Sleep duration, timing, variability and measures of adiposity among 8- to 12-year-old children with obesity.

OBJECTIVES: Sleep disruption in laboratory studies increases adiposity and decreases glucose tolerance. However, few epidemiological studies have used objective measures of sleep. This study aims to assess associations between sleep duration, timing and regularity with measures of adiposity. METHODS: This is a cross-sectional study of 188 children with obesity (age: 10.50 ± 1.39 years; body mass index: 29.24 ± 5.04 kg m-2). Nightly sleep duration, bedtime and wake time were measured by multiple-day actigraphy and parent reports. Per cent overweight (per cent over median body mass index for age and sex) was chosen as the primary measure of obesity status. Objective measures of height, weight, waist circumference, blood pressure, fasting blood lipids, glucose, insulin, glycated haemoglobin and C-reactive protein were obtained. Television screen time and total caloric intake were assessed via parent questionnaire. RESULTS: Each hour later in weekday bedtime was associated with an additional 6.17 per cent overweight (95% confidence interval [CI]: 1.42-10.92). Each hour greater in day-to-day variability in weekday bedtime and weekday wake time was associated with an additional 10.20 (95% CI: 0.50-19.91) and 10.02 (95% CI: 1.55-18.50) per cent overweight, respectively. Associations were similar after controlling for other obesity-related behaviours (television screen time, total caloric intake and physical activity.). CONCLUSIONS: Among children with obesity, later bedtime and greater variability in bedtime and wake time are associated with greater adiposity, independent of other obesity-related behaviours. Early bedtime and wake time and consistent day-to-day sleep timing may be strategies to reduce adiposity in high-risk children.

Design and implementation of a randomized controlled social and mobile weight loss trial for young adults (project SMART).

PURPOSE: To describe the theoretical rationale, intervention design, and clinical trial of a two-year weight control intervention for young adults deployed via social and mobile media. METHODS: A total of 404 overweight or obese college students from three Southern California universities (M(age) = 22( ± 4) years; M(BMI) = 29( ± 2.8); 70% female) were randomized to participate in the intervention or to receive an informational web-based weight loss program. The intervention is based on behavioral theory and integrates intervention elements across multiple touch points, including Facebook, text messaging, smartphone applications, blogs, and e-mail. Participants are encouraged to seek social support among their friends, self-monitor their weight weekly, post their health behaviors on Facebook, and e-mail their weight loss questions/concerns to a health coach. The intervention is adaptive because new theory-driven and iteratively tailored intervention elements are developed and released over the course of the two-year intervention in response to patterns of use and user feedback. Measures of body mass index, waist circumference, diet, physical activity, sedentary behavior, weight management practices, smoking, alcohol, sleep, body image, self-esteem, and depression occur at 6, 12, 18, and 24 months. Currently, all participants have been recruited, and all are in the final year of the trial. CONCLUSION: Theory-driven, evidence-based strategies for physical activity, sedentary behavior, and dietary intake can be embedded in an intervention using social and mobile technologies to promote healthy weight-related behaviors in young adults.

Visual illusions and plate design: the effects of plate rim widths and rim coloring on perceived food portion size.

OBJECTIVE: The Delboeuf Illusion affects perceptions of the relative sizes of concentric shapes. This study was designed to extend research on the application of the Delboeuf illusion to food on a plate by testing whether a plate's rim width and coloring influence perceptual bias to affect perceived food portion size. DESIGN AND METHODS: Within-subjects experimental design. Experiment 1 tested the effect of rim width on perceived food portion size. Experiment 2 tested the effect of rim coloring on perceived food portion size. In both experiments, participants observed a series of photographic images of paired, side-by-side plates varying in designs and amounts of food. From each pair, participants were asked to select the plate that contained more food. Multilevel logistic regression examined the effects of rim width and coloring on perceived food portion size. RESULTS: Experiment 1: participants overestimated the diameter of food portions by 5% and the visual area of food portions by 10% on plates with wider rims compared with plates with very thin rims (P<0.0001). The effect of rim width was greater with larger food portion sizes. Experiment 2: participants overestimated the diameter of food portions by 1.5% and the visual area of food portions by 3% on plates with rim coloring compared with plates with no coloring (P=0.01). The effect of rim coloring was greater with smaller food portion sizes. CONCLUSION: The Delboeuf illusion applies to food on a plate. Participants overestimated food portion size on plates with wider and colored rims. These findings may help design plates to influence perceptions of food portion sizes.

Percent body fat prediction equations for 8- to 17-year-old American children.

BACKGROUND: Percent body fat equations are usually developed in specific populations and have low generalizability. OBJECTIVES: To use a nationally representative sample of the American youth population (8-17 years old) from the 1999-2004 National Health and Nutrition Examination Survey data to develop gender-specific percent body fat equations. METHODS: Percent body fat equations were developed for girls and boys using information on weight, height, waist circumference, triceps skin-folds, age, race/ethnicity and menses status compared to dual-emission X-ray absorptiometry. Terms were selected using forward and backward selection in regression models in a 2/3 development sample and were cross-validated in the remaining sample. Final coefficients were estimated in the full sample. RESULTS: Final equations included ten terms in girls and eight terms in boys including interactions with age and race/ethnicity. In the cross-validation sample, the adjusted R2 was 0.818 and the root mean squared error was 2.758 in girls. Comparable estimates in boys were 0.893 and 2.525. Systematic bias was not detected in the estimates by race/ethnicity or by body mass index categories. CONCLUSION: Gender-specific percent body fat equations were developed in youth with a strong potential for generalizability and utilization by other investigators studying adiposity-related issues in youth.

The Center for Healthy Weight: an academic medical center response to childhood obesity.

Childhood obesity represents a worldwide medical and public health challenge. Academic medical centers cannot avoid the effects of the obesity epidemic, and must adopt strategies for their academic, clinical and public policy responses to childhood obesity. The Center for Healthy Weight at Stanford University and Lucile Packard Children's Hospital at Stanford provides an example and model of one such strategy. The design provides both breadth and depth through six cores: Research, Patient Care, Community Programs, Advocating for Public Policy Change, Training and Professional Education, and the Healthy Hospital Initiative. The Center and its cores are designed to facilitate interdisciplinary collaboration across the university, medical school, children's hospital and surrounding community. The foci of these cores are likely to be relevant to almost any academic medical center's mission and functions.

Major mesh-related complications following hernia repair: events reported to the Food and Drug Administration.

Mesh material affects complications following hernia repair. Medical device reports on the use of surgical mesh for hernia repair were reviewed from the Food and Drug Administration's (FDA) Manufacturer User Facility Device Experience Database from January 1996 to September 2004. We analyzed 252 adverse event reports related to the use of surgical mesh for hernia repair. Adverse events included infection (42%, 107 reports), mechanical failure (18%, 46), pain (9%, 23), reaction (8%, 20), intestinal complications (7%, 18), adhesions (6%, 14), seroma (4%, 9), erosion (2%, 6), and other (4%, 9). Compared to all other mesh types, Sepra/polypropylene mesh had more mechanical failures (80 vs 14%, p < 0.05), biomaterial mesh had more reactions (57 vs 7%, p < 0.05), polytetrafluoroethylene (PTFE)/polypropylene mesh had more intestinal complications (14 vs 7%, p < 0.05), and PTFE mesh tended to have more infections (75 vs 41% all other, p = 0.07). Death occurred in 2% (5). We conclude that specific mesh materials are related to specific complications.

Laparoscopic palliation of polycystic liver disease.

The role of laparoscopic surgery in the management of polycystic liver disease (PCLD) is not well defined. The authors hypothesized that laparoscopic fenestration for PCLD relieves symptoms caused by polycystic liver disease. In this study, 11 patients underwent 20 laparoscopic cyst fenestration operations as treatment for symptoms of their PCLD. Symptoms leading to surgery were pain and pressure in 15 (75%) and early satiety in 12 (60%) patients. The median hospital stay was 1 day. The symptoms resolved postoperatively in all the patients. An additional laparoscopic fenestration was required in six (55%) patients for recurrent symptoms. The average time to reoperation was 22 +/- 16 months. Two patients required hepatic transplantation. Initial symptom resolution occurred in all the patients undergoing redo fenestration. The authors conclude that laparoscopic fenestration for PCLD is safe, results in minimal "down" time and relieves the symptoms caused by PCLD. Symptomatic relief usually is temporary, and repeat surgery is required for recurring symptoms in half of the patients.

Minimally invasive surgery.

Minimally invasive surgery is replacing the traditional open surgical approach for many abdominal procedures. The benefits of reduced pain, quicker return of oral intake, shorter hospitalizations, and improved cosmetic results all support the increasing use of the laparoscopic approach. This review identifies important articles published in the literature on minimally invasive surgery from June 2002 to August 2003, with the objective of identifying future trends and directions in laparoscopic surgery. The topics of articles reviewed in detail include minimally invasive techniques applied to esophageal tumors, morbid obesity, malignant liver tumors, gallbladder disease, pancreatic pathology, colon cancer, and robotic prostatectomy.

Routine preoperative laboratory analyses are unnecessary before elective laparoscopic cholecystectomy.

BACKGROUND: We formulated a clinical pathway (CP) for elective laparoscopic cholecystectomy (LC), which included the following preoperative evaluation: history and physical (H&P), right upper quadrant ultrasound (US), and liver function tests (LFTs). We hypothesized that routine LFTs did not alter management beyond that dictated by H&P and US, and could be excluded from the CP. METHODS: The study involved 387 consecutive patients undergoing elective LC. Abnormalities in the preoperative evaluation were compared with the finding of choledocholithiasis or other unexpected outcomes. RESULTS: In 187 (48%) patients, abnormalities were found by H&P (n = 7), US (n = 13), and LFTs (n = 177). Seven patients (2%) had documented choledocholithiasis; two had abnormal H & P; three had abnormal US; and four had abnormal LFTs. No patient with choledocholithiasis had abnormal LFTs but normal H&P and US. CONCLUSIONS: Routine LFTs before elective LC are not cost effective. Before LC H&P and US are warranted, but LFTs do not add any useful information and should not be routinely measured.

Are perceived neighborhood hazards a barrier to physical activity in children?

BACKGROUND: We hypothesized that children's perceptions of more neighborhood hazards would be associated with less physical activity, less aerobic fitness, and a higher body mass index. OBJECTIVE: To examine the association between a hazardous neighborhood context and physical activity in children. METHODS: Fourth-grade students (n = 796) of diverse ethnic and economic backgrounds completed measures of neighborhood hazards, self-reported physical activity, physical fitness, height, and weight. Parents (n = 518) completed telephone interviews and provided data on their education level and occupation. RESULTS: As expected, children from families of lower socioeconomic status perceived significantly more neighborhood hazards. Contrary to our hypothesis, the perception of more hazards was significantly associated with more reported physical activity. This finding was not explained by school heterogeneity, alteration of the hazards measure, or differences in socioeconomic status. CONCLUSION: To further examine the relationship between neighborhood hazards and physical activity, we suggest that future studies include assessments of sedentary behavior, parental fear of violence, parental regulation of children's leisure activities, and cost and quality of available play areas and organized sports.

Television viewing and childhood obesity.

Children spend a substantial portion of their lives watching television. Investigators have hypothesized that television viewing causes obesity by one or more of three mechanisms: (1) displacement of physical activity, (2) increased calorie consumption while watching or caused by the effects of advertising, and (3) reduced resting metabolism. The relationship between television viewing and obesity has been examined in a relatively large number of cross-sectional epidemiologic studies but few longitudinal studies. Many of these studies have found relatively weak, positive associations, but others have found no associations or mixed results; however, the weak and variable associations found in these studies may be the result of limitations in measurement. Several experimental studies of reducing television viewing recently have been completed. Most of these studies have not tested directly the effects of reducing television viewing behaviors alone, but their results support the suggestion that reducing television viewing may help to reduce the risk for obesity or help promote weight loss in obese children. Finally, one school-based, experimental study was designed specifically to test directly the causal relationship between television viewing behaviors and body fatness. The results of this randomized, controlled trial provide evidence that television viewing is a cause of increased body fatness and that reducing television viewing is a promising strategy for preventing childhood obesity.

Do adolescent smokers experience withdrawal effects when deprived of nicotine?

This is the first controlled prospective study of the effects of nicotine deprivation in adolescent smokers. Heart rate and subjective withdrawal symptoms were measured over an 8-hr period while participants smoked normally. Seven days later, participants were randomized to wear a 15-mg (16-hr) nicotine patch or a placebo patch for 8 hr, and they refrained from smoking during the session. Those wearing the placebo experienced a decrease in heart rate across sessions and an increase in subjective measures of nicotine withdrawal. Those wearing the active patch also reported significant increases for some subjective symptoms. Expectancy effects were also observed. The findings indicate that adolescent smokers experience subjective and objective changes when deprived of nicotine. As in previous research with adults, expectancies concerning the effects of nicotine replacement also influenced perceptions of withdrawal.

Effects of reducing television viewing on children's requests for toys: a randomized controlled trial.

Previous attempts to reduce the effects of television advertising on children's purchase requests have had little success. Therefore, we tested the effects of a classroom intervention to reduce television, videotape, and video game use on children's toy purchase requests, in a school-based randomized controlled trial. Third- and fourth-grade children (mean age, 8.9 years) in two sociodemographically and scholastically matched public elementary schools were eligible to participate. Children in one randomly selected elementary school received an 18-lesson, 6-month classroom curriculum to reduce television, videotape, and video game use. In both schools, in September (before intervention) and April (after intervention) of a single school year, children and parents reported children's prior week's purchase requests for toys seen on television. After intervention, children in the intervention school were significantly less likely to report toy purchase requests than children in the control school, with adjusting for baseline purchase requests, gender, and age (odds ratio, 0.29; 95% confidence interval, 0.12-0.69). Among intervention school children, reductions in self-reported purchase requests were also associated with reductions in television viewing. There was no significant difference between schools in parent reports of children's requests for toy purchases. These findings suggest that reducing television viewing is a promising approach to reducing the influences of advertising on children's behavior.

TNF receptor I is required for induction of macrophage heat shock protein 70.

Expression of heat shock proteins (HSP) is an adaptive response to cellular stress. Stress induces tumor necrosis factor (TNF)-alpha production. In turn, TNF-alpha induces HSP70 expression. However, osmotic stress or ultraviolet radiation activates TNF-alpha receptor I (TNFR-I) in the absence of TNF-alpha. We postulated that TNF-alpha receptors are involved in the induction of HSP70 by cellular stress. Peritoneal Mphi were isolated from wild-type (WT), TNF-alpha knockout (KO), and TNFR (I or II) KO mice. Cells were cultured overnight and then heat stressed at 43 +/- 0.5 degrees C for 30 min followed by a 4-h recovery at 37 degrees C. Cellular HSP70 expression was induced by heat stress or exposure to endotoxin [lipopolysaccharide (LPS)] as determined by immunoblotting. HSP70 expression induced by either heat or LPS was markedly decreased in TNFR-I KO Mphi, whereas TNFR-II KO Mphi exhibited HSP70 expression comparable to that in WT mice. Expression of HSP70 after heat stress in TNF-alpha KO Mphi was also similar to that in WT mice, suggesting that induction of HSP70 by TNFR-I occurs independently of TNF-alpha. In addition, levels of steady-state HSP70 mRNA were similar by RT-PCR in WT and TNFR-I KO Mphi despite differences in protein expression. Furthermore, the effect of TNFR-I appears to be cell specific, since HSP70 expression in splenocytes isolated from TNFR-I KO was similar to that in WT splenocytes. These studies demonstrate that TNFR-I is required for the synthesis of HSP70 in stressed Mphi by a TNF-independent mechanism and support an intracellular role for TNFR-I.

Is parental control over children's eating associated with childhood obesity? Results from a population-based sample of third graders.

OBJECTIVE: Identifying parental behaviors that influence childhood obesity is critical for the development of effective prevention and treatment programs. Findings from a prior laboratory study suggest that parents who impose control over their children's eating may interfere with their children's ability to regulate intake, potentially resulting in overweight. These findings have been widely endorsed; however, the direct relationship between parental control of children's intake and their children's degree of overweight has not been shown in a generalized sample. RESEARCH METHODS AND PROCEDURES: This study surveyed 792 third-grade children with diverse ethnic and socioeconomic backgrounds from 13 public elementary schools. Parental control over children's intake was assessed through telephone interviews using a state-of-the-art instrument, and children were measured for height, weight, and triceps skinfold thickness. RESULTS: Counter to the hypothesis, parental control over children's intake was inversely associated with overweight in girls, as measured by body mass index, r = -0.12, p < 0.05, and triceps skinfolds, r = -0.11, p < 0.05. This weak relationship became only marginally significant when controlling for parents' perceptions of their own weight, level of household education, and children's age. No relationship between parental control of children's intake and their children's degree of overweight was found in boys. DISCUSSION: Previous observations of the influence of parental control over children's intake in middle-class white families did not generalize to 8- to 9-year-olds in families with diverse socioeconomic and ethnic backgrounds. The present findings reveal a more complex relationship between parental behaviors and children's weight status.

Overweight concerns and body dissatisfaction among third-grade children: the impacts of ethnicity and socioeconomic status.

OBJECTIVE: To examine the prevalence of overweight concerns and body dissatisfaction among third-grade girls and boys and the influences of ethnicity and socioeconomic status (SES). STUDY DESIGN: Nine hundred sixty-nine children (mean age, 8.5 years) attending 13 northern California public elementary schools completed assessments of overweight concerns, body dissatisfaction, and desired shape, height, and weight. RESULTS: The sample was 44% white, 21% Latino, 19% non-Filipino Asian American, 8% Filipino, and 5% African American. Twenty-six percent of boys and 35% of girls reported wanting to lose weight, and 17% of boys and 24% of girls reported dieting to lose weight. Among girls, Latinas and African Americans reported significantly more overweight concerns than Asian Americans and Filipinas, and Latinas reported significantly more overweight concerns than whites. White and Latina girls also reported greater body dissatisfaction than Asian American girls. Some differences persisted even after controlling for actual body fatness. Higher SES African American girls reported significantly more overweight concerns than lower SES African American girls, but higher SES white girls reported less overweight concerns than lower SES white girls. CONCLUSION: Overweight concerns and body dissatisfaction are highly prevalent among third-grade girls and boys, across ethnicity and SES. Young Latina and African American girls manifest equivalent or higher levels of disordered eating attitudes and behaviors as white and Asian American girls.

The 30-second effect: an experiment revealing the impact of television commercials on food preferences of preschoolers.

OBJECTIVE: To examine whether televised food commercials influence preschool children's food preferences. DESIGN: In this randomized, controlled trial, preschool children viewed a videotape of a popular children's cartoon either with or without embedded commercials. Children were then asked to identify their preferences from pairs of similar products, one of which was advertised in the videotape with embedded commercials. Preschoolers' parents were interviewed to determine children's demographic characteristics and media use patterns. SUBJECTS: Forty-six 2- to 6-year-olds from a Head Start program in northern California. STATISTICAL ANALYSES: For demographic and media use characteristics, univariate data were examined and Student t and chi 2 tests were used to test for differences between the control and treatment groups. We calculated the Cochran Q statistic to assess whether the proportion of those choosing advertised food items was significantly higher in the treatment group than in the control group. RESULTS: Children exposed to the videotape with embedded commercials were significantly more likely to choose the advertised items than children who saw the same videotape without commercials (Qdiff = 8.13, df = 1, P < .01). CONCLUSIONS/APPLICATIONS: Even brief exposures to televised food commercials can influence preschool children's food preferences. Nutritionists and health educators should advise parents to limit their preschooler's exposure to television advertisements. Furthermore, advocates should raise the public policy issue of advertising and young children, especially given the recent epidemic of childhood obesity and the ever-changing media environment.

Effects of reducing children's television and video game use on aggressive behavior: a randomized controlled trial.

CONTEXT: The relationship between exposure to aggression in the media and children's aggressive behavior is well documented. However, few potential solutions have been evaluated. OBJECTIVE: To assess the effects of reducing television, videotape, and video game use on aggressive behavior and perceptions of a mean and scary world. DESIGN: Randomized, controlled, school-based trial. SETTING: Two sociodemographically and scholastically matched public elementary schools in San Jose, Calif. PARTICIPANTS: Third- and fourth-grade students (mean age, 8.9 years) and their parents or guardians. INTERVENTION: Children in one elementary school received an 18-lesson, 6-month classroom curriculum to reduce television, videotape, and video game use. MAIN OUTCOME MEASURES: In September (preintervention) and April (postintervention) of a single school year, children rated their peers' aggressive behavior and reported their perceptions of the world as a mean and scary place. A 60% random sample of children were observed for physical and verbal aggression on the playground. Parents were interviewed by telephone and reported aggressive and delinquent behaviors on the child behavior checklist. The primary outcome measure was peer ratings of aggressive behavior. RESULTS: Compared with controls, children in the intervention group had statistically significant decreases in peer ratings of aggression (adjusted mean difference, -2.4%; 95% confidence interval [CI], -4.6 to -0.2; P =.03) and observed verbal aggression (adjusted mean difference, -0.10 act per minute per child; 95% CI, -0.18 to -0.03; P =.01). Differences in observed physical aggression, parent reports of aggressive behavior, and perceptions of a mean and scary world were not statistically significant but favored the intervention group. CONCLUSIONS: An intervention to reduce television, videotape, and video game use decreases aggressive behavior in elementary schoolchildren. These findings support the causal influences of these media on aggression and the potential benefits of reducing children's media use.

Management of major bile duct injury associated with laparoscopic cholecystectomy.

BACKGROUND: Bile duct injury is a major complication of laparoscopic cholecystectomy. The purpose of this study was to evaluate our management strategy and outcomes for the treatment of such injuries. METHODS: We studied 54 consecutive patients who had de novo bile duct injury (n = 20) or prior biliary injury repair (n = 34) associated with laparoscopic cholecystectomy. All patients were managed using a multidisciplinary approach. RESULTS: Definitive operation, almost always Roux-en-Y hepaticojejunostomy, was required in 85% of patients. We inserted external percutaneous biliary catheters in 98% of cases prior to surgery. There were no operative deaths, and the 30-day complication rate was 20%. Eight patients (15%) were managed nonoperatively. Overall, 96% of patients had no long-term, objectively definable biliary sequelae. CONCLUSIONS: Treatment of bile duct injury associated with laparoscopic cholecystectomy is optimally done using a multidisciplinary approach. Surgical reconstruction is required in most cases and can be safely accomplished with minimal morbidity and excellent long-term outcomes.