Obesity indices and self-reported functional health in men and women in the EPIC-Norfolk

Objective: To investigate the association between two indices of obesity, BMI and waist‐to‐hip ratio (WHR), and self‐reported physical and mental functional health. Research Methods and Procedures: We examined the relationship between obesity indices and self‐reported physical and mental functional health measured by the Anglicized version of the Short‐Form 36‐item questionnaire in a population‐based cross sectional study of 16, 806 men and women 40 to 79 years old living in the general community in Norfolk, United Kingdom. Results: Higher BMI and WHR were both independently associated with poorer self‐reported physical functional health in men and women. The effect of BMI was greater in women compared with men, and the effect of WHR was greater in men compared with women, for poor physical functional health. Higher WHR but not BMI was associated with lower mental functional health in men and women. Discussion: High BMI and WHR seem to be adversely related to self‐perceived functional health in both men and women, although their relative impacts seem to differ by sex. Our findings also highlight the importance of using WHR in addition to BMI in assessing the impact of obesity on health outcome.     

Effects of muscular and aqua aerobic combined exercise on metabolic indices in elderly women with metabolic syndrome

The purpose of this study was to investigate the effects of muscle strengthening exercise using elastic thera-band and aquatic aerobic combined exercise on metabolic syndrome index in elderly with metabolic syndrome. Fifty-four were assigned to muscle strengthening exercise group (n = 19), aquatic aerobic exercise group (n = 19), and combined exercise group (n = 16). The muscle strength exercise, aquatic aerobic exercise and combined exercise were provided three times a week for 12 weeks. Metabolic syndrome indices[Fasting blood glucose, triglyceride, high density lipoprotein cholesterol (HDL-C), systolic blood pressure, diastolic blood pressure and waist circumference] were measured before and after the program. One-way ANOVA, paired t-test and two-way repeated ANOVA were used with the SPSS program for data analysis. There was a significant difference in triglyceride (p < .001), HDL-C (p = .010) and waist circumference (p = .016). Triglyceride and waist circumference was significantly decreased in combined group than muscle strength exercise group and aquatic exercise group. HDL-C was significantly increased in combined group than muscle strength exercise group. The results indicate that combined exercise was more effective in the improvement of dyslipidemia and abdominal obesity.     

Predominance of outcrossing in Lymnaea stagnalis despite low apparent fitness costs of self-fertilization

We have quantified the natural mating system in eight populations of the simultaneously hermaphroditic aquatic snail Lymnaea stagnalis, and studied the ecological and genetic forces that may be directing mating system evolution in this species. We investigated whether the natural mating system can be explained by the availability of mates, by the differential survival of self- and cross-fertilized snails in nature, and by the effects of mating system on parental fecundity and early survival. The natural mating system of L. stagnalis was found to be predominantly cross-fertilizing. Density of snails in the populations had no relationship with the mating system, suggesting that outcrossing rates are not limited by mate availability at the population densities observed. Contrary to expectations for outcrossing species, we detected no evidence for inbreeding depression in survival in nature with inferential population genetic methods. Further, experimental manipulations of mating system in the laboratory revealed that self-fertilization had no effect on parental fecundity, and only minor effects on offspring survival. Predominance of cross-fertilization despite low apparent fitness costs of self-fertilization is at odds with the paradigm that high self-fertilization depression is necessary for maintenance of cross-fertilization in self-compatible hermaphrodites.     

Role of exercise intensity on GLUT4 content,aerobic fitness and fasting plasma glucose in type 2 diabetic mice

Type 2 diabetes mellitus (T2D) results in several metabolic and cardiovascular dysfunctions, clinically characterized by hyperglycaemia due to lower glucose uptake and oxidation. Physical exercise is an effective intervention for glycaemic control. However, the effects of exercising at different intensities have not yet been addressed. The present study analysed the effects of 8 weeks of training performed at different exercise intensities on type 4 glucose transporters (GLUT4) content and glycaemic control of T2D (ob/ob) and non‐diabetic mice (ob/OB). The animals were divided into six groups, with four groups being subjected either to low‐intensity (ob/obL and ob/OBL: 3% body weight, three times/week/40 min) or high‐intensity (ob/obH and ob/OBH: 6% body weight, three times per week per 20 min) swimming training. An incremental swimming test was performed to measure aerobic fitness. After the training intervention period, glycaemia and the content of GLUT4 were quantified. Although both training intensities were beneficial, the high‐intensity regimen induced a more significant improvement in GLUT4 levels and glycaemic profile compared with sedentary controls (p < 0·05). Only animals in the high‐intensity exercise group improved aerobic fitness. Thus, our study shows that high‐intensity training was more effective for increasing GLUT4 content and glycaemia reduction in insulin‐resistant mice, perhaps because of a higher metabolic demand imposed by this form of exercise. Copyright © 2015 John Wiley & Sons, Ltd.     

Birthplace, years of residence in the United States, and obesity among Mexican-American adults

Objective: To evaluate the association between birthplace (Mexico or U.S.) and obesity in men and women and to analyze the relationship between duration of U.S. residency and prevalence of obesity in Mexican immigrants. Research Methods and Procedures: We used cross‐sectional data from 7503 adults of Mexican descent residing in Harris County, TX, to evaluate the relationships among BMI, birthplace, and years of residency in the U.S., controlling for demographic characteristics, physical activity level, and acculturation level. Results: U.S.‐born adults had an increased risk (between 34% and 65%) of obesity compared with their Mexican‐born counterparts. After controlling for recognized confounders and risk factors, this association was maintained in the highly acculturated only. Among highly acculturated obese U.S.‐born men, 6% of the cases were attributable to the joint effect of birthplace and acculturation; in women, this proportion was 25%. Among Mexican‐born women, there was an increasing trend in mean BMI with increasing duration of residency in the U.S. Compared with immigrants who had lived in the U.S. for <5 years, Mexican‐born women who had resided in the U.S. for ≥15 years had an adjusted BMI mean difference of 2.12 kg/m² (95% confidence interval, 1.53–2.72). Discussion: Mexican‐born men and women have a lower risk of obesity than their U.S.‐born counterparts, but length of U.S. residency among immigrants, especially in women, is directly associated with risk of obesity. Development of culturally specific interventions to prevent obesity in recent immigrants may have an important public health effect in this population.     

Among‐year variation in selection during early life stages and the genetic basis of fitness in Arabidopsis thaliana

Incomplete information regarding both selection regimes and the genetic basis of fitness limits our understanding of adaptive evolution. Among‐year variation in the genetic basis of fitness is rarely quantified, and estimates of selection are typically based on single components of fitness, thus potentially missing conflicting selection acting during other life‐history stages. Here, we examined among‐year variation in selection on a key life‐history trait and the genetic basis of fitness covering the whole life cycle in the annual plant Arabidopsis thaliana. We planted freshly matured seeds of >200 recombinant inbred lines (RILs) derived from a cross between two locally adapted populations (Italy and Sweden), and both parental genotypes at the native site of the Swedish population in three consecutive years. We quantified selection against the nonlocal Italian genotype, mapped quantitative trait loci (QTL) for fitness and its components, and quantified selection on timing of germination during different life stages. In all 3 years, the local Swedish genotype outperformed the nonlocal Italian genotype. However, both the contribution of early life stages to relative fitness, and the effects of fitness QTL varied among years. Timing of germination was under conflicting selection through seedling establishment vs. adult survival and fecundity, and both the direction and magnitude of net selection varied among years. Our results demonstrate that selection during early life stages and the genetic basis of fitness can vary markedly among years, emphasizing the need for multiyear studies considering the whole life cycle for a full understanding of natural selection and mechanisms maintaining local adaptation.     

Effects of Obesity Phenotype on Coronary Heart Disease Risk Factors in Response to Weight Loss

Objective: To determine whether there is a difference in risk‐factor improvement for coronary heart disease (CHD) between the intra‐abdominal fat (IF) and subcutaneous fat (SF) obesity phenotypes after weight loss. Research Methods and Procedures: Subjects included 55 mildly obese women (body mass index, 25 to 36 kg/m²; age range, 34 to 63 years) who had at least two of three CHD risk factors [systolic blood pressure (SBP), >140 mm Hg; total cholesterol (TC), >220 mg/dL; fasting plasma glucose, >110 mg/dL). Using computed tomography, IF obesity was classified as ≥110 cm² of the IF area measured; subjects with <110 cm² were classified as having SF obesity. The IF and SF obesity groups were divided into diet‐only and diet‐plus‐exercise groups. Assays and measurements were performed before and after a 14‐week (98‐day) intervention. Results: Weight was reduced by 7 to 10 kg in each group. The IF and SF areas, SBP, diastolic blood pressure, TC, and low‐density lipoprotein‐cholesterol were significantly reduced in all groups (p < 0.01). Reduction in IF area was greater in IF obesity than in SF obesity, whereas no differences were observed in the improvement of CHD risk factors. Sample sizes needed for observing a significant difference for SBP, TC, triglycerides, and fasting plasma glucose were greater than the number of subjects in this study. Discussion: Our results suggest that the influence of the obesity phenotype on improving CHD risk factors is not apparent. A larger study is needed to prove the validity of this finding.     

Designer schools: the role of school space and architecture in obesity prevention

Spatial features of obesogenic environments studied on a broad community level have been associated with childhood overweight and obesity, but little research has focused on the effects of the design of micro spaces, such as schools, on individual health behaviors. This article aims to generate thinking and research on the link between school space and architecture and obesity prevention by reviewing and synthesizing available literature in architecture, environmental psychology, and obesity research, in an effort to propose promising ideas for school space design and redesign. The school environment is defined through 5 dimensions: physical, legal, policy, social, and cultural domains. Theories underlying environmental interventions and documented associations between the environment and health behaviors and outcomes are reviewed to illustrate how existing environmental research could translate to obesity prevention. Design strategies aimed at promoting physical activity and healthful eating are proposed, with particular emphasis on the design of cafeterias, activity spaces, connectivity with the larger community, and student health centers.     

Parasite resistance predicts fitness better than fecundity in a natural population of the freshwater snail Potamopyrgus antipodarum

The cost of males should give asexual females an advantage when in competition with sexual females. In addition, high‐fecundity asexual genotypes should have an advantage over low‐fecundity clones, leading to reduction in clonal diversity over time. To evaluate fitness components in a natural population, we measured the annual reproductive rate of individual sexual and asexual female Potamopyrgus antipodarum, a New Zealand freshwater snail, in field enclosures that excluded competitors and predators. We used allozyme genotyping to assign the asexual females to particular clonal genotypes. We found that the most fecund asexual clones had similar or higher fecundity as the top 10% of sexual families, suggesting that fecundity selection, even without the cost of males, would lead to replacement of the sexual population by clones. Consequently, we expected that the clones with the highest fecundity would dominate the natural population. Counter to this prediction, we found that high annual reproductive rates did not correlate with the frequency of clones in the natural population. When we exposed the same clones to parasites in the laboratory, we found that resistance to infection was positively correlated with the frequency of clones in the population. The correlation between fecundity and parasite resistance was negative, suggesting a trade‐off between these two traits. Our results thus suggest that parasite resistance is an important short‐term predictor of the success of asexual P. antipodarum in this population.     

Antagonistic pleiotropy in species with separate sexes,and the maintenance of genetic variation in life‐history traits and fitness

Antagonistic pleiotropy (AP)—where alleles of a gene increase some components of fitness at a cost to others—can generate balancing selection, and contribute to the maintenance of genetic variation in fitness traits, such as survival, fecundity, fertility, and mate competition. Previous theory suggests that AP is unlikely to maintain variation unless antagonistic selection is strong, or AP alleles exhibit pronounced differences in genetic dominance between the affected traits. We show that conditions for balancing selection under AP expand under the likely scenario that the strength of selection on each fitness component differs between the sexes. Our model also predicts that the vast majority of balanced polymorphisms have sexually antagonistic effects on total fitness, despite the absence of sexual antagonism for individual fitness components. We conclude that AP polymorphisms are less difficult to maintain than predicted by prior theory, even under our conservative assumption that selection on components of fitness is universally sexually concordant. We discuss implications for the maintenance of genetic variation, and for inferences of sexual antagonism that are based on sex‐specific phenotypic selection estimates—many of which are based on single fitness components.     

Temperature‐sensitive fitness cost of insecticide resistance in Chinese populations of the diamondback moth Plutella xylostella

Alleles conferring a higher adaptive value in one environment may have a detrimental impact on fitness in another environment. Alleles conferring resistance to pesticides and drugs provide textbook examples of this trade‐off as, in addition to conferring resistance to these molecules, they frequently decrease fitness in pesticide/drug‐free environments. We show here that resistance to chlorpyrifos, an organophosphate (OP), in Chinese populations of the diamondback moth, Plutella xylostella, is conferred by two mutations of ace1 – the gene encoding the acetylcholinesterase enzyme targeted by OPs – affecting the amino acid sequence of the corresponding protein. These mutations were always linked, consistent with the segregation of a single resistance allele, ace1R, carrying both mutations, in the populations studied. We monitored the frequency of ace1R (by genotyping more than 20 000 adults) and the level of resistance (through bioassays on more than 50 000 individuals) over several generations. We found that the ace1R resistance allele was costly in the absence of insecticide and that this cost was likely recessive. This fitness costs involved a decrease in fecundity: females from resistant strains laid 20% fewer eggs, on average, than females from susceptible strains. Finally, we found that the fitness costs associated with the ace1R allele were greater at high temperatures. At least two life history traits were involved: longevity and fecundity. The relative longevity of resistant individuals was affected only at high temperatures and the relative fecundity of resistant females – which was already affected at temperatures optimal for development – decreased further at high temperatures. The implications of these findings for resistance management are discussed.     

Effects of early resource limitation and compensatory growth on lifetime fitness in the ladybird beetle (Harmonia axyridis)

Acceleration of growth following a period of diet restriction may result in either complete or partial catch-up in size. The existence of such compensatory growth indicates that organisms commonly grow at rates below their physiological maxima and this implies a cost for accelerated growth. We examined patterns of accelerated growth in response to temporary resource limitation, and assayed both short and long-term costs of this growth in the ladybird beetle Harmonia axyridis. Subsequent to the period of food restriction, accelerated growth resulted in complete compensation for body sizes, although we observed greater larval mortality during the period of compensation. There were no effects on female fecundity or survivorship within 3 months of maturation. Females did not discriminate against males that had undergone compensatory growth, nor did we observe effects on male mating behaviour. However, individuals that underwent compensatory growth died significantly sooner when deprived of food late in adult life, suggesting that longer-term costs of compensatory growth may be quite mild and detectable only under stressful conditions.     

Effects of 12 weeks of aerobic exercise plus dietary restriction on body composition, resting energy expenditure and aerobic fitness in mildly obese middle-aged women

This study investigated the effects of 12 weeks of aerobic exercise plus voluntary food restriction on the body composition, resting metabolic rate (RMR) and aerobic fitness of mildly obese middle-aged women. The subjects were randomly assigned to exercise/diet (n = 17) or control (n = 15) groups. The exercise/diet group participated in an aerobic training programme, 45–60 min · day ^–1 at 50%–60% of maximal oxygen uptake (VO_2max), 3–4 days · week^–1, and also adopted a self-regulated energy deficit relative to predicted energy requirements (–1.05 MJ · day ^–1 to –1.14 MJ · day ^–1 ). After the regimen had been followed for 12 weeks, the body mass of the subjects had decreased by an average of 4.5 kg, due mainly to fat loss, with little change of fat free mass (m _ff). The absolute RMR did not change, but the experimental group showed significant increases in the RMR per unit of body mass (10%) and the RMR per unit of m _ff (4%). The increase in RMR/m _ff was not correlated with any increase in VO_2max/m _ff. The resting heat production per unit of essential body mass increased by an average of 21%, but the resting heat production rate per unit of fat tissue mass remained unchanged. We concluded that aerobic exercise enhances the effect of moderate dietary restriction by augmenting the metabolic activity of lean tissue.     

Overall and central obesity and risk of type 2 diabetes in U.S. black women

Objective: Obesity has risen to epidemic proportions in the United States, leading to an emerging epidemic of type 2 diabetes. African‐American women are disproportionately affected by both conditions. While an association of overall obesity with increasing risk of diabetes has been documented in black women, the effect of fat distribution, specifically abdominal obesity, has not been studied. We examined the association of BMI, abdominal obesity, and weight gain with risk of type 2 diabetes. Research Methods and Procedures: During eight years of follow‐up of 49,766 women from the Black Women's Health Study, 2472 incident cases of diabetes occurred. Cox proportional hazard models were used to estimate incidence rate ratios (IRRs), with control for age, physical activity, family history of diabetes, cigarette smoking, years of education, and time period of data collection. Results: Sixty‐one percent of participants had a BMI ≥25 kg/m² (WHO definition of overweight). Compared with a BMI of <23 kg/m², the IRR for a BMI of >45 kg/m² was 23 (95% confidence interval, 17.0 to 31.0). The IRR for the highest quintile of waist‐to‐hip ratio relative to the lowest was 2.3 (95% confidence interval, 2.0 to 2.7) after control for BMI. Furthermore, at every level of BMI, an increased risk was observed for high waist‐to‐hip ratio relative to low. Discussion: Central obesity, as well as overall obesity, is a strong risk factor for diabetes in African‐American women. Efforts to reduce the prevalence of obesity in African‐American women are of paramount importance.     

Reflections on research ethics in a public health emergency: Experiences of Brazilian women affected by Zika

In Brazil, the epicenter of the Zika crisis, brown, black, and indigenous poor women living in municipalities with scarce resources were disproportionally affected. The gendered consequences of the epidemic exposed how intersectional lenses are central to understand the impact of public health emergencies in the lives of women and girls. The demand for Zika-affected children and women to be research participants is relevant for an ethical analysis of participant protection procedures during a crisis. We investigated how women experienced research participation by analyzing their narratives. Two-year-long longitudinal qualitative study in Brazilian sites located in the epidemic's epicenter was performed using mixed methods: ethnography with women from two distinct states and individual semi-structured interviews with five women in different Zika-affected states, four of which were community leaders. All women in the study were mothers or grandmothers of Zika-affected children. Thematic analysis was used for data evaluation. Women perceived being pressured to participate in research and a lack of benefit sharing. Structural determinants of gender inequality, such as its effect on power distribution, were found to impact research participant protection. Formal procedures for research protocols approvals were insufficient in protecting participants because these instruments were unable to account for structural aspects. Communitarian mobilization, through WhatsApp groups, was found to be an important mechanism to create conditions to challenge oppressive structures. Strengthening public health, effective community-based participation in research planning and implantation of ethical strategies that promotes gender equality can have transformative effect on unequal power structures and promote participant protection.     

Public reason in justifications of conscientious objection in health care

Current mainstream approaches to conscientious objection either uphold the standards of public health care by preventing objections or protect the consciences of health‐care professionals by accommodating objections. Public justification approaches are a compromise position that accommodate conscientious objections only when objectors can publicly justify the grounds of their objections. Public justification approaches require objectors and assessors to speak a common normative language and to this end it has been suggested that objectors should be required to cast their objection in terms of public reason. We provide critical support for such a public reason condition and argue that it would be neither too demanding nor too permissive. We also respond to objections that it unfairly favours secular over religious objectors and that public reasons cannot be held with the kind of sincerity thought to characterize conscientious objections.     

Effects of vitamin D supplementation and circuit training on indices of obesity and insulin resistance in T2D and vitamin D deficient elderly women

[Purpose]

The purpose of this study was to investigate the effects of vitamin D supplementation and circuit training on body composition, abdominal fat, blood lipids, and insulin resistance in T2D and vitamin D deficient elderly women.

[Methods]

Fifty-two elderly women were randomly assigned to either the vitamin D supplementation with circuit training group (D+T: n = 15), the circuit training group (T: n = 13), the vitamin D supplementation group (D: n = 11), or the control group (CON: n = 13). The subjects in D took vitamin D supplements at 1,200 IU per day for 12 weeks; the subjects in T exercised 3 to 4 times per week, 25 to 40 minutes per session for 12 weeks; and the subjects in D+T participated in both treatments. Subjects in CON were asked to maintain normal daily life pattern for the duration of the study. Body composition, abdominal fat, blood lipids, and surrogate indices for insulin resistance were measured at pre- and post-test and the data were compared among the four groups and between two tests by utilizing two-way ANOVA with repeated measures. The main results of the present study were as follows:

[Results]

1) Body weight, fat mass, percent body fat, and BMI decreased significantly in T, whereas there were no significant changes in the variables in D and CON. Lean body mass showed no significant changes in all groups. 2) TFA and SFA decreased significantly in T, whereas there were no significant changes in the variables in D and CON. The other abdominal fat related variables showed no significant changes in all groups. 3) TC, TG, HDL-C, and LDL-C showed improvements in T, whereas there were no significant changes in the variables in D and CON. 4) Fasting glucose, fasting insulin, and HOMA-IR tended to be lower in D+T.

[Conclusion]

It was concluded that the 12 weeks of vitamin D supplementation and circuit training would have positive effects on abdominal fat and blood lipid profiles in T2D and vitamin D deficient elderly women. Vitamin D supplementation was especially effective when it was complemented with exercise training.     

Climate and landscape drivers of tree decline in a Mediterranean ecoregion

Climate change and anthropogenic land use are increasingly affecting the resilience of natural ecosystems. In Mediterranean ecoregions, forests and woodlands have shown progressive declines in health. This study focuses on the decline of an endemic woodland tree species, Eucalyptus wandoo (wandoo), occurring in the biodiversity hotspot of southwest Western Australia. We determined the change in health of wandoo stands between 2002 and 2008 across its geographic and climatic range, and associated this change in health with non‐biotic variables focusing on: (1) fragment metrics; (2) topography; (3) soil characteristics; and (4) climate. Only fragment metrics and climate variables were found to be significantly related to the observed change in health. Stands that were small with high perimeter/area ratios were found to be most sensitive to health declines. Recent increases in autumn temperatures and decreases in annual rainfall were negatively affecting health of wandoo most prominently in the low rainfall zone of its climatic range. Together, these results suggest the onset of range contraction for this ecologically important species, which is likely to be exacerbated by projected future changes in climate. Our results emphasize the importance of establishing monitoring programs to identify changes in health and decline trends early to inform management strategies, particularly in the sensitive Mediterranean ecoregions.     

Cognitive costs of reproduction: life‐history trade‐offs explain cognitive decline during pregnancy in women

Life‐history theory predicts that access to limited resources leads to trade‐offs between competing body functions. Women, who face higher costs of reproduction when compared to men, should be especially vulnerable to these trade‐offs. We propose the ‘cognitive costs of reproduction hypothesis’, which states that energy trade‐offs imposed by reproduction may lead to a decline in maternal cognitive function during gestation. In particular, we hypothesize that the decline in cognitive function frequently observed during pregnancy is associated with the allocation of resources between the competing energetic requirements of the mother's brain and the developing foetus. Several distinctive anatomical and physiological features including a high metabolic rate of the brain, large infant size, specific anatomical features of the placenta and trophoblast, and the lack of maternal control over glucose flow through the placenta make the occurrence of these trade‐offs likely. Herein, we review several lines of evidence for trade‐offs between gestation and cognition that are related to: (i) energy metabolism during reproduction; (ii) energy metabolism of the human brain; (iii) links between energy metabolism and cognitive function; and (iv) links between gestation and cognitive function. We also review evidence for the important roles of cortisol, corticotropin‐releasing hormone and sex hormones in mediating the effects of gestation on cognition, and we discuss possible neurophysiological mechanisms underlying the observed effects. The evidence supports the view that energy trade‐offs between foetal growth and maternal endocrine and brain function lead to changes in maternal cognition, and that this phenomenon is mediated by neuroendocrine mechanisms involving the hypothalamic–pituitary–adrenal axis, brainstem nucleus locus coeruleus and hippocampus.