Dynapenic obesity and the risk of incident Type 2 diabetes: the English Longitudinal Study of Ageing

Aim Obesity is a well‐established risk factor for developing Type 2 diabetes. Evidence suggests that sarcopenia, the age‐related decline in muscle mass and strength, may exacerbate diabetes risk in obese individuals. The aim of this study was to determine the combined effect of obesity and low muscle strength, dynapenia, on the risk of incident Type 2 diabetes in older adults. Methods Participants were 5953 (1670 obese) men and women from the English Longitudinal Study of Ageing without known Type 2 diabetes at baseline and for whom handgrip strength, biochemical and other clinical data were collected. A diagnosis of Type 2 diabetes was recorded from self‐reported physician diagnosis over 6 years. Results For each unit increase in grip strength, there was a reduction in diabetes risk (age‐, sex‐ and BMI adjusted HR; 0.98; 95% CI 0.96–0.99). The risk of Type 2 diabetes was elevated in all obese participants, but was greatest in those with low handgrip strength (HR = 4.93, 95% CI 2.85, 8.53) compared with non‐obese individuals with high handgrip strength. Eleven per cent of the sample met the threshold for weakness (handgrip strength: men < 26 kg; women < 16 kg) that was associated with elevated Type 2 diabetes risk in obese (HR = 3.57, 95% CI 2.04, 6.24) but not in non‐obese (HR = 0.86, 95% CI, 0.44, 1.68) compared with normal/non‐obese participants. Conclusion Dynapenic obesity, determined by high BMI and low handgrip strength, is associated with increased risk of incident Type 2 diabetes in older people

Metabolically healthy and unhealthy obesity: differential effects on myocardial function according to metabolic syndrome, rather than obesity.

BACKGROUND: The term 'metabolically healthy obese (MHO)' is distinguished using body mass index (BMI), yet BMI is a poor index of adiposity. Some epidemiological data suggest that MHO carries a lower risk of cardiovascular disease (CVD) or mortality than being normal weight yet metabolically unhealthy. OBJECTIVES: We aimed to undertake a detailed phenotyping of individuals with MHO by using imaging techniques to examine ectopic fat (visceral and liver fat deposition) and myocardial function. We hypothesised that metabolically unhealthy individuals (irrespective of BMI) would have adverse levels of ectopic fat and myocardial dysfunction compared with MHO individuals. SUBJECTS: Individuals were categorised as non-obese or obese (BMI ⩾30 kg m(-2)) and as metabolically healthy or unhealthy according to the presence or absence of metabolic syndrome. METHODS: Sixty-seven individuals (mean±s.d.: age 49±11 years) underwent measurement of (i) visceral, subcutaneous and liver fat using magnetic resonance imaging and proton magnetic resonance spectroscopy, (ii) components of metabolic syndrome, (iii) cardiorespiratory fitness and (iv) indices of systolic and diastolic function using tissue Doppler echocardiography. RESULTS: Cardiorespiratory fitness was similar between all groups; abdominal and visceral fat was highest in the obese groups. Compared with age- and BMI-matched metabolically healthy counterparts, the unhealthy (lean or obese) individuals had higher liver fat and decreased early diastolic strain rate, early diastolic tissue velocity and systolic strain indicative of subclinical systolic and diastolic dysfunction. The magnitude of dysfunction correlated with the number of components of metabolic syndrome but not with BMI or with the degree of ectopic (visceral or liver) fat deposition. CONCLUSIONS: Myocardial dysfunction appears to be related to poor metabolic health rather than simply BMI or fat mass. These data may partly explain the epidemiological evidence on CVD risk relating to the different obesity phenotypes

Physical Activity and Sedentary Time: Association with Metabolic Health and Liver Fat.

INTRODUCTION/PURPOSE: To investigate whether a) lower levels of daily physical activity (PA) and greater sedentary time accounted for contrasting metabolic phenotypes (higher liver fat/presence of metabolic syndrome [MetS+] vs lower liver fat/absence of metabolic syndrome [MetS-]) in individuals of similar BMI and b) the association of sedentary time on metabolic health and liver fat. METHODS: Ninety-eight habitually active participants (53 female, 45 male; age 39±13 years; BMI 26.9±5.1 kg/m), underwent assessments of PA (SenseWear armband; wear time ~98%), cardio-respiratory fitness (V[Combining Dot Above]O2 peak), body composition (MRI and MRS) and multi-organ insulin sensitivity (OGTT). We undertook a) cross-sectional analysis comparing four groups: non-obese or obese, with and without metabolic syndrome (MetS+ vs MetS-) and b) univariate and multivariate regression for sedentary time and other levels of PA in relation to liver fat. RESULTS: Light, moderate and vigorous PA did not account for differences in metabolic health between individuals, whether non-obese or obese, although MetS+ individuals were more sedentary, with a higher number, and prolonged bouts (~1-2 hours). Overall, sedentary time, average daily METS and V[Combining Dot Above]O2 peak were each independently associated with liver fat percentage. Each additional hour of daily sedentary time was associated with a 1.15% (95% CI, 1.14-1.50%) higher liver fat content. CONCLUSIONS: Greater sedentary time, independent of other levels of PA, is associated with being metabolically unhealthy; even in habitually active people, lesser sedentary time, and higher cardio-respiratory fitness and average daily METS is associated with lower liver fat.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

The impact of an intervention to introduce malaria rapid diagnostic tests on fever case management in a high transmission setting in Uganda: A mixed-methods cluster-randomized trial (PRIME).

Rapid diagnostic tests for malaria (mRDTs) have been scaled-up widely across Africa. The PRIME study evaluated an intervention aiming to improve fever case management using mRDTs at public health centers in Uganda. A cluster-randomized trial was conducted from 2010-13 in Tororo, a high malaria transmission setting. Twenty public health centers were randomized in a 1:1 ratio to intervention or control. The intervention included training in health center management, fever case management with mRDTs, and patient-centered services; plus provision of mRDTs and artemether-lumefantrine (AL) when stocks ran low. Three rounds of Interviews were conducted with caregivers of children under five years of age as they exited health centers (N = 1400); reference mRDTs were done in children with fever (N = 1336). Health worker perspectives on mRDTs were elicited through semi-structured questionnaires (N = 49) and in-depth interviews (N = 10). The primary outcome was inappropriate treatment of malaria, defined as the proportion of febrile children who were not treated according to guidelines based on the reference mRDT. There was no difference in inappropriate treatment of malaria between the intervention and control arms (24.0% versus 29.7%, adjusted risk ratio 0.81 95\% CI: 0.56, 1.17 p = 0.24). Most children (76.0\%) tested positive by reference mRDT, but many were not prescribed AL (22.5\% intervention versus 25.9\% control, p = 0.53). Inappropriate treatment of children testing negative by reference mRDT with AL was also common (31.3\% invention vs 42.4\% control, p = 0.29). Health workers appreciated mRDTs but felt that integrating testing into practice was challenging given constraints on time and infrastructure. The PRIME intervention did not have the desired impact on inappropriate treatment of malaria for children under five. In this high transmission setting, use of mRDTs did not lead to the reductions in antimalarial prescribing seen elsewhere. Broader investment in health systems, including infrastructure and staffing, will be required to improve fever case management

The impact of predation by marine mammals on Patagonian toothfish longline fisheries

Predatory interaction of marine mammals with longline fisheries is observed globally, leading to partial or complete loss of the catch and in some parts of the world to considerable financial loss. Depredation can also create additional unrecorded fishing mortality of a stock and has the potential to introduce bias to stock assessments. Here we aim to characterise depredation in the Patagonian toothfish (Dissostichus eleginoides) fishery around South Georgia focusing on the spatio-temporal component of these interactions. Antarctic fur seals (Arctocephalus gazella), sperm whales (Physeter macrocephalus), and orcas (Orcinus orca) frequently feed on fish hooked on longlines around South Georgia. A third of longlines encounter sperm whales, but loss of catch due to sperm whales is insignificant when compared to that due to orcas, which interact with only 5% of longlines but can take more than half of the catch in some cases. Orca depredation around South Georgia is spatially limited and focused in areas of putative migration routes, and the impact is compounded as a result of the fishery also concentrating in those areas at those times. Understanding the seasonal behaviour of orcas and the spatial and temporal distribution of “depredation hot spots” can reduce marine mammal interactions, will improve assessment and management of the stock and contribute to increased operational efficiency of the fishery. Such information is valuable in the effort to resolve the human-mammal conflict for resources

Raman spectroscopy of GaSe and InSe post-transition metal chalcogenides layers

This is the author accepted manuscript. The final version is available on open access from the Royal Society of Chemistry via the DOI in this recordIII-VI post-transition metal chalcogenides (InSe and GaSe) are a new class of layered semiconductors, which feature a strong variation of size and type of their band gaps as a function of number of layers (N). Here, we investigate exfoliated layers of InSe and GaSe ranging from bulk crystals down to monolayer, encapsulated in hexagonal boron nitride, using Raman spectroscopy. We present the N-dependence of both intralayer vibrations within each atomic layer, as well as of the interlayer shear and layer breathing modes. A linear chain model can be used to describe the evolution of the peak positions as a function of N, consistent with first principles calculationsNational Science Centre, PolandEngineering and Physical Sciences Research Council (EPSRC)Scientific and Technological Research Council of Turkey (TUBITAK)Royal SocietySamsung Advanced Institute of Technology (SAIT)European Research Council (ERC

Determinants of the accuracy of rapid diagnostic tests in malaria case management: evidence from low and moderate transmission settings in the East African highlands

BACKGROUND: The accuracy of malaria diagnosis has received renewed interest in recent years due to changes in treatment policies in favour of relatively high-cost artemisinin-based combination therapies. The use of rapid diagnostic tests (RDTs) based on histidine-rich protein 2 (HRP2) synthesized by Plasmodium falciparum has been widely advocated to save costs and to minimize inappropriate treatment of non-malarial febrile illnesses. HRP2-based RDTs are highly sensitive and stable; however, their specificity is a cause for concern, particularly in areas of intense malaria transmission due to persistence of HRP2 antigens from previous infections. METHODS: In this study, 78,454 clinically diagnosed malaria patients were tested using HRP2-based RDTs over a period of approximately four years in four highland sites in Kenya and Uganda representing hypoendemic to mesoendemic settings. In addition, the utility of the tests was evaluated in comparison with expert microscopy for disease management in 2,241 subjects in two sites with different endemicity levels over four months. RESULTS: RDT positivity rates varied by season and year, indicating temporal changes in accuracy of clinical diagnosis. Compared to expert microscopy, the sensitivity, specificity, positive predictive value and negative predictive value of the RDTs in a hypoendemic site were 90.0%, 99.9%, 90.0% and 99.9%, respectively. Corresponding measures at a mesoendemic site were 91.0%, 65.0%, 71.6% and 88.1%. Although sensitivities at the two sites were broadly comparable, levels of specificity varied considerably between the sites as well as according to month of test, age of patient, and presence or absence of fever during consultation. Specificity was relatively high in older age groups and increased towards the end of the transmission season, indicating the role played by anti-HRP2 antibodies. Patients with high parasite densities were more likely to test positive with RDTs than those with low density infections. CONCLUSION: RDTs may be effective when used in low endemicity situations, but high false positive error rates may occur in areas with moderately high transmission. Reports on specificity of RDTs and cost-effectiveness analyses on their use should be interpreted with caution as there may be wide variations in these measurements depending upon endemicity, season and the age group of patients studied

Infrared-to-violet tunable optical activity in atomic films of GaSe, InSe, and their heterostructures

Two-dimensional semiconductors - atomic layers of materials with covalent intra-layer bonding and weak (van der Waals or quadrupole) coupling between the layers - are a new class of materials with great potential for optoelectronic applications. Among those, a special position is now being taken by post-transition metal chalcogenides (PTMC), InSe and GaSe. It has recently been found that the band gap in 2D crystals of InSe more than doubles in the monolayer compared to thick multilayer crystals, while the high mobility of conduction band electrons is promoted by their light in-plane mass. Here, we use Raman and PL measurements of encapsulated few layer samples, coupled with accurate atomic force and transmission electron microscope structural characterisation to reveal new optical properties of atomically thin GaSe preserved by hBN encapsulation. The band gaps we observe complement the spectral range provided by InSe films, so that optical activity of these two almost lattice-matched PTMC films and their heterostructures densely cover the spectrum of photons from violet to infrared. We demonstrate the realisation of the latter by the first observation of interlayer excitonic photoluminescence in few-layer InSe-GaSe heterostructures. The spatially indirect transition is direct in k-space and therefore is bright, while its energy can be tuned in a broad range by the number of layers.Comment: 8 pages 4 figure

Diagnostic Testing of Pediatric Fevers: Meta-Analysis of 13 National Surveys Assessing Influences of Malaria Endemicity and Source of Care on Test Uptake for Febrile Children under Five Years.

In 2010, the World Health Organization revised guidelines to recommend diagnosis of all suspected malaria cases prior to treatment. There has been no systematic assessment of malaria test uptake for pediatric fevers at the population level as countries start implementing guidelines. We examined test use for pediatric fevers in relation to malaria endemicity and treatment-seeking behavior in multiple sub-Saharan African countries in initial years of implementation. We compiled data from national population-based surveys reporting fever prevalence, care-seeking and diagnostic use for children under five years in 13 sub-Saharan African countries in 2009-2011/12 (n = 105,791). Mixed-effects logistic regression models quantified the influence of source of care and malaria endemicity on test use after adjusting for socioeconomic covariates. Results were stratified by malaria endemicity categories: low (PfPR2-10<5%), moderate (PfPR2-10 5-40%), high (PfPR2-10>40%). Among febrile under-fives surveyed, 16.9% (95% CI: 11.8%-21.9%) were tested. Compared to hospitals, febrile children attending non-hospital sources (OR: 0.62, 95% CI: 0.56-0.69) and community health workers (OR: 0.31, 95% CI: 0.23-0.43) were less often tested. Febrile children in high-risk areas had reduced odds of testing compared to low-risk settings (OR: 0.51, 95% CI: 0.42-0.62). Febrile children in least poor households were more often tested than in poorest (OR: 1.63, 95% CI: 1.39-1.91), as were children with better-educated mothers compared to least educated (OR: 1.33, 95% CI: 1.16-1.54). Diagnostic testing of pediatric fevers was low and inequitable at the outset of new guidelines. Greater testing is needed at lower or less formal sources where pediatric fevers are commonly managed, particularly to reach the poorest. Lower test uptake in high-risk settings merits further investigation given potential implications for diagnostic scale-up in these areas. Findings could inform continued implementation of new guidelines to improve access to and equity in point-of-care diagnostics use for pediatric fevers