Body size and shape changes and the risk of diabetes in the Diabetes Prevention Program

Prezentowane badanie przeprowadzono w celu sprawdzenia hipotezy, zgodnie z którą ryzyko rozwoju cukrzycy typu 2 zmniejsza się wraz z redukcją masy ciała i otyłości brzusznej. Do badania Diabetes Prevention Program (DPP) włączono osoby, u których rozpoznawano upośledzoną tolerancję glukozy, i zakwalifikowano je do grup otrzymujących placebo lub metforminę albo wprowadzono tylko modyfikację stylu życia. U uczestników badania określono wzrost, masę ciała oraz zmierzono tkankę tłuszczową na poziomie L2-L3 i L4-L5 za pomocą tomografii komputerowej na początku badania oraz po roku. Zastosowano modele proporcjonalnego ryzyka Coxa w celu oceny, zależnie od płci, wpływu zmiany tych parametrów w ciągu roku na rozwój cukrzycy w okresie dalszej obserwacji, którą prowadzono u 758 osób. Modyfikacja stylu życia doprowadziła do redukcji trzewnej tkanki tłuszczowej na poziomie L2-L3 (mężczyźni: -24,3%; kobiety: -18,2%) oraz na poziomie L4-L5 (mężczyźni: -22,4%, kobiety: -17,8%), tkanki tłuszczowej podskórnej na poziomie L2-L3 (mężczyźni: -15,7%, kobiety: -11,4%) i L4-L5 (mężczyźni: -16,7%, kobiety: -11,9%), do zmniejszenia masy ciała (mężczyźni: -8,2%, kobiety: -7,8%), wskaźnika masy ciała (mężczyźni: -8,2%, kobiety: -7,8%) oraz obwodu talii (mężczyźni: -7,5%, kobiety -6,1%). W grupie otrzymującej metforminę zaobserwowano redukcję masy ciała (-2,9%) i obniżenie wskaźnika masy ciała (-2,9%) u mężczyzn oraz zmniejszenie ilości podskórnej tkanki tłuszczowej (-3,6% na poziomie L2-L3 i -4,7% na poziomie L4-L5), masy ciała (-3,3%), wskaźnika masy ciała (-3,3%) oraz obwodu talii (-2,8%) u kobiet. Zmniejszenie ryzyka rozwoju cukrzycy poprzez zmianę stylu życia wiązało się z redukcją masy ciała, wskaźnika masy ciała oraz rozkładu tkanki tłuszczowej po skorygowaniu względem wieku oraz pochodzenia etnicznego (ustalano je na podstawie informacji uzyskanej od uczestników). Zmniejszenie ryzyka rozwoju cukrzycy poprzez zmianę stylu życia może nastąpić zarówno poprzez wpływ na całą tkankę tłuszczową, jak i brzuszną tkankę tłuszczową; wpływ metforminy wydawał się niezależny od zmian tkanki tłuszczowej.The researchers conducted this study to test the hypothesis that risk of type 2 diabetes is less following reductions in body size and central adiposity. The Diabetes Prevention Program (DPP) recruited and randomized individuals with impaired glucose tolerance to treatment with placebo, metformin, or lifestyle modification. Height, weight, waist circumference, and subcutaneous and visceral fat at L2-L3 and L4-L5 by computed tomography were measured at baseline and at 1 year. Cox proportional hazards models assessed by sex the effect of change in these variables over the 1st year of intervention upon development of diabetes over subsequent follow- up in a subset of 758 participants. Lifestyle reduced visceral fat at L2-L3 (men -24.3%, women -18.2%) and at L4-L5 (men -22.4%, women -17.8%), subcutaneous fat at L2-L3 (men -15.7%, women -11.4%) and at L4-L5 (men -16.7%, women -11.9%), weight (men –8.2%, women –7.8%), BMI (men -8.2%, women -7.8%), and waist circumference (men -7.5%, women -6.1%). Metformin reduced weight (-2.9%) and BMI (-2.9%) in men and subcutaneous fat (-3.6% at L2-L3 and -4.7% at L4-L5), weight (-3.3%), BMI (-3.3%), and waist circumference (-2.8%) in women. Decreased diabetes risk by lifestyle intervention was associated with reductions of body weight, BMI, and central body fat distribution after adjustment for age and self-reported ethnicity. Reduced diabetes risk with lifestyle intervention may have been through effects upon both overall body fat and central body fat but with metformin appeared to be independent of body fat

Tourism and transformation: negotiating metaphors, experiencing change

WOS:000338007000001 (Nº de Acesso Web of Science)The article introduces this special issue on tourism and transformation. After offering a brief review of the place and significance of ‘transformation’ in social sciences studies of tourism – from ‘impact studies’ to ethnographies of tourists and, more recently, ‘tourist media studies’ – we propose to take one step further and focus our attention on the performativity and reflexivity of ‘transformation’. Our main argument is that much may be gained analytically by considering how notions and experiences of transformation are addressed, negotiated and purposefully deployed in tourism contexts. We conclude with an outline of each of the contributions to this special issue, stressing that the collection re-opens the issue of transformation in tourism and provides new insights into how experiences-turned metaphors and metaphors-turnedexperiences influence both the travel experience and the development of theory

Metabolic effects of diets differing in glycaemic index depend on age and endogenous GIP

Aims/hypothesis High- vs low-glycaemic index (GI) diets unfavourably affect body fat mass and metabolic markers in rodents. Different effects of these diets could be age-dependent, as well as mediated, in part, by carbohydrate-induced stimulation of glucose-dependent insulinotrophic polypeptide (GIP) signalling. Methods Young-adult (16 weeks) and aged (44 weeks) male wild-type (C57BL/6J) and GIP-receptor knockout (Gipr −/− ) mice were exposed to otherwise identical high-carbohydrate diets differing only in GI (20–26 weeks of intervention, n = 8–10 per group). Diet-induced changes in body fat distribution, liver fat, locomotor activity, markers of insulin sensitivity and substrate oxidation were investigated, as well as changes in the gene expression of anorexigenic and orexigenic hypothalamic factors related to food intake. Results Body weight significantly increased in young-adult high- vs low-GI fed mice (two-way ANOVA, p < 0.001), regardless of the Gipr genotype. The high-GI diet in young-adult mice also led to significantly increased fat mass and changes in metabolic markers that indicate reduced insulin sensitivity. Even though body fat mass also slightly increased in high- vs low-GI fed aged wild-type mice (p < 0.05), there were no significant changes in body weight and estimated insulin sensitivity in these animals. However, aged Gipr −/− vs wild-type mice on high-GI diet showed significantly lower cumulative net energy intake, increased locomotor activity and improved markers of insulin sensitivity. Conclusions/interpretation The metabolic benefits of a low-GI diet appear to be more pronounced in younger animals, regardless of the Gipr genotype. Inactivation of GIP signalling in aged animals on a high-GI diet, however, could be beneficial

Proinflammatory cytokine levels in fibromyalgia patients are independent of body mass index

<p>Abstract</p> <p>Background</p> <p>Fibromyalgia (FM) is characterized by chronic, widespread muscular pain and tenderness and is generally associated with other somatic and psychological symptoms. Further, circulatory levels of proinflammatory cytokines (IL-1β, TNF-α, and IL-6) may be altered in FM patients, possibly in association with their symptoms. Recently, rises in BMI have been suggested to contribute to increased circulating levels of proinflammatory cytokines in FM patients. Our aim was to measure the circulatory levels of proinflammatory cytokines to determine the influence of BMI on these levels in FM patients and healthy volunteers (HVs). In Spanish FM patients (n = 64) and HVs (n = 25), we measured BMI and serum concentrations of proinflammatory cytokines by capture ELISA.</p> <p>Findings</p> <p>There were significant differences in BMI levels between FM patients (26.40 ± 4.46) and HVs (23.64 ± 3.45) and significant increase in IL-6 in FM patients (16.28 ± 8.13 vs 0.92 ± 0.32 pg/ml) (P < 0.001). IL-1β and TNF-α decreased in FM patients compared with HVs. By ANCOVA, there was no significant association between BMI and TNF-α (F = 0.098, p = 0.75) or IL-6 (F = 0.221, p = 0.63) levels in FM patients.</p> <p>Conclusions</p> <p>Our analysis in FM patients of BMI as a covariate of proinflammatory cytokines levels showed that serum TNF-α and IL-6 levels are independent of BMI. Further studies are necessary to dissect these findings and their implication in future therapeutic approaches for FM patients.</p

Non-Invasive Quantification of White and Brown Adipose Tissues and Liver Fat Content by Computed Tomography in Mice

OBJECTIVES: Obesity and its distribution pattern are important factors for the prediction of the onset of diabetes in humans. Since several mouse models are suitable to study the pathophysiology of type 2 diabetes the aim was to validate a novel computed tomograph model (Aloka-Hitachi LCT-200) for the quantification of visceral, subcutaneous, brown and intrahepatic fat depots in mice. METHODS: Different lean and obese mouse models (C57BL/6, B6.V-Lep(ob), NZO) were used to determine the most adequate scanning parameters for the detection of the different fat depots. The data were compared with those obtained after preparation and weighing the fat depots. Liver fat content was determined by biochemical analysis. RESULTS: The correlations between weights of fat tissues on scale and weights determined by CT were significant for subcutaneous (r(2) = 0.995), visceral (r(2) = 0.990) and total white adipose tissue (r(2) = 0.992). Moreover, scans in the abdominal region, between lumbar vertebrae L4 to L5 correlated with whole-body fat distribution allowing experimenters to reduce scanning time and animal exposure to radiation and anesthesia. Test-retest reliability and measurements conducted by different experimenters showed a high reproducibility in the obtained results. Intrahepatic fat content estimated by CT was linearly related to biochemical analysis (r(2) = 0.915). Furthermore, brown fat mass correlated well with weighted brown fat depots (r(2) = 0.952). In addition, short-term cold-expose (4 °C, 4 hours) led to alterations in brown adipose tissue attributed to a reduction in triglyceride content that can be visualized as an increase in Hounsfield units by CT imaging. CONCLUSION: The 3D imaging of fat by CT provides reliable results in the quantification of total, visceral, subcutaneous, brown and intrahepatic fat in mice. This non-invasive method allows the conduction of longitudinal studies of obesity in mice and therefore enables experimenters to investigate the onset of complex diseases such as diabetes and obesity

Tourism culture(s): The Hospitality Dimension

The focus of the paper is on tourism culture as it operates where commercial hospitality is on offer, especially at hotels and resorts in developing countries. It is suggested that three quite distinct perspectives can assist in helping us understand this aspect of tourism culture, which emerges where worker and tourist roles inevitably converge and interact. In themselves, such perspectives are not new, but they rarely seem to have been applied in the context of hotels and resorts. The first perspective, derived from the work of Homi Bhabha, conceives of tourism culture as hybrid in nature, operating in a ‘third space’ between tourist and ‘host,’ and directs attention to the uncertain and negotiated aspects of tourism culture. In the second, that of the socio-technical system, tourism culture is seen as an interface between, on the one hand, the formal operational rules and procedures designed to deliver an organisation’s mission and, on the other hand, the on-going and lived-in cultures brought into the ‘system’ by tourists and the hospitality providers. The third perspective, that of the total institution, derived from Goffman, focuses to the social and physical boundaries that separate the hotel or resort from the outside world and on the cultural practices that serve to further differentiate it and its population from the outside. It is suggested that use of these perspectives can further our understanding of the nature of tourism at different destinations and the ways hotels and similar institutions impact on both staff members and holidaymakers. As a consequence, they are theoretically, empirically relevant and politically important