Influence of the Antenna Orientation on WiFi-Based Fall Detection Systems.

The growing elderly population living independently demands remote systems for health monitoring. Falls are considered recurring fatal events and therefore have become a global health problem. Fall detection systems based on WiFi radio frequency signals still have limitations due to the difficulty of differentiating the features of a fall from other similar activities. Additionally, the antenna orientation has not been taking into account as an influencing factor of classification performance. Therefore, we present in this paper an analysis of the classification performance in relation to the antenna orientation and the effects related to polarization and radiation pattern. Furthermore, the implementation of a device-free fall detection platform to collect empirical data on falls is shown. The platform measures the Doppler spectrum of a probe signal to extract the Doppler signatures generated by human movement and whose features can be used to identify falling events. The system explores two antenna polarization: horizontal and vertical. The accuracy reached by horizontal polarization is 92% with a false negative rate of 8%. Vertical polarization achieved 50% accuracy and false negatives rate.

Wearable Urban Mobility Assistive Device for Visually Impaired Pedestrians Using a Smartphone and a Tactile-Foot Interface.

This paper reports on the progress of a wearable assistive technology (AT) device designed to enhance the independent, safe, and efficient mobility of blind and visually impaired pedestrians in outdoor environments. Such device exploits the smartphone's positioning and computing capabilities to locate and guide users along urban settings. The necessary navigation instructions to reach a destination are encoded as vibrating patterns which are conveyed to the user via a foot-placed tactile interface. To determine the performance of the proposed AT device, two user experiments were conducted. The first one requested a group of 20 voluntary normally sighted subjects to recognize the feedback provided by the tactile-foot interface. The results showed recognition rates over 93%. The second experiment involved two blind voluntary subjects which were assisted to find target destinations along public urban pathways. Results show that the subjects successfully accomplished the task and suggest that blind and visually impaired pedestrians might find the AT device and its concept approach useful, friendly, fast to master, and easy to use.

Socioeconomic Disparities and Gender Inequalities in Dementia: a Community-Dwelling Population Study from a Middle-Income Country.

The proportion of the world's older adults and of its dementia cases is increasing in low and middle-income countries. This is particularly true in Colombia. There, the number of individuals with dementia may increase five-fold by 2050. Yet research is lacking on dementia in such settings. This work estimates the prevalence of dementia in a community-dwelling population in Colombia. It also assesses how gender-based differences in cardiovascular conditions and socioeconomic disparities affect dementia. This work analyzes data on 2000 respondents at least 60 years of age in the Health, Well-Being, And Aging (SABE) study in Bogota. Respondents with dementia are those who have cognitive impairment and at least two limitations in instrumental activities of daily living. The SABE study finds 8.4% of respondents have dementia. Age, cardiovascular risks, and socioeconomic disparities contributed to higher odds of dementia. The contributors to dementia can differ for men and women. For example, socioeconomic disparities were a larger contributor to dementia for women than men. The findings support the cognitive reserve hypothesis on dementia. This holds that pre-existing cognitive processes and compensatory mechanisms influence dementia. Women in Latin America are more likely to suffer from socioeconomic disparities that limit their cognitive reserve. This research points to several policy implications that can help offset these disparities and reduce the prevalence of dementia.

Distinctive Neuroanatomical Substrates for Depression in Bipolar Disorder versus Major Depressive Disorder.

No neuroanatomical substrates for distinguishing between depression of bipolar disorder (dBD) and major depressive disorder (dMDD) are currently known. The aim of the current multicenter study was to identify neuroanatomical patterns distinct to depressed patients with the two disorders. Further analysis was conducted on an independent sample to enable generalization of results. We directly compared MR images of these subjects using voxel-based morphometry (VBM) and a support vector machine (SVM) algorithm using 1531 participants. The VBM analysis showed significantly reduced gray matter volumes in the bilateral dorsolateral prefrontal (DLPFC) and anterior cingulate cortices (ACC) in patients with dBD compared with those with dMDD. Patients with the two disorders shared small gray matter volumes for the right ACC and left inferior frontal gyrus when compared with healthy subjects. Voxel signals in these regions during SVM analysis contributed to an accurate classification of the two diagnoses. The VBM and SVM results in the second cohort also supported these results. The current findings provide new evidence that gray matter volumes in the DLPFC and ACC are core regions in displaying shared and distinct neuroanatomical substrates and can shed light on elucidation of neural mechanism for depression within the bipolar/major depressive disorder continuum.

Diagnostic challenges of Brugada Syndrome in pediatric patients.

Although most cases of Brugada syndrome have been described in adults, pediatric patients with the disease have been reported since the original article from Josep and Pedro Brugada. Herein is presented the case series of Brugada syndrome in pediatric population of the National Institute of Cardiology Ignacio Chavez. One boy and two adolescent males had palpitations as clinical presentation of the disease. Atrial arrhythmias were documented in two, in the third case there was a high clinical suspicion and quinidine abolished symptoms. The aim of this report is to highlight the importance of performing a detailed clinical history as well as the usefulness of high precordial leads for the diagnosis of this entity.

A control system analysis of the dynamic response of N-methyl-D-aspartate glutamate receptors to alcoholism and alcohol withdrawal.

BACKGROUND: N-methyl-D-Aspartate (NMDA) and its receptors (NMDAR) play a critical role in glutamatergic neurotransmission. Ethanol molecules inhibit these receptors, and if the brain is exposed to ethanol chronically, NMDA-induced glutamatergic changes can result in physical dependence to ethanol in order to sustain normal brain function. In these cases, removal of ethanol from the system results in excitotoxic withdrawal. One compensatory mechanism the brain uses to regulate extracellular glutamate concentration is modulating the number of NMDARs at the synapse. Previous work has shown that the number of functional NMDARs at the synapse can be changed by three mechanisms: additional receptors can be synthesized and inserted, receptors can be recruited to the synapse from extrasynaptic regions, or the functionality of existing receptors can be modified. METHODS: In this study, we consider the dynamic relocation control of NMDARs in response to chronic alcoholism and withdrawal. Specifically, we (1) propose and construct a mathematical model of the relocation control as a negative feedback system with an explicit set point, (2) investigate the effect of various ethanol consumption and withdrawal profiles on the NMDAR population, and (3) propose and calculate quantitative measures for the extent of withdrawal based on modeled NMDAR populations. RESULTS: A relocation-only model with an explicit set point was developed. The model was shown to apply across a wide range of controller parameters. The results suggest that withdrawal severity does not depend upon the dynamics involved in the development of dependence, and that regulating the blood alcohol level throughout the progression of withdrawal can minimize excitotoxic withdrawal symptoms. CONCLUSIONS: The negative feedback control system produced characteristic behaviors of NMDAR populations in response to simulations of alcohol dependence and abrupt withdrawal. The model can also predict the severity of excitotoxic withdrawal following various alcohol consumption and/or withdrawal patterns in order to generate testable hypotheses regarding ameliorating withdrawal.

Network efficient power control for wireless communication systems.

We introduce a two-loop power control that allows an efficient use of the overall power resources for commercial wireless networks based on cross-layer optimization. This approach maximizes the network's utility in the outer-loop as a function of the averaged signal to interference-plus-noise ratio (SINR) by considering adaptively the changes in the network characteristics. For this purpose, the concavity property of the utility function was verified with respect to the SINR, and an iterative search was proposed with guaranteed convergence. In addition, the outer-loop is in charge of selecting the detector that minimizes the overall power consumption (transmission and detection). Next the inner-loop implements a feedback power control in order to achieve the optimal SINR in the transmissions despite channel variations and roundtrip delays. In our proposal, the utility maximization process and detector selection and feedback power control are decoupled problems, and as a result, these strategies are implemented at two different time scales in the two-loop framework. Simulation results show that substantial utility gains may be achieved by improving the power management in the wireless network.

Scanning Spin Probe Based on Magnonic Vortex Quantum Cavities.

Performing nanoscale scanning electron paramagnetic resonance (EPR) requires three essential ingredients: First, a static magnetic field together with field gradients to Zeeman split the electronic energy levels with spatial resolution; second, a radio frequency (rf) magnetic field capable of inducing spin transitions; finally, a sensitive detection method to quantify the energy absorbed by spins. This is usually achieved by combining externally applied magnetic fields with inductive coils or cavities, fluorescent defects, or scanning probes. Here, we theoretically propose the realization of an EPR scanning sensor merging all three characteristics into a single device: the vortex core stabilized in ferromagnetic thin-film discs. On one hand, the vortex ground state generates a significant static magnetic field and field gradients. On the other hand, the precessional motion of the vortex core around its equilibrium position produces a circularly polarized oscillating magnetic field, which is enough to produce spin transitions. Finally, the spin-magnon coupling broadens the vortex gyrotropic frequency, suggesting a direct measure of the presence of unpaired electrons. Moreover, the vortex core can be displaced by simply using external magnetic fields of a few mT, enabling EPR scanning microscopy with large spatial resolution. Our numerical simulations show that, by using low damping magnets, it is theoretically possible to detect single spins located on the disc's surface. Vortex nanocavities could also attain strong coupling to individual spin molecular qubits with potential applications to mediate qubit-qubit interactions or to implement qubit readout protocols.

Deep Learning Multi-Class Approach for Human Fall Detection Based on Doppler Signatures.

Falling events are a global health concern with short- and long-term physical and psychological implications, especially for the elderly population. This work aims to monitor human activity in an indoor environment and recognize falling events without requiring users to carry a device or sensor on their bodies. A sensing platform based on the transmission of a continuous wave (CW) radio-frequency (RF) probe signal was developed using general-purpose equipment. The CW probe signal is similar to the pilot subcarriers transmitted by commercial off-the-shelf WiFi devices. As a result, our methodology can easily be integrated into a joint radio sensing and communication scheme. The sensing process is carried out by analyzing the changes in phase, amplitude, and frequency that the probe signal suffers when it is reflected or scattered by static and moving bodies. These features are commonly extracted from the channel state information (CSI) of WiFi signals. However, CSI relies on complex data acquisition and channel estimation processes. Doppler radars have also been used to monitor human activity. While effective, a radar-based fall detection system requires dedicated hardware. In this paper, we follow an alternative method to characterize falling events on the basis of the Doppler signatures imprinted on the CW probe signal by a falling person. A multi-class deep learning framework for classification was conceived to differentiate falling events from other activities that can be performed in indoor environments. Two neural network models were implemented. The first is based on a long-short-term memory network (LSTM) and the second on a convolutional neural network (CNN). A series of experiments comprising 11 subjects were conducted to collect empirical data and test the system's performance. Falls were detected with an accuracy of 92.1% for the LSTM case, while for the CNN, an accuracy rate of 92.1% was obtained. The results demonstrate the viability of human fall detection based on a radio sensing system such as the one described in this paper.

A synthesis of carcass decomposition studies conducted at a tropical (Aw) taphonomy facility: 2013-2022.

Decomposition studies have been conducted in several regions of the world, but relatively few have investigated taphonomy in tropical environments. Even fewer have explored carcass decomposition during multiple tropical seasons, leaving the relationships between season and decomposition in tropical environments poorly understood. Ten decomposition studies using 30 carcasses were conducted in Honolulu, Hawaii, USA to start addressing this knowledge gap. These studies show that some postmortem processes were observed regardless of season. Carcass temperature and chemistry were spatiotemporally variable. Fly larval masses were consistently observed within 3 days (∼75 ADD) postmortem and carcasses lost 60%-90% of mass by 10 days (∼250 ADD) postmortem (Total Body Score ∼26). Season had a significant effect on decomposition, yet the warmest and most humid seasons did not always result in the most rapid and extensive decomposition. Seasonal variation appears to be less pronounced than at other tropical decomposition sites.

Use of subcutaneous cardioverter-defibrillator. First cases reported from National Institute of Cardiology Ignacio Chávez-Mexico.

INTRODUCTION: The transvenous implantable cardioverter defibrillator (ICD) is the treatment of choice for the prevention of sudden cardiac death (SCD). Its use could be restricted when device-related infections occurs or in the pediatric population. In the later, an ICD represents a challenge, due to the minimal dimensions of the venous system in children, the length of the electrodes, the size of the generator, as well as the anatomical complexity in cases with associated congenital heart disease. OBJECTIVE: This article presents the first Mexican patients with a subcutaneous ICD (SC-ICD) implant as a therapy for the prevention of SCD. METHODS: The first four cases were implanted at the Ignacio Chávez National Institute of Cardiology with a SC-ICD (Emblem, Boston Scientific, USA), three of them were pediatric patients, including the first implant of this type of device in a pediatric patient in Latin America. The 3-incision and 2-incision techniques were used under general anesthesia. RESULTS: A successful implantation was obtained with the 3-incision technique in the first 2 cases and the last 2 with the 2-incision technique. Proper functioning of the device was corroborated in the operating room with proof of appropriate therapy (65 J) for ventricular fibrillation induced with 50 Hz stimulation. No immediate complications were observed. One patient had appropriate shocks two months after the implant. During follow-up, one child developed skin erosion at the level of the curve of the electrode on the sternum, with no signs of infection. In the operating room, the damaged skin was resected, the barrel and the fixation silk were removed, surgical lavage was performed, and the skin was closed again, thus avoiding removal of the system. CONCLUSIONS: The SC-ICD is an alternative therapy to the transvenous ICD. It can be considered first choice in subjects who do not require ventricular pacing, including pediatric patients. Skin complications can occur but do not pose a threat as venous complications of conventional ICDs.

INTRODUCCIÓN: El desfibrilador automático implantable (DAI) transvenoso es el tratamiento de elección para la prevención de muerte súbita (MS) cardiaca por arritmias ventriculares malignas. Su uso se puede ver limitado cuando existe infección del sistema de estimulación o en población pediátrica donde representa un reto por diversas razones, incluyendo: las mínimas dimensiones del sistema venoso de los niños, la longitud de los electrodos, el tamaño del generador, así como por la complejidad anatómica en casos de cardiopatía congénita asociada. OBJETIVO: El presente artículo tiene por objetivo presentar la primera serie de casos de pacientes mexicanos a los cuales se les implantó un DAI subcutáneo (DAI-SC) como terapia para la prevención de MS. MÉTODOS: Se presentan los cuatro primeros casos que fueron implantados en el Instituto Nacional de Cardiología Ignacio Chávez con un DAI-SC (Emblem, Boston Scientific, EE.UU.), tres de ellos eran pacientes pediátricos, incluyendo el primer implante de este tipo de dispositivo en un paciente pediátrico en América Latina. Las técnicas de tres y dos incisiones fueron empleadas bajo anestesia general. RESULTADOS: Se realizó el implante exitoso con técnica de tres incisiones en los dos primeros casos y con técnica de dos incisiones en los dos últimos casos. Se corroboró el adecuado funcionamiento del dispositivo en sala, con la verificación de terapia apropiada (65 J) de la fibrilación ventricular inducida mediante estimulación a 50 Hz. No hubo complicaciones inmediatas. Un paciente presentó descargas apropiadas a los dos meses del implante. En el seguimiento, un niño desarrolló erosión de la piel a nivel de la curva del electrodo en el esternón, sin datos de infección. En quirófano se resecó la piel dañada, se retiró el barril y la seda de fijación, se realizó lavado quirúrgico y se volvió a cerrar la piel, logrando así evitar el retiro del sistema. CONCLUSIONES: El DAI-SC es una terapia alternativa al DAI endovenoso y puede ser considerado de primera elección en aquellos casos que no requieran de estimulación ventricular, incluyendo pacientes pediátricos. Pueden ocurrir complicaciones cutáneas, pero no representan una amenaza como las complicaciones venosas de los DAI convencionales.

Theoretical and Computational Analysis of a Wurtzite-AlGaN DUV-LED to Mitigate Quantum-Confined Stark Effect with a Zincblende Comparison Considering Mg- and Be-Doping.

In this work, an AlGaN-based Deep-Ultraviolet Light-Emitting Diode structure has been designed and simulated for the zincblende and wurtzite approaches, where the polarization effect is included. DFT analysis was performed to determine the band gap direct-to-indirect cross-point limit, AlN carrier mobility, and activation energies for p-type dopants. The multiple quantum wells analysis describes the emission in the deep-ultraviolet range without exceeding the direct-to-indirect bandgap cross-point limit of around 77% of Al content. Moreover, the quantum-confined Stark effect on wavefunctions overlapping has been studied, where Al-graded quantum wells reduce it. Both zincblende and wurtzite have improved electrical and optical characteristics by including a thin AlGaN with low Al content. Mg and Be acceptor activation energies have been calculated at 260 meV and 380 meV for Be and Mg acceptor energy, respectively. The device series resistance has been decreased by using Be instead of Mg as the p-type dopant from 3 kΩ to 0.7 kΩ.

Numerical Study of a Solar Cell to Achieve the Highest InGaN Power Conversion Efficiency for the Whole In-Content Range.

A solar cell structure with a graded bandgap absorber layer based on InGaN has been proposed to overcome early predicted efficiency. Technological issues such as carrier concentration in the p- and n-type are based on the data available in the literature. The influence of carrier concentration-dependent mobility on the absorber layer has been studied, obtaining considerable improvements in efficiency and photocurrent density. Efficiency over the tandem solar cell theoretical limit has been reached. A current density of 52.95 mA/cm2, with an efficiency of over 85%, is determined for a PiN structure with an InGaN step-graded bandgap absorption layer and 65.44% of power conversion efficiency for the same structure considering piezoelectric polarization of fully-strained layers and interfaces with electron and hole surface recombination velocities of 10-3 cm/s.

Role for Physical Fitness in the Association between Age and Cognitive Function in Older Adults: A Mediation Analysis of the SABE Colombia Study.

Objectives. We investigated the association between physical fitness and cognitive status. Further, we examined whether physical fitness mediates the association between cognitive functioning and aging. Design. Cross-sectional study. Setting. Urban and rural Colombian older adults. Methods. 4416 participants from the SABE study were included in the current analysis. Physical fitness was assessed with the handgrip test and the usual gait speed test. Cognitive status was evaluated through the Folstein Mini-Mental State Examination. A parallel mediation path was used to test the possible mediator role of physical fitness between aging and cognitive functioning. Results. Older adults with lower handgrip strength (HGS) were more likely to have mild-cognitive status than older adults with healthy HGS (OR = 1.53, 95% CI = 1.15; 2.02). In addition, older adults with a slower gait speed were more likely to have mild cognitive impairment (OR = 2.05, 95% CI = 1.54; 2.78). Age had an inverse relationship with cognitive function (ß = -0.110, 95% CI = -0.130; -0.100) and it was also inversely associated with HGS (ß = -0.003, 95% CI = -0.005; -0.002) and gait speed (ß = -0.010, 95% CI = -0.011; -0.009). The indirect effects, which indicate that the effect of age on cognitive function is transmitted through mediators, showed that both gait speed (ß = -0.028, 95% CI = -0.036; -0.020) and HGS (ß = -0.014, 95% CI = -0.024; -0.005) were independent mediators of the detrimental effect of aging on cognitive function. Conclusions. Physical fitness mediates the effects of aging on cognitive functioning. Our findings suggest that physical activity can be a key factor to prevent cognitive deterioration during aging process.

High Prevalence of Probable Sarcopenia in a Representative Sample From Colombia: Implications for Geriatrics in Latin America.

OBJECTIVES: The European Working Group on Sarcopenia in Older People 2 (EWGSOP2) recently defined the new concept of probable sarcopenia to help improve screening and prevent future sarcopenia. We investigated the prevalence of probable sarcopenia, defined as weak grip strength, in community-dwelling older Colombian adults, and examined the long-term associated conditions. DESIGN: Cross-sectional study. SETTING: Urban and rural Colombian older adults from the "Estudio Nacional de Salud, Bienestar y Envejecimiento (SABE) study". PARTICIPANTS: 5237 Colombian older adults aged ≥60 years. MEASUREMENTS: Probable sarcopenia was assessed following the cut-off points for weak grip strength recommended by EWGSOP2 guidelines. Odds ratios (ORs) of the relationship between long-term conditions and probable sarcopenia were determined using logistic regression. RESULTS: The prevalence of probable sarcopenia defined as weak grip strength was 46.5% [95% confidence interval (CI), 45.1-47.8]. Physical inactivity "proxy" (OR 1.35, 95% CI 1.14-1.59); diabetes (OR 1.32, 95% CI 1.11-1.56); and arthritis, osteoarthritis, and rheumatism (OR 1.44, 95% CI 1.25-1.67) were independently associated with probable sarcopenia. CONCLUSIONS AND IMPLICATIONS: We found that almost half of all the Colombian older adults in our sample had probable sarcopenia. Individuals with physical inactivity, diabetes, arthritis, or osteoarthritis and rheumatism had a higher prevalence of probable sarcopenia. Probable sarcopenia is clinically highly relevant, and several of the factors associated with this condition are potentially preventable, treatable, and reversible.

Relative Handgrip Strength Diminishes the Negative Effects of Excess Adiposity on Dependence in Older Adults: A Moderation Analysis.

The adverse effects of fat mass on functional dependence might be attenuated or worsened, depending on the level of muscular strength. The aim of this study was to determine (i) the detrimental effect of excess adiposity on dependence in activities of daily living (ADL), and (ii) whether relative handgrip strength (HGS) moderates the adverse effect of excess adiposity on dependence, and to provide the threshold of relative HGS from which the adverse effect could be improved or worsened. A total of 4169 participants (69.3 ± 7.0 years old) from 244 municipalities were selected following a multistage area probability sampling design. Measurements included anthropometric/adiposity markers (weight, height, body mass index, waist circumference, and waist-to-height ratio (WHtR)), HGS, sarcopenia "proxy" (calf circumference), and ADL (Barthel Index scale). Moderation analyses were performed to identify associations between the independent variable (relative HGS) and outcomes (dependence), as well as to determine whether relative HGS moderates the relationship between excess adiposity and dependence. The present study demonstrated that (i) the adverse effect of having a higher WHtR level on dependence in ADL was moderated by relative HGS, and (ii) two moderation thresholds of relative HGS were estimated: 0.35, below which the adverse effect of WHtR levels on dependency is aggravated, and 0.62, above which the adverse effect of fat on dependency could be improved. Because muscular strength represents a critically important and modifiable predictor of ADL, and the increase in adiposity is inherent in aging, our results underscore the importance of an optimal level of relative HGS in the older adult population.

Metabolic Syndrome and Its Associated Factors in Older Adults: A Secondary Analysis of SABE Colombia in 2015.

Background: Understanding the metabolic syndrome (MetS) prevalence at the national level is important to develop effective programs and strategies to prevent and control MetS. This study aimed to analyze the prevalence of MetS according to gender and aging stage, and its association with potential factors in older individuals ≥60 years of age in Colombia. Methods: The data for this study came from a secondary cross-sectional, nationally representative SABE study Survey on Health, Well-Being, and Aging in Colombia, 2015. A total of 1637 participants (60.7% women, 70.5 ± 7.9 years) from 86 Colombian municipalities participated. A structured questionnaire was used to collect data on socio-demography, lifestyle, and self-report medical conditions. Measurements included anthropometric (weight, waist circumference, body mass index), sarcopenia "proxy" status (calf circumference) handgrip strength levels, high-density lipoprotein cholesterol, triglycerides, fasting glucose, and blood pressure. Univariate and multiple regression models were established as part of the main analysis. Results: Using the harmonized Joint Scientific Statement criteria, MetS was present in 54.9% of the study population, with a higher prevalence among females than males (59.8% vs. 47.3%). Individuals who were cigarette smokers (odds ratio [OR] = 1.5; 95% confidence interval [CI] = 1.0-2.4; P = 0.034), female gender (OR = 1.3; 95% CI = 1.0-1.8; P = 0.020), and sarcopenia "proxy" (OR = 1.6; 95% CI = 1.0-2.5; P = 0.026) were more likely to have a higher prevalence estimate of MetS, after controlling for relevant covariates. Conclusions: Overall prevalence of MetS among older adults in Colombia is high. Smoking, female gender, and sarcopenia "proxy" status are associated with MetS. These results suggested that MetS is still a serious public burden in Colombia, and screening for promotion of healthy lifestyle and nutrition counseling should be offered routinely in old age.

Glucose Levels as a Mediator of the Detrimental Effect of Abdominal Obesity on Relative Handgrip Strength in Older Adults.

Excess central adiposity accelerates the decline of muscle strength in older people. Additionally, hyperglycemia, independent of associated comorbidities, is related to the loss of muscle mass and strength, and contributes to functional impairment in older adults. We studied the mediation effect of glucose levels, in the relationship between abdominal obesity and relative handgrip strength (HGS). A total of 1571 participants (60.0% women, mean age 69.1 ± 7.0 years) from 86 municipalities were selected following a multistage area probability sampling design. Measurements included demographic and anthropometric/adiposity markers (weight, height, body mass index, and waist circumference). HGS was measured using a digital dynamometer for three sets and the mean value was recorded. The values were normalized to body weight (relative HGS). Fasting glucose was analyzed by enzymatic colorimetric methods. Mediation analyses were performed to identify associations between the independent variable (abdominal obesity) and outcomes (relative HGS), as well as to determine whether fasting glucose levels mediated the relationship between excess adiposity and relative HGS. A total of 1239 (78.8%) had abdominal obesity. Abdominal obesity had a negative effect on fasting glucose (ß = 9.04, 95%CI = 5.87 to 12.21); while fasting glucose to relative HGS was inversely related (ß = -0.003, 95%CI = -0.005 to -0.001), p < 0.001. The direct effect of abdominal obesity on relative HGS was statistically significant (ß = -0.069, 95%CI = -0.082 to -0.057), p < 0.001. Lastly, fasting glucose levels mediates the detrimental effect of abdominal obesity on relative HGS (indirect effect ß = -0.002, 95%CI = -0.004 to -0.001), p < 0.001. Our results suggest that the glucose level could worsen the association between abdominal obesity status and lower HGS. Thus, it is plausible to consider fasting glucose levels when assessing older adults with excess adiposity and/or suspected loss of muscle mass.

Normative Values for the Short Physical Performance Battery (SPPB) and Their Association With Anthropometric Variables in Older Colombian Adults. The SABE Study, 2015.

Background: The short physical performance battery (SPPB) is a physical performance test of lower extremity function designed for non-disabled older adults. We aimed to establish reference values for community-dwelling Colombian adults aged 60 years or older in terms of (1) the total score; (2) the three subtest scores (walking speed, standing balance performance, and five times sit-to-stand test); and (3) the time to complete the five times sit-to-stand test, s and the walking speed test. Additionally, we sought to explore how much of the variance in the SPPB subtest scores could be explained by anthropometric variables (age, body mass, height, body mass index, and calf circumference). Methods: Participants were men and women aged 60 years or older who participated in the Health and Well-being and Aging Survey in Colombia, 2015. A sample of 4,211 participants (57.3% women) completed the SPPB test, and their anthropometric variables were evaluated. Age-specific percentiles were calculated using the LMS method (3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles). Results: The mean SPPB total score for the entire sample was 8.73 (2.0) points. On average, the total SPPB score was 0.85 points greater in men than in women (p < 0.001). Significant sex differences were observed in all three age groups tested (60-69, 70-79, and 80+ years). In the full sample, our findings suggested that age, body mass, height, body mass index, and calf circumference are significant contributors to walking speed (p < 0.001) after controlling for confounding factors, including ethnicity, socioeconomic status, and urbanicity. Conclusions: Percentile values are of interest to identify target populations for primary prevention and to estimate the proportion of high or low values for SPPB measures in community-dwelling Colombians aged at least 60 years.

Validation of Surrogate Anthropometric Indices in Older Adults: What Is the Best Indicator of High Cardiometabolic Risk Factor Clustering?

The present study evaluated the ability of five obesity-related parameters, including a body shape index (ABSI), conicity index (CI), body roundness index (BRI), body mass index (BMI), and waist-to-height ratio (WtHR) for predicting increased cardiometabolic risk in a population of elderly Colombians. A cross-sectional study was conducted on 1502 participants (60.3% women, mean age 70 ± 7.6 years) and subjects' weight, height, waist circumference, serum lipid indices, blood pressure, and fasting plasma glucose were measured. A cardiometabolic risk index (CMRI) was calculated using the participants' systolic and diastolic blood pressure, triglycerides, high-density lipoprotein and fasting glucose levels, and waist circumference. Following the International Diabetes Federation definition, metabolic syndrome was defined as having three or more metabolic abnormalities. All surrogate anthropometric indices correlated significantly with CMRI (p < 0.01). Receiver operating characteristic curve analysis of how well the anthropometric indices identified high cardiometabolic risk showed that WtHR and BRI were the most accurate indices. The best WtHR and BRI cut-off points in men were 0.56 (area under curve, AUC 0.77) and 4.71 (AUC 0.77), respectively. For women, the WtHR and BRI cut-off points were 0.63 (AUC 0.77) and 6.20 (AUC 0.77), respectively. In conclusion, BRI and WtHR have a moderate discriminating power for detecting high cardiometabolic risk in older Colombian adults, supporting the idea that both anthropometric indices are useful screening tools for use in the elderly.