74 research outputs found

    Pancreatic metabolism, blood flow, and β-cell function in obese humans.

    Get PDF
    Context: Glucolipotoxicity is believed to induce pancreatic &beta;-cell dysfunction in obesity. Previously, it has not been possible to study pancreatic metabolism and blood flow in humans. Objective: The objective of the study was to investigate whether pancreatic metabolism and blood flow are altered in obesity using positron emission tomography (PET). In the preclinical part, the method was validated in animals. Design: This was a cross-sectional study. Setting: The study was conducted in a clinical research center. Participants: Human studies consisted of 52 morbidly obese and 25 healthy age-matched control subjects. Validation experiments were done with rodents and pigs. Interventions: PET and magnetic resonance imaging studies using a glucose analog ([18F]fluoro-2-deoxy-d-glucose), a palmitate analog [14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid], and radiowater ([15O]H2O) were performed. In animals, a comparison between ex vivo and in vivo data was performed. Main Outcome Measures: Pancreatic glucose/fatty acid (FA) uptake, fat accumulation, and blood flow parameters of &beta;-cell function were measured. Results: PET proved to be a feasible method to measure pancreatic metabolism. Compared with healthy participants, obese participants had elevated pancreatic FA uptake (P &lt; .0001), more fat accumulation (P = .0001), lowered glucose uptake both during fasting and euglycemic hyperinsulinemia, and blunted blood flow (P &lt; .01) in the pancreas. Blood flow, FA uptake, and fat accumulation were negatively associated with multiple markers of &beta;-cell function. Conclusions: Obesity leads to changes in pancreatic energy metabolism with a substrate shift from glucose to FAs. In morbidly obese humans, impaired pancreatic blood flow may contribute to &beta;-cell dysfunction and in the pathogenesis of type 2 diabetes. &nbsp;</div

    Definitions and methods of measuring and reporting on injurious falls in randomised controlled fall prevention trials: a systematic review

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The standardisation of the assessment methodology and case definition represents a major precondition for the comparison of study results and the conduction of meta-analyses. International guidelines provide recommendations for the standardisation of falls methodology; however, injurious falls have not been targeted. The aim of the present article was to review systematically the range of case definitions and methods used to measure and report on injurious falls in randomised controlled trials (RCTs) on fall prevention.</p> <p>Methods</p> <p>An electronic literature search of selected comprehensive databases was performed to identify injurious falls definitions in published trials. Inclusion criteria were: RCTs on falls prevention published in English, study population ≥ 65 years, definition of injurious falls as a study endpoint by using the terms "injuries" and "falls".</p> <p>Results</p> <p>The search yielded 2089 articles, 2048 were excluded according to defined inclusion criteria. Forty-one articles were included. The systematic analysis of the methodology applied in RCTs disclosed substantial variations in the definition and methods used to measure and document injurious falls. The limited standardisation hampered comparability of study results. Our results also highlight that studies which used a similar, standardised definition of injurious falls showed comparable outcomes.</p> <p>Conclusions</p> <p>No standard for defining, measuring, and documenting injurious falls could be identified among published RCTs. A standardised injurious falls definition enhances the comparability of study results as demonstrated by a subgroup of RCTs used a similar definition. Recommendations for standardising the methodology are given in the present review.</p

    New insights into the genetic etiology of Alzheimer's disease and related dementias

    Get PDF
    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

    Vilka pojkar blev civilingenjörer och vad hände med de smarta flickorna?

    Get PDF
    corecore