Gait speed is a simple, inexpensive and clinically useful marker of physical function in older adults. We aimed to establish gait speed reference values for community-dwelling older adults. To this ...end, we further explored the association of age, sex and height with gait speed.
This study included community-dwelling participants aged 50 years and over enrolled in the Rotterdam Study. Participants completed the gait protocol between 2009 and 2016. The mean gait speed was calculated for age and height groups, stratified by sex. Reference values for gait speed were calculated using a quantile regression model adjusted for sex, the non-linear effects of age and height, as well as the interaction between age and sex plus the interaction between age and height.
The study population included 4656 Dutch participants with a mean (standard deviation) age of 67.7 (9.5) years, comprising 2569 (55.2%) women. The mean height of the participants was 1.69 (0.10) meters and the mean gait speed was 1.20 (0.20) m/s. Gait speed was lower with older age and greater with taller stature, but the effect of height disappeared above the age of 80 years. Sex did not affect gait speed after accounting for age and height. Age-, sex-, and height-specific reference values for gait speed are available for use at https://emcbiostatistics.shinyapps.io/GaitSpeedReferenceValues/.
We found that height explains the commonly noted difference in usual gait speed between sexes and that neither height nor sex impacts gait speed in the very oldest adults. We developed reference values for usual gait speed in Western European community-dwelling older adults.
•Height explains commonly noted sex differences in usual gait speed.•Neither height nor sex impacts gait speed in the very oldest adults.•We established gait speed reference values for a community based Dutch population.•We created a web application to allow interpretation of gait speed reference values.
The aim of this study was to examine whether work capabilities differ between workers with Multiple Sclerosis (MS) and workers from the general population. The second aim was to investigate whether ...the capability set was related to work and health outcomes.
A total of 163 workers with MS from the MS@Work study and 163 workers from the general population were matched for gender, age, educational level and working hours. All participants completed online questionnaires on demographics, health and work functioning. The Capability Set for Work Questionnaire was used to explore whether a set of seven work values is considered valuable (A), is enabled in the work context (B), and can be achieved by the individual (C). When all three criteria are met a work value can be considered part of the individual's 'capability set'.
Group differences and relationships with work and health outcomes were examined. Despite lower physical work functioning (U = 4250, p = 0.001), lower work ability (U = 10591, p = 0.006) and worse self-reported health (U = 9091, p ≤ 0.001) workers with MS had a larger capability set (U = 9649, p ≤ 0.001) than the general population. In workers with MS, a larger capability set was associated with better flexible work functioning (r = 0.30), work ability (r = 0.25), self-rated health (r = 0.25); and with less absenteeism (r = - 0.26), presenteeism (r = - 0.31), cognitive/neuropsychiatric impairment (r = - 0.35), depression (r = - 0.43), anxiety (r = - 0.31) and fatigue (r = - 0.34).
Workers with MS have a larger capability set than workers from the general population. In workers with MS a larger capability set was associated with better work and health outcomes.
This observational study is registered under NL43098.008.12: 'Voorspellers van arbeidsparticipatie bij mensen met relapsing-remitting Multiple Sclerose'. The study is registered at the Dutch CCMO register ( https://www.toetsingonline.nl ). This study is approved by the METC Brabant, 12 February 2014. First participants are enrolled 1
of March 2014.
The aim of this study was to assess the classification accuracy of an e-Nose in detecting acute liver failure (ALF) in rats. Exhaled breath from 14 rats was repeatedly sampled by e-Nose (8 sensors) ...and an additional external CO2 sensor at three stages: healthy period; portacaval shunt; and during the development of ALF due to surgically induced complete liver ischemia. We performed principal component analysis (PCA) on the (grouped) sensor data in each stage and the classification accuracy of the first two principal components was assessed by the leave-one-out approach. In addition we performed gas chromatography-mass spectrometry (GC-MS) analysis of the exhaled breath from three rats. The first and second principal components from the PCA analysis of e-Nose data accounted for more than 95% variance in the data. Measurements in the ALF stage were contrasted with the measurements in the control stage. Leave-one-out validation showed classification accuracy of 96%. This accuracy was reached after 3h of ALF development, and was reached already after 2h when data of an external CO2 sensor were also included. GC-MS identified 2-butanol, 2-butanone, 2-pentanone and 1-propanol to be possibly elevated in the ALF stage. This is the first study to demonstrate that ALF in rats can be detected by e-Nose data analysis of the exhaled breath. Confirmation of these results in humans will be an important step forward in the non-invasive diagnosis of ALF.
cAMP is a second messenger that is essential for relaying hormonal responses in many biological processes. The discovery of the cAMP target Epac explained various effects of cAMP that could not be ...attributed to the established targets PKA and cyclic nucleotide-gated ion channels. Epac1 and Epac2 function as guanine nucleotide exchange factors for the small G protein Rap. cAMP analogs that selectively activate Epac have helped to reveal a role for Epac in processes ranging from insulin secretion to cardiac contraction and vascular permeability. Advances in the understanding of the activation mechanism of Epac and its regulation by diverse anchoring mechanisms have helped to elucidate the means by which cAMP fulfills these functions via Epac.
Abstract
Background
Circulating desphospho-uncarboxylated matrix γ-carboxyglutamate (Gla) protein (dp-ucMGP), a marker of vitamin K status, is associated with renal function and may serve as a ...potentially modifiable risk factor for incident chronic kidney disease (CKD). We aimed to assess the association between circulating dp-ucMGP and incident CKD.
Methods
We included 3969 participants with a mean age of 52.3 ± 11.6 years, of whom 48.0% were male, enrolled in the general population–based Prevention of REnal and Vascular ENd-stage Disease study. Study outcomes were incident CKD, defined as either development of an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or microalbuminuria. Associations of dp-ucMGP with these outcomes were quantified using Cox proportional hazards models and were adjusted for potential confounders.
Results
Median plasma dp-ucMGP was 363 interquartile range (IQR) 219–532 pmol/L and mean serum creatinine- and serum cystatin C-based eGFR (eGFRSCr-SCys) was 95.4 ± 21.8 mL/min/1.73 m2. During 7.1 years of follow-up, 205 (5.4%) participants developed incident CKD and 303 (8.4%) developed microalbuminuria. For every doubling of plasma dp-ucMGP, hazard ratios for the development of incident CKD and microalbuminuria were 1.85 95% confidence interval (CI) 1.59–2.16; P < 0.001 and 1.19 (95% CI 1.07–1.32; P = 0.001), respectively. These associations lost significance after adjustment for baseline eGFRSCr-SCys 0.99 (95% CI 0.88–1.12; P = 0.86) and baseline age 1.03 (95% CI 0.94–1.14; P = 0.50), respectively.
Conclusions
The associations of plasma dp-ucMGP with incident CKD and microalbuminuria were driven by the respective baseline effects of renal function and age.
Abstract
A new approach is presented for gaining additional insights from the molecular weight distribution and intrinsic viscosity of polymers as obtained using size‐exclusion chromatography in ...combination with refractive index, viscometry, and multiangle light scattering detectors. The approach allows for a more quantitative interpretation of the Mark‐Houwink plot by assessing the variation of the slope as a function of molecular weight. No prior information on the inter‐ and intramolecular interactions of the polymer is needed. The proposed curvature parameter can be correlated to the structural and chemical properties (e.g., branching, composition, randomness) of the polymer. The influence of the covered molecular weight interval and the sample concentration on the precision of the method was studied. This new workflow can be utilized to assess the effect of the solvent system and conditions on the solvation behavior of polymers. To evaluate the applicability of the workflow, three case studies have been performed, including an analysis of ethylene‐propylene‐diene monomer, cellulose ether, and polyamide‐4,10 samples. In addition, an open‐access tool is provided, to aid polymer researchers in incorporating this approach in their work. The developed method can be used to quickly investigate whether an industrial polymer batch contains unwanted branched species or exhibits particular solvation behavior.
Purpose
Although thyroid hormones are irrefutably implicated in cardiovascular physiology, the impact of within-reference range variations of thyroid function on cardiovascular disease (CVD) remains ...unclear. Elucidating this is important, since it could foster preventive treatment and reduce global CVD burden. We therefore investigated the impact of within-reference range variations of thyroid function on all-cause and cardiovascular mortality.
Methods
We included community-dwelling individuals aged 28–75 years from a prospective cohort study, without known use of thyroid-affecting therapy and with thyrotropin within reference range. Associations of thyroid function with mortality were quantified using Cox models and adjusted for sociodemographic and cardiovascular risk factors.
Results
Mean (SD) age of the 6,054 participants (52.0% male) was 53.3 (12.0) years. During 47,594 person-years of follow-up, we observed 380 deaths from all causes and 103 from CVDs. Although higher thyrotropin was not associated with all-cause mortality (adjusted HR 1.02, 95% CI 0.92–1.14), point estimates for cardiovascular mortality diverged toward increased risk in younger (<72 years) participants (1.31, 1.00–1.72) and decreased risk in elderly (≥72 years) (0.77, 0.56–1.06). Higher free thyroxine (FT
4
) was associated with all-cause mortality (1.18, 1.07–1.30) and with cardiovascular mortality only in elderly (1.61, 1.19–2.18), but not in younger participants (1.03, 0.78–1.34). Higher free triiodothyronine (FT
3
) was associated with all-cause mortality in females only (1.18, 1.02–1.35). FT
3
was not associated with cardiovascular mortality (0.91, 0.70–1.18).
Conclusions
Community-dwelling elderly individuals with high-normal thyroid function are at increased risk of all-cause and cardiovascular mortality, reinforcing the need of redefining the current reference ranges of thyroid function.
Lateral epicondylitis is generally treated with corticosteroid injections or physiotherapy. Dutch clinical guidelines recommend a wait-and-see policy. We compared the efficacy of these approaches.
...Patients with lateral epicondylitis of at least 6 weeks' duration were recruited by family doctors. We randomly allocated eligible patients to 6 weeks of treatment with corticosteroid injections, physiotherapy, or a wait-and-see policy. Outcome measures included general improvement, severity of the main complaint, pain, elbow disability, and patient satisfaction. Severity of elbow complaints, grip strength, and pressure pain threshold were assessed by a research physiotherapist who was unaware of treatment allocation. We assessed all outcomes at 3, 6, 12, 26, and 52 weeks. The principal analysis was done on an intention-to-treat basis.
We randomly assigned 185 patients. At 6 weeks, corticosteroid injections were significantly better than all other therapy options for all outcome measures. Success rates were 92% (57) compared with 47% (30) for physiotherapy and 32% (19) for wait-and-see policy. However, recurrence rate in the injection group was high. Long-term differences between injections and physiotherapy were significantly in favour of physiotherapy. Success rates at 52 weeks were 69% (43) for injections, 91% (58) for physiotherapy, and 83% (49) for a wait-and-see policy. Physiotherapy had better results than a wait-and-see policy, but differences were not significant.
Patients should be properly informed about the advantages and disadvantages of the treatment options for lateral epicondylitis. The decision to treat with physiotherapy or to adopt a wait-and-see policy might depend on available resources, since the relative gain of physiotherapy is small.
We analyze the trajectories of 313 particles seen in the near‐Bennu environment between December 2018 and September 2019. Of these, 65% follow suborbital trajectories, 20% undergo more than one ...orbital revolution around the asteroid, and 15% directly escape on hyperbolic trajectories. The median lifetime of these particles is ∼6 hr. The trajectories are sensitive to Bennu's gravitational field, which allows us to reliably estimate the spherical harmonic coefficients through degree 8 and to resolve nonuniform mass distribution through degree 3. The particles are perturbed by solar radiation pressure, enabling effective area‐to‐mass ratios to be estimated. By assuming that particles are oblate ellipsoids of revolution, and incorporating photometric measurements, we find a median axis ratio of 0.27 and diameters for equivalent‐volume spheres ranging from 0.22–6.1 cm, with median 0.74 cm. Our size distribution agrees well with that predicted for fragmentation due to diurnal thermal cycling. Detailed models of known accelerations do not produce a match to the observed trajectories, so we also estimate empirical accelerations. These accelerations appear to be related to mismodeling of radiation pressure, but we cannot rule out contributions from mass loss. Most ejections take place at local solar times in the afternoon and evening (12:00–24:00), although they occur at any time of day. We independently identify ten ejection events, some of which have previously been reported. We document a case where a particle ricocheted off the surface, revealing a coefficient of restitution 0.57±0.01 and demonstrating that some apparent ejections are not related to surface processes.
Plain Language Summary
The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS‐REx) mission discovered that near‐Earth asteroid (101955) Bennu is periodically ejecting small particles from its surface, placing it in the uncommon class of “active asteroids.” We linked together individual detections of ejected particles and used numerical models of the forces acting on them to ascertain their trajectories and fates. We found that most particles have suborbital trajectories, meaning they fall back to Bennu's surface shortly after being ejected, but some orbit Bennu for days at a time, and some escape directly into space. From the particle trajectories, we are able to estimate their sizes (comparable to pebbles, from a few millimeters to a few centimeters in diameter) and shapes (probably flake like). Their trajectories also make it possible to estimate Bennu's gravity field more precisely than spacecraft measurements and help shed light on the possible causes of the ejections.
Key Points
Most of the 313 particles we study have suborbital trajectories, but some orbit Bennu and others directly escape
The particles appear to have flake‐like shapes and have effective diameters 0.22–6.1 cm with median 0.74 cm
Ejections tend to take place in the local afternoon and evening but can occur anytime
Background
Creatinine is the most widely used test to estimate the glomerular filtration rate (GFR), but muscle mass as key determinant of creatinine next to renal function may confound such ...estimates. We explored effects of 24‐h height‐indexed creatinine excretion rate (CER index) on GFR estimated with creatinine (eGFRCr), muscle mass‐independent cystatin C (eGFRCys), and the combination of creatinine and cystatin C (eGFRCr‐Cys) and predicted probabilities of discordant classification given age, sex, and CER index.
Methods
We included 8076 adults enrolled in the PREVEND study. Discordant classification was defined as not having eGFRCr <60 mL/min per 1.73 m2 when eGFRCys was <60 mL/min/1.73 m2. Baseline effects of age and sex on CER index were quantified with linear models using generalized least squares. Baseline effects of CER index on eGFR were quantified with quantile regression and logistic regression. Effects of annual changes in CER index on trajectories of eGFR were quantified with linear mixed‐effects models. Missing observations in covariates were multiply imputed.
Results
Mean (SD) CER index was 8.0 (1.7) and 6.1 (1.3) mmol/24 h per meter in male and female participants, respectively (Pdifference < 0.001). In male participants, baseline CER index increased until 45 years of age followed by a gradual decrease, whereas a gradual decrease across the entire range of age was observed in female participants. For a 70‐year‐old male participant with low muscle mass (CER index of 2 mmol/24 h per meter), predicted baseline eGFRCr and eGFRCys disagreed by 24.7 mL/min/1.73 m2 (and 30.1 mL/min/1.73 m2 when creatinine was not corrected for race). Percentages (95% CI) of discordant classification in male and female participants aged 60 years and older with low muscle mass were 18.5% (14.8–22.1%) and 15.2% (11.4–18.5%), respectively. For a 70‐year‐old male participant who lost muscle during follow‐up, eGFRCr and eGFRCys disagreed by 1.5, 5.0, 8.5, and 12.0 mL/min/1.73 m2 (and 6.7, 10.7, 13.5, and 15.9 mL/min/1.73 m2 when creatinine was not corrected for race) at baseline, 5 years, 10 years, and 15 years of follow‐up, respectively.
Conclusions
Low muscle mass may cause considerable overestimation of single measurements of eGFRCr. Muscle wasting may cause spurious overestimation of repeatedly measured eGFRCr. Implementing muscle mass‐independent markers for estimating renal function, like cystatin C as superior alternative to creatinine, is crucial to accurately assess renal function in settings of low muscle mass or muscle wasting. This would also eliminate the negative consequences of current race‐based approaches.
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