Trends in obesity and extreme obesity among US adults

Dynamic regulation of the extracellular matrix in reward memory processes: a question of time

Substance use disorders are a global health problem with increasing prevalence resulting in significant socioeconomic burden and increased mortality. Converging lines of evidence point to a critical role of brain extracellular matrix (ECM) molecules in the pathophysiology of substance use disorders. An increasing number of preclinical studies highlight the ECM as a promising target for development of novel cessation pharmacotherapies. The brain ECM is dynamically regulated during learning and memory processes, thus the time course of ECM alterations in substance use disorders is a critical factor that may impact interpretation of the current studies and development of pharmacological therapies. This review highlights the evidence for the involvement of ECM molecules in reward learning, including drug reward and natural reward such as food, as well as evidence regarding the pathophysiological state of the brain's ECM in substance use disorders and metabolic disorders. We focus on the information regarding time-course and substance specific changes in ECM molecules and how this information can be leveraged for the development of therapeutic strategies.

Eating Frequency Is Not Associated with Obesity in Chinese Adults

The prevalence of overweight and obesity has been increasing globally. Recent studies suggest that eating frequency (EF) might be a factor influencing the development of overweight and obesity. This study aims to explore the association between eating frequency and obesity in Chinese adults. A cross-sectional study was conducted in Wuhan, China, from March to June 2016. A self-administered questionnaire and 24-h dietary recall were used to collect data on sociodemographic variables, lifestyle factors, nutrition knowledge, and eating frequency. Participants were divided into four groups according to eating frequency and meal timing: traditional time pattern (TTP), traditional time plus late snack pattern (TTLSP), irregular time pattern (ITP), and all-day pattern (ADP). We performed the chi-squared test and multiple logistic regression to assess associations among variables using JMP statistical software version 14.0.0 (SAS Institute Inc., Cary, NC, USA). Respondents were Chinese adults (N = 2290; range 29⁻74 years; 1162 men). Lower education level, higher food budget, and lower nutrition knowledge were associated with higher likelihood of irregular EF patterns (TTLSP, ITP, or ADP). Men, non-smokers, and participants with less physical activity, lower education level, or lower nutrition knowledge were more likely to be obese. Body mass index (BMI) categorization was significantly different among EF pattern groups (χ² = 25.40, p = 0.003); however, this association was no longer significant in the regression model after adjustment for age, sex, education, smoking, food budget, nutrition knowledge, and physical activity. Thus, EF is not associated with obesity in Chinese adults.

Single-plane retroperitoneoscopic adrenalectomy: a new operative procedure for benign adrenal disease

To evaluate the therapeutic effect of single-plane retroperitoneoscopic adrenalectomy. From February 2014 to March 2017, 251 patients underwent single-plane retroperitoneoscopic adrenalectomy, and their operative outcomes were compared with those of 98 patients who underwent anatomical three-plane retroperitoneoscopic adrenalectomy. Among 35 patients with a body mass index (BMI) of ≥30 kg/m², their operative outcomes were compared between two operative procedures. The demographic data and perioperative outcomes of the patients were statistically analysed. The single-plane and three-plane groups were comparable in terms of estimated blood loss, time to oral intake, hospital stay, and incidence of complications among patients with similar baseline demographics. The single-plane group had a significantly shorter operation time (46.9 ± 5.8 vs 54.8 ± 7.0 mins, P < 0.0001) and lower analgesia requirement (56/251 vs 33/98, p = 0.03). For obese patients with a BMI of ≥30 kg/m², single-plane adrenalectomy was also associated with a significantly shorter operation time(48.1 ± 6.2 vs 64.1 ± 5.1 mins, p < 0.0001). Single-plane retroperitoneoscopic adrenalectomy is feasible, safe, and effective in the treatment of adrenal masses <5 cm in size and provides a shorter operation time and better pain control than anatomical retroperitoneal adrenalectomy, especially in obese patients.

Role of Epicardial Adipose Tissue in Health and Disease: A Matter of Fat?

Epicardial adipose tissue (EAT) is a small but very biologically active ectopic fat depot that surrounds the heart. Given its rapid metabolism, thermogenic capacity, unique transcriptome, secretory profile, and simply measurability, epicardial fat has drawn increasing attention among researchers attempting to elucidate its putative role in health and cardiovascular diseases. The cellular crosstalk between epicardial adipocytes and cells of the vascular wall or myocytes is high and suggests a local role for this tissue. The balance between protective and proinflammatory/profibrotic cytokines, chemokines, and adipokines released by EAT seem to be a key element in atherogenesis and could represent a future therapeutic target. EAT amount has been found to predict clinical coronary outcomes. EAT can also modulate cardiac structure and function. Its amount has been associated with atrial fibrillation, coronary artery disease, and sleep apnea syndrome. Conversely, a beiging fat profile of EAT has been identified. In this review, we describe the current state of knowledge regarding the anatomy, physiology and pathophysiological role of EAT, and the factors more globally leading to ectopic fat development. We will also highlight the most recent findings on the origin of this ectopic tissue, and its association with cardiac diseases. © 2017 American Physiological Society. Compr Physiol 7:1051-1082, 2017.

Effects of a tailored lifestyle self-management intervention (TALENT) study on weight reduction: a randomized controlled trial

OBJECTIVE

Overweight and obesity are globally increasing risk factors for diseases in the context of metabolic syndrome. A randomized controlled trial was conducted to investigate whether there are any existing differences between two lifestyle intervention strategies with respect to weight reduction after 1 year.

SUBJECTS AND METHODS

A total of 166 subjects with a body mass index of 28-35 kg/m² were enrolled in this trial at seven study centers; 109 were randomly allocated to the intervention group (comprehensive lifestyle modification program: web-based Individual Health Management [IHM]) with 3-month reduction phase plus 9-month maintenance phase, and 57 were allocated to the control group (written information with advice for healthy food habits: usual care [UC]). Body weight, waist circumference, blood pressure, laboratory findings, and bioimpedance analysis used to determine body composition were measured at baseline and after 3, 6, 9, and 12 months. The primary outcome parameter was body weight at month 12 compared to baseline.

RESULTS

With respect to baseline status there were no statistically significant differences between the groups. Based on the intent-to-treat population, body weight showed a mean decrease of 8.7 kg (SD 6.1) in the intervention group (IHM) and 4.2 kg (SD 5) in the control group (UC) at month 12. This statistically significant difference (P<0.001) was confirmed by various sensitivity analyses. Body mass index, waist circumference, high-density lipid cholesterol, body fat, and the ratio of fat and body cell mass improved to a significantly higher degree in the IHM group.

CONCLUSION

IHM proved to be superior to UC in weight reduction after 1 year. With a mean loss of about 10% of the baseline weight, a clinically high relevant risk reduction for cardio-metabolic diseases is achievable.

Maternal Fat Feeding Augments Offspring Nephron Endowment in Mice

Increasing consumption of a high fat 'Western' diet has led to a growing number of pregnancies complicated by maternal obesity. Maternal overnutrition and obesity have health implications for offspring, yet little is known about their effects on offspring kidney development and renal function. Female C57Bl6 mice were fed a high fat diet (HFD, 21% fat) or matched normal fat diet (NFD, 6% fat) for 6 weeks prior to pregnancy and throughout gestation and lactation. HFD dams were overweight and glucose intolerant prior to mating but not in late gestation. Offspring of NFD and HFD dams had similar body weights at embryonic day (E)15.5, E18.5 and at postnatal day (PN)21. HFD offspring had normal ureteric tree development and nephron number at E15.5. However, using unbiased stereology, kidneys of HFD offspring were found to have 20-25% more nephrons than offspring of NFD dams at E18.5 and PN21. Offspring of HFD dams with body weight and glucose profiles similar to NFD dams prior to pregnancy also had an elevated nephron endowment. At 9 months of age, adult offspring of HFD dams displayed mild fasting hyperglycaemia but similar body weights to NFD offspring. Renal function and morphology, measured by transcutaneous clearance of FITC-sinistrin and stereology respectively, were normal. This study demonstrates that maternal fat feeding augments offspring nephron endowment with no long-term consequences for offspring renal health. Future studies assessing the effects of a chronic stressor on adult mice with augmented nephron number are warranted, as are studies investigating the molecular mechanisms that result in high nephron endowment.

Organic Cation Transporter 2 Overexpression May Confer an Increased Risk of Gentamicin-Induced Nephrotoxicity

Nephrotoxicity is a relevant limitation of gentamicin, and obese patients have an increased risk for gentamicin-induced kidney injury. This damage is thought to depend on the accumulation of the drug in the renal cortex. Obese rats showed substantially higher levels of gentamicin in the kidney than did lean animals. This study characterized the role of organic cation transporters (OCTs) in gentamicin transport and elucidated their possible contribution in the increased renal accumulation of gentamicin in obesity. The mRNA and protein expression levels of the organic cation transporters Oct2 (Slc22a2) and Oct3 (Slc22a3) were increased in kidney samples from obese mice fed a high-fat diet. Similarly, OCT2 (∼2-fold) and OCT3 (∼3-fold) showed increased protein expression in the kidneys of obese patients compared with those of nonobese individuals. Using HEK293 cells overexpressing the different OCTs, human OCT2 was found to transport [(3)H]gentamicin with unique sigmoidal kinetics typical of homotropic positive cooperativity (autoactivation). In mouse primary proximal tubular cells, [(3)H]gentamicin uptake was reduced by approximately 40% when the cells were coincubated with the OCT2 substrate metformin. The basolateral localization of OCT2 suggests that gentamicin can enter proximal tubular cells from the blood side, probably as part of a slow tubular secretion process that may influence intracellular drug concentrations and exposure time. Increased expression of OCT2 may explain the higher accumulation of gentamicin, thereby conferring an increased risk of renal toxicity in obese patients.

Mitochondrial Reactive Oxygen Species Mediate Cardiac Structural, Functional, and Mitochondrial Consequences of Diet-Induced Metabolic Heart Disease

BACKGROUND

Mitochondrial reactive oxygen species (ROS) are associated with metabolic heart disease (MHD). However, the mechanism by which ROS cause MHD is unknown. We tested the hypothesis that mitochondrial ROS are a key mediator of MHD.

METHODS AND RESULTS

Mice fed a high-fat high-sucrose (HFHS) diet develop MHD with cardiac diastolic and mitochondrial dysfunction that is associated with oxidative posttranslational modifications of cardiac mitochondrial proteins. Transgenic mice that express catalase in mitochondria and wild-type mice were fed an HFHS or control diet for 4 months. Cardiac mitochondria from HFHS-fed wild-type mice had a 3-fold greater rate of H2O2 production (P=0.001 versus control diet fed), a 30% decrease in complex II substrate-driven oxygen consumption (P=0.006), 21% to 23% decreases in complex I and II substrate-driven ATP synthesis (P=0.01), and a 62% decrease in complex II activity (P=0.002). In transgenic mice that express catalase in mitochondria, all HFHS diet-induced mitochondrial abnormalities were ameliorated, as were left ventricular hypertrophy and diastolic dysfunction. In HFHS-fed wild-type mice complex II substrate-driven ATP synthesis and activity were restored ex vivo by dithiothreitol (5 mmol/L), suggesting a role for reversible cysteine oxidative posttranslational modifications. In vitro site-directed mutation of complex II subunit B Cys100 or Cys103 to redox-insensitive serines prevented complex II dysfunction induced by ROS or high glucose/high palmitate in the medium.

CONCLUSION

Mitochondrial ROS are pathogenic in MHD and contribute to mitochondrial dysfunction, at least in part, by causing oxidative posttranslational modifications of complex I and II proteins including reversible oxidative posttranslational modifications of complex II subunit B Cys100 and Cys103.

Successful aging: Advancing the science of physical independence in older adults

The concept of 'successful aging' has long intrigued the scientific community. Despite this long-standing interest, a consensus definition has proven to be a difficult task, due to the inherent challenge involved in defining such a complex, multi-dimensional phenomenon. The lack of a clear set of defining characteristics for the construct of successful aging has made comparison of findings across studies difficult and has limited advances in aging research. A consensus on markers of successful aging is furthest developed is the domain of physical functioning. For example, walking speed appears to be an excellent surrogate marker of overall health and predicts the maintenance of physical independence, a cornerstone of successful aging. The purpose of the present article is to provide an overview and discussion of specific health conditions, behavioral factors, and biological mechanisms that mark declining mobility and physical function and promising interventions to counter these effects. With life expectancy continuing to increase in the United States and developed countries throughout the world, there is an increasing public health focus on the maintenance of physical independence among all older adults.

The talent study: a multicentre randomized controlled trial assessing the impact of a 'tailored lifestyle self-management intervention' (talent) on weight reduction

Background

Overweight is considered an important risk factor for diseases in the context of metabolic syndrome. Lifestyle modifications are the means of choice to reduce weight in persons with a Body Mass Index of 28 to 35. The study examines whether there are any differences between two intervention strategies regarding weight reduction in overweight persons.

Methods/Design

The study is a multicentre randomized controlled trial with observation duration of 12 months. Eight study centres are involved to include a minimal sample size of 150 participants. Randomization ratio is 2:1. Feasible persons are checked according to inclusion and exclusion criteria and after given informed consent are assigned randomly to one of two intervention programs: A) intervention group: comprehensive lifestyle modification program (Individual Health Management IHM) with 3 months reduction phase plus 9 months maintaining phase, B) control group: written information with advice for healthy food habits (Usual care UC). Participants of the IHM group have access to a web-based health portal and join 3 full-day and 10 two-hour training sessions during the first 3 months. During the remaining 9 months four refresh trainings will be performed. There are 3 different diet strategies (fasting, two-day diet, meal replacement) for free choice. Participants of the control group are provided with acknowledged rules for healthy food according to the German Nutrition Society (DGE). Examinations are conducted at baseline, after 3, 6, 9 and 12 months. They include body weight, waist circumference, blood pressure, laboratory findings and a bio-impedance analysis to measure body composition. Statistical analysis of the primary outcome ‘change of body weight after 12 months’ is based on ITT population including analysis of variance of the weight differences between month 0 and 12 with the factors ‘group’, ‘baseline value’ and ‘study centre’. Secondary outcomes will be analyzed exploratively.

Discussion

The monitoring of the study will implement different measures to enhance compliance, avoid attrition and ensure data quality. Based on a blended learning concept and using web-based e-health tools the program promises to achieve sustainable effects in weight reduction.

Trial registration

German Clinical Trials Register Freiburg (DRKS): DRKS00006736 (date registered 20/09/2014).

Electronic supplementary material

The online version of this article (doi:10.1186/s40608-015-0069-x) contains supplementary material, which is available to authorized users.

Self-weighing in weight management: a systematic literature review

OBJECTIVE

Regular self-weighing, which in this article is defined as weighing oneself regularly over a period of time (e.g., daily, weekly), is recommended as a weight loss strategy. However, the published literature lacks a review of the recent evidence provided by prospective, longitudinal studies. Moreover, no paper has reviewed the psychological effects of self-weighing. Therefore, the objective is to review the literature related to longitudinal associations between self-weighing and weight change as well as the psychological outcomes.

METHODS

Electronic literature searches in PubMed, Ovid PsycINFO, and Ebscohost CINAHL were conducted. Keywords included overweight, obesity, self-weighing, etc. Inclusion criteria included trials that were published in the past 25 years in English; participants were adults seeking weight loss treatment; results were based on longitudinal data.

RESULTS

The results (N=17 studies) revealed that regular self-weighing was associated with more weight loss and not with adverse psychological outcomes (e.g., depression, anxiety). Findings demonstrated that the effect sizes of association between self-weighing and weight change varied across studies and also that the reported frequency of self-weighing varied across studies.

CONCLUSIONS

The findings from prospective, longitudinal studies provide evidence that regular self-weighing has been associated with weight loss and not with negative psychological outcomes.

Laparoscopic colectomy is feasible in the mega-obese patient using a standardized technique

The use of laparoscopic colectomy in morbidly obese individuals is controversial. There are significant safety issues including increased risk of bleeding, increased anastomotic leak and high operative conversion rates. We report the first successful laparoscopic colectomy in a patient with the most extreme category of morbid obesity, mega-obesity (body mass index [BMI]>70). We describe a standardized technique using a completely intracorporeal technique with all resection lines reinforced with a bioabsorbable staple line reinforcement material. This technique has the potential of making laparoscopic colectomy more feasible for patients with morbid obesity in general.

Impact of informing overweight individuals about the role of genetics in obesity: an online experimental study

BACKGROUND/AIMS

Increasing public awareness of obesity genetics could have beneficial or harmful effects on overweight individuals. This study examined the impact of genetic information on weight-related cognitions as well as interest in personalized genetic information about obesity among overweight individuals.

METHODS

Online survey respondents (n = 655) were randomly assigned to read either genetic, gene-environment, or nongenetic obesity causal information. Fifty-two percent of the participants were female, 82.4% were White, 45% had an annual income of USD <40,000, and the mean BMI was 32.5. Internalized weight stigma was measured using the Weight Bias Internalization Scale.

RESULTS

Participants in the genetic and gene-environment conditions were more likely to believe genetics increase obesity risk than participants in the nongenetic condition (both p < 0.05); however, they did not differ regarding internalized weight stigma. Sixty-four percent of the participants expressed interest in receiving personalized genetic information about their obesity risk.

CONCLUSION

Dissemination of information about obesity genetics may have neither a beneficial nor a harmful impact on how overweight individuals perceive themselves. Some overweight individuals may be interested in receiving personalized genetic information. The actual effects of obesity genetic information being incorporated into public health messages and of personalized genetic information on obesity prevention and treatment interventions remain to be seen.

Body fat distribution and insulin resistance

The burden of obesity has increased globally over the last few decades and its association with insulin resistance and related cardio-metabolic problems have adversely affected our ability to reduce population morbidity and mortality. Traditionally, adipose tissue in the visceral fat depot has been considered a major culprit in the development of insulin resistance. However, there is a growing body of evidence supporting the role of subcutaneous truncal/abdominal adipose tissue in the development of insulin resistance. There are significant differences in the functional characteristics of subcutaneous abdominal/truncal vs. intraabdominal vs. gluteo-femoral fat depots. More recently, mounting evidence has been supporting the role of adipose tissue function in the development of metabolic complications independent of adipose tissue volume or distribution. Decreased capacity for adipocyte differentiation and angiogenesis along with adipocyte hypertrophy can trigger a vicious cycle of inflammation leading to subcutaneous adipose tissue dysfunction and ectopic fat deposition. Therapeutic lifestyle change continues to be the most important intervention in clinical practice to improve adipose tissue function and avoid development of insulin resistance and related cardio-metabolic complications.

Role of subcutaneous adipose tissue in the pathogenesis of insulin resistance

Burden of obesity has increased significantly in the United States over last few decades. Association of obesity with insulin resistance and related cardiometabolic problems is well established. Traditionally, adipose tissue in visceral fat depot has been considered a major culprit in development of insulin resistance. However, growing body of the literature has suggested that adipose tissue in subcutaneous fat depot, not only due to larger volume but also due to inherent functional characteristics, can have significant impact on development of insulin resistance. There are significant differences in functional characteristics of subcutaneous abdominal/truncal versus gluteofemoral depots. Decreased capacity for adipocyte differentiation and angiogenesis along with adipocyte hypertrophy can trigger vicious cycle of inflammation in subcutaneous adipose tissue and subsequent ectopic fat deposition. It is important to shift focus from fat content to functional heterogeneity in adipose tissue depots to better understand the relative role of subcutaneous adipose tissue in metabolic complications of obesity. Therapeutic lifestyle change continues to be the most important intervention in clinical practice at any level of increased adiposity. Future pharmaceutical interventions aimed at improving adipose tissue function in various subcutaneous depots have potential to help maintain adequate insulin sensitivity and reduce risk for development of insulin resistance complications.

Static mechanical stretching accelerates lipid production in 3T3-L1 adipocytes by activating the MEK signaling pathway

Understanding mechanotransduction in adipocytes is important for research of obesity and related diseases. We cultured 3T3-L1 preadipocytes on elastic substrata and applied static tensile strains of 12% to the substrata while inducing differentiation. Using an image processing method, we monitored lipid production for a period of 3-4 wk. The ratio of %-lipid area per field of view (FOV) in the stretched over nonstretched cultures was significantly greater than unity (P < 0.05), reaching ∼1.8 on average starting from experimental day ∼10. The superior coverage of the FOV by lipids in the stretched cultures was due to significantly greater sizes of lipid droplets (LDs) with respect to nonstretched cultures, starting from experimental day ∼10 (P < 0.05), and due to significantly more LDs per cell between days ∼10 and ∼17 (P < 0.05). The statically stretched cells also differentiated significantly faster than the nonstretched cells within the first ∼10 days (P < 0.05). Adding peroxisome proliferator-activated receptor-γ (PPARγ) antagonist did not change these trends, as the %-lipid area per FOV in the stretched cultures that received this treatment was still significantly greater than in the nonstretched cultures without the PPARγ antagonist (14.44 ± 1.96% vs. 10.21 ± 3%; P < 0.05). Hence, the accelerated adipogenesis in the stretched cultures was not mediated through PPARγ. Nonetheless, inhibiting the MEK/MAPK signaling pathway reduced the extent of adipogenesis in the stretched cultures (13.53 ± 5.63%), bringing it to the baseline level of the nonstretched cultures without the MEK inhibitor (10.21 ± 3.07%). Our results hence demonstrate that differentiation of adipocytes can be enhanced by sustained stretching, which activates the MEK signaling pathway.

Predictors of chronic breathlessness: a large population study

Background

Breathlessness causes significant burden in our community but the underlying socio-demographic and lifestyle factors that may influence it are not well quantified. This study aims to define these predictors of chronic breathlessness at a population level.

Methods

Data were collected from adult South Australians in 2007 and 2008 (n = 5331) as part of a face-to-face, cross-sectional, whole-of-population, multi-stage, systematic area sampling population health survey. The main outcome variable was breathlessness in logistic regression models. Lifestyle factors examined included smoking history, smoke-free housing, level of physical activity and body mass index (obesity).

Results

The participation rate was 64.1%, and 11.1% of individuals (15.0% if aged ≥50 years) chronically had breathlessness that limited exertion. Significant bivariate associations with chronic breathlessness for the whole population and only those ≥50 included: increasing age; female gender; being separated/divorced/widowed; social disadvantage; smoking status; those without a smoke-free home; low levels of physical activity; and obesity. In multi-variate analyses adjusted for age, marital status (p < 0.001), physical activity (p < 0.001), obesity (p < 0.001), gender (p < 0.05) and social disadvantage (p < 0.05) remained significant factors. Smoking history was not a significant contributor to the model.

Conclusions

There is potential benefit in addressing reversible lifestyle causes of breathlessness including high body mass index (obesity) and low levels of physical activity in order to decrease the prevalence of chronic breathlessness. Clinical intervention studies for chronic breathlessness should consider stratification by body mass index.