Genetic and Environmental Influences on Biological Essentialism, Heuristic Thinking, Need for Closure, and Conservative Values: Insights From a Survey and Twin Study.

Biological essentialism, the belief that human attributes are determined by biology, is a core component of essentialist thinking. Previous studies have shown that individual differences in essentialist thinking are associated with heuristic thinking, cognitive ability and style, conservative values, and prejudice. None, however, have examined whether biological essentialism is itself heritable, or the extent to which familial aggregation explains associations with core correlates. In order to do this, we analyzed data from a genetically informative sample of families with twins in Australia (N = 2,103), as well as general population samples from the UK (N = 501) and the US (N = 500). Genetic factors had little influence in individual differences in biological essentialism or in its relationship with heuristic thinking. Conservative values were genetically correlated with cognitive styles (i.e., need for closure and heuristic thinking). These findings support a bigger role of genes in explaining the relationship between cognitive processes and moral reasoning and ideology than they do the association between cognitive processes and essentialist thinking.

Uso del soporte respiratorio no invasivo en pacientes con distrés moderado-severo por SARS-CoV-2. Experiencia en un hospital de segundo nivel / Use of non-invasive respiratory support in patients with moderate-severe distress due to sars-cov-2. Experience in a second level hospital

Objetivo: Describir las características de los pacientes ingresados en una unidad de cuidados respiratorios intermedios (UCRI) creada a raíz de la pandemia, analizar los factores asociados a la supervivencia y techo terapéutico. Material y método: Estudio descriptivo observacional, incluye todos los casos con neumonía por SARS-CoV-2 que requirieron ingreso en UCRI. Variables analizadas: clínicas, analíticas, terapéuticas, supervivencia, soporte respiratorio y evolución oximétrica. Se realizó un análisis univariante para las diferencias según techo terapéutico y supervivencia a 90 días, para la evolución de la SpO2/FiO2 en el tiempo se ajustaron modelos lineales mixtos. Resultados: Participaron 37 pacientes. El 46% no eran candidatos a cuidados críticos. Características asociadas a orden de no intubación de manera significativa: edad más avanzada (p=0,001), mayor índice de Charlson (p=0,003), EPOC (p=0,014) o cáncer (p=0,033). Supervivencia global en UCRI del 58%, según techo terapéutico en no intubables la supervivencia fue del 41% mientras en intubables asciende al 89%. Las variables asociadas a mortalidad fueron mayor edad (p=0,012), mayor índice de Charlson (p=0,030), mayor valor de proteína C reativa (p=0,045), menor nº de linfocitos (p=0,019) y tratamiento con lopinovir/ritonavir (p=0,006). La SpO2/FiO2 media al inicio del soporte respiratorio no invasivo (SRNI) fue 112 (DE:23), el 81% padecían distrés grado moderado-severo. A menor SpO2/FiO2 inicial peor pronóstico (p<0,001), el uso de SRNI mejora de manera progresiva la SpO2/FiO2 a mayor número de horas de uso (p=0,006). Conclusiones: El SRNI en UCRI es seguro, mejora la oxigenación y ofrece opciones terapéuticas en pacientes no intubables.(AU)

Objective: To describe the characteristics of the patients admitted to an intermediate respiratory care unit (UCRI) created as a result of the pandemic, to analyze the factors associated with survival and therapeutic ceiling. Material and metho: Descriptive observational study, includes all cases with SARS-CoV-2 pneumonia that required admission to UCRI. Variables analyzed: clinical, analytical, therapeutic, survival, respiratory support and oximetric evolution. A univariate analysis was performed for the differences according to therapeutic ceiling and survival at 90 days, for the evolution of SpO2/FiO2 over time, mixed linear models were adjusted. Results: 37 patients participated. The 46% of them were not candidates for critical care. Characteristics significantly associated with the order of non-intubation: older age (p = 0.001), higher Charlson index (p = 0.003), COPD (p = 0.014) or cancer (p = 0.033). Overall survival in UCRI 58%, according to the therapeutic ceiling in non-intubable patients, survival was 41%, while in intubable it was 89%. The variables associated with mortality were older age (p = 0.012), higher charlson index (p = 0.030), higher value of reactive protein C (p = 0.045), lower number of lymphocytes (p = 0.019) and treatment with lopinovir/ritonavir (p = 0.006). The mean SpO2/FiO2 at the beginning of non-invasive respiratory support (SRNI) was 112 (SD: 23), 81% suffered from moderate-severe distress. The lower the initial SpO2/FiO2, the worse the prognosis (p <0.001), the use of NIRS progressively improves the SpO2/FiO2 with the greater number of hours of use (p = 0.006). Conclusions: SRNI in UCRI is safe, improves oxygenation and offers therapeutic options in non-intubable patients.(AU)

Dynamic characteristics of three-dimensional strongly coupled plasmas.

The dynamic structure factor and other dynamic characteristics of strongly coupled one-component plasmas have been studied [Yu. V. Arkhipov et al., Phys. Rev. Lett. 119, 045001 (2017)PRLTAO0031-900710.1103/PhysRevLett.119.045001] using the self-consistent version of the method of moments. Within any version of the latter, the system dielectric function satisfies all involved sum rules and other exact relations automatically, and the advantage of this version is that, in addition, the dynamic characteristics (the dynamic structure factor, the dispersion, and decay parameters of the collective modes) are all expressed in terms of the static ones (the static structure factor) without any adjustment to the simulation data. The approach outlined in the aforementioned Letter is justified in detail and applied mainly to the classical Coulomb systems achieving satisfactory agreement with new numerical simulation data. It is shown how the realm of applicability of the method can be extended to partly degenerate and multicomponent systems, even to simple liquids. Some additional theoretical results are presented in the Supplemental Material.

Thrust stand based on a single point load cell for impulse measurements from plasma thrusters.

We introduce a simple thrust stand for the direct measurement of the millinewton impulses or thrusts delivered by small thrusters intended for in-space electric propulsion. The thruster under test, with a weight below 1.5 kg, is disposed on a horizontal platform and its impulse is measured as an overweight by using a strain gauge cell physically protected from the ambient plasma and vacuum conditions. This system provides ten thrust readings per second with noise peak to peak amplitudes of 0.10-0.18 mN. The calibration procedures to verify its dynamic response to time dependent thrusts in the range of 0-15 mN using control weights as well as its minimum thrust sensitivity δTs = 0.3 mN are discussed. Additionally, its simple conception permits a plain data reduction and analysis of steady state and low frequency thrust transients. This thrust stand was employed under low pressure and plasma ambient conditions to measure the steady impulses delivered by the Alternative Low Power Hybrid Ion Engine (ALPHIE) of 0.4-4.0 mN with absolute errors ΔT = ±0.3 mN. Finally, the experimental results show that a control electric voltage governs the ALPHIE thruster throttle.

Síndrome de Löfgren en Neiva - Colombia: reporte de un caso / Löfgren Syndrome in Neiva - Colombia: A Case Report

Resumen La sarcoidosis es una enfermedad inflamatoria granulomatosa multisistémica crónica de etiología desconocida, que afecta en su mayoría a adultos jóvenes. Se presenta el caso de un paciente masculino de 35 años de edad, que asistió a nuestro hospital por un cuadro clínico de fiebre prolongada asociada a poliartritis y eritema nodoso, que fue diagnosticado con síndrome de Löfgren, entidad poco frecuente en nuestro país. A pesar de la baja prevalencia, la sarcoidosis y su variante, síndrome de Löfgren, se deben tener siempre en cuenta en pacientes con eritema nodoso y/o adenopatías hiliares.

Abstract Sarcoidosis is a chronic multisystemic granulomatous inflammatory disease of unknown etiology which affects mainly young adults, characterized by formation of non-caseous granulomas. Löfgren syndrome refers to an acute presentation of sarcoidosis, characterized by the triad of bilateral hilar lymphadenopathies, erythema nodosum and periarticular swelling. This paper presents the case of a 35-year-old man, who attended our hospital with prolonged fever associated to polyarthritis and erythema nodosum. After medical assessment, laboratory test results, X-ray and CT scans, the patient was diagnosed with Löfgren syndrome, a disease seldom encountered in Colombia. Despite the low prevalence of sarcoidosis and Löfgren syndrome in our country, erythema nodosum and/or hilar adenopathies should increase suspicion of this rare disease, and Löfgren syndrome should be considered in patients with this presentation.

The CODATwins Project: The Current Status and Recent Findings of COllaborative Project of Development of Anthropometrical Measures in Twins.

The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural-geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.

Public Understanding of Behavioral Genetics: Integrating Heuristic Thinking, Motivated Reasoning and Planned Social Change Theories for Better Communication Strategies.

The field of behavioral genetics is experiencing a revolution following the development of genome-wide association studies and the availability of large datasets from international consortia. This rapid change could increase the existing gaps between basic research, translation, and public understanding of science. In the present work, we aim to synthesize key explanations of how public understanding of socio-scientific issues develop. We propose that integrating dual-process, motivated reasoning, and change management theories will increase the extent to which we understand, and can change, how people respond to findings from behavior genetics.

No evidence of association of oxytocin polymorphisms with breastfeeding in 2 independent samples.

Oxytocin has an important function in breastfeeding via its role in the milk ejection reflex and in attachment and bonding processes. Genetic factors account for a significant part of the individual differences in breastfeeding behavior. OXT and OXTR have been proposed as gene candidates for breastfeeding. Previous studies have focused on certain single-nucleotide polymorphisms (SNPs) within these genes, finding null or inconsistent results. The present study analyses the associations between a wide coverage of polymorphisms in OXT and OXTR and breastfeeding duration from 2 large and independent unselected samples comprising a total of 580 and 2112 female twin mothers from the Murcia Twin Registry (Spain) and QIMR Berghofer Medical Research Institute (Australia), respectively. A total of 19 SNPs in OXT and 137 in OXTR SNPs were covered in both samples. Effects of the OXT and OXTR polymorphisms on breastfeeding duration were calculated by means of linear regression controlling for age at survey time, educational level, interaction between age and educational level and principal components of genetic ancestry. The analyses were conducted independently in the 2 samples and also meta-analyzed. Although some SNPs were associated at an alpha level of .05 with breastfeeding, they did not survive multiple testing correction. We conclude that SNPs within or nearby OXT and OXTR are unlikely to have large effects on breastfeeding behavior.

A direct test of the diathesis-stress model for depression.

The diathesis-stress theory for depression states that the effects of stress on the depression risk are dependent on the diathesis or vulnerability, implying multiplicative interactive effects on the liability scale. We used polygenic risk scores for major depressive disorder (MDD) calculated from the results of the most recent analysis from the Psychiatric Genomics Consortium as a direct measure of the vulnerability for depression in a sample of 5221 individuals from 3083 families. In the same we also had measures of stressful life events and social support and a depression symptom score, as well as DSM-IV MDD diagnoses for most individuals. In order to estimate the variance in depression explained by the genetic vulnerability, the stressors and their interactions, we fitted linear mixed models controlling for relatedness for the whole sample as well as stratified by sex. We show a significant interaction of the polygenic risk scores with personal life events (0.12% of variance explained, P-value=0.0076) contributing positively to the risk of depression. Additionally, our results suggest possible differences in the aetiology of depression between women and men. In conclusion, our findings point to an extra risk for individuals with combined vulnerability and high number of reported personal life events beyond what would be expected from the additive contributions of these factors to the liability for depression, supporting the multiplicative diathesis-stress model for this disease.

Prescripción de opioides mayores en pacientes con dolor no oncológico: descripción de sus características en una zona de salud de atención primaria / Strong opioids prescription in patients with noncancer pain: description of its characteristics in an area of primary health care

Objetivo: Analizar todas las prescripciones de opioides mayores en pacientes con dolor no oncológico y revisar su frecuencia y características. Diseño: Estudio descriptivo transversal. Emplazamiento: Zona de salud de atención primaria, 24 médicos de familia, 38.000 usuarios. Participantes: Todos los pacientes con dolor no oncológico que tenían prescritos opioides mayores en una fecha determinada. Método de recogida de datos: Datos farmacológicos del programa informático de prescripciones del SAS, datos clínicos de la historia digital Diraya. Resultados: 138 pacientes recibían este tratamiento en la fecha de estudio (3,6 ‰ de la población); media de edad: 78 años (± 11,6); 76,8 % mujeres. Duración media de los tratamientos: 555,4 días (± 667,7). Dosis media de opioide: 82 mg (± 54,9) equivalente morfina/día. Fármaco más utilizado al inicio del tratamiento (25 %) y en el momento del audit (18,9 %): fentanilo transdérmico 25 mcg. Dosis inicial apropiada: 76 %. Modificaciones progresivas de dosis: 83 %. Causa más frecuente de la prescripción: patología lumbar (22 %). En el 66,6 % se utilizaron escalones analgésicos previos. Constaban efectos secundarios en el 11 %. El 70 % tomaba simultáneamente benzodiacepinas. Conclusiones: La frecuencia de prescripción de opioides mayores en pacientes no oncológicos es del 3,6 ‰ de nuestra población. En el momento del audit, el tratamiento está iniciado desde hace un año y medio, el fármaco más utilizado es el fentanilo transdérmico, que también lo es como inicio del tratamiento, y dos de cada tres pacientes están utilizando simultáneamente fármacos del grupo de las benzodiacepinas (AU)

Objective: Analyze all strong opioids prescriptions in patients with non-cancer pain of our health zone, and review the frecuency and characteristics. Design: Transversal descriptive study. Location: Primary health care, attended by 24 GPs, with 38,000 people in the reference population. Participants: All patients with non-cancer pain who were prescribed strong opioids drugs in a certain date. Method of data collection: The pharmacological data were collected from the database requirements of the Andalusian Health Service. The clinical data from clinical digital history “Diraya”. Results: 138 patients were receiving this treatment in the date of study (3.6 ‰ of the population). Mean age: 78 years (± 11.6); 76.8 % women. Duration of treatment: 555.4 days (± 667.7). Average dose of opioid: 82 mg (± 54.9) morphine equivalent/day. Drug most used at baseline (25 %) and at the time of the audit (18.9 %): transdermal fentanyl 25 mcg. Appropriate starting dose: 76 %. Progressive modifications dose: 83 %. Most frequent reason for prescribing: lumbar pathology (22 %). Analgesics steps were used in 66 %. Side effects consisted: 11 %. 70 % were taking benzodiazepines simultaneously. Conclusions: The prevalence of prescription strong opioids in non-cancer patients is 3.6 ‰ of our population. At the time of the audit, treatment is initiated for a year and a half ago, the drug most commonly used is transdermal fentanyl, which is also as the beginning of treatment and two out of three patients are simultaneously using drugs from the group of benzodiazepines (AU)

Direct Determination of Dynamic Properties of Coulomb and Yukawa Classical One-Component Plasmas.

Dynamic characteristics of strongly coupled classical one-component Coulomb and Yukawa plasmas are obtained within the nonperturbative model-free moment approach without any data input from simulations so that the dynamic structure factor (DSF) satisfies the first three nonvanishing sum rules automatically. The DSF, dispersion, decay, sound speed, and other characteristics of the collective modes are determined using exclusively the static structure factor calculated from various theoretical approaches including the hypernetted chain approximation. A good quantitative agreement with molecular dynamics simulation data is achieved.

Network visualization for outbreak response: Mapping the Ebola Virus Disease (EVD) chains of transmission in N'Zérékoré, Guinea.

BACKGROUND: During the 2014-2015 Ebola Virus Disease (EVD) outbreak in N'Zérékoré, Forested Guinea, modes of transmission remained unexamined for a number of new cases. We used network visualization to investigate EVD transmission chains (TC) in seven sub-prefectures of N'Zérékoré in order to adapt outbreak response. METHODS: Between August 2014 and February 2015, the EVD outbreak response team including the World Health Organization (WHO) and local health authorities routinely collected information among new cases regarding hospital visits, cases within a household, participation in burials, as well as dates of symptom onset, serial intervals (SI) and exposure to EVD. SI's were defined as the interval between symptom onset in an index case and symptom onset in a secondary case infected by that index case. Cases who reported hospital visits, contact with a case in the household or participating in burials were attributed to these exposures. RESULTS: We identified seven TC (two urban and five rural) gathering characteristics of 109 probable/confirmed cases. Overall, 61% (66 cases, SI range: 7-20 days) were household related, 32% (35 cases, SI range 8-30 days) were household or burial related and 7% (8 cases, SI range: 4-20 days) were hospital-related. In the urban chains (18 cases, SI range: 7-20 days), 12 cases were household related and 6 cases were hospital related, none where household or burial related. In the rural chains (84 cases, SI range: 7-30 days), 60% (50 cases) were household related, 1% (1 case) was hospital related and 39% (34 cases) were household or burial related. No cases reported multiple exposures. CONCLUSIONS: Network visualization during field response is crucial in enhancing local control strategies, refining outbreak response and aiding rapid response teams in insuring psychosocial and socio-economic recovery. Urban settings need to focus on reducing hospital EVD transmission whereas rural settings should focus on raising awareness of transmission within a household and safeguarding EVD burials.

Genome-wide analysis of over 106 000 individuals identifies 9 neuroticism-associated loci.

Neuroticism is a personality trait of fundamental importance for psychological well-being and public health. It is strongly associated with major depressive disorder (MDD) and several other psychiatric conditions. Although neuroticism is heritable, attempts to identify the alleles involved in previous studies have been limited by relatively small sample sizes. Here we report a combined meta-analysis of genome-wide association study (GWAS) of neuroticism that includes 91 370 participants from the UK Biobank cohort, 6659 participants from the Generation Scotland: Scottish Family Health Study (GS:SFHS) and 8687 participants from a QIMR (Queensland Institute of Medical Research) Berghofer Medical Research Institute (QIMR) cohort. All participants were assessed using the same neuroticism instrument, the Eysenck Personality Questionnaire-Revised (EPQ-R-S) Short Form's Neuroticism scale. We found a single-nucleotide polymorphism-based heritability estimate for neuroticism of ∼15% (s.e.=0.7%). Meta-analysis identified nine novel loci associated with neuroticism. The strongest evidence for association was at a locus on chromosome 8 (P=1.5 × 10(-15)) spanning 4 Mb and containing at least 36 genes. Other associated loci included interesting candidate genes on chromosome 1 (GRIK3 (glutamate receptor ionotropic kainate 3)), chromosome 4 (KLHL2 (Kelch-like protein 2)), chromosome 17 (CRHR1 (corticotropin-releasing hormone receptor 1) and MAPT (microtubule-associated protein Tau)) and on chromosome 18 (CELF4 (CUGBP elav-like family member 4)). We found no evidence for genetic differences in the common allelic architecture of neuroticism by sex. By comparing our findings with those of the Psychiatric Genetics Consortia, we identified a strong genetic correlation between neuroticism and MDD and a less strong but significant genetic correlation with schizophrenia, although not with bipolar disorder. Polygenic risk scores derived from the primary UK Biobank sample captured ∼1% of the variance in neuroticism in the GS:SFHS and QIMR samples, although most of the genome-wide significant alleles identified within a UK Biobank-only GWAS of neuroticism were not independently replicated within these cohorts. The identification of nine novel neuroticism-associated loci will drive forward future work on the neurobiology of neuroticism and related phenotypes.

Application of multiparametric procedures for assessing the heritability of circadian health.

At present, the measurement of circadian system status under free-living conditions by the use of sensors is a relatively new technique. The data obtained using these methods are influenced by strong environmental masking factors and artifacts that can affect its recording. Therefore, the use of integrative variables such as TAP, a measure that includes temperature, activity and position that reduces these drawbacks and the number of parameters obtained is necessary. However, the relative genetic contribution to this circadian marker is unknown. The aim of our study was to ascertain the relative importance of genetic influences in TAP, and for each of its components using classical twin models. The study was performed in 53 pairs of female twins [28 monozygotic (MZ) and 25 dizygotic (DZ)] with mean age 52 ± 6 years. Circadian patterns were studied by analyzing temperature, body position and activity for 1 week every 1 min with "Circadianware®.". Genetic influences affecting the variability of each of the measurements were estimated by comparing the observed data in twin pairs. MZ twins showed higher intrapair correlations than DZ twins for most of the parameters. Genetic factors (broad sense heritability) were responsible for about 40-72% of TAP variance in parameters such as mesor, acrophase, amplitude, Rayleigh test, percentage of rhythmicity and circadian function index. We found more homogeneous heritability estimates of the circadian system when using an integrative technique such as TAP than with individual variables alone, suggesting that this measurement can be more reliable and less subject to environmental artifacts.

Otro gran imitador..., con desenlace fatal / Another great wannabe..., with fatal outcome

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Maternal-calf relationships and their influence on calves up to 120 days / Relaciones materno-filiales y su influencia en terneros hasta los 120 días de edad

Objectives. To research parental behavior and measure the weight of Nelore and Guzerat calves up to 120 days of age, collecting data from birth up to the first lactation. Materials and methods. Seven different corporal positions were considered to obtain specific data for each of the following categories: time to stand (TP), time to intend to feed after standing (TPTM), weight at birth (PN), weight at 120 days (P120), and time in contact with the calf (TCC). Additionally, independent variables were also evaluated, organized by class: weight at birth (CPN), number of calvings (CNP), order of calving in relation with the herd (CLPR), time of calving (CHP), and finally, hindering to feed (CTAT). Results. There was a significant result in favor of the Nelore race over the Guzerat race. The statistical averages for Nelore and Guzerat were: Time to stand averaged 71 and 153 minutes; time to intend to feed after standing, 39 minutes for Nelore and of 114 minutes for Guzerat. For variable weight at 120 days, Nelore reached an average of 122 kg, and Guzerat 109 kg. For the time in contact with the calf variable there was no significant variance between races. Conclusions. Results showed the superiority of the Nelore race, considering it better adapted to local environmental conditions.

Objetivo. Investigar el comportamiento materno y observar su influencia en el peso de los terneros de las razas Nelore y Guzerat hasta los 120 días de edad, evaluándolos desde su nacimiento hasta el primer amamantamient. Materiales y métodos. Se consideraron siete posturas corporales diferentes, las cuales fueron usadas para obtener las observaciones específicas en cada una de las siguientes categorías: Tiempo para ponerse de pie (TP), Tiempo para intentar lactar después de ponerse de pie (TPTM), peso al nacer (PN), peso a los 120 días (P120) y tiempo de contacto con la cría (TCC). Se evaluaron las variables independientes, organizadas en clases: peso al nacer (CPN); número de partos (CNP); orden del parto en relación al rebaño (CLPR); hora del parto (CHP) y obstaculización de mamada (CTAT). Resultados. Se obtuvo un mejor resultado en los terneros de la raza Nelore en relación a los de la raza Guzerat. Los promedios estadísticos para Nelore y Guzerat fueron los siguientes: TP con media de 71 y 153 minutos; TPTM de 39 y 114 minutos; P120 con 122 kg para terneros Nelore y 109 kg para los de la raza Guzerat. La variable TCC no obtuvo una diferencia significativa entre las razas. Conclusiones. Los resultados demuestran una superioridad para animales de la raza Nelore, lo que permite inferir que poseen una mejor adaptación a las condiciones ambientales locales.

Obesidad, actividad física y dolor lumbar: un análisis genéticamente informativo / Obesity, physical activity and low back pain: a genetically informative analysis

Objetivo: Analizar la relación entre obesidad, actividad física y dolor lumbar a través de un estudio transversal de gemelos caso-control. Material y método: La muestra general la componen 1.613 individuos gemelos, de entre 47 y 73 años, y participantes en el Registro de Gemelos de Murcia. Los datos fueron obtenidos mediante entrevista telefónica y se recogió información sobre dolor de espalda, datos antropométricos y actividad física. La cigosidad fue evaluada mediante cuestionario. El análisis caso-control se realizó sobre 199 parejas completas y discordantes para dolor lumbar. Resultados: La prevalencia del dolor lumbar en la muestra total fue del 33,1% (mujeres: 36,4%; varones: 29,1%). El Índice de Masa Corporal (IMC) fue de 27.2 (DE: 4,3). En la muestra general, ser mujer, IMC elevado, frecuencia baja de actividad física moderada e intensa y sedentarismo se asociaron con mayor riesgo de padecer dolor lumbar. Sin embargo, todas las asociaciones perdieron significación estadística en el análisis caso-control. Conclusión: Es necesario considerar las características individuales o grupales al valorar el papel del IMC o la actividad física en la prevención del dolor lumbar. Esto incluye la necesidad de tener en cuenta el papel de los factores genéticos en futuras investigaciones sobre esta relación (AU)

Objective: Our main objective was to analyse the relationship between obesity, physical activity and low back pain using a cross-sectional co-twin design. Material and method: The total sample comprised 1,613 subjects, aged 47 to 73, from the Murcia Twin Registry. Data were obtained through telephone interview, and information about back pain, anthropometric data and physical activity was collected. One-hundred and ninety-nine pairs complete and discordant for low back pain were available for the case-control analysis. Results: Prevalence of low back pain was 33.1% (females: 36.4%; males: 29.1%). Mean Body Mass Index (BMI) was 27.2 (SD: 4.3). For the general sample, being female, a high BMI, low frequency of moderate or intense physical activity and sedentarism were associated to a higher risk of low back pain. However, all associations lost statistical significance in the case-control analyses. Conclusion: Individual and group characteristics must be considered when evaluating the role of BMI or physical activity on prevention of low back pain. This includes the need to take into account the role of genetic factors in future research about this relationship (AU)