Gender‐Specific Association of a Perilipin Gene Haplotype with Obesity Risk in a White Population

Objective: Perilipin is a class of protein‐coating lipid droplets in adipocytes and steroidogenic cells. Our purpose was to examine the association between common single‐nucleotide polymorphisms (SNPs) at the perilipin (PLIN) locus and obesity, as well as related phenotypes, in unrelated American adults. Research Methods and Procedures: Four PLIN SNPs (PLIN 6209T>C, 11482G>A, 13041A>G, and 14995A>T) were typed in 734 white subjects (373 men and 361 women) attending a residential lifestyle intervention program. The baseline anthropometric and biochemical measures were used. Obesity was defined as BMI ≥ 30 kg/m². Results: Multivariate analysis demonstrated that, in women, two of the SNPs (13041A>G, and 14995A>T) were significantly associated with percentage body fat (p = 0.016 for 13041A>G and p = 0.010 for 14995A>T) and waist circumference (p = 0.020 for 13041A>G and p = 0.045 for 14995A>T). Moreover, haplotype analysis using these two SNPs indicated that haplotypes A/T and G/T were both associated with significantly increased obesity risk (odds ratio = 1.76, 95% confidence interval 1.07 to 2.90 for haplotype A/T, and odds ratio = 1.73, 95% confidence interval 1.06 to 2.82 for haplotype G/T) when compared with haplotype A/A. No significant associations between PLIN variations and obesity were found in men. Discussion: Our data support the hypothesis that the PLIN locus may be a significant genetic determinant for obesity risk in whites and that women are more sensitive to the genetic effects of perilipin than men.     

Gender‐specific Effect of Obesity on Balance

Obesity modifies the body geometry by adding mass to different regions and it influences the biomechanics of activities of daily living. Weight influences postural stability, but there is no consensus as to whether the different fat distribution in males and females produces gender‐related effects on balance. The aim of this study was to investigate the effect of body weight increases on postural performance in males and females. A total of 22 obese females (BMI: 41.1 ± 4.1 kg/m²) and 22 obese males (BMI: 40.2 ± 5 kg/m²) were analyzed during a static posture trial on a force platform in standardized conditions. Twenty healthy subjects (10 females, 10 males) constituted the control group. We computed the following parameters related to the center of pressure (CoP): velocity and displacements along the antero‐posterior (AP) and medio‐lateral axis (ML). We found several statistically significant differences between healthy and obese men, in particular regarding the AP and ML CoP parameters, which were correlated to body weight (r = 0.36–0.58). The comparison between healthy and obese females pointed out statistically significant differences in AP parameters and no significant differences in ML displacements. Body weight was found to correlate with AP parameters (r = 0.36–0.74), but not with ML displacements. The increased body mass seems to produce AP instability in both genders and ML destabilization only in males. Rehabilitation programs should take these findings into account by adopting specific interventions to improve ML control in obese males, and through weight loss and strengthening of ankle flexors/extensors in both genders.     

Effects of Nutritional Supplementation during Pregnancy on Early Adult Disease Risk: Follow Up of Offspring of Participants in a Randomised Controlled Trial Investigating Effects of Supplementation on Infant Birth Weight

Background

Observational evidence suggests that improving fetal growth may improve adult health. Experimental evidence from nutritional supplementation trials undertaken amongst pregnant women in the less developed world does not show strong or consistent effects on adult disease risk and no trials from the more developed world have previously been reported.

Objective

To test the hypothesis that nutritional supplementation during pregnancy influences offspring disease risk in adulthood

Design

Clinical assessment of a range of established diseases risk markers in young adult offspring of 283 South Asian mothers who participated in two trials of nutritional supplementation during pregnancy (protein/energy/vitamins; energy/vitamins or vitamins only) at Sorrento Maternity Hospital in Birmingham UK either unselected or selected on the basis of nutritional status.

Results

236 (83%) offspring were traced and 118 (50%) of these were assessed in clinic. Protein/energy/vitamins supplementation amongst undernourished mothers was associated with increased infant birthweight. Nutritional supplementation showed no strong association with any one of a comprehensive range of markers of adult disease risk and no consistent pattern of association with risk across markers in offspring of either unselected or undernourished mothers.

Conclusions

We found no evidence that nutritional supplements given to pregnant women are an important influence on adult disease risk however our study lacked power to estimate small effects. Our findings do not provide support for a policy of nutritional supplementation for pregnant women as an effective means to improve adult health in more developed societies.     

Decision‐Making Deficits and Overeating: A Risk Model for Obesity

Objective: To demonstrate that human overeating is not just a passive response to salient environmental triggers and powerful physiological drives; it is also about making choices. The ventromedial prefrontal cortex has been strongly implicated in the neural circuitry necessary for making advantageous decisions when various options for action are available. Decision‐making deficits have been found in patients with ventromedial prefrontal cortex lesions and in those with substance dependence—impairments that reflect an inability to advantageously assess future consequences. That is, they choose immediate rewards in the face of future long‐term negative consequences. Research Methods and Procedures: We extended this research to the study of overeating and overweight, testing a regression model that predicted that poor decision making (as assessed by a validated computerized gambling task) and a tendency to overeat under stress would correlate with higher BMI in a group of healthy adult women (N = 41) representing a broad range of body weights. Results: We found statistically significant main effects for both independent variables in the predicted direction (p < 0.05; R² = 0.35). Indeed, the decision‐making impairments across the 100 trials of the computer task were greater in those with high BMI than in previous studies with drug addicts. Discussion: Findings suggested that cortical and subcortical processes, which regulate one's ability to inhibit short‐term rewards when the long‐term consequences are deleterious, may also influence eating behaviors in a culture dominated by so many, and such varied, sources of palatable and calorically dense sources of energy.     

Adult Obesity and Office‐based Quality of Care in the United States

Nationally representative data on the quality of care for obese patients in US‐ambulatory care settings are limited. We conducted a cross‐sectional analysis of the 2005 and 2006 National Ambulatory Medical Care Survey (NAMCS). We examined obesity screening, diagnosis, and counseling during adult visits and associations with patient and provider characteristics. We also assessed performance on 15 previously published ambulatory quality indicators for obese vs. normal/overweight patients. Nearly 50% (95% confidence interval (CI): 46–54%) of visits lacked complete height and weight data needed to screen for obesity using BMI. Of visits by patients with clinical obesity (BMI ≥30.0 kg/m²), 70% (66–74%) were not diagnosed and 63% (59–68%) received no counseling for diet, exercise, or weight reduction. The percentage of visits not being screened (48%), diagnosed (66%), or counseled (54%) for obesity was also notably higher than expected even for patients with known obesity comorbidities. Performance (defined as the percentage of applicable visits receiving appropriate care) on the quality indicators was suboptimal overall. In particular, performance was no better than 50% for eight quality indicators, which are all related to the prevention and treatment of obesity comorbidities, e.g., coronary artery disease, hypertension, hyperlipidemia, asthma, and depression. Performance did not differ by weight status for any of the 15 quality indicators; however, poorer performance was consistently associated with lack of height and weight measurements. In conclusion, many opportunities are missed for obesity screening and diagnosis, as well as for the prevention and treatment of obesity comorbidities, in office‐based practices across the United States, regardless of patient and provider characteristics.     

Eleven‐year Prevalence Trends of Obesity in Greek Children: First Evidence that Prevalence of Obesity Is Leveling Off

We examined 11‐year (1997–2007) trends in underweight, overweight, and obesity in Greek children. Population data derived from a yearly, school‐based health survey carried out between 1997 and 2007 in >80% of all Greek schools. Height and weight measurements from 651,582 children, aged 8–9 years (boys: 51.2%) were analyzed. The gender‐ and age‐specific BMI cutoff points by the International Obesity Task Force (IOTF) were used in order to define underweight, normal weight, overweight, and obesity. Trend analysis showed an increase in the prevalence of obesity from 7.2 ± 0.2% in 1997 to 11.3 ± 0.2% in 2004 for girls (P < 0.001) and from 8.1 ± 0.2% in 1997 to 12.3 ± 0.2% in 2004 for boys (P < 0.001). An apparent leveling off in obesity rates was observed during 2004–2007 for both boys and girls. The prevalence of overweight rose between 1997 and 2007 from 20.2 ± 0.2% to 26.7 ± 0.2% for girls (P < 0.001) and from 19.6 ± 0.2% to 26.5 ± 0.2% for boys (P < 0.001). The overall prevalence of thinness in the same period remained constant in both sexes. The presented population‐based data revealed that the prevalence of overweight and obesity among 8‐ to 9‐year‐old Greek children is alarmingly elevated, with the overweight rates rising continuously. However, an apparent leveling off in obesity rates for the past 4 consecutive years was documented for the first time in both genders.     

Treatment of Morbid Obesity in Low‐income Adolescents: Effects of Parental Self‐monitoring

Objective: This study examined the extent to which consistency of self‐monitoring by participants and their parents was related to weight control over an initial period of 3 months within the context of a treatment program for morbidly obese low‐income minority adolescents. Research Methods and Procedures: Eighty‐three obese adolescents (mean age, 13.0 years; 51% boys; 92% African American; mean BMI, 43.0 kg/m²; mean BMI z‐score, 6.0) and at least one parent participated in a long‐term treatment program that included a very‐low‐fat dietary focus, weekly group cognitive‐behavior therapy, monthly nutrition education classes, a 12‐week physical therapy class, and medical monitoring. Results: Participants who self‐monitored on the majority of days compared with those who did not self‐monitor at all or who self‐monitored infrequently attended more sessions and generally lost more weight over the first 3 months. Although parents signed behavioral contracts committing to self‐monitor their own eating and exercising over the first month, only 12% did so. Nonetheless, participants whose parents self‐monitored were much more likely to self‐monitor consistently and lose weight during the first 3 months. Discussion: These results indicate that self‐monitoring is a cornerstone of successful weight control even for morbidly obese low‐income minority adolescents; targeting consistency of self‐monitoring among these high‐risk weight controllers and their parents should be just as important as it is for more affluent and less overweight adolescents.     

Parental Feeding Style and the Inter‐generational Transmission of Obesity Risk

Objective: This study was designed to determine whether a community sample of obese mothers with young children used different feeding styles compared with a matched sample of normal‐weight mothers. Four aspects of feeding style were assessed: emotional feeding, instrumental feeding (using food as a reward), prompting/encouragement to eat, and control over eating. Research Methods and Procedures: Participants were from 214 families with same‐sex twins; 100 families in which both parents were overweight or obese and 114 in which both parents were normal weight or lean. Results: We found that obese mothers were no more likely than normal‐weight mothers to offer food to deal with emotional distress, use food as a form of reward, or encourage the child to eat more than was wanted. The obese and normal‐weight mothers did differ on “control”; obese mothers reported significantly less control over their children's intake, and this was seen for both first‐born and second‐born twins. Twin analyses showed that these differences were not in response to children's genetic propensities, because monozygotic correlations were no greater than dizygotic correlations for maternal feeding style. Discussion: These results suggest that the stereotype of the obese mother, who uses food in nonnutritive ways so that her child also becomes obese, is more likely to be myth than fact. However, the results raise the possibility that lack of control of food intake might contribute to the emergence of differences in weight.     

Obesity and Risk of Colorectal Cancer: A Systematic Review of Prospective Studies

Background

Mounting evidence indicates that obesity may be associated with the risk of colorectal cancer (CRC). To conduct a systematic review of prospective studies assessing the association of obesity with the risk of CRC using meta-analysis.

Methodology/Principal Findings

Relevant studies were identified by a search of MEDLINE and EMBASE databases before January 2012, with no restrictions. We also reviewed reference lists from retrieved articles. We included prospective studies that reported relative risk (RR) estimates with 95% confidence intervals (CIs) for the association between general obesity [measured using body mass index (BMI)] or central obesity [measured using waist circumference (WC)] and the risk of colorectal, colon, or rectal cancer. Approximately 9, 000, 000 participants from several countries were included in this analysis. 41 studies on general obesity and 13 studies on central obesity were included in the meta-analysis. The pooled RRs of CRC for the obese vs. normal category of BMI were 1.334 (95% CI, 1.253–1.420), and the highest vs. lowest category of WC were 1.455 (95% CI, 1.327–1.596). There was heterogeneity among studies of BMI (P<0.001) but not among studies of WC (P = 0.323).

Conclusions

Both of general and central obesity were positively associated with the risk of CRC in this meta-analysis.     

Hand‐Rearing Wild Caribou Calves for Studies of Nutritional Ecology

Caribou (Rangifer tarandus) are considered difficult to hand‐rear in captivity because they are sensitive to the composition and volume of formulated milks. We used a strict feeding schedule and a commercial milk formula designed specifically for caribou to bottle‐feed neonates captured from five wild caribou herds in Alaska. Under a feeding protocol adjusted for age and mass, the growth rates and body mass of 26 hand‐reared caribou calves to weaning were similar to those of three maternally nursed caribou. This protocol allows caretakers to hand‐rear caribou that are as representative as possible of maternally raised neonates. Zoo Biol. 32:163–171, 2013. © 2012 Wiley Periodicals, Inc.     

The Longitudinal Association From Obesity to Depression: Results From the 12‐year National Population Health Survey

Prior observational studies have investigated the association between obesity and depression but evidence remains weak and mixed. There has been a call for high‐quality longitudinal studies to elucidate the etiologic relationship from obesity to depression. The main objective of this study was therefore to investigate whether obesity was a risk factor for depression in a nationally representative sample followed for 12 years. Seven waves of data collection (1994–1995 to 2006–2007) were obtained from the National Population Health Survey (NPHS). Our analyses included 10,545 adults without depression at baseline. Past‐year major depression episode (MDE) was assessed from the Composite International Diagnostic Interview‐Short Form for Major Depression (CIDI‐SFMD). Obesity was estimated using baseline BMI from self‐reported weight and height (obesity: BMI ≥30 kg/m²). Kaplan–Meier survival curves were generated and Cox proportional hazard regression modeling was used to estimate the risk of MDE by obesity status, controlling for sociodemographic and health and lifestyle variables. We found that obesity at baseline did not significantly predict subsequent MDE in women (adjusted hazard ratio (AHR): 1.03, 95% confidence interval (CI) 0.84–1.26) and negatively predicted MDE in men (HR: 0.71, CI 0.51–0.98), after adjusting for important confounders. In summary, our findings suggest that obesity is a significant (negative) predictor of depression in adult men but not in women. These results moderate prior evidence supporting a positive link from obesity to depression.     

Obesity and Depression in US Women: Results From the 2005–2006 National Health and Nutritional Examination Survey

Research is needed to better elucidate the relationship between obesity and depression, which has been most consistently demonstrated for women, but not for men. We examined exclusively a population‐based sample of US women who participated in the 2005 or 2006 National Health and Nutritional Examination Survey. Current depression was defined as having a score of ≥10 (a conventional threshold for moderate symptoms of depression) or meeting the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM‐IV) diagnostic criteria for major depression on the nine‐item Patient Health Questionnaire. Weight and height were measured and BMI was calculated. Waist circumference, a clinical measure of abdominal obesity, was also measured. BMI was positively associated with the probability of moderate/severe depressive symptoms (r = 0.49, P = 0.03) and major depression (r = 0.72, P < 0.0001). The probability curves increased progressively, beginning at BMI of 30. Degree of obesity was an independent risk factor for depression even within the obese population, and women in obesity class 3 (BMI ≥40) were at particular risk (odds ratio (OR) = 4.91, 95% confidence interval (CI): 1.17–20.57), compared to those in obesity class 1 (BMI 30 to <35). Abdominal obesity was positively associated with depressive symptoms, but not major depression, independent of general obesity (BMI). In addition to severe obesity, compromised physical health status, young or middle‐aged adulthood, low income, and relatively high education were also independently associated with greater odds of depressive symptoms among obese women. These characteristics may identify specific at‐risk subgroups of obese women in which hypothesized causal pathways and effective preventive and therapeutic interventions can be profitably investigated.     

Diet‐Dependent Genetic and Genomic Imprinting Effects on Obesity in Mice

Although the current obesity epidemic is of environmental origin, there is substantial genetic variation in individual response to an obesogenic environment. In this study, we perform a genome‐wide scan for quantitative trait loci (QTLs) affecting obesity per se, or an obese response to a high‐fat diet in mice from the LG/J by SM/J Advanced Intercross (AI) Line (Wustl:LG, SM‐G16). A total of 1,002 animals from 78 F₁₆ full sibships were weaned at 3 weeks of age and half of each litter placed on high‐ and low‐fat diets. Animals remained on the diet until 20 weeks of age when they were necropsied and the weights of the reproductive, kidney, mesenteric, and inguinal fat depots were recorded. Effects on these phenotypes, along with total fat depot weight and carcass weight at necropsy, were mapped across the genome using 1,402 autosomal single‐nucleotide polymorphism (SNP) markers. Haplotypes were reconstructed and additive, dominance, and imprinting genotype scores were derived every 1 cM along the F₁₆ map. Analysis was performed using a mixed model with additive, dominance, and imprinting genotype scores, their interactions with sex, diet, and with sex‐by‐diet as fixed effects and with family and its interaction with sex, diet, and sex‐by‐diet as random effects. We discovered 95 trait‐specific QTLs mapping to 40 locations. Most QTLs had additive effects with dominance and imprinting effects occurring at two‐thirds of the loci. Nearly every locus interacted with sex and/or diet in important ways demonstrating that gene effects are primarily context dependent, changing depending on sex and/or diet.     

Adipose Tissue Dysfunction Occurs Independently of Obesity in Adipocyte‐Specific Oncostatin Receptor Knockout Mice

Objective

This study examined the phenotypic effects of adipocyte‐specific oncostatin M receptor (OSMR) loss in chow‐fed mice.

Methods

Chow‐fed adipocyte‐specific OSMR knockout (FKO) mice and littermate OSMR^fl/fl controls were studied. Tissue weights, insulin sensitivity, adipokine production, and stromal cell immunophenotypes were assessed in epididymal fat (eWAT); serum adipokine production was also assessed. In vitro, adipocytes were treated with oncostatin M, and adipokine gene expression was assessed.

Results

Body weights, fasting blood glucose levels, and eWAT weights did not differ between genotypes. However, the eWAT of OSMR^FKO mice was modestly less responsive to insulin stimulation than that of OSMR^fl/fl mice. Notably, significant increases in adipokines, including C‐reactive protein, lipocalin 2, intercellular adhesion molecule‐1, and insulinlike growth factor binding protein 6, were observed in the eWAT of OSMR^FKO mice. In addition, significant increases in fetuin A and intercellular adhesion molecule‐1 were detected in OSMR^FKO serum. Flow cytometry revealed a significant increase in leukocyte number and modest, but not statistically significant, increases in B cells and T cells in the eWAT of OSMR^FKO mice.

Conclusions

The chow‐fed OSMR^FKO mice exhibited adipose tissue dysfunction and increased proinflammatory adipokine production. These results suggest that intact adipocyte oncostatin M–OSMR signaling is necessary for adipose tissue immune cell homeostasis.

     

The Bias in Self‐reported Obesity From 1976 to 2005: A Canada–US Comparison

The objective of this study was to determine whether the bias in self‐reported estimates of obesity has changed over time and followed different patterns in Canada and the United States. Using age‐standardized data from three waves of the National Health and Nutrition Examination Survey (NHANES) in the United States and the Canadian Community Health Survey (CCHS) and the Canadian Heart Health Survey (CHHS) in Canada, discrepancies were compared between reported and measured estimates of height, weight, and obesity (based on the BMI) from 1976 to 2005. Results indicated that obesity increased in both countries, but rates were higher in the United States. The discrepancy between self‐reported and measured obesity was small in the United States with reported data underestimating measured prevalence by about 3%; this stayed relatively constant over time. In Canada, the discrepancy was large and doubled in the past decade (from 4 to 8%). In the United States, self‐reported data may be more accurate in monitoring changes in obesity over time, as the estimates have consistently remained about 3% below the measured estimates, whereas in Canada, monitoring obesity based solely on self‐reported height and weight may produce inaccurate estimates because of the increasing discrepancy between self‐reported and measured data.