Identifying Opportunities for Advancing Weight Management in Primary Care.

Objective: Much has been written about the patients' perspective concerning weight management in health care. The purpose of this survey study was to assess perspectives of primary care providers (PCPs) and nurses toward patient weight management and identify possible areas of growth. Patients and Methods: We emailed a weight management-focused survey to 674 eligible participants (437 [64.8%] nurses and 237 [35.2%] PCPs) located in 5 outpatient primary care clinics. The survey focused on opportunities, practices, knowledge, confidence, attitudes, and beliefs. A total of 219 surveys were returned (137 [62.6%] from nurses and 82 [34.4%] from PCPs). Results: Among 219 responders, 85.8% were female and 93.6% were white non-Hispanic. In this study, PCPs and nurses believed obesity to be a major health problem. While PCPs felt more equipped than nurses to address weight management (P < .001) and reported receiving more training than nurses (50.0% vs 17.6%, respectively), both felt the need for more training on obesity (73.8% and 79.4%, respectively). Although, PCPs also spent more patient contact time providing weight management services versus nurses (P < .001), the opportunity/practices score was lower for PCPs than nurses (-0.35 ± 0.44 vs -0.17 ± 0.41, P < .001) with PCPs more likely to say they lacked the time to discuss weight and they worried it would cause a poor patient-PCP relationship. The knowledge/confidence score also differed significantly between the groups, with nurses feeling less equipped to deal with weight management issues than PCPs (-0.42 ± 0.43 vs -0.03 ± 0.55, P < .001). Neither group seemed very confident, with those in the PCP group only answering with an average score of neutral. Conclusion: By asking nurses and PCP general questions about experiences, attitudes, knowledge, and opinions concerning weight management in clinical care, this survey has identified areas for growth in obesity management. Both PCPs and nurses would benefit from additional educational training on weight management.

Is Exposure to Famine in Childhood and Economic Development in Adulthood Associated With Diabetes?

CONTEXT: The Chinese were afflicted by great famine between 1959 and 1962. These people then experienced rapid economic development during which the gross domestic product per capita increased from $28 in 1978 to $6807 in 2013. We hypothesize that these two events are associated with the booming rate of diabetes in China. OBJECTIVE: We aimed to explore whether exposure to famine in early life and high economic status in adulthood was associated with diabetes in later life. DESIGN AND SETTING: Our data of 6897 adults were from a cross-sectional Survey on Prevalence in East China for Metabolic Diseases and Risk Factors study in 2014. Among them, 3844 adults experienced famine during different life stages and then lived in areas with different economic statuses in adulthood. MAIN OUTCOME MEASURE: Diabetes was considered as fasting plasma glucose of 7.0 mmol/L or greater, hemoglobin A1c of 6.5% or greater, and/or a previous diagnosis by health care professionals. RESULTS: Compared with nonexposed subjects, famine exposure during the fetal period (odds ratio [OR]1.53, 95% confidence interval [CI]1.09-2.14) and childhood (OR 1.82, 95% CI 1.21-2.73) was associated with diabetes after adjusting for age and gender. Further adjustments for adiposity, height, the lipid profile, and blood pressure did not significantly attenuate this association. Subjects living in areas with high economic status had a greater diabetes risk in adulthood (OR 1.46, 95% CI 1.20-1.78). In gender-specific analyses, fetal-exposed men (OR 1.64, 95% CI, 1.04-2.59) and childhood-exposed women (OR 2.81, 95% CI, 1.59-4.97) had significantly greater risk of diabetes. CONCLUSIONS: The rapid increase in the prevalence of diabetes in middle-aged and elderly people in China is associated with the combination of exposure to famine during the fetal stage and childhood and high economic status in adulthood. Our findings may partly explain the booming diabetes phenomenon in China.

Implementation and commissioning of an integrated micro-CT∕RT system with computerized independent jaw collimation.

PURPOSE: To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT∕RT system to perform conformal image-guided small animal radiotherapy. METHODS: The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2×2 to 60×60 mm2 were measured using EBT2 film in the center of a 70×70×22 mm3 solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50×50×50 mm3. A calibrated Farmer ion chamber in a 70×70×20 mm3 solid water block was used to measure the output of three field sizes: 50×50, 40×40, and 30×30 mm2. Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated. RESULTS: The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%-20%) from 3.9 to 0.8 mm. CONCLUSIONS: A set of computer-controlled motorized jaws for a micro-CT∕RT system were constructed with position reliably better than a tenth of a millimeter. The hardware system is ready for image-guided conformal radiotherapy for small animals with capability of respiratory-gated delivery.

Study of the IMRT interplay effect using a 4DCT Monte Carlo dose calculation.

Respiratory motion may lead to dose errors when treating thoracic and abdominal tumours with radiotherapy. The interplay between complex multileaf collimator patterns and patient respiratory motion could result in unintuitive dose changes. We have developed a treatment reconstruction simulation computer code that accounts for interplay effects by combining multileaf collimator controller log files, respiratory trace log files, 4DCT images and a Monte Carlo dose calculator. Two three-dimensional (3D) IMRT step-and-shoot plans, a concave target and integrated boost were delivered to a 1D rigid motion phantom. Three sets of experiments were performed with 100%, 50% and 25% duty cycle gating. The log files were collected, and five simulation types were performed on each data set: continuous isocentre shift, discrete isocentre shift, 4DCT, 4DCT delivery average and 4DCT plan average. Analysis was performed using 3D gamma analysis with passing criteria of 2%, 2 mm. The simulation framework was able to demonstrate that a single fraction of the integrated boost plan was more sensitive to interplay effects than the concave target. Gating was shown to reduce the interplay effects. We have developed a 4DCT Monte Carlo simulation method that accounts for IMRT interplay effects with respiratory motion by utilizing delivery log files.

Comparisons of energy intake and energy expenditure in overweight and obese women with and without binge eating disorder.

The purpose of this study was to determine whether there are differences in energy intake or energy expenditure that distinguish overweight/obese women with and without binge eating disorder (BED). Seventeen overweight/obese women with BED and 17 overweight/obese controls completed random 24-h dietary recall interviews, and had total daily energy expenditure (TDEE) assessed by the doubly labeled water (DLW) technique with concurrent food log data collection. Participants received two baseline dual-energy X-ray absorptiometry (DXA) scans and had basal metabolic rate (BMR) and thermic effect of food (TEF) measured using indirect calorimetry. Results indicated no between group differences in TDEE, BMR, and TEF. As in our previous work, according to dietary recall data, the BED group had significantly higher caloric intake on days when they had binge eating episodes than on days when they did not (3,255 vs. 2,343 kcal). There was no difference between BED nonbinge day intake and control group intake (2,233 vs. 2,140 kcal). Similar results were found for food log data. Dietary recall data indicated a trend toward higher average daily intake in the BED group (2,587 vs. 2,140 kcal). Furthermore, when comparing TDEE to dietary recall and food log data, both groups displayed significant under-reporting of caloric intake of similar magnitudes ranging from 20 to 33%. Predicted energy requirements estimated via the Harris-Benedict equation (HBE) underestimated measured TDEE by 23-24%. Our data suggest that increased energy intake reported by BED individuals is due to increased food consumption and not metabolic or under-reporting differences.

Effects of estrogen and testosterone on resting energy expenditure in older men.

The mechanisms by which sex hormones cause changes in body composition are unclear. Sex steroid deficiency might directly reduce energy expenditure/fat oxidation and thereby predispose to increased body fat. Alternatively, sex steroid deficiency could result in lean tissue loss and thus reduced energy expenditure. Our objective was to examine the independent and combined effects of acute testosterone and estrogen withdrawal on respiratory exchange ratio (RER) and resting energy expenditure (REE) in men. The objective of the study was to examine the independent and combined effects of acute estrogen and testosterone withdrawal on RER and REE in men. A total of 54 men aged 50-80 years, BMI range of 17-35 kg/m(2) underwent a 3-week eugonadal run-in hormone-treatment period involving suppression of endogenous sex steroids using letrozole and leuprolide acetate (Lupron) while sex steroid concentrations were maintained with transdermal testosterone (T) and estradiol (E). A second Lupron injection was then given and participants were randomized to one of the following four 3-week treatment groups: group A (-T, -E), group B (-T, +E), group C (+T, -E), and group D (+T, +E). REE and RER were measured via indirect calorimetry before and after the 3-week treatment period. Three-week suppression and/or repletion of estrogen or testosterone did not produce changes in RER or REE within or between groups. We conclude that abrupt changes in sex steroids does not change resting substrate oxidation, indicating that changes that can be observed after more prolonged periods of deficiency are most likely due to direct effects of sex steroids on body composition.

Assessment and preparation of patients for bariatric surgery.

The number of bariatric surgical procedures performed in the United States has increased steadily during the past decade. Currently accepted criteria for consideration of bariatric surgery include a body mass index (calculated as weight in kilograms divided by the square of height in meters) of 40 kg/m2 or greater (or >35 kg/m2 with obesity-related comorbidities), documented or high probability of failure of nonsurgical weight loss treatments, and assurance that the patient is well informed, motivated, and compliant. Appropriate patient selection is important in achieving optimal outcomes after bariatric surgery. In this article, we review our approach to the medical and psychological assessment of patients who want to undergo bariatric surgery. The medical evaluation is designed to identify and optimally treat medical comorbidities that may affect perioperative risks and long-term outcomes. The psychiatric and psychological assessment identifies factors that may influence long-term success in maintaining weight loss and prepares the patient for the lifestyle changes needed both before and after surgery.

Energy expenditure, insulin, and VLDL-triglyceride production in humans.

Hypertriglyceridemia is considered a cardiovascular risk factor in diabetic and nondiabetic subjects. In this study, we aimed to determine potential regulators of very low density lipoprotein-triglyceride (TG) production. VLDL-TG kinetics were measured in 13 men and 12 women [body mass index [mean (range)]: 24.8 (20.2-35.6) kg/m(2)]. VLDL-TG production was assessed from the plasma decay of a bolus injection of ex vivo labeled VLDL particles ([1-(14)C]triolein-VLDL-TG). Similar VLDL-TG production (micromol/min) was found in men and women. VLDL-TG production was not significantly correlated with palmitate flux ([9,10-(3)H]palmitate) (r = 0.09, P = 0.67) or palmitate concentration (r = -0.29, P = 0.2) but was correlated significantly with fasting insulin concentration (r = 0.46, P < 0.05) and resting energy expenditure (REE) (r = 0.45, P < 0.05). The latter correlation improved when adjusted for sex. The best multivariate model with VLDL-TG production as the dependent variable and REE, body composition, hormones, and substrate levels as independent variables included fasting insulin (P = 0.02) and REE (P = 0.02) (r(2) = 0.32, P < 0.001). We conclude that VLDL kinetics are similar in men and women and that REE and plasma insulin are significant independent predictors of VLDL-TG production. FFA availability and body fat distribution are unrelated to VLDL production. We suggest that REE plays a greater role in VLDL-TG production than previously anticipated. REE and insulin should be taken into account when VLDL-TG production comparisons between groups are made.

Preventing overestimation of pixels in computed tomography assessment of visceral fat.

OBJECTIVE: Computed tomography (CT) is a common research procedure for measuring abdominal fat distribution, but little is written about the software used to analyze images. Our objective was to compare in-house and commercially available software for quantitative measurement of abdominal fat distribution. In the process, we encountered some unexpected problems. RESEARCH METHODS AND PROCEDURES: A total of 123 volunteers had single-slice abdominal CT images taken that were used to evaluate various aspects of the commercial image analysis program. RESULTS: The agreement between the commercial and in-house programs was excellent (r = 0.996, p < 0.00,001) for both total and intraabdominal fat, and we were able to reduce between-observer variability in measured fat areas through the use of statistical handling of region of interest information. We also noted that intracolonic contents sometimes had the same Hounsfield units as adipose tissue. We analyzed single-slice CT images from 50 volunteers to determine the potential impact of this effect on visceral fat area; the overestimate of visceral fat area was 19 +/- 22% (maximum, 112% overestimate). The commercial program could prevent this error, whereas our in-house program could not. DISCUSSION: We concluded that a readily available commercial image analysis program compares well with a previously validated in-house program and that it offers some advantages with respect to preventing overestimation of pixels as visceral fat.

Managing risk in normal volunteers participating in metabolic studies.

BACKGROUND: Much emphasis has been placed on the risks volunteers face when participating in research studies, but little has been said about how to mitigate against such risks. METHODS: We review our experiences in over 15 years of managing risk in metabolic studies and the results of an intervention study designed to reduce the risk of femoral artery and femoral vein catheterization. RESULTS: Assessing the causes of adverse events and the context of a research study allowed us to design educational processes that reduced the incidence of adverse events. CONCLUSIONS: Although risk is inherent in any research study, approaching the risk issues in a manner designed to minimize the risk is possible. Ongoing efforts to further reduce risk in the context of research studies can benefit both the volunteers and the scientific community.

Energy expenditure, sex, and endogenous fuel availability in humans.

Adipose tissue lipolysis supplies circulating FFAs, which largely meet lipid fuel needs; however, excess FFAs, can contribute to the adverse health consequences of obesity. Because "normal" FFA release has not been well defined, average (mean of 4 days) basal FFA release and its potential regulation factors were measured in 50 lean and obese adults (25 women). Resting energy expenditure (REE), but not body composition, predicted most of the interindividual variation in FFA release. There was a significant, positive linear relationship between palmitate release and REE; however, women released approximately 40% more FFA than men relative to REE. Neither plasma palmitate concentrations nor respiratory quotient by indirect calorimetry differed between men and women. Glucose release rates were not different in men and women whether related to REE or fat free mass. These findings indicate that nonoxidative FFA clearance is greater in women than in men. This could be an advantage at times of increased fuel needs. We conclude that "normal" adipose tissue lipolysis is different in men and women and that the fuel export role of adipose tissue in obesity will need to be reassessed.