Dual-Energy X-Ray Absorptiometry for Quantification of Visceral Fat

Obesity is the major risk factor for metabolic syndrome and through it diabetes as well as cardiovascular disease. Visceral fat (VF) rather than subcutaneous fat (SF) is the major predictor of adverse events. Currently, the reference standard for measuring VF is abdominal X-ray computed tomography (CT) or magnetic resonance imaging (MRI), requiring highly used clinical equipment. Dual-energy X-ray absorptiometry (DXA) can accurately measure body composition with high-precision, low X-ray exposure, and short-scanning time. The purpose of this study was to validate a new fully automated method whereby abdominal VF can be measured by DXA. Furthermore, we explored the association between DXA-derived abdominal VF and several other indices for obesity: BMI, waist circumference, waist-to-hip ratio, and DXA-derived total abdominal fat (AF), and SF. We studied 124 adult men and women, aged 18–90 years, representing a wide range of BMI values (18.5–40 kg/m2) measured with both DXA and CT in a fasting state within a one hour interval. The coefficient of determination (r2) for regression of CT on DXA values was 0.959 for females, 0.949 for males, and 0.957 combined. The 95% confidence interval for r was 0.968 to 0.985 for the combined data. The 95% confidence interval for the mean of the differences between CT and DXA VF volume was −96.0 to −16.3 cm3. Bland–Altman bias was +67 cm3 for females and +43 cm3 for males. The 95% limits of agreement were −339 to +472 cm3 for females and −379 to +465 cm3 for males. Combined, the bias was +56 cm3 with 95% limits of agreement of −355 to +468 cm3. The correlations between DXA-derived VF and BMI, waist circumference, waist-to-hip ratio, and DXA-derived AF and SF ranged from poor to modest. We conclude that DXA can measure abdominal VF precisely in both men and women. This simple noninvasive method with virtually no radiation can therefore be used to measure VF in individual patients and help define diabetes and cardiovascular risk

Association of Lifestyle Factors With Abdominal Subcutaneous and Visceral Adiposity: The Framingham Heart Study

OBJECTIVE— The purpose of this study was to assess the relationship between lifestyle factors and abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in a community-based setting

Cholesterol and Lipoprotein Dynamics in a Hibernating Mammal

Hibernating mammals cease feeding during the winter and rely primarily on stored lipids to fuel alternating periods of torpor and arousal. How hibernators manage large fluxes of lipids and sterols over the annual hibernation cycle is poorly understood. The aim of this study was to investigate lipid and cholesterol transport and storage in ground squirrels studied in spring, summer, and several hibernation states. Cholesterol levels in total plasma, HDL and LDL particles were elevated in hibernators compared with spring or summer squirrels. Hibernation increased plasma apolipoprotein A-I expression and HDL particle size. Expression of cholesterol 7 alpha-hydroxylase was 13-fold lower in hibernators than in active season squirrels. Plasma triglycerides were reduced by fasting in spring but not summer squirrels. In hibernators plasma β-hydroxybutyrate was elevated during torpor whereas triglycerides were low relative to normothermic states. We conclude that the switch to a lipid-based metabolism during winter, coupled with reduced capacity to excrete cholesterol creates a closed system in which efficient use of lipoproteins is essential for survival

EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

Estimation of CT-derived abdominal visceral and subcutaneous adipose tissue depots from anthropometry in Europeans, South Asians and African Caribbeans

Background South Asians and African Caribbeans experience more cardiometabolic disease than Europeans. Risk factors include visceral (VAT) and subcutaneous abdominal (SAT) adipose tissue, which vary with ethnicity and are difficult to quantify using anthropometry. Objective We developed and cross-validated ethnicity and gender-specific equations using anthropometrics to predict VAT and SAT. Design 669 Europeans, 514 South Asians and 227 African Caribbeans (70±7 years) underwent anthropometric measurement and abdominal CT scanning. South Asian and African Caribbean participants were first-generation migrants living in London. Prediction equations were derived for CT-measured VAT and SAT using stepwise regression, then cross-validated by comparing actual and predicted means. Results South Asians had more and African Caribbeans less VAT than Europeans. For basic VAT prediction equations (age and waist circumference), model fit was better in men (R2 range 0.59-0.71) than women (range 0.35-0.59). Expanded equations (+ weight, height, hip and thigh circumference) improved fit for South Asian and African Caribbean women (R2 0.35 to 0.55, and 0.43 to 0.56 respectively). For basic SAT equations, R2 was 0.69-0.77, and for expanded equations it was 0.72-0.86. Cross-validation showed differences between actual and estimated VAT of <7%, and SAT of <8% in all groups, apart from VAT in South Asian women which disagreed by 16%. Conclusion We provide ethnicity- and gender-specific VAT and SAT prediction equations, derived from a large tri-ethnic sample. Model fit was reasonable for SAT and VAT in men, while basic VAT models should be used cautiously in South Asian and African Caribbean women. These equations will aid studies of mechanisms of cardiometabolic disease in later life, where imaging data are not available

Le rôle de l\u27information sur Internet dans la consommation médicale : le cas des patients canadiens francophones et anglophones

The aim of this research is to study the relationship between Internet information use and medical resources consumption by French-speaking and English-speaking Canadian patients. This relationship is assessed directly and indirectly through attitude variables. The choice to distinguish between French-speaking and English-speaking patients was justified by a mean comparison analysis. The analysis of the data obtained from the diffused quantitative questionnaire was performed using SPSS and PLS statistic tools. Results showed that the direct relationship between Internet information use and medical resources consumption is significant and positive for the two samples. However, it is stronger for the Frenchspeaking sample. This result probably reflects a greater concern regarding the offer of medical information on the Internet in the French language. Research contributions are theoretical and practical. On one hand, this research is the first to test the proposed model for two different populations in terms of used languages. On the other hand, the results of this study allow becoming aware of the existence of a possible problem regarding the offer of health information on the Web

Le rôle de l'information sur Internet dans la consommation médicale : le cas des patients canadiens francophones et anglophones

The aim of this research is to study the relationship between Internet information use and medical resources consumption by French-speaking and English-speaking Canadian patients. This relationship is assessed directly and indirectly through attitude variables. The choice to distinguish between French-speaking and English-speaking patients was justified by a mean comparison analysis. The analysis of the data obtained from the diffused quantitative questionnaire was performed using SPSS and PLS statistic tools. Results showed that the direct relationship between Internet information use and medical resources consumption is significant and positive for the two samples. However, it is stronger for the Frenchspeaking sample. This result probably reflects a greater concern regarding the offer of medical information on the Internet in the French language. Research contributions are theoretical and practical. On one hand, this research is the first to test the proposed model for two different populations in terms of used languages. On the other hand, the results of this study allow becoming aware of the existence of a possible problem regarding the offer of health information on the Web.L'objectif de cette recherche est d'&eacute;tudier la relation entre l'utilisation de l'information d'Internet et la consommation des ressources m&eacute;dicales par des patients canadiens francophones et anglophones. Cette relation est &eacute;valu&eacute;e de mani&egrave;re directe et indirecte &agrave; travers les variables d'attitude. Le choix de s&eacute;parer les patients francophones des anglophones a &eacute;t&eacute; justifi&eacute; par une analyse de comparaison des moyennes. Les analyses des donn&eacute;es recueillies suite &agrave; la diffusion d'un questionnaire quantitatif ont &eacute;t&eacute; effectu&eacute;es &agrave; l'aide des outils statistiques SPSS et PLS. Les r&eacute;sultats ont montr&eacute; que la relation directe entre l'utilisation de l'information d'Internet et la consommation des ressources m&eacute;dicales est significative et positive pour les deux &eacute;chantillons. Toutefois, elle est plus forte pour l'&eacute;chantillon francophone. Ce r&eacute;sultat refl&egrave;te probablement une pr&eacute;occupation plus importante par rapport &agrave; l'offre de l'information m&eacute;dicale sur Internet en langue fran&ccedil;aise. Les contributions de cette recherche sont d'ordre th&eacute;orique et pratique. D'une part, cette recherche est la premi&egrave;re &agrave; tester le mod&egrave;le propos&eacute; pour deux populations diff&eacute;rentes en termes de langue. D'autre part, les r&eacute;sultats de cette &eacute;tude permettent de prendre conscience de l'existence d'un probl&egrave;me &eacute;ventuel au niveau de l'offre de l'information en sant&eacute; obtenue du Web

Acquisition de connaissances pour un syst\ue8me conseiller m\ue9thodologique

NRC publication: Ye