Changes in lipid and carnitine concentrations following repeated fasting-refeeding in mice

The purpose of this study was to evaluate the effects of repeated fasting and refeeding on lipid metabolism. Thirty male ICR mice, aged 6 weeks, were fed an AIN-93 control diet during the experimental period. The mice were divided into 5 groups: Non fasting group (ad libitum-fed, NF), fasting for 3 days (F), fasting for 3 days and then refeeding for 4 days repeated once (FRF1), fasting for 3 days and then refeeding for 4 days repeated twice (FRF2), and fasting for 3 days and then refeeding for 4 days repeated three times (FRF3). Rates of body weight gain, epididymal fat weight, and serum TG were significantly decreased in the F, FRF1, FRF2, and FRF3 groups, compared to the NF group. LDL-cholesterol was significantly higher in the FRF3 group than the NF and F groups, but HDL-cholesterol and HDL/TC were significantly lower in the FRF3 group than in the NF and F groups. Serum total carnitine was significantly lower in the FRF1, FRF2, FRF3 groups than the NF and F groups. However, rates of serum and hepatic acyl-carnitine concentration were significantly lower in FRF1, FRF2, and FRF3 than in NF and F. Repeated fasting-refeeding resulted in visible reductions of body weight and fat mass, but it caused ill-effects with lipid and carnitine metabolism in the body

Association of Cortisol and the Metabolic Syndrome in Korean Men and Women

Obesity and the metabolic syndrome are closely related and have become increasingly prevalent in Korea. The cardiovascular disease (CVD) risk factors comprising the metabolic syndrome have previously been associated with increased hypothalamic-pituitary-adrenal axis (HPAA) activity, but the associations have not been extensively examined in non-Caucasian populations. The aim of the present study was to investigate the relationships between cortisol, adiposity and the metabolic syndrome in a Korean population. A total of 1,881 adults participated in the study between January 2001 and February 2008. Sociodemographic data were assessed by questionnaires. Body composition, clinic blood pressures as well as metabolic variables including glucose, insulin, and lipid profile were assessed and analyzed in relation to cortisol levels. Mean age of the participants was 58.7 ± 10.8 yr. Higher levels of cortisol was associated with elevated blood pressure, fasting glucose and total cholesterol in men, and between cortisol and systolic blood pressure, fasting glucose and total cholesterol in women. There was an increased risk for the metabolic syndrome associated with higher cortisol levels in both men (P < 0.001) and women (P = 0.040) adjusting for age and body mass index. Higher cortisol levels are associated with several CVD risk factors and the metabolic syndrome, independent of overall of adiposity level, in Korean men and women

Biomarkers of browning of white adipose tissue and their regulation during exercise- and diet-induced weight loss

Background: A hypothesis exists whereby an exercise- or dietary-induced negative energy balance reduces human subcutaneous white adipose tissue (scWAT) mass through the formation of brown-like adipocyte (brite) cells. However, the validity of biomarkers of brite formation has not been robustly evaluated in humans, and clinical data that link brite formation and weight loss are sparse. Objectives: We used rosiglitazone and primary adipocytes to stringently evaluate a set of biomarkers for brite formation and determined whether the expression of biomarker genes in scWAT could explain the change in body composition in response to exercise training combined with calorie restriction in obese and overweight women (n = 79). Design: Gene expression was derived from exon DNA microarrays and preadipocytes from obesity-resistant and -sensitive mice treated with rosiglitazone to generate candidate brite biomarkers from a microarray. These biomarkers were evaluated against data derived from scWAT RNA from obese and overweight women before and after supervised exercise 5 d/wk for 16 wk combined with modest calorie restriction (∼0.84 MJ/d). Results: Forty percent of commonly used brite gene biomarkers exhibited an exon or strain-specific regulation. No biomarkers were positively related to weight loss in human scWAT. Greater weight loss was significantly associated with less uncoupling protein 1 expression (P = 0.006, R(2) = 0.09). In a follow-up global analysis, there were 161 genes that covaried with weight loss that were linked to greater CCAAT/enhancer binding protein α activity (z = 2.0, P = 6.6 × 10(−7)), liver X receptor α/β agonism (z = 2.1, P = 2.8 × 10(−7)), and inhibition of leptin-like signaling (z = −2.6, P = 3.9 × 10(−5)). Conclusion: We identify a subset of robust RNA biomarkers for brite formation and show that calorie-restriction–mediated weight loss in women dynamically remodels scWAT to take on a more-white rather than a more-brown adipocyte phenotype

Body Mass Index, abdominal adiposity, obesity, and cardiovascular reactions to psychological stress in a large community sample

OBJECTIVE: To examine the association between adiposity and the magnitude of cardiovascular reactions to acute psychological stress cross-sectionally and prospectively in a large community sample.\ud \ud METHODS: Blood pressure and heart rate (HR) were measured at rest and in response to a brief time-pressured mental arithmetic stress in 1647 adults. At the same session and 5 years later, height, weight, waist and hip circumference were measured and body mass index (BMI) and waist-hip ratio were computed. Obesity was defined as a body mass index of > or = 30 kg/m(2).\ud \ud RESULTS: Contrary to expectations, the most robust and consistent results to emerge from cross-sectional analyses were negative associations between all three measures of adiposity and HR reactivity; those with greater BMI and waist-hip ratios and those categorized as obese displayed smaller HR reactions to stress. In prospective analyses, high HR reactivity was associated with a reduced likelihood of becoming obese in the subsequent 5 years.\ud \ud CONCLUSIONS: Our analyses suggest that it is low, not high, HR reactivity that is related to adiposity. Low HR reactivity, probably by reflecting generally blunted sympathetic nervous system reactions to challenge, may be a risk marker for developing obesity.\ud \u

Salivary cortisol differs with age and sex and shows inverse associations with WHR in Swedish women: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Most studies on cortisol have focused on smaller, selected samples. We therefore aimed to sex-specifically study the diurnal cortisol pattern and explore its association with abdominal obesity in a large unselected population.</p> <p>Methods</p> <p>In 2001–2004, 1811 men and women (30–75 years) were randomly selected from the Vara population, south-western Sweden (81% participation rate). Of these, 1671 subjects with full information on basal morning and evening salivary cortisol and anthropometric measurements were included in this cross-sectional study. Differences between groups were examined by general linear model and by logistic and linear regression analyses.</p> <p>Results</p> <p>Morning and Δ-cortisol (morning – evening cortisol) were significantly higher in women than men. In both genders older age was significantly associated with higher levels of all cortisol measures, however, most consistently with evening cortisol. In women only, age-adjusted means of WHR were significantly lower in the highest compared to the lowest quartile of morning cortisol (p = 0.036) and Δ-cortisol (p < 0.001), respectively. Furthermore, when comparing WHR above and below the mean, the age-adjusted OR in women for the lowest quartile of cortisol compared to the highest was 1.5 (1.0–2.2, p = 0.058) for morning cortisol and 1.9 (1.3–2.8) for Δ-cortisol. All findings for Δ-cortisol remained after adjustments for multiple covariates and were also seen in a linear regression analysis (p = 0.003).</p> <p>Conclusion</p> <p>In summary, our findings of generally higher cortisol levels in women than men of all ages are novel and the stronger results seen for Δ-cortisol as opposed to morning cortisol in the association with WHR emphasise the need of studying cortisol variation intra-individually. To our knowledge, the associations in this study have never before been investigated in such a large population sample of both men and women. Our results therefore offer important knowledge on the descriptive characteristics of cortisol in relation to age and gender, and on the impact that associations previously seen between cortisol and abdominal obesity in smaller, selected samples have on a population level.</p

Cortisol metabolism, postnatal depression and weight changes in the first 12 months postpartum

Background & Objectives Postnatal depression correlates with postpartum weight retention, and dysregulated cortisol metabolism is evident in depressed individuals. Cortisol metabolism, BMI and metabolic phenotype are robustly associated, but the role of cortisol metabolism in postnatal mental health and weight loss has never been examined. Design A longitudinal observation. Patients Forty nine healthy women with uncomplicated pregnancy. Measurements BMI and urinary steroid metabolites at 1 week and 1, 3, 6 and 12 months postpartum. Validated urinary steroid metabolite ratios were measured to determine the activities of 11β‐hydroxysteroid dehydrogenases (11β‐HSD) that interconvert inactive cortisone and active cortisol and the 5α‐reductases that clear cortisol to its inactive metabolites. Postnatal depression symptoms were measured at 1, 6 and 12 months. Results Low 5α‐reductase activity was associated with greater weight loss across the first year, independent of demographics, breastfeeding and depression. Postpartum BMI change was unrelated to postnatal depression at any time. Symptoms of postnatal depression were related to higher cortisol metabolite production at 12 months, independent of demographics and breastfeeding. Conclusions Greatest weight loss in the postpartum year was associated with lower conversion of cortisone to cortisol and lower conversion of cortisol to its metabolites, supporting previous work that demonstrates the facilitative role of lower 5α‐reductase and 11β‐HSD‐1 in weight loss. Greater depression symptoms were associated with higher cortisol metabolite production rates. Whilst weight and mental health are both associated with dysregulation of the HPA axis, there may be different pathways towards depressed and obese phenotypes in healthy postpartum samples

Farming fit? Dispelling the Australian agrarian myth

Background: Rural Australians face a higher mental health and lifestyle disease burden (obesity, diabetes andcardiovascular disease) than their urban counterparts. Our ongoing research reveals that the Australian farmingcommunity has even poorer physical and mental health outcomes than rural averages. In particular, farm men andwomen have high rates of overweightness, obesity, abdominal adiposity, high blood pressure and psychologicaldistress when compared against Australian averages. Within our farming cohort we observed a significantassociation between psychological distress and obesity, abdominal adiposity and body fat percentage in thefarming population.Presentation of hypothesis: This paper presents a hypothesis based on preliminary data obtained from anongoing study that could potentially explain the complex correlation between obesity, psychological distress andphysical activity among a farming population. We posit that spasmodic physical activity, changing farm practicesand climate variability induce prolonged stress in farmers. This increases systemic cortisol that, in turn, promotesabdominal adiposity and weight gain.Testing the hypothesis: The hypothesis will be tested by anthropometric, biochemical and psychological analysismatched against systemic cortisol levels and the physical activity of the subjects.Implications of the hypothesis tested: Previous studies indicate that farming populations have elevated rates ofpsychological distress and high rates of suicide. Australian farmers have recently experienced challenging climaticconditions including prolonged drought, floods and cyclones. Through our interactions and through the media it isnot uncommon for farmers to describe the effect of this long-term stress with feelings of &lsquo;defeat&rsquo;. By gaining agreater understanding of the role cortisol and physical activity have on mental and physical health we maypositively impact the current rates of psychological distress in farmers.<br /

The adipocyte: a model for integration of endocrine and metabolic signaling in energy metabolism regulation

The ability to ensure continuous availability of energy despite highly variable supplies in the environment is a major determinant of the survival of all species. In higher organisms, including mammals, the capacity to efficiently store excess energy as triglycerides in adipocytes, from which stored energy could be rapidly released for use at other sites, was developed. To orchestrate the processes of energy storage and release, highly integrated systems operating on several physiological levels have evolved. The adipocyte is no longer considered a passive bystander, because fat cells actively secrete many members of the cytokine family, such as leptin, tumor necrosis factor-alpha, and interleukin-6, among other cytokine signals, which influence peripheral fuel storage, mobilization, and combustion, as well as energy homeostasis. The existence of a network of adipose tissue signaling pathways, arranged in a hierarchical fashion, constitutes a metabolic repertoire that enables the organism to adapt to a wide range of different metabolic challenges, such as starvation, stress, infection, and short periods of gross energy excess