Acute Sarcopenia Secondary to Hospitalisation - An Emerging Condition Affecting Older Adults

There has been increasing interest and research into sarcopenia in community-dwelling older adults since the European Working Group on Sarcopenia in Older People (EWGSOP) agreed a consensus definition in 2010. Sarcopenia has been defined as loss of muscle mass with loss of muscle function (strength or physical performance), with measurements two Standard Deviations (SDs) below the mean of a young reference population. This definition does not necessitate longitudinal measurements, or the absence of acute illness and diagnosis can be made from single measurements. We hypothesise that hospitalisation, due to a combination of acute inflammatory burden and muscle disuse, leads to an acute decline in muscle mass and function and may lead to some individuals meeting criteria for sarcopenia, acutely, based on the EWGSOP definition. This may be partially recoverable or may lead to increased risk of developing sarcopenia long-term. We have denoted the term “acute sarcopenia” to refer to acute loss of muscle mass and function associated with hospitalisation. This review discusses some of the current available research in this context and also identifies some of the knowledge gaps and potential areas for future research.

Does the presence of a urinary catheter predict severe sepsis in a bacteraemic cohort?

BACKGROUND

Sepsis is a major cause of mortality with an estimated 37,000 deaths in the UK each year. This study aimed to determine host factors that can predict severe sepsis in a bacteraemic cohort.

METHODS

From December 2012 to November 2013, demographic, clinical and microbiological data were collected on consecutive patients with bacteraemia at a London teaching hospital. These data were used to categorize patients as having severe or non-severe sepsis. Multi-variate logistic regression was used to determine the association between host factors and severe sepsis.

FINDINGS

Five hundred and ninety-four bacteraemic episodes occurred in 500 patients. The majority of cases were in patients aged >50 years (382/594, 64.3%) and in males (346/594, 58.2%). The most common isolates were Escherichia coli (207/594, 34.8%) and meticillin-susceptible Staphylococcus aureus (57/594, 9.6%). In logistic regression multi-variable analysis, site of infection was significantly associated with severe sepsis. For catheter-associated urinary tract infections, the association was significant after adjustment for age, sex, Charlson comorbidity index and where infection was acquired (odds ratio 3.94, 95% confidence interval 1.70-9.11).

CONCLUSIONS

Urinary catheters increase the risk of severe sepsis. They should only be used if clinically indicated. If inserted, a care bundle approach should be used and the anticipated removal date should be recorded unless a long-term catheter is required. In the context of sepsis, the presence of a urinary catheter should prompt immediate implementation of 'Sepsis Six' and consideration of transfer to a critical care unit.

Light scattering study of the "pseudo-layer" compression elastic constant in a twist-bend nematic liquid crystal

The nematic twist-bend (TB) phase, exhibited by certain achiral thermotropic liquid crystalline (LC) dimers, features a nanometer-scale, heliconical rotation of the average molecular long axis (director) with equally probable left- and right-handed domains. On meso to macroscopic scales, the TB phase may be considered as a stack of equivalent slabs or "pseudo-layers", each one helical pitch in thickness. The long wavelength fluctuation modes should then be analogous to those of a smectic-A phase, and in particular the hydrodynamic mode combining "layer" compression and bending ought to be characterized by an effective layer compression elastic constant B_eff and average director splay constant K. The magnitude of K is expected to be similar to the splay constant of an ordinary nematic LC, but due to the absence of a true mass density wave, B_eff could differ substantially from the typical value of ∼10⁶ Pa in a conventional smectic-A. Here we report the results of a dynamic light scattering study, which confirms the "pseudo-layer" structure of the TB phase with B_eff in the range 10³-10⁴ Pa. We show additionally that the temperature dependence of B_eff at the TB to nematic transition is accurately described by a coarse-grained free energy density, which is based on a Landau-deGennes expansion in terms of a heli-polar order parameter that characterizes the TB state and is linearly coupled to bend distortion of the director.

Anomalous Increase in Nematic-Isotropic Transition Temperature in Dimer Molecules Induced by a Magnetic Field

We have determined the nematic-isotropic transition temperature as a function of an applied magnetic field in three different thermotropic liquid crystalline dimers. These molecules are comprised of two rigid calamitic moieties joined end to end by flexible spacers with odd numbers of methylene groups. They show an unprecedented magnetic field enhancement of nematic order in that the transition temperature is increased by up to 15 K when subjected to a 22 T magnetic field. The increase is conjectured to be caused by a magnetic-field-induced decrease of the average bend angle in the aliphatic spacers connecting the rigid mesogenic units of the dimers.

Second harmonic light scattering induced by defects in the twist-bend nematic phase of liquid crystal dimers

The nematic twist-bend (NTB) phase, exhibited by certain thermotropic liquid crystalline (LC) dimers, represents a new orientationally ordered mesophase - the first distinct nematic variant discovered in many years. The NTB phase is distinguished by a heliconical winding of the average molecular long axis (director) with a remarkably short (nanoscale) pitch and, in systems of achiral dimers, with an equal probability to form right- and left-handed domains. The NTB structure thus provides another fascinating example of spontaneous chiral symmetry breaking in nature. The order parameter driving the formation of the heliconical state has been theoretically conjectured to be a polarization field, deriving from the bent conformation of the dimers, that rotates helically with the same nanoscale pitch as the director field. It therefore presents a significant challenge for experimental detection. Here we report a second harmonic light scattering (SHLS) study on two achiral, NTB-forming LCs, which is sensitive to the polarization field due to micron-scale distortion of the helical structure associated with naturally-occurring textural defects. These defects are parabolic focal conics of smectic-like "pseudo-layers", defined by planes of equivalent phase in a coarse-grained description of the NTB state. Our SHLS data are explained by a coarse-grained free energy density that combines a Landau-deGennes expansion of the polarization field, the elastic energy of a nematic, and a linear coupling between the two.

The stabilisation of the Nx phase in mixtures

The phase behaviour of mixtures between two symmetric dimers, CBC9CB and the ether-linked analogue CBOC9OCB was investigated by Polarizing Optical Microscopy (POM), Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD) studies. The dimeric constituents are fully miscible and the construction of a temperature-composition phase diagram reveals a surprising amplification of the stability of the Nx phase in compositions of up to 37 wt% of CBOC9OCB in CBC9CB. The origin for this enhancement of stability is discussed and an explanation based on chiral recognition is developed.

Mesophase structure and behaviour in bulk and restricted geometry of a dimeric compound exhibiting a nematic–nematic transition

We demonstrate a liquid crystal system exhibiting a variety of modulated structures on different length-scales: from helicoidal nematic to modulated smectic.

The design and investigation of the self-assembly of dimers with two nematic phases

Non-symmetric nematic dimers are designed and investigated by OPM, DSC and XRD; assembly models for the N_x phase are developed.

Brain wave maturation and neurodevelopmental outcome in extremely low gestational age neonates

OBJECTIVE

Infants born at extremely low gestational ages are at high risk for developmental impairments. Early predictors of these impairments are useful for both clinicians and researchers. Our objective was to assess the correlation between the rate of brain wave maturation as measured by serial amplitude-integrated electroencephalograms (aEEGs) and scores on standardized measures of infant development in extremely low gestational age neonates.

STUDY DESIGN

This was a prospective observational study of 65 infants born before 28 weeks' gestational age who were assessed with an aEEG monthly between 28 and 36 weeks' postmenstrual age and with the Bayley Scales of Infant and Toddler Development-III at 18 to 22 months adjusted age. We analyzed the correlation between the rate of brain wave maturation on aEEG and Bayley Scales of Infant and Toddler Development-III Cognitive and Motor Scales.

RESULT

The mean rate of brain wave maturation was 0.83 (±0.36) points per week. Brain wave maturation was not correlated with either the Cognitive or Motor Scale (adjusted regression coefficients for Cognitive and Motor Scales were 1.61 (s.e.: 4.20; P=0.70) and 2.39 (s.e.: 4.62; P=0.61), respectively.

CONCLUSION

Among extremely preterm infants, the rate of maturational changes in brain wave characteristics between 28 and 36 weeks' postmenstrual age is not predictive of developmental abilities at 18 to 22 months adjusted age.

30-day mortality in UK patients with bacteraemic community-acquired pneumonia

OBJECTIVES

To determine 7 and 30-day mortality in consecutive patients with bacteraemic community-acquired pneumonia (CAP) and the association between predicted variables and likelihood of death.

METHODS

From August 2007 to July 2011, demographic, clinical and microbiological data were prospectively collected on patients with bacteraemic CAP. Patients were followed until death, hospital discharge or recovery from infection. Univariate and multivariate analysis was performed to determine the association between predictor variables and 30-day mortality.

RESULTS

7-day mortality was 61/252 [24.4%, 95% confidence interval (CI) 19.1-30.0%] and by 30 days, this had risen to 77/252 (30.6%, 95% CI 24.9-36.6%). In univariate analysis, factors associated with 30-day mortality were age, speciality within 48 h of admission, blood culture isolate and Charlson co-morbidity index (CCI). In multivariate analysis, age and CCI remained significantly associated. There was also a trend towards significance for meticillin-sensitive Staphylococcus aureus (MSSA) and Pseudomonas aeruginosa blood culture isolates compared to Streptococcus pneumoniae.

CONCLUSIONS

Overall, bacteraemic CAP was associated with high inpatient mortality. Because of their association with poor outcomes, patients with MSSA and P. aeruginosa bacteraemic CAP require further study.

Thirty-day mortality in UK patients with community-onset and hospital-acquired meticillin-susceptible Staphylococcus aureus bacteraemia

BACKGROUND

The difference in mortality between patients with community-onset and hospital-acquired Staphylococcus aureus infections has rarely been described and where it has, results have been conflicting.

AIM

To determine 30-day mortality in consecutive patients with meticillin-susceptible Staphylococcus aureus (MSSA) bacteraemia and the association between community-onset infection and outcome.

METHODS

From August 2007 to July 2011, demographic, clinical and microbiological data were prospectively collected on patients with MSSA bacteraemia. Patients were followed until death, hospital discharge or recovery from infection. Multivariate logistic regression was used to determine the association between community-onset infection and 30-day mortality.

FINDINGS

A total of 403 bacteraemic episodes occurred in 392 patients. Overall, there were 44 deaths (11.2%; 95% confidence interval: 7.9-14.0%) at 7 days and 101 deaths (25.8%; 21.5-30.4%) at 30 days. The difference in 30-day mortality between patients with community-onset and hospital-acquired infection was 71/256 (27.7%) versus 31/147 21.1%). Community-onset infection more frequently caused infective endocarditis (13/14, 92.9%), vertebral osteomyelitis (12/13, 92.3%) and skin and soft tissue infection (61/71, 85.9%) whereas intravascular catheter-associated infections were predominantly hospital-acquired (60/82, 73.2%). Age, Pitt score, Charlson comorbidity index (CCI), specific sites of infection (skin and soft tissue, lower respiratory tract and peripheral joints) and delay in appropriate treatment were strongly associated with 30-day mortality. In multivariate analysis, after adjustment for age, CCI and delay in appropriate treatment, community-onset infection was strongly associated with 30-day mortality (odds ratio: 1.59; 95% confidence interval: 0.91-2.80).

CONCLUSIONS

Compared with hospital-acquired MSSA bacteraemic infection, community-onset infection was associated with worse 30-day outcomes. Hospital-acquired MSSA bacteraemic infections were rarely metastatic, frequently associated with medical devices and patients had better outcomes.

Two-stage method to remove population- and individual-level outliers from longitudinal data in a primary care database

PURPOSE: In the UK, primary care databases include repeated measurements of health indicators at the individual level. As these databases encompass a large population, some individuals have extreme values, but some values may also be recorded incorrectly. The challenge for researchers is to distinguish between records that are due to incorrect recording and those which represent true but extreme values. This study evaluated different methods to identify outliers. METHODS: Ten percent of practices were selected at random to evaluate the recording of 513,367 height measurements. Population-level outliers were identified using boundaries defined using Health Survey for England data. Individual-level outliers were identified by fitting a random-effects model with subject-specific slopes for height measurements adjusted for age and sex. Any height measurements with a patient-level standardised residual more extreme than ±10 were identified as an outlier and excluded. The model was subsequently refitted twice after removing outliers at each stage. This method was compared with existing methods of removing outliers. RESULTS: Most outliers were identified at the population level using the boundaries defined using Health Survey for England (1550 of 1643). Once these were removed from the database, fitting the random-effects model to the remaining data successfully identified only 75 further outliers. This method was more efficient at identifying true outliers compared with existing methods. CONCLUSIONS: We propose a new, two-stage approach in identifying outliers in longitudinal data and show that it can successfully identify outliers at both population and individual level. Copyright © 2011 John Wiley & Sons, Ltd.

Expression analysis of loci associated with type 2 diabetes in human tissues

AIMS/HYPOTHESIS

Genetic mapping has identified over 20 loci contributing to genetic risk of type 2 diabetes. The next step is to identify the genes and mechanisms regulating the contributions of genetic risk to disease. The goal of this study was to evaluate the effect of age, height, weight and risk alleles on expression of candidate genes in diabetes-associated regions in three relevant human tissues.

METHODS

We measured transcript abundance for WFS1, KCNJ11, TCF2 (also known as HNF1B), PPARG, HHEX, IDE, CDKAL1, CDKN2A, CDKN2B, IGF2BP2, SLC30A8 and TCF7L2 by quantitative RT-PCR in human pancreas (n = 50), colon (n = 195) and liver (n = 50). Tissue samples were genotyped for single nucleotide polymorphisms (SNPs) associated with type 2 diabetes. The effects of age, height, weight, tissue and SNP on RNA expression were tested by linear modelling.

RESULTS

Expression of all genes exhibited tissue bias. Immunohistochemistry confirmed the findings for HHEX, IDE and SLC30A8, which showed strongest tissue-specific mRNA expression bias. Neither age, height nor weight were associated with gene expression. We found no evidence that type 2 diabetes-associated SNPs affect neighbouring gene expression (cis-expression quantitative trait loci) in colon, pancreas and liver.

CONCLUSIONS/INTERPRETATION

This study provides new evidence that tissue-type, but not age, height, weight or SNPs in or near candidate genes associated with increased risk of type 2 diabetes are strong contributors to differential gene expression in the genes and tissues examined.

The global momentum for smokefree public places: best practice in current and forthcoming smokefree policies

The Global Smokefree Partnership has recently prepared a map of smokefree campaigns and policies around the world. It focuses primarily on countries that are parties to the WHO Framework Convention on Tobacco Control, but other countries were included. The smokefree status of 172 countries was mapped. Of these countries, 31 (18.0%) have established comprehensive smokefree policies, either nationally or at state or city level - best practice; 25 (14.6%) are planning to implement smokefree policies in 2008 or 2009; and 51(29.6%) are making significant progress with smokefree policies. Only 65 countries (37.8%) have limited or no smokefree polices. A selection of countries representing best practices in smokefree policies or planning to implement smokefree policies in 2008 or 2009 is highlighted. They illustrate the significant global momentum for smokefree policies, the success of established policies, the importance of civil society and the sharing of experience between countries.