Obesity and physical inactivity: the relevance of reconsidering the notion of sedentariness

The population statistics of most countries of the world are indicating that industrialization and computerization have been associated with an increase in sedentariness and more recently with a significant shift from healthy weight to overweight. In general, this change in the overweight/obesity prevalence is attributed by health professionals to suboptimal diet and physical activity practices. However, recent data raised the possibility that excess weight gain might also be the outcome of changes imposed by our '24-hour', hectic lifestyle. Parallel to an increase in body weight, one has observed a reduction in sleep time and an increase in knowledge-based work (KBW) that appear as a growing necessity in a context of economic competitiveness and globalization. Sleep and cognitive work both exert a trivial effect on energy expenditure and may thus be considered as sedentary activities. However, their respective effect on energy intake is opposite. Indeed, an increase in the practice of the most sedentary activity, i.e. sleep, is associated with a hormonal profile facilitating appetite control whereas KBW appears as a stimulus favoring a significant enhancing effect on food intake. Television viewing is another example of sedentary activity that has been shown to increase the intake of high-density foods. These observations demonstrate that the modern way of living has favored a change in human activities whose impact goes well beyond what has traditionally been attributed to a lack of physical exercise. Therefore, we will need to reconsider the notion of 'sedentariness' which includes several activities having opposing effects on energy balance.

Grape seed extract (Vitis vinifera) partially reverses high fat diet-induced obesity in C57BL/6J mice

The aim of the present study was to assess the anti-obesity effects of grape seed extract (GSE) supplement in C57BL/6J mice. Thirty mice were divided into three groups; normal diet control group (ND), high fat diet control group (HD) and high fat diet plus grape seed extract supplemented group (HD+GSE). Results were as follows: 1. GSE supplement reduced the weight gain in mice fed high fat diets; epididymal and back fat weights were lower compared to non-supplemented HD group. 2. Blood lipid concentrations were lower in the HD+GSE group than in the HD group. Serum HDL-C concentrations were higher in the HD+GSE group compared with the other groups. 3. The concentrations of acid-insoluble acylcarnitines (AIAC) in serum and liver were higher in the HD+GSE group than in the HD group. 4. GSE supplementation increased mRNA levels of lipolytic genes such as carnitine palmitoyltransferase-1 (CPT-1) and decreased mRNA levels of lipogenic genes such as acetyl CoA carboxylase (ACC). These findings suggest that grape seed extract supplements in high fat diet might normalize body weight, epididymal and back fat weights, lipid concentrations, and carnitine levels through controlling lipid metabolism.

Modest effects of repeated fluoxetine on estrous cyclicity and sexual behavior in Sprague Dawley female rats

In an earlier study, we reported that daily fluoxetine treatment (10 mg/kg/day) rapidly disrupted estrous cyclicity and sexual receptivity in adult, regularly cycling Fischer rats. The current study was designed to investigate if comparable fluoxetine treatment would similarly affect intact, regularly cycling Sprague Dawley rats. In the first experiment, fluoxetine was injected for 24 days. After 11-14 days of daily fluoxetine treatment, 40% of the rats showed a transient disturbance of the estrous cycle with elimination of sexual receptivity. In these affected rats, reduced sexual receptivity generally preceded disruption of vaginal cyclicity. In a second experiment, a shorter exposure was used to attempt to dissociate effects of fluoxetine on behavior and estrous cyclicity. Nine days of fluoxetine treatment eliminated sexual receptivity and proceptivity (hops/darts) in 40% and 46%, respectively, of rats without altering the estrous cycle. Female rats then received a 10th fluoxetine injection 30 min prior to assessment of sexual motivation (measured with the male preference paradigm). There was no effect of fluoxetine on male preference, but fluoxetine significantly reduced the number of crossings and seconds of grooming during preference testing. Therefore, effects of fluoxetine on estrous cyclicity and behavior of Sprague Dawley female rats were smaller and required longer to develop than previously reported in Fischer female rats. These findings reinforce a probable relationship between fluoxetine's effect on sexual activity and neuroendocrine disturbances and illustrate the importance of strain selection in attempting to model human disease.

Effect of laser acupoint treatment on blood pressure and body weight-a pilot study

OBJECTIVE

This study reports on the effects of laser acupuncture on blood pressure, body weight, and heart rate variability by stimulating acupuncture points and meridians on college students and faculty members.

METHODS

Forty-five students and faculty members from a chiropractic college were recruited in the study. All subjects signed a written informed consent before their participation in the study. This study was a randomized controlled pilot study with subjects divided into control and experimental groups. The control group received a sham low-level laser therapy treatment with no power output to the laser during their "treatment." The experimental group was treated with an activated laser. The acupuncture points used in this study were LI 4 and LI 11 for body weight and blood pressure. The treatment groups received 16 J of laser energy output for a total treatment time of 8 minutes (4 minutes for each of the 2 points).

RESULTS

After using the laser treatment for 90 days (at least 12 treatments per subject), both the systolic and diastolic blood pressures decreased significantly (P < .01). The mean systolic blood pressure was 129.6 +/- 14.7 mm Hg before the treatment and was reduced to 122.5 +/- 17.2 mm Hg (P < .001). The mean diastolic blood pressure was 85.6 +/- 8.0 mm Hg before treatment and was reduced to 77.2 +/- 8.7 mm Hg (P < .001). Subject's body weight was reduced in the active acupoint group, but the weight reduction did not reach a significant level. There were no significant changes in the heart rate variability.

CONCLUSION

It was concluded that low-level laser treatment of acupoint resulted in lower blood pressure by stimulating the LI 11 and LI 4. No significant difference was observed in both the body weight and heart rate variability after the laser acupoint treatment.

Altered response to metabolic challenges in mice with genetically targeted deletions of galanin-like peptide

Galanin-like peptide (GALP) is expressed in the arcuate nucleus and is implicated in the neuroendocrine regulation of metabolism and reproduction. To investigate the physiological significance of GALP, we generated and characterized a strain of mice with a genetically targeted deletion in the GALP gene [GALP knockout (KO) mice]. We report that GALP KO mice have a subtle, but notable, metabolic phenotype that becomes apparent during adaptation to changes in nutrition. GALP KO mice are indistinguishable from wild-type (WT) controls in virtually all aspects of growth, sexual development, body weight, food and water consumption, and motor behaviors, when they are allowed unlimited access to standard rodent chow. However, GALP KO mice have an altered response to changes in diet. 1) Male GALP KO mice consumed less food during refeeding after a fast than WT controls (P < 0.01). 2) GALP KO mice of both sexes gained less weight on a high-fat diet than WT controls (P < 0.01), despite both genotypes having consumed equal amounts of food. We conclude that although GALP signaling may not be essential for the maintenance of energy homeostasis under steady-state nutritional conditions, GALP may play a role in readjusting energy balance under changing nutritional circumstances.

Monitoring the obesity epidemic in France: the Obepi surveys 1997-2006

The objective of the study was to describe the prevalences of obesity in French adults over a 9-year period. Mailed questionnaire surveys, in 1997, 2000, 2003, and 2006, sampled 20,000 representative French households by the method of quotas. Weight, height, and waist circumference were reported by all members of the selected households > or = 18-years. Obesity was defined according to the WHO criteria, BMI > 30 kg/m2. The prevalence of adult obesity increased progressively from 8.6% (95% confidence interval: 8.2-8.8) in 1997 to 13.1% (12.7-13.5) in 2006. The increase affected all ages, socioeconomic strata, and regions. Although the prevalence of obesity increased in parallel in men and women from 1997 to 2003, the rate of increase was lower in men between 2003 and 2006. These surveys showed a sharp increase in the prevalence of obesity in France in recent years contrasting with a stable prevalence in the 1980s. The results of the first Obepi surveys prompted the French government to implement a Nutrition and Health National Plan in 2001. Regular monitoring of obesity prevalence in France and neighboring countries is needed to compare future trends.

Sleep deprivation of rats: the hyperphagic response is real

STUDY OBJECTIVES

Chronic sleep deprivation of rats causes hyperphagia without body weight gain. Sleep deprivation hyperphagia is prompted by changes in pathways governing food intake; hyperphagia may be adaptive to sleep deprivation hypermetabolism. A recent paper suggested that sleep deprivation might inhibit ability of rats to increase food intake and that hyperphagia may be an artifact of uncorrected chow spillage. To resolve this, a palatable liquid diet (Ensure) was used where spillage is insignificant.

DESIGN

Sleep deprivation of male Sprague Dawley rats was enforced for 10 days by the flowerpot/platform paradigm. Daily food intake and body weight were measured. On day 10, rats were transcardially perfused for analysis of hypothalamic mRNA expression of the orexigen, neuropeptide Y (NPY).

SETTING

Morgan State University, sleep deprivation and transcardial perfusion; University of Maryland, NPY in situ hybridization and analysis.

MEASUREMENTS AND RESULTS

Using a liquid diet for accurate daily measurements, there was no change in food intake in the first 5 days of sleep deprivation. Importantly, from days 6-10 it increased significantly, peaking at 29% above baseline. Control rats steadily gained weight but sleep-deprived rats did not. Hypothalamic NPY mRNA levels were positively correlated to stimulation of food intake and negatively correlated with changes in body weight.

CONCLUSION

Sleep deprivation hyperphagia may not be apparent over the short term (i.e., < or = 5 days), but when extended beyond 6 days, it is readily observed. The timing of changes in body weight and food intake suggests that the negative energy balance induced by sleep deprivation prompts the neural changes that evoke hyperphagia.

Long-term effects of ghrelin and ghrelin receptor agonists on energy balance in rats

Ghrelin, an endogenous ligand of the growth hormone secretagogue receptor (GHS-R), is the only circulating agent to powerfully promote a positive energy balance. Such action is mediated predominantly by central nervous system pathways controlling food intake, energy expenditure, and nutrient partitioning. The ghrelin pathway may therefore offer therapeutic potential for the treatment of catabolic states. However, the potency of the endogenous hormone ghrelin is limited due to a short half-life and the fragility of its bioactivity ensuring acylation at serine 3. Therefore, we tested the metabolic effects of two recently generated GHS-R agonists, BIM-28125 and BIM-28131, compared with ghrelin. All agents were administered continuously for 1 mo in doses of 50 and 500 nmol x kg(-1) x day(-1) using implanted subcutaneous minipumps in rats. High-dose treatment with single agonists or ghrelin increased body weight gain by promoting fat mass, whereas BIM-28131 was the only one also increasing lean mass significantly. Food intake increased during treatment with BIM-28131 or ghrelin, whereas no effects on energy expenditure were detected. With the lower dose, only BIM-28131 had a significant effect on body weight. This also held true when the compound was administered by subcutaneous injection three times/day. No symptoms or signs of undesired effects were observed in any of the studies or treated groups. These results characterize BIM-28131 as a promising GHS-R agonist with an attractive action profile for the treatment of catabolic disease states such as cachexia.

Perceived or true obesity: which causes more suffering in adolescents? Findings of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS)

INTRODUCTION

The consequences of perceived obesity on quality of life are compared with those of genuine obesity in adolescents.

METHODS

Within the framework of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), the height and weight of the participants were measured. Children over 11 years of age were asked whether they thought of themselves as underweight, normal, or overweight. As a measure of their health-related quality of life they completed the internationally employed KINDL-R generic questionnaire.

RESULTS

While 74.8% of 11- to 17-year-old girls and boys are of normal weight, only 40.4% believe that they are "just the right weight." Only 60.9% of obese girls and 32.2% of obese boys think of themselves as overweight. The data showed that genuinely obese adolescents, as classified by body mass index, have a better quality of life than those who only perceive themselves as being overweight.

DISCUSSION

A realistic body image on the part of obese adolescents is a prerequisite for their acceptance of interventions. The marked deterioration in quality of life resulting from perceived obesity, even for young people of normal weight, illustrates the complexity of the struggle against obesity.

A cohort study of incident hypertension in relation to changes in vigorous physical activity in men and women

OBJECTIVE

To assess the dose-response relationship between changes in vigorous exercise (running distance, Deltakm per week) and physician-diagnosed hypertension.

DESIGN

Twenty-four thousand, five hundred and fifty men and 10 113 women were followed prospectively for (mean +/- SD) 7.8 +/- 1.8 and 7.5 +/- 2.0 years, respectively.

RESULTS

Among those who maintained their running distance within +/-5 km per week (5841 men), logistic regression showed that the log odds for hypertension was significantly lower for those who ran longer distances (coefficient+/-SE:-0.019 +/- 0.003 per km per week; P < 0.0001) even when adjusted for body mass index (-0.010 +/- 0.003 per km per week; P = 0.002). Analyses of all 24 550 male and 10,113 female runners showed that the log odds for hypertension declined significantly in relation to Deltakm per week in men (-0.009 +/- 0.001; P < 0.0001) and women (-0.006 +/- 0.003; P = 0.03), which remained significant when adjusted for body mass index in men (-0.005 +/- 0.001; P < 0.0001) but not in women (-0.004 +/- 0.003; P = 0.13). In both sexes, the decline was related to the distance run at the end of follow-up but not at baseline. Compared with men who ran less than 8 km per week, the age-specific rate for incident hypertension in those who ran more than 40 km per week at the end of follow-up was 80% lower in those aged between 35 and 44 years, 66% lower in those between 45 and 54 years, 69% lower in those aged between 55 and 64 years (all P < 0.0001), and 57% lower in those older than 65 years (P = 0.08).

CONCLUSION

The odds of developing hypertension are reduced in those who remain vigorously active and increased in those whose vigorous activity declined. These effects are dependent on the exercise dose and are due in part to metabolic processes associated with body weight.

Dietary interventions in prostate cancer

Our understanding of the relationship between diet and prostate cancer is still developing. Currently, randomized, controlled trials are under way that will yield evidence on which to base recommendations regarding dietary regimens, functional foods, and supplement use. For now, data mostly derive from epidemiologic investigations with limited ability to demonstrate cause and effect, or from benchtop research that may have limited application to in vivo systems, especially in humans. Insufficient evidence currently exists to support the use of specific dietary supplements or functional food. Clinicians striving for best clinical practice should therefore encourage weight management because data consistently show that overweight and obesity are associated with progressive disease and increased overall mortality from prostate cancer and other diseases, especially cardiovascular disease.

Effects of clozapine administration on body weight, glucose tolerance, blood glucose concentrations, plasma lipids, and insulin in male C57BL/6 mice: A parallel controlled study

BACKGROUND

Clozapine has been associated with metabolic adverse events (AEs) (eg, elevated body weight, blood glucose concentrations, cholesterol, triglycerides [TG]), all of which have deleterious effects on health and medication compliance. However, little focus has been directed toward finding a suitable experimental model to study the metabolic AEs associated with clozapine.

OBJECTIVE

The aim of this study was to assess the effects of clozapine administration for 28 days on body weight, glucose tolerance, blood glucose concentrations, plasma lipids, and insulin in C57BL/6 mice.

METHODS

C57BL/6 mice were grouped and treated with clozapine 2 or 10 mg/kg or vehicle intraperitoneally QD for 28 days. Body weight was assessed on days 0 (baseline), 7, 14, 21, and 28, and glucose tolerance, blood glucose concentrations, insulin (calculated by insulin resistance index [IRI]), and plasma lipids (including total cholesterol, TG, high-density lipoprotein cholesterol [HDL-C], and low-density lipoprotein cholesterol) were assessed on day 29.

RESULTS

Sixty 10-week-old, male C57BL/6 mice were included in the study and were divided into 3 groups (20 mice per group). The body weight significantly decreased in the clozapine 10-mg-treated group on days 14, 21, and 28 compared with the vehicle group (mean [SD] body weight: 21.61 [1.05] vs 22.79 [1.11], 22.53 [1.05] vs 24.17 [1.24], and 22.21 [1.07] vs 24.99 [1.39] g, respectively; all, P < 0.05). In the clozapine 10-mg/kg group, blood glucose concentrations significantly increased 0, 30, 60, and 120 minutes after glucose administration compared with the vehicle group (mean [SD]: 6.67 [1.25], 25.34 [5.85], 12.68 [3.39], and 7.52 [1.45] mmol/L, respectively, vs 4.61 [0.78], 21.54 [6.55], 11.46 [3.46], and 6.55 [1.42] mmol/L, respectively; all P < 0.05). The clozapine 10-mg/kg group also had significant increases in plasma insulin concentrations compared with the vehicle group (12.70 [5.27] vs 7.62 [4.54] μIU/mL; P < 0.05) and IRI (3.01 [1.26] vs 1.51 [0.96]; P < 0.05). Plasma HDL-C concentration also significantly decreased in the clozapine 10-mg/kg group compared with the vehicle group (1.23 [0.25] vs 1.47 [0.16]; P < 0.05).

CONCLUSION

Clozapine 10 mg/kg was associated with significant decreases in body weight and significant increases in fasting blood glucose and glucose tolerance in these male C57BL/6 mice.

The Relationship between Body Size and Depressed Mood: Findings from a Sample of African American Middle School Girls

The relationship between body weight and depression among adolescent females has been the subject of considerable attention from researchers. The risk of experiencing this distress, however, is not equally distributed across members of all racial groups. African American girls are generally more satisfied with their bodies and thus may be less vulnerable to experiencing depression as a result of weight concerns. Several scholars have suggested that membership in African American culture provides social resources that protect black females from experiencing high levels of weight-based psychological distress. We examine the relationship between body size and depression and the potentially moderating role of African American cultural experiences using data from the Family and Community Health Study (FACHS). Assessing a cohort of 342 African American girls ages 12-14, we found support for a link between weight and depression. There was no evidence, however, that exposure to African American culture moderated this relationship.

A randomised, 52-week, treat-to-target trial comparing insulin detemir with insulin glargine when administered as add-on to glucose-lowering drugs in insulin-naive people with type 2 diabetes

AIMS/HYPOTHESIS

This 52-week multinational, randomised, open-label, parallel-group, non-inferiority trial compared clinical outcomes following supplementation of oral glucose-lowering drugs with basal insulin analogues detemir and glargine in type 2 diabetic patients.

METHODS

Insulin-naive adults (n=582, HbA(1c) 7.5-10.0%, BMI <or= 40.0 kg/m(2)) were randomised 1:1 to receive insulin detemir or glargine once daily (evening) actively titrated to target fasting plasma glucose (FPG) <or= 6.0 mmol/l. An additional morning insulin detemir dose was permitted if pre-dinner plasma glucose (PG) was >7.0 mmol/l after achieving FPG <7.0 mmol/l. Due to labelling restrictions, no second glargine dose was allowed.

RESULTS

Baseline HbA(1c) decreased from 8.6 to 7.2 and 7.1% (NS) with detemir and glargine, respectively. FPG improved from 10.8 to 7.1 and 7.0 mmol/l (NS), respectively. With detemir, 45% of participants completed the study on once daily dosing and 55% on twice daily dosing, with no difference in HbA(1c). Overall, 52% of participants achieved HbA(1c) <or= 7.0%: 33% (detemir) and 35% (glargine) without hypoglycaemia. Within-participant variability for self-monitored FPG and pre-dinner PG did not differ by insulin treatment, nor did the relative risk of overall or nocturnal hypoglycaemia. Modest reductions in weight gain were seen with detemir vs glargine in completers (3.0 vs 3.9 kg, p=0.01) and in the intention-to-treat population (2.7 vs 3.5 kg, p=0.03), primarily related to completers on once-daily detemir. Mean daily detemir dose was higher (0.78 U/kg [0.52 with once daily dosing, 1.00 U/kg with twice daily dosing]) than glargine (0.44 IU/kg). Injection site reactions were more frequent with detemir (4.5 vs 1.4%).

CONCLUSIONS/INTERPRETATION

Supplementation of oral agents with detemir or glargine achieves clinically important improvements in glycaemic control with low risk of hypoglycaemia. Non-inferiority was demonstrated for detemir using higher insulin doses (mainly patients on twice daily dosing); weight gain was somewhat reduced with once daily insulin detemir.

The effects of early environmental conditions on the reproductive and somatic development of juvenile guinea pigs (Cavia aperea f. porcellus)

Little is known about the effects of the early environment on the development of non-seasonally reproducing species like the domestic guinea pig (Cavia aperea f. porcellus). Although guinea pigs reproduce throughout the year, there is evidence for environmental sensitivity of their reproductive physiology. To investigate the sensitivity of juvenile body weight and puberty to differences in the prenatal and early postnatal environment, subjects were exposed to either of two experimental conditions mimicking seasonal variation: a long photoperiod with 25 degrees C ambient temperature ("LD/25 degrees C"), or a short photoperiod with 15 degrees C ("SD/15 degrees C"). Mean body weight of F1-males from LD/25 degrees C-conditions was higher than that of SD/15 degrees C-males during the whole pubertal period, although the difference was significant only during the early growth phase. Testosterone concentrations also differed significantly between the two treatment groups, pointing to an earlier pubertal onset in LD/25 degrees C- than SD/15 degrees C-males. In F1-females, treatment effects on body weight or age at first estrus were absent. This indicates that the somatic and reproductive development is more sensitive to early photoperiod and temperature conditions in male than female guinea pigs, and that other environmental factors may also play a crucial role for reproductive maturation in this species.

Reduced white fat mass in adult mice bearing a truncated Patched 1

Hedgehog (Hh) signaling emerges as a potential pathway contributing to fat formation during postnatal development. In this report, we found that Patched 1 (Ptc1), a negative regulator of Hh signaling, was expressed in the epididymal fat pad of adult mice. Reduced total white fat mass and epididymal adipocyte cell size were observed in naturally occurring spontaneous mesenchymal dysplasia (mes) adult mice (Ptc1^mes/mes), which carry a deletion of Ptc1 at the carboxyl-terminal cytoplasmic region. Increased expression of truncated Ptc1, Ptc2 and Gli1, the indicators of ectopic activation of Hh signaling, was observed in epididymal fat pads of adult Ptc1^mes/mes mice. In contrast, expression of peroxisome proliferator-activated receptor gamma, CCAAT/enhancer binding protein alpha, adipocyte P2 and adipsin were reduced in epididymal fat pads of adult Ptc1^mes/mes mice. Taken together, our results indicate that deletion of carboxyl-terminal tail of Ptc1 can lead to the reduction of white fat mass during postnatal development.

The effects of galanin-like peptide on energy balance, body temperature and brain activity in the mouse and rat are independent of the GALR2/3 receptor

Galanin-like peptide (GALP) is a neuropeptide that is thought to act on the galanin receptors GALR1, GALR2 and GALR3. In rats, i.c.v. injection of GALP has dichotomous actions on energy balance, stimulating feeding over the first hour, but reducing food intake and body weight at 24 h, as well as causing an increase in core body temperature. In mice, GALP only induces an anorexic action, and its effects on core body temperature are unknown. One aim of the present study was to determine the effects of GALP on core body temperature in mice. Intracerebroventricular injection of GALP into conscious mice had no effect on feeding over 1 h, but caused a significant reduction in food intake and body weight at 24 h. It also caused an immediate drop in core body temperature, which was followed by an increase in body temperature. To understand these different effects of GALP on energy balance in mice compared to rats, and to determine the involvement of GALR2 and GALR3, immunohistochemistry was performed to localise c-Fos, a marker of cell activation. Intracerebroventricular injection of GALP induced c-Fos expression in the parenchyma surrounding the ventricles, the ventricular ependymal cells and the meninges in mice and rats. GALP also induced c-Fos expression in the supraoptic nucleus, dorsomedial hypothalamic nucleus, lateral hypothalamus and nucleus tractus solitarius in rats but not in mice. Central administration of a GALR2/3 agonist in rats did not induce c-Fos in any of the brain regions that expressed this protein after GALP injection, and had no effect on food intake, body weight and body temperature in rats or mice. These data suggest that GALP induces differential effects on energy balance and brain activity in mice compared to rats, which are unlikely to be due to activation of the GALR2 or GALR3 receptor.

Alcohol drinking, tobacco smoking, and anthropometric characteristics as risk factors for thyroid cancer: a countrywide case-control study in New Caledonia

Exceptionally high incidence rates of thyroid cancer are observed in New Caledonia, particularly in Melanesian women. To investigate further the etiology of thyroid cancer and to clarify the reasons of this elevated incidence, the authors conducted a countrywide population-based case-control study in this multiethnic population. The study included 332 cases with histologically verified papillary or follicular carcinoma (293 women and 39 men) diagnosed in 1993-1999 and 412 population controls (354 women and 58 men) frequency matched by gender and 5-year age group. Thyroid cancer was negatively associated with tobacco smoking and alcohol drinking, but no inverse dose-response relation was observed. Height was positively associated with thyroid cancer, particularly in men. Strong positive associations with weight and body mass index were observed in Melanesian women aged 50 years or more, with an odds ratio of 5.5 (95% confidence interval: 1.5, 20.3) for a body mass index of 35 kg/m2 or greater compared with normal-weight women, and there was a clear dose-response trend. This study clarifies the role of overweight for thyroid cancer in postmenopausal women. Because of the high prevalence of obesity among Melanesian women of New Caledonia, this finding may explain in part the exceptionally elevated incidence of thyroid cancer in this group.

Identification of weight-control behaviors practiced by diverse groups of college students

THIS STUDY INVESTIGATED: 1) what weight-related behaviors college students practiced; 2) if the behaviors were performed for weight-related reasons; and 3) whether the behavioral practices differed by gender, race, and body weight status. This cross-sectional study used a questionnaire to collect information from a non-probability sample of undergraduate students (n=379; 48% men) recruited from large introductory psychology classes. Chi-square tests were conducted to examine simple comparisons, and multiple logistic regression analyses assessed differences. Male students reported adopting significantly fewer weight-related behaviors than females. Most frequently males increased exercise (69.2%), increased fruit and vegetable consumption (50%), skipped meals (46%), cut out sweets and junk foods (40%), and cut out between-meal snacks (35%). Female students most frequently increased exercise (67.4%), skipped meals (63%), increased fruit and vegetable consumption (62%), reduced the amount of food eaten (60%), and cut out between-meal snacks (51%). Negative behaviors were engaged in by only a few participants. Weight-related reasons were a significant factor for weight-related behavior adoption. Multiple logistic regression analyses showed that gender was consistently and significantly associated with the adoption of weight-related behaviors, while race and weight status were less consistently associated. Findings of this study will be helpful to dietitians who counsel college students. Results of this study may support efforts to bring more comprehensive behaviorally-focused health and nutrition interventions to college campuses.

Walking age does not explain term versus preterm difference in bone geometry

OBJECTIVE

To elucidate the relationship between bone geometry and onset of walking in former term and preterm children.

STUDY DESIGN

We conducted a cross-sectional study of 128 preschool children aged 3 to 5 years who underwent peripheral quantitative computerized tomography measures of bone size at the distal tibia. Linear models were developed, stratifying by sex, to determine whether bone differences between children born term and preterm were caused by differences in walking age.

RESULTS

Children with a history of preterm birth walked later than children born at term (12.4 +/- 0.5 versus 10.9 +/- 0.2 months; P = .004); however, gestation-corrected walking age (11.4 +/- 0.5 for children born preterm) did not differ. In multiple regression analysis, boys born preterm had larger periosteal and endosteal circumferences and smaller cortical thickness and area than boys born term (least square means, 49.7 +/- 1.3 mm, 43.0 +/- 1.8 mm, 1.1 +/- 0.11 mm, and 49.3 +/- 3.2 mm2 versus 47.0 +/- 0.5 mm, 38.5 +/- 0.7 mm, 1.4 +/- 0.04 mm, and 56.9 +/- 1.2 mm2, respectively; all P < .05). Preterm birth remained statistically significant after adding the age of walking to the models, but no longer significant when current activity levels were included.

CONCLUSION

Greater periosteal and endosteal circumferences, with smaller cortical bone thickness and area, were found in former preterm boys, but not girls, and were explained by differences in current activity levels, not age of walking.

Study of association between common variation in the insulin-like growth factor 2 gene and indices of obesity and body size in middle-aged men and women

CONTEXT

The IGF2 gene (IGF2) plays a key role in growth and is a candidate for association with obesity. Previous studies have reported that polymorphisms in IGF2 are associated with body weight and body mass index (BMI), but the results have been inconsistent.

OBJECTIVES

The aim of this study was primarily to confirm the association with BMI and, secondarily, to study the associations with other indices of body size.

METHODS

In a sample of 2797 women and 2203 men aged 39-79 participating in the Norfolk arm of the European Prospective Investigation of Cancer, we genotyped three single nucleotide polymorphisms (SNPs) in the IGF2 gene that were previously associated with BMI [6815 A/T, 1156 T/C (G/A), and 820 G/A (ApaI)].

RESULTS

No significant associations were observed between these SNPs and BMI. However, all three SNPs were significantly associated with height (P = 0.03 to 0.001). In a backward elimination regression analysis, two SNPs, 1156 T/C (G/A) and 820 G/A, remained independently associated with height (P = 0.003 and P = 0.038, respectively). Haplotype analysis of these two SNPs showed that carriers of the GA haplotype were shorter than carriers of each of the other three haplotypes (P < 0.001 for all comparisons).

CONCLUSIONS

We did not confirm the previously reported associations between IGF2 polymorphisms and BMI. However, our results suggest that common variation in the IGF2 gene may be associated with adult height. IGF2 could be considered as a candidate gene for future research on mechanisms for the association between height and chronic diseases, such as cancer, diabetes, and coronary heart disease.

Mammary gland development as a sensitive end point after acute prenatal exposure to an atrazine metabolite mixture in female Long-Evans rats

BACKGROUND

Atrazine (ATR), a widely used chlorotriazine herbicide, inhibits a number of endocrine-dependent processes, including gonadotrophin surges and mammary gland development in rats. Chlorotriazine herbicides are rapidly metabolized in plants and animals to form a group of metabolites that are detected both in the environment and in exposed animals. The extent to which these metabolites are responsible directly for the observed health effects is not understood.

OBJECTIVES

Our goal was to determine if a mixture of ATR metabolites, in proportions found in the environment, might produce developmental effects in Long-Evans rats following exposure late in pregnancy.

METHODS

We administered an ATR metabolite mixture (AMM) containing ATR, hydroxyatrazine, diaminochlorotriazine, deethylatrazine, and deisopropylatrazine orally to pregnant Long-Evans rats at 0.09, 0.87, or 8.73 mg/kg body weight (bw)/day, on gestation days 15-19, using 0 and 100 mg ATR/kg bw/day as negative and positive controls, respectively.

RESULTS

We observed no significant effect of acute AMM exposure on body weight gain in dams during the dosing period, weight loss in pups on postnatal day (PND)4, or pubertal timing, as is seen with ATR alone. However, as with ATR, we detected delayed mammary gland development, evaluated by whole mount analysis, as early as PND4 in all treatment groups.

CONCLUSIONS

Our data suggest that acute exposure to AMM at levels as low as 0.09 mg/kg bw during late pregnancy causes persistent alterations in mammary gland development of female offspring, and that these effects do not appear to be related to bw or associated with pubertal timing.

Long Term Effects of Energy-Restricted Diets Differing in Glycemic Load on Metabolic Adaptation and Body Composition

A randomized controlled trial of high glycemic load (HG) and low glycemic load (LG) diets with food provided for 6 months and self-administered for 6 additional months at 30% caloric restriction (CR) was performed in 29 overweight adults (mean+/-SD, age 35+/-5y; BMI 27.5+/-1.5 kg/m(2)). Total energy expenditure (TEE), resting metabolic rate (RMR), fat and fat free mass (FFM), were measured at 3, 6 and 12 months. Changes in TEE, but not changes in RMR, were greater than accounted for by the loss of FFM and fat mass (P=0.001-0.013) suggesting an adaptive response to long-term CR. There was no significant effect of diet group on change in RMR or TEE. However, in subjects who lost >5% body weight (n=26), the LG diet group had a higher percentage of weight loss as fat than the HG group (p<0.05), a finding that may have implications for dietary recommendations during weight reduction.

Assessment of adolescent neurotoxicity: rationale and methodological considerations

This introduction to the special issue of Neurotoxicology and Teratology on "Risk of neurobehavioral toxicity in adolescence" begins by broadly considering the ontogeny and phylogeny of adolescence, and the potential value of animal models of adolescence. Major findings from the emerging neuroscience of adolescence are then highlighted to establish the importance of studies of adolescent neurotoxicity. A variety of methodological issues that are of particular relevance to adolescent exposures are then discussed. These include consideration of pharmacokinetic factors, inclusion of other-aged comparison group(s), and issues involving timing, route of administration, and exposure-induced alterations in growth rate. Despite such methodological challenges, research to determine whether adolescence is a time of increased vulnerability (or greater resiliency) to specific drugs and environmental toxicants is progressing rapidly, as exemplified by the work presented in the articles of this special issue.

Childhood obesity: a new menace

Childhood obesity is increasing in prevalence in the United States. Comorbid diseases once thought of as adult issues such as hypertension, diabetes, and dyslipidemia, are now being encountered in the pediatric population as a result of obesity. Primary prevention is still the most cost-effective approach to this growing problem. In terms of management, the treatment of obesity in children is not identical to that in adults. Thus far, the only accepted weight loss therapy for children are diet, exercise, modification of eating behaviors and family education. Further options for morbidly obese children include weight loss medications or surgery, regarding which long-term benefits are still under investigation.

Influence of water-filtered infrared-A (wIRA) on reduction of local fat and body weight by physical exercise

AIM OF THE STUDY

Investigation, whether water-filtered infrared-A (wIRA) irradiation during moderate bicycle ergometer endurance exercise has effects especially on local fat reduction and on weight reduction beyond the effects of ergometer exercise alone.

METHODS

Randomised controlled study with 40 obese females (BMI 30-40 (median: 34.5), body weight 76-125 (median: 94.9) kg, age 20-40 (median: 35.5) years, isocaloric nutrition), 20 in the wIRA group and 20 in the control group. In both groups each participant performed 3 times per week over 4 weeks for 45 minutes bicycle ergometer endurance exercise with a constant load according to a lactate level of 2 mmol/l (aerobic endurance load, as determined before the intervention period). In the wIRA group in addition large parts of the body (including waist, hip, and thighs) were irradiated during all ergometries of the intervention period with visible light and a predominant part of water-filtered infrared-A (wIRA), using the irradiation unit "Hydrosun 6000" with 10 wIRA radiators (Hydrosun Medizintechnik, Müllheim, Germany, radiator type 500, 4 mm water cuvette, yellow filter, water-filtered spectrum 500-1400 nm) around a speed independent bicycle ergometer. MAIN VARIABLE OF INTEREST: change of "the sum of circumferences of waist, hip, and both thighs of each patient" over the intervention period (4 weeks). Additional variables of interest: body weight, body mass index BMI, body fat percentage, fat mass, fat-free mass, water mass (analysis of body composition by tetrapolar bioimpedance analysis), assessment of an arteriosclerotic risk profile by blood investigation of variables of lipid metabolism (cholesterol, triglycerides, high density lipoproteins HDL, low density lipoproteins LDL, apolipoprotein A1, apolipoprotein B), clinical chemistry (fasting glucose, alanin-aminotransferase ALT (= glutamyl pyruvic transaminase GPT), gamma-glutamyl-transferase GGT, creatinine, albumin), endocrinology (leptin, adiponectin (= adipo Q), homocysteine, insulin). All variables were at least measured before and after the intervention period. Ergometry (ECG, blood pressure behaviour, lactate curve with power at 2, 3 and 4 mmol/l) before the intervention period. In addition: nutrition training ahead of and during the intervention period with a nutrition protocol over one week for assessment of the daily energy intake; calculation of basic metabolic rate and total energy requirement. Assessment of undesired effects. Only methods of non-parametric statistics were used, both descriptive (median, percentiles of 25 and 75 (= interquartile range), minimum, maximum) and confirmatory (two-sided Mann-Whitney U test for unpaired samples for the only one main variable of interest). Total error probability: .05 (5%). An intention to treat analysis ITT with last observed carry forward method was used preferably (presented results) and in addition an on treatment analysis OT. Only 2 (treatment group) and 4 (control group) drop-outs occurred (mostly due to lack of time).

RESULTS

The "sum of circumferences of waist, hip, and both thighs of each patient" decreased during the 4 weeks significantly more (p<.001) in the wIRA group than in the control group: medians and interquartile ranges: -8.0 cm (-10.5 cm/-4.1 cm) vs. -1.8 cm (-4.4 cm/0.0 cm). As well "body weight of each patient" decreased during the 4 weeks markedly more in the wIRA group than in the control group: medians and interquartile ranges: -1.9 kg (-4.0 kg/0.0 kg) vs. 0.0 kg (-1.5 kg/+0.4 kg); median of body weight changed from 99.3 kg to 95.6 kg (wIRA) vs. 89.9 kg to 89.6 kg (control). A similar effect showed the body mass index BMI. Blood variables of interest remained unchanged or showed some slight improvements during the treatment period, concerning most variables with no obvious differences between the two groups; insulin showed a slight trend to decrease in the wIRA group and to increase in the control group. Undesired effects of the treatment were not seen.

DISCUSSION

The results of the study suggest, that wIRA - during moderate bicycle ergometer endurance exercise as lipolytic stimulus - increases local lipolysis with a local fat reduction (thighs) in the otherwise bradytrophic fatty tissue. The presumably underlying mechanisms of wIRA have already been proven: wIRA acts both by thermal effects and by non-thermal effects. Thermal effects of wIRA are the generation of a therapeutic field of warmth with the increase of tissue temperature, tissue oxygen partial pressure, and tissue blood flow, and by this regional metabolism. As fatty tissue normally has a slow metabolism (bradytrophic and hypothermic tissue) with a low rate of lipolysis, wIRA can increase lipolysis in fatty tissue and the mobilized fats are burned in musculature during the ergometer exercise.

CONCLUSION

The results of the study indicate, that wIRA irradiation during moderate ergometer endurance exercise can be used - in combination with an appropriate nutrition - to improve body composition, especially local fat distribution, and the reduction of fat and body weight in obese persons.

A profile of olympic taekwondo competitors

The purpose of this study was to identify the profile of the Olympic champions and the other competitors who were involved in the Games. The information on each of the athletes was obtained from the "Official Site of the Sydney 2000 Olympic Games, www.olympics.com/eng/sports/TK "and included weight category, weight, height, age, points obtained, warnings, deduction point, defensive/offensive kicks and punches. One hundred and two athletes competed (54 males and 48 females) in the Games. The mean average age and BMI (Body Mass Index) of 16 male winners was 24.4 ± 3.3 years and 21.9 ± 2.4 respectively compared to 25.2 ± 4.3 years and 22.8 ± 3.3 for the 38 male non-winners. The mean average age and BMI of the 16 female winners was 23.1 ± 3.9 years and 20.8 ± 2.3 respectively compared to 24.9 ± 4.7 years and 21.3 ± 2.7 for the 32 female non-winners. For all four types of athletes, offensive kicks accounted for at least 52% of the techniques to score a point. Ninety-eight percent of all techniques used to score were kicks. Although not statistically significant, winners overall tended to be younger in age and taller with slightly lower BMI than their weight category average. Taking into account the literature cited in this article, future studies should be designed to examine the relationship between performance and functional variables such as muscle power, muscle endurance, reaction time and aerobic capacity. Key PointsWinners tended to be younger in age and taller with slightly lower BMI than their weight category average.An offensive technique was used to score slightly more often than a defensive one.Overall, 98% of all techniques used to score were kicks.

Dietary and cancer-related behaviors of vitamin/mineral dietary supplement users in a large cohort of French women

BACKGROUND

Several epidemiological studies suggested an association between vitamin/mineral dietary supplement use and cancer risk. However, characteristics of supplement users may themselves be related to cancer risk, and therefore could confound such etiological studies. Very little is known about the characteristics of French supplement users.

AIM OF THE STUDY

To identify cancer-related behaviors and dietary characteristics of vitamin/mineral supplement users in the E3N cohort of French women.

METHODS

Data on supplement use and cancer-related and socio-demographic characteristics were collected by self-administered questionnaires completed by 83,058 women, 67,229 of whom also completed a food frequency questionnaire. Supplement users were compared to non-users by unconditional logistic regression.

RESULTS

Vitamin/mineral supplement users were significantly older and leaner (odds ratio [OR] for BMI >or= 30 vs. <18.5 kg/m2 = 0.35, 95% confidence interval [CI] 0.31-0.39), were less often current smokers, had a higher level of education and had more leisure physical activity. They used more phytooestrogen supplements (OR=3.95, 95 % CI 3.69-4.23), had more often a family history of breast cancer and had more often undergone cancer-screening. Users tended to have a healthier diet: less alcohol, more vegetables, fruit, dairy products, fish and soups. They had higher dietary intakes for most micro-nutrients, fiber and omega3 fatty acids, lower fat intake and either similar or lower prevalence of inadequate dietary intake for all relevant nutrients except magnesium.

CONCLUSIONS

To avoid major confounding, the lifestyle characteristics of supplement users should be considered in studies investigating the association between supplement use and cancer risk.

Ghrelin treatment reverses the reduction in weight gain and body fat in gastrectomised mice

BACKGROUND AND AIMS

The gastric hormone ghrelin has been reported to stimulate food intake, increase weight gain, and cause obesity but its precise physiological role remains unclear. We investigated the long term effects of gastrectomy evoked ghrelin deficiency and of daily ghrelin injections on daily food intake, body weight, fat mass, lean body mass, and bone mass in mice.

METHODS

Ghrelin was given by subcutaneous injections (12 nmol/mouse once daily) for eight weeks to young female mice subjected to gastrectomy or sham operation one week previously.

RESULTS

Gastrectomy reduced plasma concentrations of total ghrelin (octanoylated and des-octanoylated) and active (octanoylated) ghrelin by approximately 80%. Immediately after injection of ghrelin, the plasma concentration was supraphysiological and was still elevated 16 hours later. Daily food intake was not affected by either gastrectomy or ghrelin treatment. The effect of ghrelin on meal initiation was not studied. At the end point of the study, mean body weight was 15% lower in gastrectomised mice than in sham operated mice (p<0.001); daily ghrelin injections for eight weeks partially prevented this weight loss. In sham operated mice, ghrelin had no effect on body weight. The weight of fat was reduced in gastrectomised mice (-30%; p<0.01). This effect was reversed by ghrelin, enhancing the weight of fat in sham operated mice also (+20%; p<0.05). Gastrectomy reduced lean body mass (-10%; p<0.01) and bone mass (-20%; p<0.001) compared with sham operated mice. Ghrelin replacement prevented the gastrectomy induced decrease in lean body mass but did not affect bone. In sham operated mice, ghrelin affected neither of these two parameters.

CONCLUSIONS

Ghrelin replacement partially reversed the gastrectomy induced reduction in body weight, lean body mass, and body fat but not in bone mass. In sham operated mice, ghrelin only increased fat mass. Our results suggest that ghrelin is mainly concerned with the control of fat metabolism and that ghrelin replacement therapy may alleviate the weight loss associated with gastrectomy.

Thin is "in" and stout is out" what animated cartoons tell viewers about body weight

Relying upon a content analysis of one specific type of medium to which young people are exposed beginning at an early age, on a regular basis, and for many years (i.e., animated cartoons), the present study examines what types of messages are provided about being underweight, overweight and normal weight. This research examines the following issues: (1) How prevalent is weight-related content in animated cartoons? (2) Has this prevalence changed over time? (3) What "types" of characteristics tend to be associated with being thinner-than-normal or heavier-than normal? Results indicate that the prevalence of both underweight and overweight characters has changed dramatically over the course of the past several decades. These relationships are both curvilinear in nature, but in recent decades have demonstrated a significant increase in the proportion of all cartoons showing characters that are underweight and a simultaneous decrease in the prevalence of characters that are overweight. Many variables were found to differ based on cartoon characters' body weight including gender, age, intelligence, physical attractiveness, emotional states experienced, prosocial behaviors, antisocial behaviors, and overall goodness/badness. Whenever differences were found, the overriding tendency was for cartoons to provide positive messages about being thin and negative messages about being overweight.

Adjusting data to body size: a comparison of methods as applied to quantitative trait loci analysis of musculoskeletal phenotypes

The aim of this study was to compare three methods of adjusting skeletal data for body size and examine their use in QTL analyses. It was found that dividing skeletal phenotypes by body mass index induced erroneous QTL results. The preferred method of body size adjustment was multiple regression.

INTRODUCTION

Many skeletal studies have reported strong correlations between phenotypes for muscle, bone, and body size, and these correlations add to the difficulty in identifying genetic influence on skeletal traits that are not mediated through overall body size. Quantitative trait loci (QTL) identified for skeletal phenotypes often map to the same chromosome regions as QTLs for body size. The actions of a QTL identified as influencing BMD could therefore be mediated through the generalized actions of growth on body size or muscle mass.

MATERIALS AND METHODS

Three methods of adjusting skeletal phenotypes to body size were performed on morphologic, structural, and compositional measurements of the femur and tibia in 200-day-old C57BL/6J x DBA/2 (BXD) second generation (F(2)) mice (n = 400). A common method of removing the size effect has been through the use of ratios. This technique and two alternative techniques using simple and multiple regression were performed on muscle and skeletal data before QTL analyses, and the differences in QTL results were examined.

RESULTS AND CONCLUSIONS

The use of ratios to remove the size effect was shown to increase the size effect by inducing spurious correlations, thereby leading to inaccurate QTL results. Adjustments for body size using multiple regression eliminated these problems. Multiple regression should be used to remove the variance of co-factors related to skeletal phenotypes to allow for the study of genetic influence independent of correlated phenotypes. However, to better understand the genetic influence, adjusted and unadjusted skeletal QTL results should be compared. Additional insight can be gained by observing the difference in LOD score between the adjusted and nonadjusted phenotypes. Identifying QTLs that exert their effects on skeletal phenotypes through body size-related pathways as well as those having a more direct and independent influence on bone are equally important in deciphering the complex physiologic pathways responsible for the maintenance of bone health.

Lifelong vitamin E intake retards age-associated decline of spatial learning ability in apoE-deficient mice

The potential for lifelong vitamin E supplementation to delay age-associated cognitive decline was tested in apoE-deficient and wild-type C57BL/6 mice. Beginning at eight weeks of age, the mice were maintained on a control diet or diets supplemented with dl-α-tocopheryl acetate yielding approximate daily intakes of either 20 or 200 mg/kg body weight. When 6 or 18 months of age, cognitive functioning of the mice was assessed using swim maze and discriminated avoidance testing procedures. For the mice maintained on control diets, the age-related declines in swim maze performance were relatively larger in apoE-deficient mice when compared with wild-type. On the other hand, age-associated declines in learning and working memory for discriminated avoidance were similar in the two genotypes. The 200-mg/kg dose of vitamin E prevented the accelerated decline in spatial learning apparent in 18-month-old apoE-deficient mice, but had no equivalent effect on performance declines attributable to normal aging in the wild-type mice. Vitamin E supplementation failed to prevent age-related impairments in learning and memory for discriminated avoidance observed in both the wild-type and apoE-deficient mice. The current findings are consistent with the hypothesis that apoE deficiency confers an accelerated, though probably selective, loss of brain function with age. This loss of function would appear to involve pathogenic oxidative mechanisms that can be prevented or offset by antioxidant supplementation.

Quantitative trait loci analysis of structural and material skeletal phenotypes in C57BL/6J and DBA/2 second-generation and recombinant inbred mice

QTL analyses identified several chromosomal regions influencing skeletal phenotypes of the femur and tibia in BXD F2 and BXD RI populations of mice. QTLs for skeletal traits co-located with each other and with correlated traits such as body weight and length, adipose mass, and serum alkaline phosphatase.

INTRODUCTION

Past research has shown substantial genetic influence on bone quality, and the impact of reduced bone mass on our aging population has heightened the interest in skeletal genetic research.

MATERIALS AND METHODS

Quantitative trait loci (QTL) analyses were performed on morphologic measures and structural and material properties of the femur and tibia in 200-day-old C57BL/6J x DBA/2 (BXD) F2 (second filial generation; n = 400) and BXD recombinant inbred (RI; n = 23 strains) populations of mice. Body weight, body length, adipose mass, and serum alkaline phosphatase were correlated phenotypes included in the analyses.

RESULTS

Skeletal QTLs for morphologic bone measures such as length, width, cortical thickness, and cross-sectional area mapped to nearly every chromosome. QTLs for both structural properties (ultimate load, yield load, or stiffness) and material properties (stress and straincharacteristics and elastic modulus) mapped to chromosomes 4, 6, 9, 12, 13, 15, and 18. QTLs that were specific to structural properties were identified on chromosomes 1, 2, 3, 7, 8, and 17, and QTLs that were specific to skeletal material properties were identified on chromosomes 5, 11, 16, and 19. QTLs for body size (body weight, body length, and adipose mass) often mapped to the same chromosomal regions as those identified for skeletal traits, suggesting that several QTLs identified as influencing bone could be mediated through body size.

CONCLUSION

New QTLs, not previously reported in the literature, were identified for structural and material properties and morphological measures of the mouse femur and tibia. Body weight and length, adipose mass, and serum alkaline phosphatase were correlated phenotypes that mapped in close proximity of skeletal chromosomal loci. The more specific measures of bone quality included in this investigation enhance our understanding of the functional significance of previously identified QTLs.

Stomach regulates energy balance via acylated ghrelin and desacyl ghrelin

BACKGROUND/AIMS

The gastric peptide ghrelin, an endogenous ligand for growth-hormone secretagogue receptor, has two major molecular forms: acylated ghrelin and desacyl ghrelin. Acylated ghrelin induces a positive energy balance, while desacyl ghrelin has been reported to be devoid of any endocrine activities. The authors examined the effects of desacyl ghrelin on energy balance.

METHODS

The authors measured food intake, gastric emptying, c-Fos expression in the hypothalamus, and gene expression of hypothalamic neuropeptides in mice after administration of desacyl ghrelin. To explore the effects of long term overexpression of desacyl ghrelin, transgenic mice that overexpressed desacyl ghrelin were created.

RESULTS

Administration of desacyl ghrelin decreased food intake and gastric emptying rate through an action on the paraventricular nucleus and the arcuate nucleus in the hypothalamus. Gene expression of anorexigenic cocaine and amphetamine regulated transcript and urocortin in the hypothalamus was increased by desacyl ghrelin. Desacyl ghrelin overexpressing mice exhibited a decrease in body weight, food intake, and fat pad mass weight accompanied by moderately decreased linear growth. Gastric emptying was also decreased in desacyl ghrelin overexpressing mice.

CONCLUSIONS

These findings indicate that in contrast to acylated ghrelin, desacyl ghrelin induces a negative energy balance by decreasing food intake and delaying gastric emptying. The effect is mediated via the hypothalamus. Although derived from the same precursor, the inverse effects of these two peptides suggest that the stomach might be involved as an endocrine organ in the regulation of the energy balance.

Body mass index, follicle-stimulating hormone and their predictive value in in vitro fertilization

PURPOSE

The objective was to explore whether body mass and day 3 follicle-stimulating hormone have predictive value on odds of pregnancy after in vitro fertilisation. Few studies show that obesity produces a variety of alterations in the reproductive system, and that women with an elevation of day 3 FSH have declining ovarian function.

METHODS

The data of one-hundred-seventy-one women who underwent a standard regime of controlled ovarian hyperstimulation was analyzed with particular reference to variations in body mass and hormone levels.

RESULTS

By raising BMI and FSH (mIU/mL) by one unit, the odds for pregnancy were decreased by the respective factors 0.84 (95% confidence interval 0.73-0.97) and 0.77 (95% confidence interval 0.59-1.00).

CONCLUSIONS

The results demonstrate that for the purpose of raising the odds of pregnancy BMI should be reduced. A low FSH value may cause the same effect. Nontheless, obesity and hormonal function may be independent risk factors for failure in assisted reproduction.

What is the best size descriptor to use for pharmacokinetic studies in the obese?

The prevalence of obesity in the western world is dramatically rising, with many of these individuals requiring therapeutic intervention for a variety of disease states. Despite the growing prevalence of obesity there is a paucity of information describing how doses should be adjusted, or indeed whether they need to be adjusted, in the clinical setting. This review is aimed at identifying which descriptors of body size provide the most information about the relationship between dose and concentration in the obese. The size descriptors, weight, lean body weight, ideal body weight, body surface area, body mass index, fat-free mass, percent ideal body weight, adjusted body weight and predicted normal body weight were considered as potential size descriptors. We conducted an extensive review of the literature to identify studies that have assessed the quantitative relationship between the parameters clearance (CL) and volume of distribution (V) and these descriptors of body size. Surprisingly few studies have addressed the relationship between obesity and CL or V in a quantitative manner. Despite the lack of studies there were consistent findings: (i) most studies found total body weight to be the best descriptor of V. A further analysis of the studies that have addressed V found that total body weight or another descriptor that incorporated fat mass was the preferred descriptor for drugs that have high lipophilicity; (ii) in contrast, CL was best described by lean body mass and no apparent relationship between lipophilicity or clearance mechanism and preference for body size descriptor was found. In conclusion, no single descriptor described the influence of body size on both CL and V equally well. For drugs that are dosed chronically, and therefore CL is of primary concern, dosing for obese patients should not be based on their total weight. If a weight-based dose individualization is required then we would suggest that chronic drug dosing in the obese subject should be based on lean body weight, at least until a more robust size descriptor becomes available.

Physical activity levels before and after a diagnosis of breast carcinoma: the Health, Eating, Activity, and Lifestyle (HEAL) study

BACKGROUND

Increased body weight at the time patients are diagnosed with breast carcinoma has been associated with an increased risk of recurrence and reduced survival. Weight gain also is common after diagnosis. Increasing physical activity (PA) after diagnosis may minimize these adverse outcomes. In this population-based study, the authors investigated whether PA levels after diagnosis declined from prediagnosis levels and whether any changes in PA varied by disease stage, adjuvant treatment, patient age, or body mass index (BMI) in 812 patients with incident breast carcinoma (from in situ to Stage IIIa).

METHODS

Types of sports and household activities and their frequency and duration for the year prior to diagnosis and for the month prior to the interview (i.e., 4-12 months postdiagnosis) were assessed during a baseline interview.

RESULTS

Patients decreased their total PA by an estimated 2.0 hours per week from prediagnosis to postdiagnosis, an 11% decrease (P < 0.05). Greater decreases in sports PA were observed among women who were treated with radiation and chemotherapy (50% decrease) compared with women who underwent surgery only (24% decrease) or who were treated with radiation only (23%; (P < 0.05). Greater decreases in sports PA were observed among obese patients (41% decrease) compared with patients of normal weight (24% decrease; P < 0.05).

CONCLUSIONS

PA levels were reduced significantly after patients were diagnosed with breast carcinoma. Greater decreases in PA observed among heavier patients implied a potential for greater weight gain among women who already were overweight. Randomized, controlled trials are needed to evaluate how PA may improve the prognosis for patients with breast carcinoma.

Bone turnover and body weight relationships differ in normal-weight compared with heavier postmenopausal women

Low body weight is associated with increased risk for fractures, whereas higher body weight has been shown to be protective against osteoporosis. This study evaluated whether body weight plays a role regulating bone turnover and mass in normal-weight (body mass index (BMI) <25 kg/m2), overweight (BMI 25-29.9 kg/m2) and obese (BMI> or =30 kg/m2) postmenopausal women who were either receiving hormone replacement therapy [HRT(+)] or not [HRT(-)] (total of six groups). Body weight, BMI, total body bone mineral content (TBBMC), and markers of bone formation (serum osteocalcin) and bone resorption (urinary pyridinoline (PYD) and deoxypyridinoline) were retrospectively analyzed in 210 postmenopausal women. The mean age was 67+/-6 years, with mean body weight of 70.8+/-14.2 kg, ranging from 45.0 to 115.5 kg. Body weight was positively correlated with TBBMC ( r=0.50, p<0.0001). There was a lower TBBMC and higher bone formation rate in normal-weight than obese HRT(-) women, but in women taking HRT there were no differences between BMI categories. In addition, in normal-weight HRT(-) women only, PYD and body weight showed a negative correlation (r=-0.39, p=0.01). Among normal-weight, but not overweight or obese subjects, we observed higher TBBMC and lower bone turnover in the HRT(+) compared with the HRT(-) group. Regression models explained 36% of the variance in TBBMC, mainly through body weight. Additional models could only explain 11-15% of the variance in bone turnover. Taken together, these data suggest that among normal-weight but not obese postmenopausal women, higher bone turnover is associated with lower bone mass, and that only normal-weight women show a different bone turnover profile with HRT treatment. Body weight should be considered an important factor in bone metabolism with relevant clinical implications.

Physical activity, body weight, and pancreatic cancer mortality

In a study of 32 687 subjects with data on physical activity and body mass index (BMI) collected serially over time, we examined associations with pancreatic cancer mortality (n=212). Despite plausible biologic mechanisms, neither physical activity (multivariate relative risks for increasing levels: 1.00, 0.98, 0.92, and 1.31, respectively) nor BMI (corresponding findings: 1.00, 0.84, 1.08, and 0.99, respectively) significantly predicted pancreatic cancer mortality.

Effectiveness of estrogen replacement in restoration of cognitive function after long-term estrogen withdrawal in aging rats

Recent studies suggest that some aspects of learning and memory may be altered by a midlife loss of estrogen, indicating a potential causal relationship between the deficiency of ovarian hormones and cognitive aging. In this study, the effects of estrogen withdrawal and replacement were tested in middle-aged Fischer-344 rats using different memory tasks. Estrogen withdrawal accelerated the rate of cognitive aging. A deficit first occurred 4 months after ovariectomy in working memory, which was tested in a delayed-nonmatching-to-position task, and progressed from long-delay to short-delay trials. Reference memory, which was tested in a place discrimination task and a split-stem T-maze, was not affected by aging or ovariectomy. The efficacy of estrogen in ameliorating the cognitive deficit in old rats depended on the type of treatment (acute vs chronic) and whether the aging-related decline in a particular cognitive process was aggravated by estrogen withdrawal. Chronic estrogen treatment (implants) was effective in improving working memory only when primed with repeated injections of estrogen, indicating that simulating the estrogen fluctuations of the estrous cycle may be more effective than the widely used mode of chronic pharmacological treatment. A challenge with scopolamine revealed that ovariectomy-induced cognitive deterioration coincided with a compromised cholinergic system. Importantly, the estrogen treatment that had restored effectively the cognitive abilities of old ovariectomized rats did not reduce their sensitivity to scopolamine. Taking into consideration that estrogen was highly effective against the amnestic action of scopolamine when tested in young-adult rats, these data emphasize that mechanisms of the protective effect of estrogen differ in young and old rats.

Anthropometric measurements and body silhouette of women: validity and perception

OBJECTIVE

To examine the validity of self-reported values for current anthropometric measurements and factors related to misreporting.

DESIGN

E3N, a prospective cohort study of cancer risk factors, conducted in France and part of the European Prospective Investigation on Cancer. E3N comprises 100,000 women, born between 1925 and 1950, followed with self-administered questionnaires sent every 18 to 24 months starting in 1990.

SUBJECTS

152 women for the validation study of self-reported anthropometric measurements, and 91,815 women selected to evaluate factors affecting misreporting of body silhouette.

STATISTICAL ANALYSIS

Paired t tests, Pearson and Spearman correlations were applied to evaluate the validity of self-reported measures, and analysis of variance and logistic regression were used to assess the factors influencing misreporting of silhouette.

RESULTS

The correlation coefficients between self- and external measurements were high. All but sitting height (r = 0.56) were more than 0.80, with weight and bust (nipples) measurement correlation coefficients attaining 0.94. The correlation between body mass index (BMI), measured by the technician and the self-reported silhouette, was 0.78. Small height was always associated with misclassification. Specific factors related to a more favorable perception of body silhouette were: being overweight, small height, younger age, and a lower level of education. These women were also more frequently unmarried, more physically active, and had had a slender body shape during adolescence. Results denoting a less favorable perception of body shape were reversed. CONCLUSION/APPLICATIONS: Self-reported measurements (made with or without help) are valid measures in epidemiological studies. Body silhouettes are simple and useful indicators of body mass index. However they should be interpreted with caution in certain instances, especially for overweight subjects.

Obesity and colorectal cancer risk in women

BACKGROUND

Several large studies of obesity and colorectal cancer risk have found no association among women but a reasonably consistent positive association among men. In women, a positive association that is stronger among, or limited to, those who are premenopausal has been suggested by studies that stratified analyses by age, although no previous study has examined the association by menopausal status.

METHODS

We used proportional hazards analyses to estimate hazard ratios relating obesity to colorectal cancer risk among 89,835 women aged 40-59 years at recruitment into the Canadian National Breast Screening Study, a multicentre randomised controlled trial of mammography screening for breast cancer. During an average 10.6 years of follow up (936,433 person years), a total of 527 women were diagnosed with incident colorectal cancer (363 colon and 164 rectal).

RESULTS

We found that obesity (body mass index > or = 30 kg/m(2)) was associated with an approximately twofold increased risk of colorectal cancer among women who were premenopausal at baseline (hazard ratio 1.88, 95% confidence interval 1.24-2.86). There was no association among postmenopausal women (p for interaction=0.01), and there was only a weak positive association in the entire cohort.

CONCLUSIONS

Our data suggest that obesity is associated with a twofold increased risk of colorectal cancer in premenopausal women but is not associated with altered risk in postmenopausal women. Effect modification by menopausal status may better explain the inconsistent or weak findings in previous studies than the presumed lack of an association among women.

Preventing sarcopenic obesity among breast cancer patients who receive adjuvant chemotherapy: results of a feasibility study

PURPOSE: Weight gain is a common side effect of adjuvant chemotherapy for breast cancer - a side effect that decreases quality of life and also may decrease both disease-free and overall survival. This weight gain also is unique, since patients lose lean body mass while they gain weight. These body composition changes become apparent within six months of diagnosis. METHODS: We explored whether a clinic-based exercise program, which promoted a specialized program of strength training, aerobic activity and a healthful ( Collapse

Key Words

• breast neoplasms
• exercise
• body composition
• body weight

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MESH Headings Collapse

Grants

• K07 CA062215 NCI NIH HHS
• K07 CA062215-05 NCI NIH HHS
• R21 CA092468 NCI NIH HHS

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Affiliation(s)

Wendy Demark-Wahnefried Department of Surgery
Anne Jacobs Kenyon Duke Center for Living
Pamela Eberle Duke Center for Living
Ann Skye Duke Center for Living
William E. Kraus Duke Center for Living Department of Internal Medicine Duke University Medical Center Durham, NC 27710

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Body weight and colorectal cancer risk in a cohort of Swedish women: relation varies by age and cancer site

The relation between relative body weight and colorectal cancer among women is unclear. In a large prospective cohort study, we found a positive association only for distal cancers among younger women that became attenuated at older ages. These results support previous reports in which results were stratified by age or colorectal cancer site.

A meta-analysis of the effects of cigarette smoking on bone mineral density

To determine the magnitude and mediators of the association between cigarette smoking and bone mass in the epidemiologic literature we reviewed articles, published abstracts, and conference proceedings, identified through MEDLINE, psychological abstracts, conference proceedings, and article bibliographies. We studied cross-sectional and prospective human studies that provided a quantitative measure of bone mass (X-ray, absorptiometry, or computed tomography) as a function of cigarette smoking exposure. Effects were expressed as pooled standardized mean differences for categorical comparisons (e.g., bone mass in current versus nonsmokers), and as pooled correlation coefficients for continuous comparisons (e.g., correlation of bone mass and pack-years of smoking). Effects were derived for combined bone sites (all bone sites pooled within each study) and four specific sites (hip, lumbar spine, forearm, and os calcis), and were examined overall and as a function of subject and methodologic characteristics (gender, age, body weight, menopausal status, health status). Data were pooled across 86 studies, enrolling 40,753 subjects. Smokers had significantly reduced bone mass compared with nonsmokers (never and former smokers) at all bone sites, averaging a one-tenth standard deviation (SD) deficit for combined sites. Deficits were especially pronounced at the hip, where the bone mass of current smokers was one-third of a SD less than that of never smokers. Overall, effects were greatest in men and in the elderly, and were dose-dependent. In prospective studies, smokers had greater rates of bone loss over time compared with nonsmokers. Bone mass differences remained significant after controlling for age and body weight differences between the two groups. Absolute effect sizes at most bone sites were greatest for current smokers compared with never smokers, intermediate for current smokers compared with former smokers, and lowest for former smokers compared with never smokers, suggesting that smoking cessation may have a positive influence on bone mass. Based on these data, it is estimated that smoking increases the lifetime risk of developing a vertebral fracture by 13% in women and 32% in men. At the hip, smoking is estimated to increase lifetime fracture risk by 31% in women and 40% in men. It appears that smoking has an independent, dose-dependent effect on bone loss, which increases fracture risk, and may be partially reversed by smoking cessation. Given the public health implications of smoking on bone health, it is important that this information be incorporated into smoking prevention and cessation efforts.

Mutations in the small heterodimer partner gene are associated with mild obesity in Japanese subjects

Mutations in several genes encoding transcription factors of the hepatocyte nuclear factor (HNF) cascade are associated with maturity-onset diabetes of the young (MODY), a monogenic form of early-onset diabetes mellitus. The ability of the orphan nuclear receptor small heterodimer partner (SHP, NR0B2) to modulate the transcriptional activity of MODY1 protein, the nuclear receptor HNF-4alpha, suggested SHP as a candidate MODY gene. We screened 173 unrelated Japanese subjects with early-onset diabetes for mutations in this gene and found five different mutations (H53fsdel10, L98fsdel9insAC, R34X, A195S, and R213C) in 6 subjects as well as one apparent polymorphism (R216H), all present in the heterozygous state. Interestingly, all of the subjects with the mutations were mildly or moderately obese at onset of diabetes, and analysis of the lineages of these individuals indicated that the SHP mutations were associated with obesity rather than with diabetes. Therefore, an additional group of 101 unrelated nondiabetic subjects with early-onset obesity was screened for mutations in the SHP gene. Two of the previously observed mutations (R34X and A195S) and two additional mutations (R57W and G189E) were identified in 6 subjects, whereas no mutations were identified in 116 young nondiabetic lean controls (P = 0.0094). Functional studies of the mutant proteins show that the mutations result in the loss of SHP activity. These results suggest that genetic variation in the SHP gene contributes to increased body weight and reveal a pathway leading to this common metabolic disorder in Japanese.

Predilection muscles and physical condition of raccoon dogs (Nyctereutes procyonoides) experimentally infected with Trichinella spiralis and Trichinella nativa

The predilection muscles of Trichinella spiralis and T. nativa were studied in 2 experimental groups of 6 raccoon dogs (Nyctereutes procyonoides), the third group serving as a control for clinical signs. The infection dose for both parasites was 1 larva/g body weight. After 12 weeks, the animals were euthanized and 13 sampling sites were analysed by the digestion method. Larvae were found in all sampled skeleton muscles of the infected animals, but not in the specimens from the heart or intestinal musculature. Both parasite species reproduced equally well in the raccoon dog. The median density of infection in positive tissues was 353 larvae per gram (lpg) with T. spiralis and 343 lpg with T. nativa. All the infected animals had the highest larvae numbers in the carpal flexors (M. flexor carpi ulnaris). Also tongue and eye muscles had high infection levels. There were no significant differences in the predilection sites between these 2 parasite species. Trichinellosis increased the relative amount of fat, but not the body weight in the captive raccoon dogs. Thus, Trichinella as a muscle parasite might have catabolic effect on these animals.

Hypothalamic melanin-concentrating hormone and estrogen-induced weight loss

Melanin-concentrating hormone (MCH) is an orexigenic neuropeptide produced by neurons of the lateral hypothalamic area (LHA). Because genetic MCH deficiency induces hypophagia and loss of body fat, we hypothesized that MCH neurons may represent a specific LHA pathway that, when inhibited, contributes to the pathogenesis of certain anorexia syndromes. To test this hypothesis, we measured behavioral, hormonal, and hypothalamic neuropeptide responses in two models of hyperestrogenemia in male rats, a highly reproducible anorexia paradigm. Whereas estrogen-induced weight loss engaged multiple systems that normally favor recovery of lost weight, the expected increase of MCH mRNA expression induced by energy restriction was selectively and completely abolished. These findings identify MCH neurons as specific targets of estrogen action and suggest that inhibition of these neurons may contribute to the hypophagic effect of estrogen.

Behavioural and physiological effects induced by an infusion of antisense to alpha(2D)-adrenoceptors in the rat

1. The aim of this study was to investigate the behavioural and physiological effects of an i.c.v. infusion of antisense oligonucleotide to the alpha(2D)-adrenoceptor subtype. Behavioural and physiological parameters were monitored for 2 days before the infusion, throughout the 3-day infusion period and for 3 days following the end of the infusion. 2. The antisense infusion resulted in a significant increase in behavioural activity characterized by increased locomotion and grooming scores. Behavioural activity scores of rats treated with antisense to alpha(2D)-adrenoceptors were significantly higher than those of rats treated with vehicle (H(2)O) or the mismatch toxicity control on day 4 and day 5 and, significantly higher than vehicle controls on day 6. 3. Body weight gain was significantly reduced in the antisense-treated rats at the end of the study compared to the vehicle (34%) and mismatch groups (30%), although daily food and water intakes were not significantly different at any time point. 4. Pupil diameters of rats infused with antisense to alpha(2D)-adrenoceptors were significantly greater than those of animals treated either with vehicle or mismatch oligonucleotide on day 5 of the study. On day 6, the pupil diameters of these animals were still significantly greater than the mismatch group. 5. In conclusion, an i.c.v. infusion of antisense to the alpha(2D)-adrenoceptor induced behavioural activation in rats, increased pupil diameter and reduced total weight gain. These effects were specific to the antisense-treated group and were fully reversed post-infusion.