05) Zigman, Jeffrey M.Item Ghrelin: The Hunger Hormone that Isn't(2014-06-09) McFarlane, Matthew Ryan; Elmquist, Joel; Brown, Michael S.; Goldstein, Joseph L.; Olson, Eric N.; Horton, Jay D.Ghrelin is a 28-amino acid acylated peptide hormone secreted by endocrine cells in the stomach. It was first identified in 1999 and shortly thereafter shown to stimulate appetite when injected into rodents and humans. While ghrelin knockout mice have failed to show a decrease in appetite or bodyweight, the literature -- as well as the lay press -- continues to presume ghrelin levels are a mediator of appetite in vivo. For example, the suppression of ghrelin levels secondary to gastric bypass surgery is frequently invoked as a contributing factor in the resulting weight loss. In the literature, this incongruity has been rationalized as embryonic or neonatal compensation, a claim predicated on a study by Luquet et al. which showed that AgRP/NPY neurons (which express the ghrelin receptor and are thought to be the critical target for appetite stimulation) can be ablated without consequence in neonatal mice, while in adult mice ablation causes a rapid and profound loss of appetite. Widespread acceptance notwithstanding, the hypothesis that a reduction in ghrelin levels decreases appetite in adults has never been tested. We generated a mouse line expressing the simian diphtheria toxin receptor on ghrelin cells. With these mice we are able to rapidly ablate ghrelin cells in adulthood with the injection of diphtheria toxin. Despite an 80-95% loss of circulating ghrelin, our mice show no decrease in appetite or body weight in the short or long term and become obese and hyperinsulinemic in response to high fat feeding. To investigate why ghrelin seems to be sufficient but not necessary for hunger, we injected increasing doses of ghrelin and measured both food intake and the resulting plasma concentration. We found that the threshold dose for an appetite response raised blood concentrations more than 50-fold above physiologic levels -- well above the highest concentration we have observed even during extreme starvation. We show that at physiologic levels ghrelin is neither necessary nor sufficient for hunger and conclude that it is not a key regulator of appetite or weight gain in mice. Ghrelin's only essential role in mice appears to be the maintenance of plasma glucose during periods of starvation.Item Obstructive Sleep Apnea (OSA): Differences Between Normal-Weight, Overweight, Obese and Morbidly Obese Children(2015-01-26) Scott, Brian; Johnson, Romaine; Mitchell, RonThe severity of obstructive sleep apnea (OSA) in children determines perioperative management and is an indication for postoperative polysomnography (PSG). There is a paucity of data on differences and predictors of OSA severity in children in different weight categories. The primary objective was to compare demographic, clinical and polysomnography parameters in normal-weight, overweight, obese and morbidly obese children and to identify factors that are associated with OSA severity. Healthy children aged 2-18 who underwent polysomnography at an academic children's hospital were included in the study. Demographics, clinical findings, and polysomnogram parameters were recorded. Children were categorized as normal-weight, overweight, obese, or morbidly obese based on CDC criteria. Differences were assessed with linear and logistical regression models. Significance was set at p<0.05. 290 children were included. Morbidly obese were older than normal-weight children (mean 8.0±0.5 versus 5.8±0.3; p<0.001) but less likely to have a normal PSG (16% versus 48%; p=0.02). There were no differences in gender, ethnicity, birth status (term or pre-term), tonsil size or AHI between the different weight categories. Sleep efficiency and %REM were decreased in morbidly obese children (p<0.05). The AHI was positively correlated with increasing BMI z-score as a function of increasing age (p<0.001). There are important differences in children with OSA in different weight categories. OSA severity is correlated with a combination of increasing age and weight but not with either variable independently. This study suggests that obese and morbidly obese older children are most likely to have severe OSA and should undergo routine PSG.Item The role of ghrelin in body weight regulation, reward behavior and mood(2008-12-12) Zigman, Jeffrey M.Item The Wait for the Weight: Pediatricians' Communication about Weight to Overweight and Obese Latino Children and their Parents(2013-01-22) Montano, Sergio; Turer, Christy; Flores, Glenn; Hoang, KimBACKGROUND: Latinos are among the most overweight (OW) racial/ethnic groups of US children. It is unknown, however, whether language barriers impact the communication of childhood OW. Objective: To determine whether and how language incongruence is associated with communication about OW for Latino children. DESIGN/METHODS: Cross-sectional analysis of video- or audio-recorded primary-care visits with pediatricians and OW (body mass index ≥85th%) 6-12 year-old Latino children recruited from academic and community clinics. Language proficiency was assessed using US Census Bureau questions, with language incongruence (LI) defined as pediatrician limited Spanish proficiency combined with parent limited English proficiency (LEP). Recorded visits were analyzed and transcribed. Direct communication of OW, who broached the topic first, use of growth charts, and communication of a weight-management plan were determined by reviewing recordings and transcripts. RESULTS: The 26 visits (18 video and eight audio) included 26 participants and 15 pediatricians (including 10 resident/attending pairs). The mean child age was nine years old; 100% were OW and 84% were obese. 89% of parents were OW and 60% were LEP. 43% of pediatricians were Spanish-proficient. Pediatrician-parent language was incongruent in 24% of visits. Direct communication of OW occurred in 90% of language-congruent (LC) vs. 50% of LI visits (P=.03). Parents were the first to broach the topic of OW in 10% of LC vs. 50% of LI visits (P=.03). Pediatricians used growth charts in 80% of LC vs. 0% of LI visits (P<.001). Weight-management plans were conveyed in 55% of LC vs. 33% of LI visits (P=.4). One pediatrician stated, "You are not growing any taller, so you have to do the hard adult thing and [lose weight]." At least one culturally relevant dietary recommendation was made in 19% of visits. One pediatrician noted, "Less fat, less manteca, less avena, less sugar," and another, "No tacos. You need to buy fruit." CONCLUSIONS: Pediatrician-parent LI is associated with a lower likelihood of direct communication of child OW/obesity and use of growth charts, but a higher likelihood of parents, instead of doctors, being the first to broach the topic of OW. Regardless of LI, many OW Latino children do not receive weight-management plans or culturally relevant dietary recommendations.Item Weight Change in Underweight or Obese Patients Awaiting Lung Transplantation Does Not Impact Post-Trasplant Survival(2017-01-17) Li, Kevin; Huffman, Lynn; Pruszynski, Jessica E.; Wait, Michael; Bajona, PietroBACKGROUND: Lung transplantation remains the definitive treatment for end-stage COPD, respiratory complications of cystic fibrosis, and interstitial lung diseases. However, long-term survival after lung transplantation remains poor, with an overall 5-year survival rate of 54%. Initial selection of lung transplant candidates includes evaluation of body mass index (BMI), since obesity is a relative contraindication to lung transplantation. However, BMI changes occurring while waiting for transplantation may not reflect initial listing BMI and may be associated with poorer long-term survival. OBJECTIVE: To determine the effects of pre-transplant BMI change on long-term survival following lung transplantation. METHODS: A retrospective chart review of adult lung transplantations performed between January 2004 and May 2016 was conducted. Patient demographics, survival status, and date of death, hours on the mechanical ventilator (MV hours), and ICU length of stay (ICU LOS) were collected. Cases were categorized as underweight (BMI < 20 kg/m2) or obese (BMI > 30 kg/m2), with change in BMI from time of listing to time of transplantation as subsets. Kaplan-Meier plots were constructed to summarize differences in overall survival between BMI groups. The log rank test was used to assess differences between survival curves. A Z-test using Greenwood's formula was performed to compare post-transplant survival rates at 1, 3, and 5 years. P-values were adjusted using the false discovery rate (FDR). RESULTS: There were 460 cases included in this study. The group sizes were as follows: underweight and lost weight (BMI < 20 kg/m2 -), 35; underweight and gained weight (BMI < 20 kg/m2 +), 47; obese and lost weight (BMI > 30 kg/m2 -), 61; obese and gained weight (BMI > 30 kg/m2 +), 25. Patients with initial BMI between 20.1 kg/m2 - 29.9 kg/m2 were assigned to the control group (n = 292). There were no differences in 1-year, 3-year, or 5-year survival rates (1-year: control 87.6%; BMI < 20 kg/m2 -, 91.3%; BMI < 20 kg/m2 + 86.4%; BMI > 30 kg/m2 - 93.%; BMI > 30 kg/m2 + 71.2%; all comparisons non-significant [NS]) (3-year: 71.1%; 49.2%; 54.1%; 69.8%; 56.6%, NS) (5-year: 61.1%; 35.1%; 45.9%; 49.1%; 50.9%, NS). Kaplan-Meier plots similarly showed no differences in overall survival (p = 0.203). There were no significant differences among the groups in ICU LOS or MV hours. CONCLUSION: Weight change in obese or underweight patients prior to lung transplantation does not affect overall survival. Therefore, BMI > 30 kg/m2 at the time of listing may not be a relative contraindication to lung transplantation.