bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Activity in Confined Conditions as an Indicator of Free‐Living Physical Activity
Authors: Westerterp Klaas R. , Kester Arnold D.M.
Published: April 2008

Objective: The main determinants of daily energy expenditure are body size and physical activity. Activity energy expenditure is the most variable component of total energy expenditure. It was assessed whether the physical activity level in confined conditions is an indicator of free‐living physical activity.

Research Methods and Procedures: Activity energy expenditure was measured over 1 day in a confined environment of a respiration chamber (floor space, 7.0 m2), where activities were restricted to low‐intensity activities of daily living, and over 2 weeks in a free‐living environment using doubly labeled water. Subjects were 16 women and 29 men (age, 31 ± 10 years; BMI, 24.2 ± 2.7 kg/m2).

Results: The free‐living activity level of the subjects, as a multiple of resting energy expenditure, was 1.76 ± 0.13. Activity energy expenditure in the chamber was 47 ± 13% of the value in daily life, and the two values were correlated (r = 0.50, p < 0.001; partial correlation corrected for age, gender, and BMI: 0.40, p < 0.01). The chamber value explained 25% of the total variance in free‐living activity energy expenditure.

Discussion: The activity level of a subject under sedentary conditions is an indicator of activity energy expenditure in daily life, showing the importance of nonexercise activity for daily energy expenditure.
Waist Circumference, BMI, Smoking, and Mortality in Middle‐Aged Men and Women
Authors: Bigaard Janne , Tjønneland Anne , Thomsen Birthe Lykke , Overvad Kim , Heitmann Berit Lilienthal , Sørensen Thorkild I.A.
Published: April 2008

Objective: Measurement of waist circumference alone as a proxy of abdominal fat mass has been suggested as a simple clinical alternative to BMI for detecting adults with possible health risks due to obesity.

Research Methods and Procedures: From 1993 to 1997, 27, 178 men and 29, 875 women, born in Denmark, 50 to 64 years of age, were recruited in the Danish prospective study Diet, Cancer and Health. By the end of the year 2000, 1465 deaths had occurred. We evaluated the relationship between waist circumference and BMI (simultaneously included in the model) and all‐cause mortality. We used Cox regression models to estimate the mortality‐rate ratios and to consider possible confounding from smoking.

Results: Waist circumference among both men and women showed a strong dose‐response type of relationship with mortality when adjusted for BMI, whereas the low range of BMI was inversely associated with mortality when adjusted for waist circumference. A 10% larger waist circumference corresponded to a 1.48 (95% confidence interval: 1.36 to 1.61) times higher mortality over the whole range of waist circumference. The associations were independent of age and time since baseline examination. Restriction to never smokers showed a similar pattern, but a weakening of the associations.

Discussion: Despite the high correlation between waist circumference and BMI, the combination may be very relevant in clinical practice because waist circumference for given BMI was a strong predictor of all‐cause mortality. The inverse association between BMI and mortality for given waist circumference was diminished in never smokers, particularly for high values of BMI.
The Effect of the −308A Allele of the TNF‐α Gene on Insulin Action Is Dependent on Obesity
Authors: Pihlajamäki Jussi , Ylinen Mari , Karhapää Pauli , Vauhkonen Ilkka , Laakso Markku
Published: April 2008

Objective: Promoter polymorphisms of the tumor necrosis factor alpha (TNF‐α) gene are associated with insulin sensitivity and BMI. We investigated whether the effect of the G‐308A polymorphism of the TNF‐α gene on insulin action depends on BMI.

Research Methods and Procedures: The effects of the G‐308A polymorphism on the rates of glucose and lipid oxidation and free fatty acid (FFA) levels were studied using the hyperinsulinemic euglycemic clamp combined with indirect calorimetry in 129 healthy subjects.

Results: The −308A allele of the TNF‐α gene was associated with high rates of glucose oxidation (p = 0.008 adjusted for age, gender, and BMI) and lipid synthesis (p = 0.037) and suppression of FFA levels (p = 0.023) during hyperinsulinemia. In normal weight subjects (BMI < 26 kg/m2), the −308 allele was associated with high rates of glucose oxidation (p = 0.036) during the clamp but not with high rates of lipid synthesis (p = 0.896) or FFA suppression (p = 0.464). In overweight subjects (BMI ≥ 26 kg/m2), high rates of lipid synthesis and FFA suppression (p = 0.010 and p = 0.042, respectively) but not the rates of glucose oxidation during the clamp (p = 0.193) were associated with the −308A allele.

Discussion: The −308A allele of the promoter of the TNF‐α gene is associated with high rates of glucose oxidation in normal weight subjects and with effective lipid storage in overweight subjects. These findings suggest an interaction of the polymorphism with obesity.
Perilipin Expression in Human Adipose Tissues: Effects of Severe Obesity, Gender, and Depot
Authors: Wang Yanxin , Sullivan Sean , Trujillo Maria , Lee Mi‐Jeong , Schneider Stephen H. , Brolin Robert E. , Kang You Hou , Werber Yaron , Greenberg Andrew S. , Fried Susan K.
Published: April 2008

Objective: Perilipins are phosphoproteins that are localized to the surface of triacylglycerol droplets within adipocytes where they regulate the rate of lipolysis. We sought to determine the effects of severe obesity and depot [omental (Om) vs. subcutaneous (Sc)] on perilipin expression in the adipose tissue of individuals.

Research Methods and Procedures: Samples of Om and Sc adipose tissues obtained at surgery from severely obese subjects and fat aspirations from nonobese subjects were analyzed for perilipin protein and mRNA levels by Northern and Western analysis.

Results: Perilipin A (periA) was the major perilipin expressed in adipose tissues. periA mRNA relative abundance was significantly lower in Sc adipose tissue from severely obese compared to that from nonobese subjects. Western blotting of adipose tissue extracts showed that periA protein levels expressed relative to tissue protein or fat cell surface area were significantly lower (∼ −40%) in abdominal Sc adipose tissue from severely obese compared to that from nonobese subjects. However, the calculated mass of perilipin per fat cell did not differ between the two groups. Perilipin mRNA levels were higher in Sc compared to Om adipose tissue from obese individuals (p < 0.025; n = 26; 17 women, 9 men); however, periA protein levels did not differ. In addition, perilipin protein, but not mRNA, levels were higher in Sc adipose tissue from obese men than from women (p < 0.025).

Discussion: Variations in perilipin expression may contribute to the higher basal lipolytic rates observed in obese compared to nonobese individuals and in obese women compared to obese men.
Low Resting and Sleeping Energy Expenditure and Fat Use Do Not Contribute to Obesity in Women
Authors: Weinsier Roland L. , Hunter Gary R. , Zuckerman Paul A. , Darnell Betty E.
Published: April 2008

Objective: Determine whether sleeping and resting energy expenditure and sleeping, resting, and 24‐hour fuel use distinguish obesity‐prone from obesity‐resistant women and whether these metabolic factors explain long‐term weight gain.

Research Methods and Procedures: Forty‐nine previously overweight but currently normal‐weight women were compared with 49 never‐overweight controls. To date, 87% of the 98 women have been re‐evaluated after 1 year of follow‐up, without intervention, and 38% after 2 years. Subjects were studied at a General Clinical Research Center after 4 weeks of tightly controlled conditions of energy balance and macronutrient intake. Forty‐nine obesity‐prone weight‐reduced women were group‐matched with 49 never‐overweight obesity‐resistant controls. All were premenopausal, sedentary, and normoglycemic. Energy expenditure and fuel use were assessed using chamber calorimetry. Body composition was assessed using DXA.

Results: At baseline, percent body fat was not different between the obesity‐prone and control women (33 ± 4% vs. 32 ± 5%, respectively; p = 0.22). Analysis of covariance results show that after adjusting for lean and fat mass, sleeping and resting energy expenditure of obesity‐prone women was within 2% of controls. Neither sleeping nor resting energy expenditure nor sleeping, resting, or 24‐hour fuel use was significantly different between the groups (p > 0.25). None of the metabolic variables contributed significantly to patterns of weight gain at 1 or 2 years of follow‐up.

Discussion: The results suggest that when resting and sleeping energy expenditure and fuel use are assessed under tightly controlled conditions, these metabolic factors do not distinguish obesity‐prone from obesity‐resistant women or explain long‐term weight changes.
Maternal Obesity and Infant Heart Defects
Authors: Cedergren Marie I. , Källén Bengt A.J.
Published: April 2008

Objective: This study determined whether obese women have an increased risk of cardiovascular defects in their offspring compared with average weight women.

Research Methods and Procedures: In a case‐control study, prospectively collected information was obtained from Swedish medical health registers. The study included 6801 women who had infants with a cardiovascular defect and, as controls, all delivered women (N = 812, 457) during the study period (1992 to 2001). Infants with chromosomal anomalies or whose mothers had pre‐existing diabetes were excluded. Obesity was defined as BMI >29 kg/m2, and morbid obesity was defined as BMI >35 kg/m2. Comparisons were made with average weight women (BMI = 19.8 to 26 kg/m2).

Results: In the group of obese mothers, there was an increased risk for cardiovascular defects compared with the average weight mothers [adjusted odds ratio (OR) = 1.18; 95% CI, 1.09 to 1.27], which was slightly more pronounced for the severe types of cardiovascular defects (adjusted OR = 1.23; 95% CI, 1.05 to 1.44). With morbid obesity, the OR for cardiovascular defects was 1.40 (95% CI, 1.22 to 1.64), and for severe cardiovascular defects, the OR was 1.69 (95% CI, 1.27 to 2.26). There was an increased risk for all specific defects studied among the obese women, but only ventricular septal defects and atrial septal defects reached statistical significance.

Discussion: In this sample, a positive association was found between maternal obesity in early pregnancy and congenital heart defects in the offspring. A suggested explanation is undetected type 2 diabetes in early pregnancy, but other explanations may exist.
Relation of Leptin to Insulin Resistance Syndrome in Children
Authors: Steinberger Julia , Steffen Lyn , Jacobs David R. , Moran Antoinette , Hong Ching‐Ping , Sinaiko Alan R.
Published: April 2008

Objectives: To examine the relation of leptin to insulin resistance, as measured by euglycemic insulin clamp, and insulin resistance syndrome factors in thin and heavy children.

Research Methods and Procedures: Anthropometrics, insulin, blood pressure, and leptin were measured in 342 11‐ to 14‐year‐old children (189 boys, 153 girls, 272 white, 70 black). Insulin sensitivity (M) was determined by milligrams glucose uptake per kilogram per minute and expressed as M/lean body mass (Mlbm). Children were divided by median BMI (boys = 20.5 kg/m2; girls = 21.4 kg/m2) into below‐median (thin) and above‐median (heavy) groups. Correlation coefficients between log‐leptin and components of insulin resistance syndrome were adjusted for Tanner stage, gender, and race.

Results: BMI was related to leptin in boys (r = 0.70, p < 0.001) and girls (r = 0.75, p < 0.001). Leptin was higher in girls than boys (32.6 vs. 12.3 ng/mL, p = 0.0001). Leptin levels increased in girls and decreased in boys during puberty, paralleling the changes in body fat. Leptin was significantly correlated with insulin, Mlbm, triglycerides, and blood pressure in heavy children and only with insulin in thin children. After adjustment for body fat, the correlations remained significant for insulin and Mlbm in heavy children and with insulin in thin children.

Discussion: Significant associations were found between leptin and insulin resistance in children, and these associations were attenuated by adjustment for adiposity. These findings at age 13 likely have long‐term consequences in the development of the obesity‐insulin resistance‐related cardiovascular risk profile.
Predicting Total Body Fat from Anthropometry in Latino Children
Authors: Huang Terry T.‐K. , Watkins Michael P. , Goran Michael I.
Published: April 2008

Objective: To develop prediction equations for total body fat specific to Latino children, using demographic and anthropometric measures.

Research Methods and Procedures: Ninety‐six Latino children (7 to 13 years old) were studied. Two‐thirds of the sample was randomized into the equation development group; the remainder served as the cross‐validation group. Total body fat was measured by DXA. Measures included weight, height, waist and hip circumferences, and skinfolds (suprailiac, triceps, abdomen, subscapula, thigh, and calf).

Results: The previously published equation from Dezenberg et al. did not accurately predict total body fat in Latino children. However, newly developed equations with either body weight alone (intercept ± SE = 1.78 ± 1.53 kg, p > 0.05; slope ± SE = 0.90 ± 0.07, p > 0.05 against slope = 1.0; R2 = 0.86), weight plus age and gender (intercept ± SE = 2.28 ± 1.20 kg, p > 0.05; slope ± SE = 0.91 ± 0.05, p > 0.05; against slope = 1.0; R2 = 0.92), or weight plus height, gender, Tanner stage, and abdominal skinfold (intercept ± SE = 1.47 ± 1.01 kg, p > 0.05; slope ± SE = 0.93 ± 0.04, p > 0.05; against slope = 1.0, R2 = 0.97) predicted total body fat without bias.

Discussion: Unique prediction equations of total body fat may be needed for Latino children. Weight, as the single most significant predictor, can be used easily to estimate total body fat in the absence of any additional measures. Including age and gender with weight produces an equally stable prediction equation with increasing precision. Using a combination of demographic and anthropometric measures, we were able to capture 97% of the variance in measured total body fat.
Larger Thigh and Hip Circumferences Are Associated with Better Glucose Tolerance: The Hoorn Study
Authors: Snijder Marieke B. , Dekker Jacqueline M. , Visser Marjolein , Yudkin John S. , Stehouwer Coen D.A. , Bouter Lex M. , Heine Robert J. , Nijpels Giel , Seidell Jacob C.
Published: April 2008

Objective: A higher waist‐to‐hip ratio, which can be due to a higher waist circumference, a lower hip circumference, or both, is associated with higher glucose levels and incident diabetes. A lower hip circumference could reflect either lower fat mass or lower muscle mass. Muscle mass might be better reflected by thigh circumference. The aim of this study was to investigate the contributions of thigh and hip circumferences, independent of waist circumference, to measures of glucose metabolism.

Research Methods and Procedures: For this cross‐sectional study we used baseline data from the Hoorn Study, a population‐based cohort study of glucose tolerance among 2484 men and women aged 50 to 75. Glucose tolerance was assessed by a 75‐g oral glucose tolerance test; hemoglobin A1c and fasting insulin were also measured. Anthropometric measurements included body mass index (BMI) and waist, hip, and thigh circumferences.

Results: Stratified analyses and multiple linear regression showed that after adjustment for age, BMI, and waist circumference, thigh circumference was negatively associated with markers of glucose metabolism in women, but not in men. Standardized β values in women were −0.164 for fasting, −0.206 for post‐load glucose, −0.190 for hemoglobin A1c (all p < 0.001), and −0.065 for natural log insulin levels (p = 0.061). Hip circumference was negatively associated with markers of glucose metabolism in both sexes (standardized betas ranging from −0.093 to −0.296, p < 0.05) except for insulin in men. Waist circumference was positively associated with glucose metabolism.

Discussion: Thigh circumference in women and hip circumference in both sexes are negatively associated with markers of glucose metabolism independently of the waist circumference, BMI, and age. Both fat and muscle tissues may contribute to these associations.
Abnormal Neurovascular Control during Sympathoexcitation in Obesity
Authors: Kuniyoshi Fátima H.S. , Trombetta Ivani C. , Batalha Luciana T. , Rondon Maria U.P.B. , Laterza Mateus C. , Gowdak Márcia M.G. , Barretto Antonio C.P. , Halpern Alfredo , Villares Sandra M.F. , Lima Eliudem G. , Negrão Carlos E.
Published: April 2008

Objective: We tested the hypothesis that muscle sympathetic nerve activity (MSNA) and forearm vascular resistance (FVR) would be augmented during mental stress or cold pressor test in healthy obese individuals compared with healthy lean individuals.

Research Methods and Procedures: Twenty‐nine healthy obese women and 12 age‐matched healthy lean women were involved in the study. MSNA was directly measured from the peroneal nerve using microneurography. Forearm blood flow was measured by venous occlusion plethysmography. Blood pressure (BP) was monitored noninvasively by an automatic BP cuff, and heart rate (HR) was measured by electrocardiogram. Stroop color word test was performed for 4 minutes, and the cold pressor test was performed for 2 minutes.

Results: Baseline MSNA and FVR were greater in the obese group than in the lean group. BP and HR were similar between groups. During mental stress, MSNA and FVR were greater in obese individuals than in lean individuals, although the magnitude of response was similar between groups. BP and HR similarly increased in obese and lean individuals. During the cold pressor test, MSNA, FVR, and BP were greater in obese individuals, but the magnitude of response was similar between groups. HR increased similarly during the cold pressor test in both obese and lean individuals.

Discussion: Obesity increases MSNA and FVR during mental stress and the cold pressor test. This inappropriate neurovascular control can be expected to have an adverse effect on the risk factors for cardiovascular events and, hence, should be considered in the treatment of obese patients.
Dietary Regulation of Fat Oxidative Gene Expression in Different Skeletal Muscle Fiber Types
Authors: McAinch Andrew J. , Lee Jong‐Sam , Bruce Clinton R. , Tunstall Rebecca J. , Hawley John A. , Cameron‐Smith David
Published: April 2008

Objective: To determine the effect of a high‐fat diet on the expression of genes important for fat oxidation, the protein abundance of the transcription factors peroxisome proliferator‐activated receptor (PPAR) isoforms α and γ, and selected enzyme activities in type I and II skeletal muscle.

Research Methods and Procedures: Sprague‐Dawley rats consumed either a high‐fat (HF: 78% energy, n = 8) or high‐carbohydrate (64% energy, n = 8) diet for 8 weeks while remaining sedentary.

Results: The expression of genes important for fat oxidation tended to increase in both type I (soleus) and type II (extensor digitorum longus) fiber types after an HF dietary intervention. However, the expression of muscle type carnitine palmitoyltransferase I was not increased in extensor digitorum longus. Analysis of the gene expression of both peroxisome proliferator‐activated receptor‐γ coactivator and forkhead transcription factor O1 demonstrated no alteration in response to the HF diet. Similarly, PPARα and PPARγ protein levels were also not altered by the HF diet.

Discussion: An HF diet increased the expression of an array of genes involved in lipid metabolism, with only subtle differences evident in the response within differing skeletal muscle fiber types. Despite changes in gene expression, there were no effects of diet on peroxisome proliferator‐activated receptor‐γ coactivator and forkhead transcription factor O1 mRNA and the protein abundance of PPARα and PPARγ.
Central Adiposity Determines Prevalence Differences of the Metabolic Syndrome
Authors: Lorenzo Carlos , Serrano‐Ríos Manuel , Martínez‐Larrad María T. , Gabriel Rafael , Williams Ken , Gómez‐Gerique Juan A. , Stern Michael P. , Haffner Steven M.
Published: April 2008

Objective: To compare the expression of the metabolic syndrome in Spain and San Antonio, TX, two populations with major differences regarding their cardiovascular risk profile.

Research Methods and Procedures: Cross‐sectional analysis of population‐based, epidemiological surveys using the metabolic syndrome definition of the National Cholesterol Education Program. In San Antonio, we limited our analysis to non‐Hispanic whites because non‐Hispanic whites are largely of European ancestry (n = 1339 in San Antonio and 2947 in Spain)

Results: In men, increased central adiposity was more prevalent in San Antonio than in Spain (29.7 vs. 23.0%, p < 0.0001); in women, it was less prevalent in San Antonio than in Spain (40.2 vs. 66.4%, p < 0.0001). The metabolic syndrome followed that same pattern: more prevalent in men (28.9 vs. 20.8%, p = 0.019) and less in women from San Antonio (27.1 vs. 30.9%, p < 0.0001). In subjects with the metabolic syndrome, most women had increased central adiposity (92.6% in San Antonio and 97.5% in Spain), and most men had either increased central adiposity or blood pressure (99.2% in San Antonio and 95.0% in Spain).

Discussion: Contrary to men, the metabolic syndrome is more prevalent in Spanish women than in women from San Antonio with differences that mirror differences in central adiposity. Central adiposity and blood pressure may be used to exclude the metabolic syndrome. Considering recent secular trends in obesity, we predict there will be an increase in the prevalence of the metabolic syndrome in both populations in the coming years.
Bariatric Surgeries in North Carolina, 1990 to 2001: A Gender Comparison
Authors: Zizza Claire A. , Herring Amy H. , Stevens June , Carey Timothy S.
Published: April 2008

Objective: The purpose of this research was to determine the number of bariatric procedures in obese men and women in a well‐defined population and to examine gender differences among bariatric patients.

Research Methods and Procedures: Data on bariatric patients were taken from the North Carolina Hospital Discharge Database, which contains information on all nonfederal hospital discharges in North Carolina from 1990 to 2001. Using North Carolina Hospital Discharge Data, Census North Carolina resident estimates, and North Carolina obesity prevalence estimates, we constructed annual rates for bariatric procedures for the obese male and female population in North Carolina.

Results: Overall, 2197 bariatric procedures were performed between 1990 and 2001. The annual rate of bariatric procedures in obese women increased rapidly, particularly between 1998 and 2001, whereas the increase for men was considerably less than that for women. Controlling for age and year of procedure, the odds ratio for obese female North Carolina residents of having a bariatric procedure was 4.96 (95% confidence interval: 4.39, 5.59) and of having a Roux‐en‐Y procedure was 5.57 (95% confidence interval: 4.67, 6.64) compared with obese male North Carolina residents. Controlling for age, comorbidity burden, payment source, and year of procedure, obese male North Carolina residents had a significantly greater (22%) amount of inpatient days than obese female North Carolina residents.

Discussion: After controlling for population rates of obesity and year of procedure, women are more likely than men to undergo bariatric surgery, suggesting that gender‐related factors may influence use. More research is needed to determine the causes for this large gender disparity.
A Prospective Study of the Effect of Childbearing on Weight Gain in African‐American Women
Authors: Rosenberg Lynn , Palmer Julie R. , Wise Lauren A. , Horton Nicholas J. , Kumanyika Shiriki K. , Adams‐Campbell Lucile L.
Published: April 2008

Objective: To prospectively assess the influence of bearing a first, second, or later child on weight gain among African‐American women in the context of other risk factors.

Research Methods and Procedures: Data were obtained in a prospective follow‐up study of African‐American women from across the U.S. who are participants in the Black Women's Health Study. Postal questionnaires were used to collect baseline data in 1995 and follow‐up data in 1997 and 1999. Parous and nulliparous women (11, 196) (21 to 39 years old at baseline), of whom 1230 had a singleton birth during follow‐up, are the subjects of the present analyses. We assessed change in BMI (kilograms per meter squared) in relation to childbearing during 4 years of follow‐up, with use of multivariable linear regression to control for important risk factors.

Results: During 4 years of follow‐up, the BMI of participants increased by an average of 1.6 kg/m2, equivalent to a weight gain of ∼4.4 kg. Women who had a child during follow‐up gained more weight than women who remained nulliparous, and those who had a first child gained more than those who had a second or later child. The weight gain associated with childbearing increased with increasing baseline BMI and was appreciable among heavier women. For example, among women with a baseline index of 36, the increase in BMI for women who bore a first child was 1.1 kg/m2 more than that of nulliparous women, equivalent to a difference in weight gain of ∼3.0 kg.

Discussion: Childbearing is an important contributor to weight gain among African‐American women.
Estimating Body Fat from Anthropometry and Isotopic Dilution: A Four‐Country Comparison
Authors: Eckhardt Cara L. , Adair Linda S. , Caballero Benjamin , Avila Josephine , Kon Igor Y. , Wang Jinzhong , Popkin Barry M.
Published: April 2008

Objective: The goal was to assess the ability of BMI to predict body fat (BF) among youths in four countries and identify the degree to which additional anthropometric measures improve this prediction. BMI is widely recommended as an indicator of overweight. However, whether BMI adequately estimates BF and has the same meaning in different ethnic groups and youths has been questioned.

Research Methods and Procedures: Data come from 456 Filipino, Chinese, Russian, and black South African youths, 6 to 16 years old. Percentage BF and fat mass index (FMI) were estimated by the deuterium dilution method. Skinfold thicknesses (triceps, subscapular, and suprailiac) and weight and height measures were collected. Percentage BF was regressed first on BMI and age and then with the addition of the skinfold measures. Linear models were run separately by country and sex. The models were repeated with FMI as the outcome.

Results: The R2 values from the percentage BF models ranged from 0.13 to 0.69 in the first models to 0.38 to 0.81 in the full models. The values were lowest among Russian males ≥ 13 years and Russian females ≥ 13 years of age in the reduced and full models, respectively, and were highest among Chinese females. Using FMI as the outcome did not meaningfully change the results.

Discussion: The ability of BMI to adequately predict BF and the additional predictivity of anthropometric measures varied widely across the samples, making its uniform use as a proxy for BF in youths from different countries questionable.
Are Current Health Behavioral Change Models Helpful in Guiding Prevention of Weight Gain Efforts?
Authors: Baranowski Tom , Cullen Karen W. , Nicklas Theresa , Thompson Deborah , Baranowski Janice
Published: April 2008

Effective procedures are needed to prevent the substantial increases in adiposity that have been occurring among children and adults. Behavioral change may occur as a result of changes in variables that mediate interventions. These mediating variables have typically come from the theories or models used to understand behavior. Seven categories of theories and models are reviewed to define the concepts and to identify the motivational mechanism(s), the resources that a person needs for change, the processes by which behavioral change is likely to occur, and the procedures necessary to promote change. Although each model has something to offer obesity prevention, the early promise can be achieved only with substantial additional research in which these models are applied to diet and physical activity in regard to obesity. The most promising avenues for such research seem to be using the latest variants of the Theory of Planned Behavior and Social Ecology. Synergy may be achieved by taking the most promising concepts from each model and integrating them for use with specific populations. Biology‐based steps in an eating or physical activity event are identified, and research issues are suggested to integrate behavioral and biological approaches to understanding eating and physical activity behaviors. Social marketing procedures have much to offer in terms of organizing and strategizing behavioral change programs to incorporate these theoretical ideas. More research is needed to assess the true potential for these models to contribute to our understanding of obesity‐related diet and physical activity practices, and in turn, to obesity prevention.
Effect of Fat Sources on Satiety
Authors: Alfenas Rita C.G. , Mattes Richard D.
Published: April 2008

Objective: There are inconsistent reports on the satiety value of different fatty acids. This study compared the appetitive effects of two fat sources rich in monounsaturated fatty acids (peanut oil and canola oil) with a source rich in saturated fatty acids (butter).

Research Methods and Procedures: After an overnight fast, lean participants completed a questionnaire eliciting information about hunger, fullness, desire to eat, and prospective consumption. They then consumed one of the preloads (muffins containing 40 g of each fat source or no fat) and 150 mL of water within 15 minutes. Questionnaires were completed again 30, 60, and 120 minutes after preload ingestion. Participants kept dietary records during the subsequent 24 hours.

Results: Canola and peanut oil muffins resulted in higher fullness, and butter, canola, and peanut oil muffins resulted in lower hunger ratings 30, 60, and 120 minutes after preload ingestion compared with the fat‐free preload. No differences were observed among the fat‐containing loads. Although energy intake 24 hours after consumption of the preloads was also comparable on days the three fat‐containing loads were consumed, energy consumption after each study session was higher when the fat‐free muffins were provided. However, total energy intake, including the calories provided by the preloads, was similar across treatments.

Discussion: These data do not support a differential satiety effect of fat sources rich in monounsaturated fatty acids relative to one rich in saturated fatty acids.
Effects of a Longitudinal Training Program on Responses to Exercise in Overweight Men
Authors: Crampes Francois , Marion‐Latard Fabrice , Zakaroff‐Girard Alexia , de Glisezinski Isabelle , Harant Isabelle , Thalamas Claire , Stich Vladimir , Rivière Daniel , Lafontan Max , Berlan Michel
Published: April 2008

Objective: The aim of this study was to determine how training modifies metabolic responses and lipid oxidation in overweight young male subjects.

Research Methods and Procedures: Eleven overweight subjects were selected for a 4‐month endurance training program. Before and after the training period, they cycled for 60 minutes at 50% of their Vo2max after an overnight fast or 3 hours after eating a standardized meal. Various metabolic and endocrine parameters, and respiratory exchange ratio values were evaluated.

Results: Exercise‐induced plasma norepinephrine concentration increases were similar before and after training in fasted or fed conditions. After food intake, exercise promoted a decrease in plasma glucose and a higher increase in epinephrine than in fasting conditions. The increase in epinephrine after the meal was more marked after training (264 ± 32 vs. 195 ± 35 pg/mL). Training lowered the resting plasma nonesterified fatty acids. During exercise, changes in glycerol were similar to those found before training. Lipid oxidation during exercise was higher in fasting than in fed conditions (15.5 ± 1.4 vs. 22.3 ± 1.7 g/h). Training did not significantly increase fat oxidation when exercise was performed in fed conditions, but it did in fasting conditions (18.6 ± 1.4 vs. 27.2 ± 1.8 g/h).

Discussion: Endurance training decreased plasma nonesterified fatty acids, cholesterol, and insulin concentrations. Training increased lipid oxidation during exercise, in fasting conditions, and not when exercise was performed after the meal. During exercise in overweight subjects, the fasting condition seems more suited to oxidizing fat and maintaining glucose homeostasis than a 3‐hour wait after a standard meal.
Measurement of Human Daily Physical Activity
Authors: Zhang Kuan , Werner Patricia , Sun Ming , Pi‐Sunyer F. Xavier , Boozer Carol N.
Published: April 2008

Objectives: To validate a new device, Intelligent Device for Energy Expenditure and Activity (IDEEA), for the measurement of duration, frequency, and intensity of various types of human physical activity (PA).

Research Methods and Procedures: The ability of IDEEA to identify and quantify 32 types of PA, including the most common daily exercise and nonexercise PA, was tested in 76 subjects: Subjects included males (N = 33) and females (N = 43) ranging in age from 13 to 72 years with a mean body mass index (BMI) of 24.7 kg/m2 (range: 18.4 to 41.0) [43 females: 13 to 72 years old and BMI 18.4 to ∼41.0 kg/m2 (mean = 24.7 kg/m2); 33 males: 15 to ∼72 years old and BMI 21.0 to ∼38.4 kg/m2 (mean = 25.9 kg/m2)]. Postures, limb movements, and jumping were tested using a timed protocol of specific activities. Walking and running were tested using a 60‐meter track, on which subjects walked and ran at 6 self‐selected speeds. Stair climbing and descending were tested by timing subjects who climbed and descended a flight of stairs at two different speeds.

Results: Correct identification rates averaged 98.9% for posture and limb movement type and 98.5% for gait type. Pooled correlation between predicted and actual speeds of walking and running was high (r = 0.986, p ≤ 0.0001).

Discussion: IDEEA accurately measured duration, frequency, type, and intensity of a variety of daily PAs.
Assessment of Cardiac Autonomic Modulation during Adolescent Obesity
Authors: Rabbia Franco , Silke Bernard , Conterno Andrea , Grosso Tiziana , De Vito Barbara , Rabbone Ivana , Chiandussi Livio , Veglio Franco
Published: April 2008

Objective: To investigate the cardiovascular autonomic function in pediatric obesity of different duration by using standard time domain, spectral heart rate variability (HRV), and nonlinear methods.

Research Methods and Procedures: Fifty obese children (13.9 ± 1.7 years) were compared with 12 lean subjects (12.9 ± 1.6 years). Obese children were classified as recent obese (ROB) (<4 years), intermediate obese (IOB) (4 to 7 years), and long‐term obese (OB) (>7 years). In all participants, we performed blood pressure (BP) measurements, laboratory tests, and 24‐hour electrocardiogram/ambulatory BP monitoring. The spectral power was quantified in total power, very low‐frequency (LF) power, high‐frequency (HF) power, and LF to HF ratio. Total, long‐term, and short‐term time domain HRV were calculated. Poincaré plot and quadrant methods were used as nonlinear techniques.

Results: All obese groups had higher casual and ambulatory BP and higher glucose, homeostasis model assessment, and triglyceride levels. All parameters reflecting parasympathetic tone (HF band, root mean square successive difference, proportion of successive normal‐to‐normal intervals, and scatterplot width) were significantly and persistently reduced in all obese groups in comparison with lean controls. LF normalized units, LF/HF, and cardiac acceleration (reflecting sympathetic activation) were significantly increased in the ROB group. In IOB and OB groups, LF, but not nonlinear, measures were similar to lean controls, suggesting biphasic behavior of sympathetic tone, whereas nonlinear analysis showed a decreasing trend with the duration of obesity. Long‐term HRV measures were significantly reduced in ROB and IOB.

Discussion: Autonomic nervous system changes in adolescent obesity seem to be related to its duration. Nonlinear methods of scatterplot and quadrant analysis permit assessment of autonomic balance, despite measuring different aspects of HRV.
Physical Activity Levels Are Low in Free‐Living Adults with Chronic Paraplegia
Authors: Buchholz Andrea C. , McGillivray Colleen F. , Pencharz Paul B.
Published: April 2008

Objectives: To compare physical activity levels (PALs) of free‐living adults with chronic paraplegia with World Health Organization recommendations and to compare energy expenditure between persons with complete vs. incomplete paraplegia.

Research Methods and Procedures: Twenty‐seven euthyroid adults (17 men and 10 women) with paraplegia (12.5 ± 9.5 years since onset; 17 with complete lesions and 10 with incomplete lesions) participated in this cross‐sectional study. Resting metabolic rate was measured by indirect calorimetry and total daily energy expenditure (TDEE) by heart rate monitoring. PAL was calculated as TDEE/resting metabolic rate. Total body water was measured by deuterium dilution and fat‐free mass (FFM) and fat mass (FM) by calculation (FFM = total body water/0.732; FM = weight − FFM). Obesity was defined using the following percentage FM cutoffs: men 18 to 40 years >22% and 41 to 60 years >25%; and women 18 to 40 years >35% and 41 to 60 years >38%.

Results: Nineteen subjects (70.4%; 13 men and six women) were obese. Fifteen subjects (56%) engaged in structured physical activity 1.46 ± 0.85 times during the observation period for a mean of 49.4 ± 31.0 minutes per session. Despite this, mean PAL of the group was 1.56 ± 0.34, indicative of limited physical activity. TDEE was 24.6% lower in subjects with complete paraplegia (2072 ± 505 vs. 2582 ± 852 kcal/d, p = 0.0372).

Discussion: PAL of the group was low, indicating that persons with paraplegia need to engage in increased frequency, intensity, and/or duration of structured physical activity to achieve a PAL ≥1.75 and, thereby, to offset sedentary activities of daily living.
What Consumers Want to Know about Commercial Weight‐Loss Programs: A Pilot Investigation**
Authors: Wang Shirley S. , Wadden Thomas A. , Womble Leslie G. , Nonas Cathy A.
Published: April 2008

Objective: In 1999, the Partnership for Healthy Weight Management recommended that providers of commercial weight‐loss programs (and products) voluntarily disclose information concerning the safety, costs, and central components of their programs, as well as the credentials of program staff. These guidelines were drafted without the benefit of data from consumers concerning the specific information they desired. The present study provides such data.

Research Methods and Procedures: Participants were 90 women with a mean age of 44.02 ± 9.17 years and body mass index of 36.11 ± 4.82 kg/m2 who were participants in one of two randomized weight‐control trials. Before treatment, respondents were asked to imagine that they were “looking for a weight‐loss plan” and to rate how important each of 16 factors would be in helping them select a plan. Ratings were made using 5‐point scales, anchored by “not at all important” and “extremely important,” (scored 1 and 5, respectively). Participants also identified the five factors that they thought were the most important, as well as the single most important.

Results: The mean rating for the importance of safety (4.57 ± 0.60) was significantly greater than that for each of the 15 other variables (all p values < 0.05). In addition, significantly more respondents (27.8%) selected safety as the single most important factor than any other variable (all p values < 0.05). Other factors that were consistently judged as very important included information about diet (4.38 ± 0.68), behavior modification (4.32 ± 0.76), cost (4.19 ± 0.92), and maintenance of weight loss (4.15 ± 0.91). Staff credentials (3.88 ± 0.83) were among the lowest rated items.

Discussion: The results generally support the disclosure guidelines proposed by the Partnership for Health Weight Management. Consumers, however, seem to desire information about weight loss, in addition to that concerning safety, cost, and central program components.
Assessing Dietary and Exercise Stage of Change to Optimize Weight Loss Interventions
Authors: Sutton Karen , Logue Everett , Jarjoura David , Baughman Kristin , Smucker William , Capers Cynthia
Published: April 2008

Objective: According to the Transtheoretical Model (TM), tailoring interventions to patients’ readiness to change can enhance patient progress and help patients use therapeutic resources more effectively. However, tailoring an intervention depends on accurate assessment of patients’ stage of change (SOC). This study describes a multi‐item algorithm of SOC (M‐SOC) for weight loss‐related behaviors that attempts to overcome some of the conceptual and methodological difficulties encountered in previously SOC assessments.

Research Methods: Data were collected from participants randomly assigned to the treatment arm of a clinical trial comparing a TM‐based, cognitive‐behavioral intervention with enhanced usual care for weight loss.

Results: The stair‐step relationships hypothesized by the TM between assessed SOC and key behavioral measures were found for all algorithms (p < 0.05), indicating that the M‐SOC algorithm performs as well as single item algorithms. However, 50% fewer patients were classified in action or maintenance for dietary fat intake and portion control (p < 0.05) by the multiple‐item algorithms, providing staging more consistent with the clinical presentation of obese individuals. In addition, logistic regression analyses indicated that the single‐item algorithms were not sufficient predictors of these behavioral domains.

Discussion: To the extent that treatment is guided by assessed SOC, there is potential for a considerable variability in interventions with different approaches to staging. For weight‐loss interventions that target portion control and decreased fat intake, the multi‐item SOC algorithms seem to be better guides for matching treatments to SOC.
Dentin non‐collagenous proteins (dNCPs) can stimulate dental follicle cells to differentiate into cementoblast lineages
Authors: Wu Junjie , Jin Fang , Tang Liang , Yu Jinhua , Xu Lin , Yang Zhenhua , Wu Gang , Duan Yinzhong , Jin Yan
Published: April 2008

Background information. Although the mechanism of cementogenesis is an area full of debate, the DFCs (dental follicle cells) are thought to be the precursors of cementoblasts. At the onset of cementogenesis, DFCs come into contact with the root dentin surface and undergo subsequent differentiation. But the exact effects of dentin or dentin matrix on DFCs remain an open question. In the present study, we hypothesized that dNCPs (dentin non‐collagenous proteins) extracted from dentin could stimulate DFCs to differentiate into cementoblast lineages.

Results. DFCs were isolated from tooth germs of SD (Sprague—Dawley) rats and then co‐cultured with dNCPs. Treated DFCs presented several features of cementoblast lineages in vitro, as indicated by morphological changes, decreased proliferation, enhanced ALP (alkaline phosphatase) activity and increased matrix mineralization. The expression of mineralization‐associated proteins and genes were up‐regulated after induction, whereas the expression of specific markers of odontoblast were not detected. Incubation of treated DFC pellets in vivo revealed that a large amount of cementum‐like tissues was formed within the novel dentin carriers, which were quite distinct from the newly formed osteodentin secreted by DPSCs (dental pulp stem cells). The negative expression of DSP (dentin sialoprotein) also excluded the possibility of producing dentin matrix by treated DFCs.

Conclusions. dNCPs can stimulate DFCs to differentiate into cementoblast lineages. The present study provides new insights into the mechanism of cementogenesis.
The role of exchange-correlation functionals in the potential energy surface and dynamics of N2 dissociation on W surfaces
Authors: Bocan G. A. , Díez Muiño R. , Alducin M. , Busnengo H. F. , Salin A.
Published: April 2008

We study the dissociative adsorption of N2 on W(100) and W(110) by means of density functional theory and classical dynamics. Working with a full six-dimensional adiabatic potential energy surface (PES), we find that the theoretical results of the dynamical problem strongly depend on the choice of approximate exchange-correlation functional for the determination of the PES. We consider the Perdew-Wang-91 [Perdew et al., Phys. Rev. B 46, 6671 (1992)] and Perdew-Burke-Ernzerhof (RPBE) [Hammer et al., Phys. Rev. B 59, 7413 (1999)] functionals and carry out a systematic comparison between the dynamics determined by the respective PESs. Even though it has been shown in earlier works that the RPBE may provide better values for the chemisorption energies, our study brings evidence that it gives rise to a PES with excessive repulsion far from the surface.
Adsorption mechanism of water molecules surrounding Au nanoparticles of different sizes
Authors: Chang Chun-I , Lee Wen-Jay , Young Tai-Fa , Ju Shin-Pon , Chang Chia-Wei , Chen Hui-Lung , Chang Jee-Gong
Published: April 2008

Molecular dynamic simulation is used to investigate the adsorption mechanism of water molecules surrounding Au nanoparticles with different sizes. Our results show that the adsorption mechanism of the water molecules in the first water shell will be influenced by the size of the Au nanoparticle. For the larger Au nanoparticles, the hydrogen bonding of water molecules adsorbed on the surface of the Au nanoparticles are arranged in a two-dimensional structure, while those adsorbed on the edge of the surface of the Au nanoparticles are arranged in a three-dimensional structure. However, in the case of the smallest Au nanoparticle, the hydrogen bonding of the water molecules on the first adsorbed layer are arranged only in a three-dimensional structure. The arrangement of the water molecules in the first water shell can be determined by orientation order parameter. The water molecules that adsorb on the larger Au nanoparticles tend to arrange in an irregular arrangement, while those adsorbed on the smallest Au nanoparticle tend to arrange a regular arrangement. Interestingly, the water molecules adsorbed on the smallest nanoparticle are arranged in a bulklike structure in the first shell.