Entry Into Romantic Partnership Is Associated With Obesity

BMI is highly correlated between spouses; however, less is understood about the underlying mechanism(s) by which the development of obesity in one individual increases the risk of obesity in his/her spouse. The objective of this study is to investigate whether romantic partnership and duration of cohabitation are related to incident obesity and obesity‐promoting behaviors. We used two data sets from the National Longitudinal Study of Adolescent Health: (i) 6,949 US adolescents (wave II, 1996) followed into adulthood (wave III, 2001–2002) and (ii) 1,293 dating, cohabiting, and married romantic couples from wave III, including measured anthropometry and self‐report behavior data. In the longitudinal cohort, we used sex‐stratified logistic regression models to examine the risk of incident obesity by longitudinal romantic relationship status and duration of time spent living with a romantic partner. In the Couples Sample, we used multinomial logistic regression to predict concordance in outcomes: obesity, moderate‐to‐vigorous physical activity, and screen time by romantic partnership and duration of time living with a romantic partner. Individuals who transitioned from single/dating to cohabiting or married were more likely to become obese than those who were dating at both waves. Partner concordance for negative, obesity‐related behaviors was strongest for married couples and couples who lived together ≥2 years. The shared household environment may increase the likelihood of becoming obese, influence partner concordance, and may be an important target for obesity intervention.     

Growth regulatory effects of cyclic AMP and polyamine depletion are dissociable in cultured mouse lymphoma cells

Treatment of mouse lymphoma S49 cells with D,L-alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, depleted cellular polyamine levels and stopped cell growth. The cells were arrested predominantly in G1. Thus, polyamine depletion may lead to a regulatory growth arrest in S49 cells. We tested two hypotheses regarding the relationship of growth arrest mediated by polyamine limitation to that mediated by cyclic AMP (cAMP). The hypothesis that cAMP-induced arrest results from polyamine depletion is not tenable, because the arrest could not be reversed by addition of exogenous polyamines, and because cellular polyamine levels do not drop in dibuturyl cyclic AMP (Bt2cAMP)-arrested cells. The hypothesis that polyamine-mediated growth arrest is effected via modulation of cAMP levels or cAMP-dependent protein kinase activity was also shown to be incorrect, because a S49 variant deficient in cAMP-dependent protein kinase was arrested by DFMO. The activities of the polyamine-synthesizing enzymes ornithine decarboxylase (ODC) and S-adenosyl methionine decarboxylase (SAMD) are both reduced in Bt2cAMP-treated cells to about 10% of that in control populations, as shown previously. DFMO diminishes ODC activity and augments SAMD activity in both untreated and Bt2cAMP-treated cells, leading to polyamine depletion in both cases.     

The Thermic Effect of Food and Obesity: A Critical Review

DE JONGE, LILIAN, GEORGE BRAY. The thermic effect of food and obesity: A critical review. This review has examined the factors that influence the thermic effect of food (TEF) by evaluating 49 studies that have compared subjects who are obese with those who are lean. Meal size, meal composition, the nature of the previous diet, insulin resistance, physical activity, and ageing influence TEF. In the studies of individuals who are obese or lean, of those who used intravenous glucose infusions, all but one found an impaired thermic response. A total of 29 out of 49 studies of individuals of normal weight or with obesity were identified where there was no difference in age between the groups, and where the subjects who were “overweight” were clearly obese. Of these 29, 22 reported a statistically significant reduction in TEF, 3 studies were not designed to look primarily at the effect of obesity on TEF, and the other 4 may not have had sufficiently palatable meals. From this review, we conclude that the reduction of TEF in obesity is related to the degree of insulin resistance, which may be influenced by a low level of sympathetic activity.     

Predictors of uptake of obesity genetic testing among affected adults

Given that a large number of candidate genes coding for a tendency toward obesity have been identified and some findings have been replicated, we explored characteristics of those who would be most likely to obtain future genetic testing for this tendency. During a series of focus groups, obese respondents rated their likelihood of obtaining testing under conditions in which either genetically-targeted drug treatment would be available, a positive test would be associated with a prognosis for developing diabetes, or neither of these. Interest in testing was greater given the first two scenarios than the third. Older age and belief that genetics were an important cause of obesity were associated with greater interest. For the first two scenarios, higher educational status was associated with greater interest, while for the third, respondents who said emotional issues caused overweight and those who crash-dieted intermittently were more likely to want genetic testing. Although further research is required to validate these findings, this study is the first published report of respondents’ ratings of likelihood to obtain genetic testing for propensity to obesity, and suggests strong interest in genetic testing among some people, even in the absence of further treatment implications of the test.     

Effects of acronycine on nucleic acid synthesis and population growth in mammalian tumor cell cultures

Acronycine — an alkaloid with antineoplastic activity against a wide range of experimental tumors — at concentrations of 0.5-12 μg/ml rapidly inhibits RNA synthesis in L5178Y mouse lymphoma and IRC rat monocytic leukemia cultures. Culture growth is arrested only at acronycine concentrations which markedly inhibit RNA synthesis. DNA synthesis is inhibited at rather higher concentrations but this is not a prerequisite of the arrest of growth. It is suggested that the arrest of growth may be a consequence of the inhibition of RNA synthesis. In both cultures arrest of growth coincides with the appearance of many cells with two apparently normal nuclei. Cells are not arrested in mitosis. It is shown these binucleated cells very probably arise from an inhibition of cell cleavage. Studies with synchronized cultures show that at low drug concentrations, more than one cell cycle may elapse before growth is arrested and binucleated cells appear, indicating the effect on cytokinesis is not immediate. The results suggest that the arrest of growth may be a result of a slow depletion of a component essential for cell cleavage. The disturbance at division is a major factor in arresting growth at low drug concentrations. At higher acronycine concentrations, when RNA synthesis may be inhibited by 80–90%, the cytotoxic effects appear earlier and are less specifically directed at cytokinesis; DNA synthesis is then also rapidly and markedly inhibited.     

Focus: Addiction: Obese Smokers as a Potential Subpopulation of Risk in Tobacco Reduction Policy

Smoking and obesity represent the largest challenges to public health. There is an established inverse relationship between body mass index (BMI) and smoking, but this relationship becomes more complicated among obese smokers. Smokers with higher BMI consume more cigarettes per day and may be more nicotine-dependent than lean smokers. Rates of obesity are lower among smokers than non-smokers, indicating that chronic exposure to tobacco smoke may prevent excess weight gain in people who would otherwise become obese. Furthermore, obese smokers may be more sensitive to the weight-suppressive and reinforcing effects of nicotine. Consequently, obese smokers may respond differently to reduction in the nicotine content of cigarettes, a tobacco control policy being considered both in the Unites States and abroad. Here, we review the interrelationship between nicotine and obesity in the context of a potential nicotine reduction policy. We discuss the implications of nicotine-induced body weight suppression in obese smokers, as well as the possibility that obesity might increase susceptibility to smoking and nicotine dependence.     

Are BMI and other anthropometric measures appropriate as indices for obesity? A study in an Asian population

We have examined the relationships between percentage of body fat (PBF) and risk factors for cardiovascular disease and insulin resistance and how good body mass index (BMI) and other anthropometric measures are as indices of obesity. High PBF levels were associated with increased risk of cardiovascular disease and insulin resistance. The World Health Organization BMI of 30 kg/m(2) for obesity has low sensitivity, 6.7% and 13.4% for men and women, respectively. For every obese man and woman identified, 6.7 and 1.76 times nonobese men and women, respectively, will be misclassified as obese. With the locally established BMI cutoff point for obesity of 27 kg/m(2) for men and 25 kg/m(2) for women, the sensitivity was improved to 46.7% and 60.8%, respectively. For every obese man and woman identified, 3.76 and 1.64 times nonobese men and women, respectively, will be misclassified as obese. None of the other anthropometric indices was better than the locally established BMIs. We showed that the BMIs for obesity for our local men and women are different. These BMIs were most precise among all indices studied. However, they still lead to high false-positive rates. For more effective management of the problem of obesity, we need to develop more precise, simple, and cost-effective methods for the measurement of PBF.     

Reduced Inhibition of Return to Food Images in Obese Individuals

Previous research has shown that obese individuals may be biased towards attending to food over non-food information, and this bias may contribute to the development and/or maintenance of obesity. The present study sought to extend our understanding of maladaptive attentional processing in this population by investigating whether obese individuals have difficulty in disengaging attention from food compared with non-food images, relative to normal-weight controls. To address this question, we measured inhibition of return (IOR) in an attentional cueing task. The participants were 29 obese and 35 normal-weight satiated females without eating disorders. The obese group displayed less IOR to food images than the normal-weight group, while there was no difference in IOR between the groups for non-food images. This suggests that obese females have greater difficulty disengaging attention from food than normal-weight females. Our findings provide a new focus for studies investigating maintenance factors in obesity and are discussed in relation to a theory of incentive-sensitisation.     

Adolescent Obesity and Future College Degree Attainment

The current impact of adolescent obesity on educational attainment is not clear. The objectives of our study were to determine whether adolescent obesity is associated with college degree attainment and how this association may have changed over time. We used data from a contemporary national cohort of over 4,000 persons who were adolescents (aged 14–18) in 1997 to assess the relationship between adolescent obesity and education. To assess for changes in this relationship over time, we also analyzed an older, similarly structured cohort of over 3,000 persons who were adolescents (aged 16–18) in 1981. Our primary outcome was college degree completion. We found that in the older cohort (adolescents in 1979), there were no differences in college degree attainment by adolescent weight status before and after adjustment. However, unadjusted analysis of the contemporary cohort (adolescents in 1997) demonstrated that those who were normal weight as adolescents had a higher prevalence of college degree attainment at follow‐up compared to obese adolescents (24% vs. 10%). After adjustment for socio‐demographic variables (age, sex, race, height, parental income‐to‐poverty ratio, parental education, aptitude test scores), obese adolescents were less likely to have attained a college degree compared to normal weight peers (adjusted risk ratio 0.61 95% confidence interval 0.38–0.83). Expectations for a future college degree did not vary by weight status and did not explain this observation. In conclusion, adolescent obesity is associated with lower likelihood of college completion. This relationship was not observed in an older cohort of adolescents.     

Pancreatic polypeptide response to secretin in obesity: effects of glucose intolerance

Pancreatic polypeptide (PP) may function as a regulator of satiety. Its secretion is impaired in certain animal models of obesity and the administration of PP may improve the hyperphagia and hyperinsulinism seen in these animals. In obese humans, decreased, normal or increased, basal and stimulated concentrations of PP in plasma have been reported. However the advent of diabetes confounds the picture since PP levels in diabetes are generally raised. We have therefore examined the PP responses to intravenous secretin, a known PP secretagogue, in 23 obese subjects, 12 with normal and 11 with abnormal glucose tolerance, and compared the results with those in 23 age and sex-matched healthy controls. The mean maximum PP level in obese subjects with normal glucose tolerance (98 +/- 13 pg/ml) was significantly less than that in normal subjects (218 +/- 23 pg/ml) but in obese subjects with abnormal glucose tolerance, it was significantly greater (578 +/- 115 pg/ml). Within each of the 3 study groups taken separately, PP response to secretin was not correlated with glucose or insulin levels, or with the degree of obesity. Thus, obesity per se appears to be associated with impaired PP responses, which may be masked by abnormalities in glucose tolerance.     

Childhood influences on youth obesity

We develop a model to estimate the influence of child and parental characteristics on the likelihood that a child will become an obese or overweight youth. We use this model to test whether it is possible to forecast obesity and overweight among youth. Comparing Receiver Operating Characteristic (ROC) scores from these forecasts, we find that a model using childhood covariates does as well in forecasting youth obesity and overweight as a model using the covariate values contemporaneous with the youth obesity and overweight outcomes. The datasets used in this paper, the National Longitudinal Survey of Youth (NLSY79) and the NLSY79 Children and Young Adults, provide data from 1986 to 2002, allowing for the study of a child's transition to and from obesity or overweight over a long period. Explanatory variables that significantly influence the likelihood of youth obesity or overweight outcomes include the mother's obesity status and education, the youth's mental health, and certain demographic features including race, sex, and family size. These factors provide potential targets for policies that could be implemented early in life among children most likely to become obese or overweight.     

Effect of obesity on the reliability of age-at-death indicators of the pelvis

During medicolegal investigations, forensic anthropologists commonly use morphological changes in the auricular surface of the ilium and the symphyseal face of the pubis to estimate age. However, obesity may impact the reliability of age estimations based on pelvic joints. Over the past several decades, the prevalence of obesity has dramatically increased in the United States (US). Since the rate of progression through age-related stages of weight-bearing joints may be influenced by excessive body mass, it is important that anthropologists understand how obesity affects age-related morphological changes in the skeleton. This study investigates the effects of obesity on the validity of the estimated age-at-death based on the Buckberry–Chamberlin and Suchey–Brooks methods by comparing US adults considered normal BMI (BMI 18.5–24.9) and obese (BMI ≥ 30). The obese group exhibits overall greater bias (overestimation of age) and inaccuracy, less precision, and lower correlations between estimated and known age than the normal BMI group using both methods, although differences in the pubic symphysis are not statistically significant. For the auricular surface the age of transition from one phase to the next is lower and the standard deviations are greater for the obese as compared to normal weight individuals. This study helps to elucidate how obesity affects the rate of age-related skeletal change of the human pelvis, and shows that the pubic symphysis may be a more reliable indicator of age in obese individuals and that greater standard deviations are needed for obese individuals when estimating age-at-death from the pelvis. Am J Phys Anthropol 156:595–605, 2015. © 2014 Wiley Periodicals, Inc.     

Erythrocyte ouabain binding and intracellular Na+ in normotensive obese women and obese women receiving medication for hypertension

People with "primary obesity" may be hypertensive because they have lost their ability to compensate for the effect of low Na+-K+-ATPase levels on blood pressure. In obese patients receiving hypertensive medication (n = 13), but not in normotensive nonmedicated patients (n = 42), diastolic blood pressure was inversely correlated with erythrocyte ouabain binding (P less than 0.02) and directly correlated with intracellular Na+ concentration (P less than 0.01). Moreover, there was a stronger inverse relationship between ouabain binding and intracellular Na+ in patients receiving medication for hypertension (P less than 0.01) than in normotensive patients (P less than 0.05). These data suggest that patients receiving hypertensive medication may be less able to compensate than normotensive patients, (a) for the potential effect of Na+-K+-ATPase levels on intracellular Na+ and (b) for the potential effect of intracellular Na+ concentration on diastolic blood pressure. We propose that obese people with low levels of ouabain binding (primary obesity) may have an increased risk of developing hypertension if their compensatory mechanisms fail.     

Does smoking affect body weight and obesity in China?

An inverse relationship between smoking and body weight has been documented in the medical literature, but the effect of cigarette smoking on obesity remains inconclusive. In addition, the evidence is mixed on whether rising obesity rates are an unintended consequence of successful anti-smoking policies. This study re-examines these relationships using data from China, the largest consumer and manufacturer of tobacco in the world that is also experiencing a steady rise in obesity rates. We focus on the impact of the total number of cigarettes smoked per day on individuals’ body mass index (BMI) and on the likelihood of being overweight and obese. Instrumental variables estimation is used to correct for the endogeneity of cigarette smoking. We find a moderate negative and significant relationship between cigarette smoking and BMI. Smoking is also negatively related to being overweight and obese, but the marginal effects are small and statistically insignificant for being obese. Quantile regression analyses reveal that the association between smoking and BMI is quite weak among subjects whose BMIs are at the high end of the distribution but are considerably stronger among subjects in the healthy weight range. Ordered probit regression analyses also confirm these findings. Our results thus reconcile an inverse average effect of smoking on body weight with the absence of any significant effect on obesity. From a policy perspective these findings suggest that, while smoking cessation may lead to moderate weight gain among subjects of healthy weight, the effects on obese subjects are modest and should not be expected to lead to a large increase in obesity prevalence rates.     

Visceral fat accumulation induced by a high-fat diet causes the atrophy of mesenteric lymph nodes in obese mice

Objective: A high intake of fat in the diet plays a crucial role in promoting obesity and obesity‐related pathologies, and especially visceral obesity is closely associated with obesity‐related complications. Because adipose tissue is anatomically associated with lymph nodes, the secondary lymphoid organ, we hypothesized that fat tissue‐derived factors may influence the cellularity of lymphoid tissue embedded in fat. Methods and Procedures: Mesenteric and inguinal lymph nodes were isolated from obese mice fed a high‐fat diet and control mice fed a regular diet. T‐cell population, activation state, and the extent of apoptosis were determined by flow cytometric analysis or terminal deoxynucleotidyl transferase biotin‐dUTP nick end labeling (TUNEL) assay. Results: The weight of mesenteric lymph nodes and the total number of lymphoid cells in the obese mice significantly decreased compared with those in the control mice; however, no change was observed in the weight of inguinal lymph nodes. The numbers of CD4⁺ and CD8⁺ T cells in the mesenteric lymph nodes of obese mice significantly decreased compared with those of the control. Enhanced T‐cell activation and apoptosis were observed in the mesenteric lymph node cells of the obese mice. The treatment of lymph node cells with free fatty acids, oxidative stress, and chylomicrons, which are obesity‐related factors, resulted in lymph node T‐cell activation and apoptosis. Discussion: These results suggest that visceral fat accumulation with a high‐fat diet can cause the atrophy of mesenteric lymph nodes by enhancing activation‐induced lymphoid cell apoptosis. Dietary fat‐induced visceral obesity may be crucial for obesity‐related immune dysfunction.     

Effects of high fat diet induced obesity on peripheral nerve regeneration and levels of GAP 43 and TGF-β in rats

The increasing frequency of obesity is important because of its accompanying related health problems. The effects of obesity on peripheral nerves have not been elucidated. We investigated the effects of obesity on sciatic nerve regeneration using electrophysiology, stereology, immunohistochemistry, histopathology and functional tests. We used control, obese, control injured and obese injured groups of rats. Electrophysiological results showed that nerve conduction velocity and EMG were same in the experimental groups, but the amplitude of the compound action potential of the control group was significantly higher than that of the obese group. Examination of the nerves showed that the control and obese groups had both larger axon diameters and thicker myelin sheaths. The number of myelinated axons was decreased in both of the injured groups. Axon diameters and myelin sheath thicknesses of the control injured group were significantly greater those of the obese injured group. There were no significant differences in functional tests among the groups. Although growth associated protein 43 immunostaining in the control injured group was significantly greater than that of the obese injured group, no significant difference was observed between the control and obese groups. There was no significant difference in immunohistochemical staining for transforming growth factor beta 3 between the control injured and obese injured groups. Our results suggest that obesity may affect peripheral nerve regeneration negatively after crush injury.     

Weight Status Continuity and Change From Adolescence to Young Adulthood: Examining Disease and Health Risk Conditions

This study examined weight status during adolescence and young adulthood, and young adult health condition diagnosis. Data are from 10,439 African‐American, Hispanic, and white men and women participating in the National Longitudinal Study of Adolescent Health during Waves 1 (adolescence: ages 12–19) and 3 (young adulthood: ages 19–26). Categories were created differentiating individuals based on their weight status during adolescence and young adulthood: (i) obese during adolescence and young adulthood (i.e., continuously obese), (ii) obese during adolescence only, (iii) obese during young adulthood only, and (iv) never obese. Multilevel random intercept regression models were used to examine the impact of obesity category, sex, and race/ethnicity on young adult asthma, diabetes, high cholesterol, and high blood pressure. Continuous obesity increased the likelihood for young adult disease and health risk conditions compared to individuals who were never obese. Obesity isolated to adolescence (Wave 1) increased the likelihood for high cholesterol and high blood pressure, whereas obesity isolated to young adulthood (Wave 3) also increased the likelihood for diabetes—all increases were relative to nonobese weight status during both periods. Associations varied in direction and degree when sex and race/ethnicity were considered. Findings clarify some of the mixed understandings regarding the associations between age of onset and stability of obesity, and health outcomes with important public health implications. Although results indicate obesity isolated to a single developmental period does have health repercussions, obesity experienced continuously during adolescence and young adulthood greatly intensified risk across all health conditions.     

Impact of obesity on health-related quality of life in schizophrenia and bipolar disorder

Objective: Studies have reported that up to 60% of individuals with schizophrenia and 68% of those with bipolar disorder are overweight/obese. This paper explores the health‐related quality of life (HRQOL) of individuals with schizophrenia or bipolar disorder as a function of obesity status. Methods and Procedures: Two hundred and eleven participants were recruited from four psychiatric programs (outpatient, day treatment, case management, and psychosocial rehabilitation). HRQOL was assessed using both a general measure (Medical Outcomes Study Short‐Form‐36 (SF‐36)) and a weight‐related measure (Impact of Weight on Quality of Life‐Lite (IWQOL‐Lite)). To interpret HRQOL scores obtained by the obese group, we compared scores to those obtained by reference groups from the weight‐loss literature. Results: Sixty‐three percent of participants with schizophrenia and 68% of those with bipolar disorder were obese. Obese participants were more likely to be women, on mood stabilizers, taking a greater number of psychiatric medications, and to have poorer weight‐related and general HRQOL. Weight‐related HRQOL in the obese psychiatric sample was more impaired than in outpatient and day treatment samples seeking weight loss but less impaired than in gastric‐bypass patients. Several of the physical domains of general HRQOL were more impaired for the obese psychiatric sample than for the outpatient weight‐loss sample. However, physical functioning was less impaired for the obese psychiatric sample than for gastric‐bypass patients. Discussion: The presence of obesity among individuals with schizophrenia or bipolar disorder is associated with decreased HRQOL. These results have implications for prevention and management of weight gain in individuals with schizophrenia or bipolar disorder.