Obesity: The allostatic load of weight loss dieting

Allostatic load in early pregnancy and sleep-disordered breathing

OBJECTIVES

To assess the association between allostatic load in early pregnancy and sleep-disordered breathing (SDB) during pregnancy.

METHODS

High allostatic load in the first trimester was defined as ≥ 4 of 12 biomarkers (systolic blood pressure, diastolic blood pressure, body mass index, cholesterol, low-density lipoprotein, high-density lipoprotein, high sensitivity C-reactive protein, triglycerides, insulin, glucose, creatinine, and albumin) in the unfavorable quartile. SDB was objectively measured using the Embletta-Gold device and operationalized as "SDB ever" in early (6-15 weeks) or mid-pregnancy (22-31 weeks); SDB at each time point was analyzed as secondary outcomes. Multivariable logistic regression was used to test the association between high allostatic load and SDB, adjusted for confounders. Moderation and sensitivity analyses were conducted to assess the role of allostatic load in racial disparities of SDB and obesity affected the relationship between allostatic load and SDB.

RESULTS

High allostatic load was present in 35.0% of the nuMoM2b cohort. The prevalence of SDB ever occurred among 8.3% during pregnancy. After adjustment, allostatic load remained significantly associated with SDB ever (aOR= 5.3; 3.6-7.9), in early-pregnancy (aOR= 7.0; 3.8-12.8), and in mid-pregnancy (aOR= 5.8; 3.7-9.1). The association between allostatic load and SDB was not significantly different for people with and without obesity. After excluding BMI from the allostatic load score, the association decreased in magnitude (aOR= 2.6; 1.8-3.9).

CONCLUSION

The association between allostatic load and SDB was independent of confounders including BMI. The complex and likely bidirectional relationship between chronic stress and SDB deserves further study in reducing SDB.

The explanation of educational disparities in adiposity by lifestyle, socioeconomic and mental health mediators: a multiple mediation model

BACKGROUND

The inverse association between education and obesity was previously found in numerous studies. This study aims to assess several possible mediators in the educational disparities in adiposity. We hypothesize the potential mediating role of lifestyle, socioeconomic, and mental health factors in the association between education and adiposity.

METHODS

Cross-sectional population-based sample from Czechia included 2,154 25-64 years old subjects (54.6% women). Education was classified as high, middle, and low. Adiposity was assessed as a latent variable based on body fat percentage, BMI, waist circumference, and visceral fat. The mediation potential of unhealthy dietary behavior, alcohol intake, smoking, sedentary behaviors, income, stress, depression, and quality of life was assessed in age-adjusted sex-specific multiple mediation models.

RESULTS

The negative direct effect of education on adiposity was statistically significant at 5% level of significance in both sexes. For men, the indirect effect was statistically significant via sedentary behavior (β = 0.041; 95% CI [0.025-0.062]) with a mediation ratio of 23.7%. In women, the indirect effect was statistically significant via dietary risk (β = -0.023, 95% CI [-0.037, -0.013]), alcohol intake (β = -0.006; 95% CI [-0.014, -0.001]), sedentary behavior (β = 0.012, 95% CI [0.004,0.023]), income (β = -0.022; 95% CI [-0.041, -0.004]), and mental health (β = -0.007; 95% CI [-0.019, -0.001]). The total mediation ratio in women was 30.5%.

CONCLUSIONS

Sedentary behaviors had mediating role in the association between education and adiposity in both sexes, with more important role in men. In addition, unhealthy diet and lower income partially mediated the educational gradient in adiposity in women.

Allostatic Load, Single, and Dual Chronic Conditions: Evidence from the National Health and Nutrition Examination Survey

Background:

Allostatic load (AL) is defined as a cumulative burden of chronic stress and life events, which involves the interaction of different physiological systems at varying degrees of activity. AL is suspected of contributing to health disparities among different populations. Suppressed or overactive physiological systems can interrupt AL affecting proper tissue and organ function leading to disease. The objective of our study was to determine the association of AL with dual chronic conditions.

Methods:

We used data from the National Health and Nutrition Examination Survey (NHANES). For the current analysis, we used the data cycles of 2007–2010, which is the most recent data that collected comprehensive measures of the composite AL outcome variable. Descriptive, bivariate, and multivariable logistic regression, with stepwise forward variable selection method (P < 0.05), were conducted using STATA/IC 15.0.

Results:

AL levels were high among 20% of the respondents (n = 2179). Having a lower income to poverty ratio, being married, physical inactivity, experiencing sleep problems, and a history of smoking were significantly associated with high AL (P < 0.05). Non-Hispanic blacks [odds ratio (OR): 1.8; 95% confidence interval (CI): 1.6–2.4] and Mexicans and other Hispanics (OR: 1.4; 95% CI: 1.1–1.7) had higher AL compared to Caucasians. Having cardiovascular disease (CVD) (OR: 1.7; 95% CI: 1.4–2.2) and diabetes (OR: 4.7; 95% CI: 3.8–5.7) independently, as well as both CVD and diabetes (OR: 3.1; 95% CI 2.7–3.6), were associated with higher odds of AL. We conducted an age-adjusted regression model that indicated higher odds of elevated AL among females with diabetes independently (OR: 1.4; 95% CI: 1.2–1.9) and with both CVD and diabetes (OR: 1.6; 95% CI: 1.2–2.1) compared to men.

Conclusions:

Despite the significant impact and association of AL with overall health, there is minimal evidence of its risk factors and linkage to disease burden. Modifiable lifestyle factors were associated with a higher AL. There is a critical need to support ethnic and gender contextual interventions to reduce the burden of AL on chronic conditions.

The effects of hydroalcoholic extract of spinach on prevention and treatment of some metabolic and histologic features in a rat model of nonalcoholic fatty liver disease

BACKGROUND

This study evaluated the effects of hydroalcoholic extract of spinach (HES) on nonalcoholic fatty liver disease (NAFLD). In the prevention phase, 18 Sprague-Dawley rats were fed a high-fat diet, a high-fat diet plus 400 mg kg^-1 HES, or a chow diet for 7 weeks. For the treatment phase, after the induction of NAFLD, they were fed a high-fat diet, a high-fat diet plus 400 mg kg^-1 HES, a chow diet, or chow diet plus 400 mg kg^-1 HES for 4 weeks (n = 6).

RESULTS

Weight gain (P = 0.01), food intake (P < 0.01), serum glucose (P = 0.01), triglyceride (TG) (P = 0.02), low-density lipoprotein cholesterol (LDL-c) (P = 0.01), aspartate aminotransferase (AST) (P = 0.02), liver steatosis, and the nonalcoholic fatty liver disease (NAFLD) activity score (NAS) (P < 0.01) in the high-fat group were statistically higher than in the other groups at the end of the prevention phase. Feeding spinach extract to rats on a high-fat diet decreased serum glucose (P = 0.01), total cholesterol (TCh) (P < 0.01), AST (P = 0.01), alkaline phosphatase (ALP) (P < 0.01), and liver steatosis (P < 0.01) in the treatment phase.

CONCLUSION

Overall, spinach extract showed beneficial effects in the prevention and treatment of NAFLD. © 2019 Society of Chemical Industry.

Increased blood levels of persistent organic pollutants (POP) in obese individuals after weight loss-A review

Lipophilic persistent organic pollutants (POP) are stored in adipose tissue. Following rapid weight loss such as when induced by bariatric surgery, an increased release of potential harmful lipophilic compounds into the blood circulation may occur. Weight reduction is recommended for overweight and obese individuals in order to decrease risk of weight-related health problems. However, in cases of significant weight reduction POP become mobilized chemicals and consequently may adversely affect health, including endocrine disruption. The objective of the present investigation was to estimate quantitatively the level of mobilization of POP following weight loss over time. According to literature search criteria, 17 studies were identified with 2061 participants. Data from 5 of the studies with 270 participants were used to assess the change in blood levels of POP in percent per kilogram weight loss. Weight loss in the included studies varied from 4.4 to 64.8 kg. In all studies, the majority of POP concentrations in blood were found to rise following weight reduction. Blood concentrations following weight reduction were elevated by 2-4% per kilogram weight loss for most POP examined. The increased POP levels were still elevated 12 mo after intervention. Most research in this field, including animal studies, is carried out on a single compound or group of selected compounds, not taking the "cocktail effect" into consideration. This does not reflect the true range of POP to which humans are actually exposed. Few chronic investigations have been published and, in particular, few studies were available that compared the increase in POP concentrations with clinical consequences as individuals lost weight. These limitations call for caution in interpreting results. The benefits of losing weight still far outweigh the potential adverse health risks. However, further studies are recommended to determine the clinical significance of increased blood levels of POPs following rapid and excessive weight loss, particularly for women attending weight reduction treatment before pregnancy.

The Use of Green Leaf Membranes to Promote Appetite Control, Suppress Hedonic Hunger and Loose Body Weight

On-going research aims at answering the question, which satiety signal is the most potent or which combination of satiety signals is the most potent to stop eating. There is also an aim at finding certain food items or food additives that could be used to specifically reduce food intake therapeutically. Therapeutic attempts to normalize body weight and glycaemia with single agents alone have generally been disappointing. The success of bariatric surgery illustrates the rationale of using several hormones to treat obesity and type-2-diabetes. We have found that certain components from green leaves, the thylakoids, when given orally have a similar rationale in inducing the release of several gut hormones at the same time. In this way satiety is promoted and hunger suppressed, leading to loss of body weight and body fat. The mechanism is a reduced rate of intestinal lipid hydrolysis, allowing the lipolytic products to reach the distal intestine and release satiety hormones. The thylakoids also regulate glucose uptake in the intestine and influences microbiota composition in the intestine in a prebiotic direction. Using thylakoids is a novel strategy for treatment and prevention of obesity.

Is there a "metabolic-mood syndrome"? A review of the relationship between obesity and mood disorders

Obesity and mood disorders are highly prevalent and co-morbid. Epidemiological studies have highlighted the public health relevance of this association, insofar as both conditions and its co-occurrence are associated with a staggering illness-associated burden. Accumulating evidence indicates that obesity and mood disorders are intrinsically linked and share a series of clinical, neurobiological, genetic and environmental factors. The relationship of these conditions has been described as convergent and bidirectional; and some authors have attempted to describe a specific subtype of mood disorders characterized by a higher incidence of obesity and metabolic problems. However, the nature of this association remains poorly understood. There are significant inconsistencies in the studies evaluating metabolic and mood disorders; and, as a result, several questions persist about the validity and the generalizability of the findings. An important limitation in this area of research is the noteworthy phenotypic and pathophysiological heterogeneity of metabolic and mood disorders. Although clinically useful, categorical classifications in both conditions have limited heuristic value and its use hinders a more comprehensive understanding of the association between metabolic and mood disorders. A recent trend in psychiatry is to move toward a domain specific approach, wherein psychopathology constructs are agnostic to DSM-defined diagnostic categories and, instead, there is an effort to categorize domains based on pathogenic substrates, as proposed by the National Institute of Mental Health (NIMH) Research Domain Criteria Project (RDoC). Moreover, the substrates subserving psychopathology seems to be unspecific and extend into other medical illnesses that share in common brain consequences, which includes metabolic disorders. Overall, accumulating evidence indicates that there is a consistent association of multiple abnormalities in neuropsychological constructs, as well as correspondent brain abnormalities, with broad-based metabolic dysfunction, suggesting, therefore, that the existence of a "metabolic-mood syndrome" is possible. Nonetheless, empirical evidence is necessary to support and develop this concept. Future research should focus on dimensional constructs and employ integrative, multidisciplinary and multimodal approaches.

Weighing the Evidence of Common Beliefs in Obesity Research

Obesity is a topic on which many views are strongly held in the absence of scientific evidence to support those views, and some views are strongly held despite evidence to contradict those views. We refer to the former as "presumptions" and the latter as "myths." Here, we present nine myths and 10 presumptions surrounding the effects of rapid weight loss; setting realistic goals in weight loss therapy; stage of change or readiness to lose weight; physical education classes; breastfeeding; daily self-weighing; genetic contribution to obesity; the "Freshman 15"; food deserts; regularly eating (versus skipping) breakfast; eating close to bedtime; eating more fruits and vegetables; weight cycling (i.e., yo-yo dieting); snacking; built environment; reducing screen time in childhood obesity; portion size; participation in family mealtime; and drinking water as a means of weight loss. For each of these, we describe the belief and present evidence that the belief is widely held or stated, reasons to support the conjecture that the belief might be true, evidence to directly support or refute the belief, and findings from randomized controlled trials, if available. We conclude with a discussion of the implications of these determinations, conjecture on why so many myths and presumptions exist, and suggestions for limiting the spread of these and other unsubstantiated beliefs about the obesity domain.

Associations of allostatic load with sleep apnea, insomnia, short sleep duration, and other sleep disturbances: findings from the National Health and Nutrition Examination Survey 2005 to 2008

PURPOSE

To examine whether allostatic load (AL), a measure of cumulative physiologic dysregulation across biological systems, was associated with sleep apnea, insomnia, and other sleep disturbances.

METHODS

Data from the National Health and Nutrition Examination Survey 2005-2008 were used. AL was measured using nine biomarkers representing cardiovascular, inflammatory, and metabolic system functioning. A total of 3330 US adults aged 18 years and older were included in this study.

RESULTS

The prevalence of high AL (AL score  ≥3) was the highest among African Americans (26.3%), followed by Hispanic Americans (20.3%), whites (17.7%), and other racial/ethnic group (13.8%). After adjustment for sociodemographic and lifestyle factors, high AL was significantly associated with sleep apnea (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.40-2.63), snoring (OR, 2.20; 95% CI, 1.79-2.69), snorting/stop breathing (OR, 2.16; 95% CI, 1.46-3.21), prolonged sleep latency (OR, 1.42; 95% CI, 1.08-1.88), short sleep duration (<6 hours) (OR, 1.35; 95% CI, 1.00-1.82), and diagnosed sleep disorder (OR, 2.26; 95% CI, 1.66-3.08). There was no clear evidence that observed associations varied by sociodemographic characteristics.

CONCLUSIONS

This study suggests significant associations of high AL with sleep apnea, sleep apnea symptoms, insomnia component, short sleep duration, and diagnosed sleep disorder among US adults.

Obesity status of middle school students in Xiangtan and its relationship with Internet addiction

OBJECTIVE

To investigate the state of middle school students' obesity in Xiangtan, China and to study the influence of Internet addiction on obesity.

SUBJECTS

1,150 junior and senior middle school students in Xiangtan, China.

DESIGN AND METHODS

The research subjects were select randomly for the study. The height and body weight of human body were measured and the obesity state was judged according to BMI value and the Working Group on Obesity in China (WGOC) standard. The questionnaire for the survey of middle school students' basic situation was designed and a survey of the respondents' personal information and the contributory factors to obesity was conducted. The Middle School Students' Internet Addiction Diagnosis Scale was adopted for measuring and judging the Internet addiction of the research subjects.

RESULTS

(1) The total detection rate of obesity was 23.57%. (2) The overall detection rate of Internet addiction was 21.23%. (3) The detection rate of obesity in middle school students with Internet addiction (32.92%) was significantly higher than that without Internet addiction (21.06%). Logistic regression showed that Internet addiction was an independent risk factor of obesity.

CONCLUSION

Internet addiction is related to obesity of middle school students.

Annual Research Review: The neurobiology and physiology of resilience and adaptation across the life course

BACKGROUND

Adaptation is key to survival. An organism must adapt to environmental challenges in order to be able to thrive in the environment in which they find themselves. Resilience can be thought of as a measure of the ability of an organism to adapt, and to withstand challenges to its stability. In higher animals, the brain is a key player in this process of adaptation and resilience, and through a process known as "allostasis" can obtain "stability through change"; protecting homeostasis in the face of stressors in the environment. Mediators of allostasis, such as glucocorticoids, can cause changes in the structure and function of neural circuits, clearly impacting behavior. How developmental stage interacts with stress and leads to long-lasting changes is a key question addressed in this review.

SCOPE AND METHODS

We discuss the concept of allostasis, its role in resilience, the neural and physiological systems mediating these responses, the modulatory role of development, and the consequences for adult functioning. We present this in the context of mediators the brain and body engage to protect against threats to homeostasis. The review has been informed by comprehensive searches on PubMed and Scopus through November 2012.

FINDINGS

Stressors in the environment can have long lasting effects on development, depending upon the stage of life at which they are experienced. As such, adverse childhood experiences can alter resilience of individuals, making it more difficult for them to respond normally to adverse situations in adulthood, but the brain maintains the capacity to re-enter a more plastic state where such effects can be mitigated.

CONCLUSIONS

The brain regulates responses that allow for adaptation to challenges in the environment. The capacity of the brain and body to withstand challenges to stability can be considered as "resilience". While adverse childhood experiences can have long-term negative consequences, under the right circumstances, the brain can re-enter plastic states, and negative outcomes may be mitigated, even later in life.

Obesity: a disease or a biological adaptation? An update

Obesity is characterized by the accumulation of excess body fat and can be conceptualized as the physical manifestation of chronic energy excess. An important challenge of today's world is that our so-called obesogenic environment is conducive to the consumption of energy and unfavourable to the expenditure of energy. The modern, computer-dependent, sleep-deprived, physically inactive humans live chronically stressed in a society of food abundance. From a physiological standpoint, the excess weight gain observed in prone individuals is perceived as a normal consequence to a changed environment rather than a pathological process. In other words, weight gain is a sign of our contemporary way of living or a 'collateral damage' in the physiological struggle against modernity. Additionally, substantial body fat loss can complicate appetite control, decrease energy expenditure to a greater extent than predicted, increase the proneness to hypoglycaemia and its related risk towards depressive symptoms, increase the plasma and tissue levels of persistent organic pollutants that promote hormone disruption and metabolic complications, all of which are adaptations that can increase the risk of weight regain. In contrast, body fat gain generally provides the opposite adaptations, emphasizing that obesity may realistically be perceived as an a priori biological adaptation for most individuals. Accordingly, prevention and treatment strategies for obesity should ideally target the main drivers or root causes of body fat gain in order to be able to improve the health of the population.