Using biological traits to assess diet selection: the case of the Pyrenean Desman.

Traditionally, researchers have assessed diet selection by comparing consumed versus available taxa. However, taxonomic assignment is probably irrelevant for predators, who likely base their selection on characteristics including prey size, habitat, or behavior. Here, we use an aquatic insectivore, the threatened Pyrenean Desman (Galemys pyrenaicus), as a model species to assess whether biological traits help unravel the criteria driving food and habitat preferences. We reanalyzed data from a previous taxonomy-based study of prey selection in two contrasting streams, one with excellent conservation status and the other affected by diversion for hydropower and forestry. Available and consumed prey were characterized according to nine biological traits, and diet selection was estimated by comparing availability-measured from Surber net samples, and consumption-analyzed by metabarcoding desman feces. Traits offered a biologically coherent image of diet and almost identical selection patterns in both streams, depicting a highly specialized rheophilic predator. Desmans positively selected prey with a preference for fast flow and boulder substrate, indicating their preferred riffle habitat. On the other hand, they positively selected prey with larger but not the largest potential size, living in the water column or the litter, and not inside sediments. They also chose agile prey, swimmers or prey attached to the substrate, prey with high body flexibility, and prey living exposed and clustered in groups. Overall, our results offer a picture of desman diet preference and point to biological traits as being better than taxonomic identity to describe the diet preference of consumers.

Tradicionalmente, los investigadores han estimado la selección de dieta comparando los taxones ingeridos con los disponibles. Sin embargo, la asignación taxonómica probablemente sea irrelevante para los depredadores, que probablemente basan su selección en características tales como el tamaño de presa, su hábitat o su comportamiento. Aquí, utilizamos como especie modelo un insectívoro acuático, el amenazado desmán ibérico (Galemys pyrenaicus), para evaluar si los rasgos biológicos ayudan a desvelar los criterios que rigen las preferencias de alimentos y de hábitat. Reanalizamos los datos de un estudio previo basado en taxonomía sobre la selección de presas de desmán en dos ríos diferentes, uno en excelente estado de conservación y el otro afectado por la derivación de agua para producción de energía hidroeléctrica y por actividades forestales. Se caracterizaron las presas disponibles y consumidas en función de nueve rasgos biológicos y se estimó la selección de dieta comparando la disponibilidad, medida a partir de muestras de redes Surber, y el consumo, determinado mediante metabarcoding de las heces del desmán. Los rasgos biológicos ofrecieron una imagen biológicamente coherente de la dieta y unos patrones de selección casi idénticos en ambos ríos, representando a un depredador reófilo altamente especializado. Los desmanes seleccionaron positivamente las presas con preferencia por corriente rápida y sustrato de bloques, indicando su preferencia de hábitat por los rápidos. Por otro lado, seleccionaron positivamente presas con tamaño potencial grande­pero no el mayor­, que vivían en la columna de agua o en la hojarasca, y no dentro de los sedimentos. También eligieron presas ágiles, presas nadadoras o adheridas al sustrato, presas con alta flexibilidad corporal y presas que viven expuestas y agrupadas. En general, nuestros resultados ofrecen una imagen de las preferencias tróficas del desmán y apuntan a que los rasgos biológicos de las presas describen las preferencias tróficas de los consumidores mejor que su identidad taxonómica.

Evaluating the use of non-invasive hair sampling and ddRAD to characterize populations of endangered species: Application to a peripheral population of the European mink.

The application of next-generation sequencing (NGS) to non-invasive samples is one of the most promising methods in conservation genomics, but these types of samples present significant challenges for NGS. The European mink (Mustela lutreola) is critically endangered throughout its range. However, important aspects such as census size and inbreeding remain still unknown in many populations, so it is crucial to develop new methods to monitor this species. In this work, we placed hair tubes along riverbanks in a border area of the Iberian population, which allowed the genetic identification of 76 European mink hair samples. We then applied a reduced representation genomic sequencing (ddRAD) technique to a subset of these samples to test whether we could extract sufficient genomic information from them. We show that several problems with the DNA, including contamination, fragmentation, oxidation, and possibly sample mixing, affected the samples. Using various bioinformatic techniques to reduce these problems, we were able to unambiguously genotype 19 hair samples belonging to six individuals. This small number of individuals showed that the demographic status of the species in this peripheral population is worse than expected. The data obtained also allowed us to perform preliminary analyses of relatedness and inbreeding. Although further improvements in sampling and analysis are needed, the application of the ddRAD technique to non-invasively obtained hairs represents a significant advance in the genomic study of endangered species.

Methodological challenges in the genomic analysis of an endangered mammal population with low genetic diversity.

Recently, populations of various species with very low genetic diversity have been discovered. Some of these persist in the long term, but others could face extinction due to accelerated loss of fitness. In this work, we characterize 45 individuals of one of these populations, belonging to the Iberian desman (Galemys pyrenaicus). For this, we used the ddRADseq technique, which generated 1421 SNPs. The heterozygosity values of the analyzed individuals were among the lowest recorded for mammals, ranging from 26 to 91 SNPs/Mb. Furthermore, the individuals from one of the localities, highly isolated due to strong barriers, presented extremely high inbreeding coefficients, with values above 0.7. Under this scenario of low genetic diversity and elevated inbreeding levels, some individuals appeared to be almost genetically identical. We used different methods and simulations to determine if genetic identification and parentage analysis were possible in this population. Only one of the methods, which does not assume population homogeneity, was able to identify all individuals correctly. Therefore, genetically impoverished populations pose a great methodological challenge for their genetic study. However, these populations are of primary scientific and conservation interest, so it is essential to characterize them genetically and improve genomic methodologies for their research.

Determining diet from faeces: Selection of metabarcoding primers for the insectivore Pyrenean desman (Galemys pyrenaicus).

Molecular techniques allow non-invasive dietary studies from faeces, providing an invaluable tool to unveil ecological requirements of endangered or elusive species. They contribute to progress on important issues such as genomics, population genetics, dietary studies or reproductive analyses, essential knowledge for conservation biology. Nevertheless, these techniques require general methods to be tailored to the specific research objectives, as well as to substrate- and species-specific constraints. In this pilot study we test a range of available primers to optimise diet analysis from metabarcoding of faeces of a generalist aquatic insectivore, the endangered Pyrenean desman (Galemys pyrenaicus, É. Geoffroy Saint-Hilaire, 1811, Talpidae), as a step to improve the knowledge of the conservation biology of this species. Twenty-four faeces were collected in the field, DNA was extracted from them, and fragments of the standard barcode region (COI) were PCR amplified by using five primer sets (Brandon-Mong, Gillet, Leray, Meusnier and Zeale). PCR outputs were sequenced on the Illumina MiSeq platform, sequences were processed, clustered into OTUs (Operational Taxonomic Units) using UPARSE algorithm and BLASTed against the NCBI database. Although all primer sets successfully amplified their target fragments, they differed considerably in the amounts of sequence reads, rough OTUs, and taxonomically assigned OTUs. Primer sets consistently identified a few abundant prey taxa, probably representing the staple food of the Pyrenean desman. However, they differed in the less common prey groups. Overall, the combination of Gillet and Zeale primer sets were most cost-effective to identify the widest taxonomic range of prey as well as the desman itself, which could be further improved stepwise by adding sequentially the outputs of Leray, Brandon-Mong and Meusnier primers. These results are relevant for the conservation biology of this endangered species as they allow a better characterization of its food and habitat requirements.

Using relatedness networks to infer contemporary dispersal: Application to the endangered mammal Galemys pyrenaicus.

Information about the degree of contemporary dispersal is important when trying to understand how populations interchange individuals and identify the specific barriers that prevent these movements. In the case of endangered species, this can represent crucial information when designing appropriate conservation strategies. Here we analyse relatedness between individuals from different localities and use these data to infer whether dispersal occurred in recent generations. We applied this approach to the Pyrenean desman (Galemys pyrenaicus), a semiaquatic and endangered species endemic to the Iberian Peninsula. We studied this species in four primary rivers in the Iberian Range, where two ancient mitochondrial lineages are separated by a strict contact zone, suggesting the existence of complex dispersal patterns. Using next-generation sequencing, we obtained 912 SNPs from each specimen and estimated relatedness values between them. While relatedness networks were dense within each river, we found surprisingly few relationships between individuals from different rivers despite their close proximity in some cases, indicating much lower dispersal between rivers compared to dispersal within a single river. In agreement with this result, the degree of inbreeding was exceedingly high in most individuals. These data show that relatedness information can be crucial to understand the contemporary dispersal patterns and conservation status of specific populations of endangered species.

Phylogeography and postglacial expansion of the endangered semi-aquatic mammal Galemys pyrenaicus.

BACKGROUND: Species with strict ecological requirements may provide new insights into the forces that shaped the geographic variation of genetic diversity. The Pyrenean desman, Galemys pyrenaicus, is a small semi-aquatic mammal that inhabits clean streams of the northern half of the Iberian Peninsula and is endangered in most of its geographic range, but its genetic structure is currently unknown. While the stringent ecological demands derived from its aquatic habitat might have caused a partition of the genetic diversity among river basins, Pleistocene glaciations would have generated a genetic pattern related to glacial refugia. RESULTS: To study the relative importance of historical and ecological factors in the genetic structure of G. pyrenaicus, we used mitochondrial and intronic sequences of specimens covering most of the species range. We show, first, that the Pyrenean desman has very low levels of genetic diversity compared to other mammals. In addition, phylogenetic and dating analyses of the mitochondrial sequences reveal a strong phylogeographic structure of a Middle Pleistocene origin, suggesting that the main lineages arose during periods of glacial isolation. Furthermore, both the spatial distribution of nuclear and mitochondrial diversity and the results of species distribution modeling suggest the existence of a major glacial refugium in the northwestern part of the Iberian Peninsula. Finally, the main mitochondrial lineages show a striking parapatric distribution without any apparent exchange of mitochondrial haplotypes between the lineages that came into secondary contact (although with certain permeability to nuclear genes), indicating incomplete mixing after the post-glacial recolonization. On the other hand, when we analyzed the partition of the genetic diversity among river basins, the Pyrenean desman showed a lower than expected genetic differentiation among main rivers. CONCLUSIONS: The analysis of mitochondrial and intronic markers in G. pyrenaicus showed the predominant effects of Pleistocene glaciations on the genetic structure of this species, while the distribution of the genetic diversity was not greatly influenced by the main river systems. These results and, particularly, the discovery of a marked phylogeographic structure, may have important implications for the conservation of the Pyrenean desman.

The impact of occult renal failure on the cardiovascular risk stratification in an elderly population: the PREV-ICTUS study.

BACKGROUND AND OBJECTIVES: To analyze the impact of occult renal failure (ORF) in the individual risk stratification and on the blood pressures (BP) and low-density lipoprotein (LDL) goals in an aged population, according to the ESH/ESC Hypertension Guidelines. METHODS: A cross-sectional, population-based study on individuals aged 60 years or more carried out in Primary Care Centers of Spain. Kidney function was estimated from calculated creatinine clearance (eGFR), Cockroft and Gault formula. Ten-year cardiovascular risk was estimated through the ESH/ESC table including or not including the eGFR. Estimates of the modification in BP and LDL-cholesterol (cLDL) goals were calculated. RESULTS: In 6419 subjects, 4242 subjects (66%) had normal renal function, 1971 (31%) had ORF (normal creatinine and low eGFR) and 206 (3%) had insufficient renal function (high creatinine and all of them low eGFR). Inclusion of ORF as target organ damage resulted in an increase in the estimated risk in 10.8% of the total sample, increasing the percentage of high-risk subjects. In the latter case, new BP and cLDL goals (<130/80 mmHg and <100 mg/dl) should be needed in 475 (7.4%) and 413 (6.4%) additional subjects, respectively. CONCLUSION: Inclusion of the ORF resulted in a significant increase in the percentage of subjects with estimated high cardiovascular risk.

[Prevalence and related factors of overweight and obesity in Spanish population aged 60 years-old or older. The PREV-ICTUS study]. / Prevalencia de sobrepeso y obesidad en población española de 60 años o más y factores relacionados. Estudio PREV-ICTUS.

BACKGROUND AND OBJECTIVE: Data on the prevalence of obesity in elderly population in Spain are scarce. The objective of this work was to describe the prevalence of obesity and the related factors in a random sample of Spanish population aged 60 years-old or more, stratified by autonomous communities. SUBJECTS AND METHOD: We analyzed the PREV-ICTUS study, a population-based study carried out between September and December 2005 in a random sample stratified by autonomous communities according to the census of inhabitants and the habitat in each community. Subjects were classified as with normal weight (body mass index [BMI] < 25 kg), overweight (BMI 25-29.9) and obesity (BMI > or = 30 kg). RESULTS: In 6,843 subjects -mean age (standard deviation): 71.9 (7.1) years-old; 53.3% women-, prevalence of obesity was 34.5% (95% confidence interval [CI], 33.3-35.5%), higher in women (38.4%; 95% CI, 36.8-39.9%) than in men (30.0%; 95% CI, 28.4-31.6%; p < 0.001), with a tendency to decrease in the older population. In total, 81.7% of the population showed overweight (BMI > or = 25). Prevalence differed among communities from 46.4% to 20.7% (p < 0.001). In the multivariate analysis, obesity was inversely related to age (odds ratio [OR] = 0.98 per each year increment), and directly to female gender (OR = 1.25), rural (OR = 1.50) or semi-urban habitat (OR = 1.38), sedentary lifestyle (OR = 1.86) and non-smoking history (OR = 1.19). CONCLUSIONS: Obesity was present in one out of 3 individuals of this reasonably representative sample of the Spanish population in an age range, 60 years-old or more, which concentrates a high cardiovascular risk. Differences in the prevalence among autonomus communities were detected.

Prevalencia de sobrepeso y obesidad en población española de 60 años o más y factores relacionados. Estudio PREV-ICTUS / Prevalence and related factors of overweight and obesity in Spanish population aged 60 years-old or older. The PREV-ICTUS study

FUNDAMENTO Y OBJETIVO: Los datos sobre prevalencia de obesidad en población de edad avanzadaen España son escasos. El objetivo de este trabajo ha sido describir la prevalencia de obesidady los factores relacionados en una muestra aleatoria de la población española de 60 años o más, estratificada por comunidades autónomas (CC.AA.).SUJETOS Y MÉTODO: Se analizó el estudio PREV-ICTUS, realizado en una muestra seleccionadaaleatoriamente entre septiembre y diciembre de 2005, estratificada por CC.AA. según el censo yel hábitat de atención. Se clasificó a los sujetos según su índice de masa corporal (IMC) enaquellos con peso normal (IMC < 25), sobrepeso (IMC de 25-29,9) y obesos (IMC 30).RESULTADOS: En 6.843 sujetos –edad media (desviación estándar) de 71,9 (7,1) años; 53,3%mujeres– la prevalencia de obesidad fue del 34,5% (intervalo de confianza [IC] del 95%, 33,3-35,5%), mayor en mujeres (38,4%; IC del 95%, 36,8-39,9%) que en varones (30,0%; IC del95%, 28,4-31,6%; p < 0,001), con tendencia a disminuir en edades más avanzadas. En total,el 81,7% mostró exceso ponderal (IMC 25). La prevalencia varió entre las CC.AA., del 46,4al 20,7% (p < 0,001). En el análisis multivariante, la obesidad guardó una relación inversa conla edad (odds ratio [OR] = 0,98 por cada incremento en un año) y directa con el sexo femenino(OR = 1,25), el medio rural (OR = 1,50) o semiurbano (OR = 1,38), el sedentarismo (OR =1,86) y el antecedente de no fumador (OR = 1,19).CONCLUSIONES: La obesidad estuvo presente en uno de cada 3 individuos en esta muestra razonablementerepresentativa de la población española de un intervalo de edad, 60 años o más, que ademásconcentra un gran riesgo cardiovascular. Se observaron diferencias en la prevalencia entre las CC.AA

BACKGROUND AND OBJECTIVE: Data on the prevalence of obesity in elderly population in Spain are scarce. The objective of this work was to describe the prevalence of obesity and the related factors in a random sample of Spanish population aged 60 years-old or more, stratified by autonomous communities. SUBJECTS AND METHOD: We analyzed the PREV-ICTUS study, a population-based study carried out between September and December 2005 in a random sample stratified by autonomous communities according to the census of inhabitants and the habitat in each community. Subjects were classified as with normal weight (body mass index [BMI] < 25 kg), overweight (BMI 25-29.9) and obesity (BMI 30 kg). RESULTS: In 6,843 subjects –mean age (standard deviation): 71.9 (7.1) years-old; 53.3% women–, prevalence of obesity was 34.5% (95% confidence interval [CI], 33.3-35.5%), higher in women (38.4%; 95% CI, 36.8-39.9%) than in men (30.0%; 95% CI, 28.4-31.6%; p < 0.001), with a tendency to decrease in the older population. In total, 81.7% of the population showed overweight (BMI 25). Prevalence differed among communities from 46.4% to 20.7% (p < 0.001). In the multivariate analysis, obesity was inversely related to age (odds ratio [OR] = 0.98 per each year increment), and directly to female gender (OR = 1.25), rural (OR = 1.50) or semiurban habitat (OR = 1.38), sedentary lifestyle (OR = 1.86) and non-smoking history (OR = 1.19). CONCLUSIONS: Obesity was present in one out of 3 individuals of this reasonably representative sample of the Spanish population in an age range, 60 years-old or more, which concentrates a high cardiovascular risk. Differences in the prevalence among autonomus communities were detected

[Prevalence of low glomerular filtration rate in the elderly population of Spain. The PREV-ICTUS study]. / Prevalencia de filtrado glomerular disminuido en la población española de edad avanzada. Estudio PREV-ICTUS.

BACKGROUND AND OBJECTIVE: To assess the prevalence of low glomerular filtration rate (GFR < 60 ml/min/1.73 m2) in general population of subjects aged 60 years or older of Spain, and the related factors. PATIENTS AND METHOD: Analysis of PREV-ICTUS, a population-based study carried out in a sample of subjects aged 60 years or more, randomly selected and stratified by Autonomic Communities according to the census of inhabitants and the habitat in each Community. Demographic data, cardiovascular risk factors and diseases were collected. GFR was calculated using the MDRD (Modification of Diet in Renal Disease) equation. RESULTS: In 6,799 subjects (age 71.9 years-old; 53.6% women; 72.9% with arterial hypertension [HT]; 27.0% with diabetes mellitus [DM]; 24.3% with cardiovascular disease), 25.9% had low GFR (95% confidence interval, 24.8-26.9). The prevalence increased linearly, from 16.5% in subjects aged 60-64 years to 46.5% in those aged 85 or more (p < 0.001), and was higher in women (36.1% vs 14.1% in men, p < 0.001). In the multivariate analysis, low GFR was independently related to advanced age (odds ratio [OR] between 1.30 y 4.20), female gender (OR = 5.82), HT older than 7 years (OR = 1.23), uric acid (OR = 1.52 for each increment of 1 mg/dl) and cardiovascular disease (OR = 1.68). The association with DM did not reach statistical significance. In a model without cardiovascular disease, related factors remained the same, increasing the significance of HT older than 7 years (OR = 1.31) and of DM (OR = 1.19). CONCLUSION: One out or 4 subjects of this sample showed low GFR. The variables directly associated with low GFR were advanced age, female gender, HT of longer evolution, cardiovascular disease, increased uric acid, and, in one model, DM.

Prevalencia de filtrado glomerular disminuido en la población española de edad avanzada. Estudio PREV-ICTUS / Prevalence of low glomerular filtration rate in the elderly population of Spain. The PREV-ICTUS study

Fundamento y objetivo: Estimar la prevalencia de filtrado glomerular (FG) disminuido (< 60 ml/min/1,73 m2) en población general española de 60 años o más y los factores asociados. Pacientes y método: Se analizó el estudio PREV-ICTUS, realizado en una muestra de individuos de 60 años o más seleccionada aleatoriamente, estratificada por comunidades autónomas según el censo y el hábitat de atención. Se recogieron datos demográficos, factores de riesgo y enfermedades cardiovasculares. Se calculó el FG utilizando la fórmula de MDRD (Modification of Diet in Renal Disease). Resultados: En 6.799 individuos (edad media 71,9 años; 53,6% mujeres; 72,9% con hipertensión arterial [HTA]; 27,0% con diabetes mellitus [DM]; 24,3% con enfermedad cardiovascular), el 25,9% presentó FG disminuido (intervalo de confianza del 95%, 24,8­26,9). La prevalencia aumentó linealmente con la edad, del 16,5% en individuos de 60-64 años al 46,5% en los de 85 años o más (p < 0,001), y fue superior en mujeres (36,1%) frente a varones (14,1%) (p < 0,001). En el análisis multivariante, el FG disminuido se asoció significativamente con edad avanzada (odds ratio [OR] entre 1,30 y 4,20), sexo femenino (OR = 5,82), HTA de más de 7 años de evolución (OR = 1,23), ácido úrico elevado (OR = 1,52 por cada incremento de 1 mg/dl) y presencia de enfermedad cardiovascular (OR = 1,68). La asociación con DM no alcanzó significación estadística. En un modelo sin la enfermedad cardiovascular, las asociaciones fueron las mismas, ganando significación la HTA de más de 7 años (OR = 1,31) y la DM (OR = 1,19). Conclusión: Uno de cada 4 individuos en esta muestra mostró un FG calculado disminuido. Las variables directamente asociadas con la presencia de FG disminuido fueron edad avanzada, sexo femenino, HTA de mayor evolución, enfermedad cardiovascular, cifras de ácido úrico elevadas y, sólo en un modelo, la DM

Background and objective: To assess the prevalence of low glomerular filtration rate (GFR < 60 ml/min/1.73 m2) in general population of subjects aged 60 years or older of Spain, and the related factors. Patients and method: Analysis of PREV-ICTUS, a population-based study carried out in a sample of subjects aged 60 years or more, randomly selected and stratified by Autonomic Communities according to the census of inhabitants and the habitat in each Community. Demographic data, cardiovascular risk factors and diseases were collected. GFR was calculated using the MDRD (Modification of Diet in Renal Disease) equation. Results: In 6,799 subjects (age 71.9 years-old; 53.6% women; 72.9% with arterial hypertension [HT]; 27.0% with diabetes mellitus [DM]; 24.3% with cardiovascular disease), 25.9% had low GFR (95% confidence interval, 24.8­26.9). The prevalence increased linearly, from 16.5% in subjects aged 60-64 years to 46.5% in those aged 85 or more (p < 0.001), and was higher in women (36.1% vs 14.1% in men, p < 0.001). In the multivariate analysis, low GFR was independently related to advanced age (odds ratio [OR] between 1.30 y 4.20), female gender (OR = 5.82), HT older than 7 years (OR = 1.23), uric acid (OR = 1.52 for each increment of 1 mg/dl) and cardiovascular disease (OR = 1.68). The association with DM did not reach statistical significance. In a model without cardiovascular disease, related factors remained the same, increasing the significance of HT older than 7 years (OR = 1.31) and of DM (OR = 1.19). Conclusion: One out or 4 subjects of this sample showed low GFR. The variables directly associated with low GFR were advanced age, female gender, HT of longer evolution, cardiovascular disease, increased uric acid, and, in one model, DM

[Prevalence of atrial fibrillation in the Spanish population aged 60 years or more. The PREV-ICTUS study]. / Prevalencia de fibrilación auricular en la población española de 60 o más años de edad. Estudio PREV-ICTUS.

INTRODUCTION AND OBJECTIVES: The aims of this study were to determine the prevalence of atrial fibrillation in individuals aged 60 years or more in Spain using a random sample of the population and to identify associated factors. METHODS: An analysis of the PREV-ICTUS study, a randomized cross-sectional population-based study of individuals aged 60 years or more, was carried out. Data on demographic variables, cardiovascular risk factors, and cardiovascular disease were obtained from medical records. The diagnosis of atrial fibrillation was based on the patient's medical history and an electrocardiogram performed during the study. RESULTS: In the 7108 individuals studied (mean age 71.9 [7.1] years, 53.6% female), the prevalence of atrial fibrillation was 8.5% (95% confidence interval [CI] 7.9-9.2%). It was higher in males (9.3% vs 7.9% in females; P=.036) and increased from 4.2% in individuals aged 60-64 years to 16.5% in those aged 85 years or more (chi-squared test for linear trend, P< .001). Multivariate analysis showed that existing cardiovascular disease, hypertension, age, and left ventricular hypertrophy had the strongest associations with atrial fibrillation. Although there was a strong relationship between hypertension and atrial fibrillation (odds ratio 2.53, 95% CI, 1.60-4.01), no association was found between poor blood pressure control and atrial fibrillation. A weak association with diabetes mellitus was found only when arterial pressure was included in the model, but not when a diagnosis of hypertension was included. CONCLUSIONS: In this cross-sectional population-based study of elderly individuals, the prevalence of atrial fibrillation was 8.5%, and was strongly associated with existing cardiovascular disease, hypertension, age and left ventricular hypertrophy.

Prevalencia de fibrilación auricular en la población española de 60 o más años de edad. Estudio PREV-ICTUS / Prevalence of atrial fibrillation in the spanish population aged 60 years or more. The PREV-ICTUS study

Introducción y objetivos. El objetivo de este estudio fue analizar la prevalencia de fibrilación auricular (FA) en sujetos ≥ 60 años en España y los factores asociados, en una muestra aleatoria de base poblacional. Métodos. Análisis del estudio PREV-ICTUS, estudio transversal de base poblacional en sujetos ≥ 60 años. Se recogieron datos demográficos, factores de riesgo y enfermedades cardiovasculares. La FA fue diagnosticada por la historia médica y un electrocardiograma realizado en el momento del estudio. Resultados. En 7.108 sujetos (edad media 71,9 ± 7,1 años, el 53,6%, mujer), la prevalencia de FA fue del 8,5% (intervalo de confianza [IC] del 95%, 7,9-9,2), mayor en varones (del 9,3%, frente al 7,9% en mujeres; p = 0,036) y aumentó desde el 4,2% en sujetos de 60-64 años al 16,5% en los ≥ 85 años (χ⊃2; de la tendencia lineal; p < 0,001). En los modelos multivariables, la enfermedad cardiovascular establecida, la hipertensión, la edad y la hipertrofia ventricular izquierda tuvieron la asociación más fuerte con la FA, mientras que la hipertensión se relacionó con fuerza con la FA (odds ratio [OR] = 2,53; IC del 95%, 1,60-4,01) y no encontramos asociación entre peor control de la presión arterial y FA. La diabetes mellitus únicamente se asoció débilmente cuando en el modelo se introdujeron los valores de presión arterial y no el diagnóstico de hipertensión. Conclusiones. En este estudio poblacional en sujetos de edad avanzada, la prevalencia de FA fue del 8,5% y se asoció con fuerza con la presencia de enfermedad cardiovascular, la hipertensión, la edad y la hipertrofia ventricular izquierda (AU)

Introduction and objectives. The aims of this study were to determine the prevalence of atrial fibrillation in individuals aged 60 years or more in Spain using a random sample of the population and to identify associated factors. Methods. An analysis of the PREV-ICTUS study, a randomized cross-sectional population-based study of individuals aged 60 years or more, was carried out. Data on demographic variables, cardiovascular risk factors, and cardiovascular disease were obtained from medical records. The diagnosis of atrial fibrillation was based on the patient's medical history and an electrocardiogram performed during the study. Results. In the 7108 individuals studied (mean age 71.9 [7.1] years, 53.6% female), the prevalence of atrial fibrillation was 8.5% (95% confidence interval [CI] 7.9­9.2%). It was higher in males (9.3% vs 7.9% in females; P=.036) and increased from 4.2% in individuals aged 60­64 years to 16.5% in those aged 85 years or more (chi-squared test for linear trend, P<.001). Multivariate analysis showed that existing cardiovascular disease, hypertension, age, and left ventricular hypertrophy had the strongest associations with atrial fibrillation. Although there was a strong relationship between hypertension and atrial fibrillation (odds ratio 2.53, 95% CI, 1.60­4.01), no association was found between poor blood pressure control and atrial fibrillation. A weak association with diabetes mellitus was found only when arterial pressure was included in the model, but not when a diagnosis of hypertension was included. Conclusions. In this cross-sectional population-based study of elderly individuals, the prevalence of atrial fibrillation was 8.5%, and was strongly associated with existing cardiovascular disease, hypertension, age and left ventricular hypertrophy (AU)

Metabolic syndrome, organ damage and cardiovascular disease in treated hypertensive patients. The ERIC-HTA study.

The aim of this study is to assess the relationship among metabolic syndrome (MS), target organ damage (TOD) and established cardiovascular disease (CVD) in non-diabetic hypertensive elderly patients. ERIC-HTA is cross-sectional, multicentre study carried out in primary care, on hypertensive patients aged 55 or older. MS was defined by the NCEP-ATP III criteria, using body mass index (>28.8 kg/m(2)) instead of abdominal perimeter. In 8331 non-diabetic hypertensive patients (3663 men and 4668 women, mean age 67.7 years), the prevalence of MS was 32.6% (men: 29.0%; women: 36.8%). A linear association was observed between a greater number of components of MS and a greater prevalence of left ventricle hypertrophy (LVH) on the electrocardiogram (p<0.001), impaired kidney function (p<0.001) and established CVD (p = 0.001). In a multivariate model, MS in non-diabetic hypertensive patients was related to a greater prevalence of LVH (OR 1.31 [95% CI: 1.15-1.48]), impaired kidney function (OR 1.45 [95% CI: 1.29-1.63]) and established CVD (OR 1.22 [95% CI: 1.08-1.37]). This relationship persisted after stratifying by gender. In conclusion, in this elderly non-diabetic hypertensive population, the presence of MS was independently related to a greater prevalence of hypertensive TOD and established CVD, suggesting a role of MS as a cardiovascular risk marker in hypertension.

Differences in blood pressure control and stroke mortality across Spain: the Prevención de Riesgo de Ictus (PREV-ICTUS) study.

The objective was to assess the stroke risk and prevalence of the cardiovascular risk factors and to analyze their relationship with the specific stroke rates of mortality in each of the autonomic communities of Spain. We conducted a multicenter, cross-sectional study of population >60 years old in Spanish primary care centers. In all of the subjects, clinical, biochemical, and electrocardiographic data were obtained, and the 10-year stroke risk was calculated using the Framingham score. Mortality rates of stroke, age and sex adjusted, were obtained for each of the autonomic communities from the Ministry of Health. A total of 7343 subjects (mean age: 71.6 years, 53.4% women, 34.4% obese, and 27.1% diabetic subjects) were analyzed. A total of 73% were already diagnosed with hypertension. Among hypertensive subjects, 29.1% had blood pressure on therapeutic objective, and, of the total population, 35.7% had blood pressure under control. ECG-left ventricular hypertrophy was present in 12.9% of the subjects. The estimated stroke risk was 19.6%. Stroke mortality rates were significantly related to the estimated 10-year stroke risk (r=0.41; P<0.05) in each autonomic community. Poor hypertension control (P=-0.42; P<0.05) and prevalence of ECG-left ventricular hypertrophy (P=0.52; P<0.05) were the main factors related to the stroke mortality rates after controlling by age, sex, obesity, diabetes, and urban setting. Differences in stroke mortality throughout the autonomic communities of Spain were associated with indexes of worse blood pressure handling, low control rates, and high left-ventricular hypertrophy.

Blood pressure and estimated risk of stroke in the elderly population of Spain: the PREV-ICTUS study.

BACKGROUND AND PURPOSE: The objective of this study was to estimate the high blood pressure values and the 10-year risk of stroke in the Spanish general population aged 60 years or older using the Framingham scale. METHODS: This was a multicenter, population-based, cross-sectional study performed in Spanish primary care centers. A randomized selection of centers and recruitment population was used. We collected clinical, biochemical, and electrocardiographic data. RESULTS: We analyzed 7343 subjects (mean age, 71.6 years; standard deviation, 7.0; 53.4% females, 34.4% obese subjects, and 27.1% diabetic subjects). Electrocardiographic-left ventricle hypertrophy was present in 12.9% of the subjects, atrial fibrillation in 8.4%, and established cardiovascular disease in 28.9%; 73.0% already had hypertension diagnosed, and 12.8% showed high blood pressure without a prior diagnosis of hypertension. Among hypertensive subjects, 29.1% had high blood pressure on therapeutic objective, and of the total population 35.7% had high blood pressure under control. Those with hypertension already diagnosed showed a higher prevalence of other stroke risk factors (left ventricle hypertrophy, atrial fibrillation, diabetes, or established cardiovascular disease). The estimated 10-year stroke risk was 19.6% (standard deviation, 17.3%), and was greater in hypertensive patients (23.7%; standard deviation, 18.5) than in patients with high blood pressure without known hypertension (12.4%; standard deviation, 9.2), or in normotensive subjects (5.3%; standard deviation, 0.2; P<0.001). CONCLUSIONS: The 10-year estimated stroke risk was 19.6%, and it was greater in hypertensive patients as compared with the remainder people at any blood pressure range. The concomitant stroke risk factors are more prevalent in patients with hypertension already diagnosed, which implies an important additional estimated risk of stroke.

Estimated risk of a first stroke and conditioning factors in Spanish hypertensive women. The RIMH study.

Stroke is the leading cause of mortality in women in Spain. RIMHA is a cross-sectional multicenter study in hypertensive women aged 55 or more in primary care to estimate the 10-year risk for a first stroke. Clinical history, cardiovascular risk factors and diseases, electrocardiogram, blood samples and blood pressure (BP) were recorded. Stroke and coronary risk were estimated using the appropriate Framingham scales; 12875 patients were included (mean age 68.0+/-8.5 years, 29.1% with diabetes, 19.7% with cardiovascular disease). Electrocardiographic left ventricular hypertrophy (LVH) was present in 19.2% BP was controlled in 42.9% of non-diabetic (BP<140/90 mmHg) and 9.7% of diabetic patients (BP<130/80 mmHg). The 10-year risk (+/- SD) for a first stroke was estimated as 15.8+/-16.3%, and the coronary risk as 12.0+/-6.3. In the multivariate analysis, the most contributing factors for stroke risk estimation were age, systolic BP, LVH and atrial fibrillation. In conclusion, the 10-year estimated stroke risk for Spanish hypertensive women aged 55 years or more was higher than the estimated coronary risk, in accordance with the high rates of morbidity and mortality due to stroke among women in Spain. The most powerful risk factors were older age, poor BP control, LVH and atrial fibrillation.

[Left ventricular hypertrophy in the Spanish hypertensive population. The ERIC-HTA study]. / Hipertrofia ventricular izquierda en la población hipertensa española. Estudio ERIC-HTA.

INTRODUCTION AND OBJECTIVES: Left ventricular hypertrophy (LVH) is the earliest manifestation of cardiac damage in hypertension. Its appearance is associated with a poor cardiovascular prognosis. The objectives of this study were to determine the prevalence of electrocardiographic LVH and to assess the epidemiological characteristics of hypertensive patients receiving primary care. PATIENTS AND METHOD: A cross-sectional multicenter study of hypertensive patients aged 55 years or more was carried out in a primary care setting. Blood pressure was measured using the standard method. Cardiovascular history was determined from medical records and LVH was assessed electrocardiographically using Cornell's criteria. RESULTS: In total, 15 798 patients (mean age 68.0 years, 55.3% women, and 30.4% with diabetes mellitus) were evaluated. Of these, 3207 (20.3%) had electrocardiographic signs of LVH. The prevalence was higher in males, diabetics, smokers, and patients with high blood pressure or renal or cardiovascular disease. Compared to patients without LVH, those with the condition were older, were more often male, and were more likely to have diabetes or renal or cardiovascular disease. Multivariate analysis showed that LVH was independently associated with advanced age, male gender, diabetes, smoking, poor blood pressure control, and the presence of cardiovascular or renal disease. Blood pressure control was poorer in patients with LVH than in those without it. CONCLUSIONS: The prevalence of electrocardiographic LVH is high, with affected patients being more likely to have diabetes or renal or cardiovascular disease. Moreover, blood pressure control is poor in these patients, and more aggressive pharmacological management is needed.

Kidney function and cardiovascular disease in the hypertensive population: the ERIC-HTA study.

BACKGROUND AND OBJECTIVES: Epidemiological data on the incidence and prevalence of cardiovascular disease in chronic renal failure are scant The objective of the present study is to assess the relationship between renal function, measured by the estimated glomerular filtration rate, and the presence of early or established cardiovascular disease, in a population of hypertensives from primary care. PATIENTS AND METHODS: Cross-sectional, multicentre study carried out in primary care centres all over Spain. Hypertensive subjects, older than 55 years, were included. In all of them a structured interview including cardiovascular risk factors or disease was performed. Blood pressure was measured following a standard procedure, and serum biochemistry and an electrocardiogram were obtained. Renal function was estimated using the abbreviated MDRD (Modification of Diet in Renal Disease Study Group) equation. For each glomerular filtration rate stratum the odds ratio and 95% confidence interval (CI) of left ventricular hypertrophy or cardiovascular disease were calculated, adjusted by confounding variables. RESULTS: A total of 13 687 patients (mean age 68.1 years, women 55.4%, diabetics 30.6%, body mass index 28.6 kg/m2) were included. Of these, 26.4% had established cardiovascular diseases and 20.3% electrocardiographic left ventricular hypertrophy. The average serum creatinine was 1.01 mg/dl, creatinine clearance 70.0 ml/min, and glomerular filtration rate 74.0 ml/min per 1.73 m2. Thirty-three patients (0.24%) had glomerular filtration rate < 5 ml/min per 1.73 m2; 89 (0.65%) from 15 to 29; 3745 (27.36%) from 30 to 59; 7798 (56.97%) from 60 to 89; and 2019 (14.75%) higher than 89 ml/min per 1.73 m2. In a multiple regression analysis, after adjusting by age, sex, body mass index, diabetes, systolic and diastolic blood pressure, and smoking, a lower glomerular filtration rate was associated with a higher prevalence of left ventricular hypertrophy. Likewise, a reduction in the glomerular filtration rate was also associated with a higher prevalence of cardiovascular disease. CONCLUSIONS: In hypertensive patients from primary care, the prevalence of cardiovascular disease is inversely proportional to the level of renal function. Estimated glomerular filtration is easy to determine and complements evaluation of the hypertensive patient.

Hipertrofia ventricular izquierda en la población hipertensa española. Estudio ERIC-HTA / Left ventricular hypertrophy in the spanish hypertensive population. The ERIC-HTA study

Introducción y objetivos. El objetivo del presente estudio es evaluar la prevalencia de hipertrofia del ventrículo izquierdo (HVI) en el electrocardiograma y el perfil epidemiológico en pacientes hipertensos atendidos en atención primaria. Pacientes y método. Estudio transversal, multicéntrico, realizado en 15.798 pacientes hipertensos ≥ 55 años de centros de atención primaria. Se midió la presión arterial y se recogieron los antecedentes cardiovasculares de la historia clínica de los pacientes. La HVI se evaluó según los criterios de Cornell. Resultados. Se evaluó a 15.798 pacientes (edad media, 68,0 años; 55,3% mujeres; 30,4% diabéticos). El 20,3% presentó HVI en el electrocardiograma. La prevalencia fue mayor en varones, diabéticos, fumadores, pacientes con presión arterial no controlada y pacientes con enfermedad renal o con cualquier antecedente de enfermedad cardiovascular. Respecto a los pacientes sin HVI, los pacientes con HVI eran de edad más avanzada, había un mayor porcentaje de varones, y más prevalencia de diabetes mellitus (el 40,5 frente al 27,8%), enfermedad renal (el 34,2 frente al 26,9%) y enfermedad cardiovascular (el 52,1 frente al 20,2%). En el análisis multivariante, la HVI se asoció, de forma independiente, con una edad más avanzada, el sexo masculino, la diabetes, el tabaquismo, la ausencia de control de la presión arterial, y la presencia de enfermedad cardiovascular y renal. El porcentaje de pacientes que cumplían objetivos de control de presión arterial fue menor entre los pacientes con HVI respecto a aquellos sin HVI. Conclusiones. La prevalencia de HVI en el electrocardiograma es elevada y se asocia con una mayor prevalencia de diabetes, y enfermedad renal y cardiovascular, además de un control de la presión arterial deficiente

Introduction and objectives. Left ventricular hypertrophy (LVH) is the earliest manifestation of cardiac damage in hypertension. Its appearance is associated with a poor cardiovascular prognosis. The objectives of this study were to determine the prevalence of electrocardiographic LVH and to assess the epidemiological characteristics of hypertensive patients receiving primary care. Patients and method. A cross-sectional multicenter study of hypertensive patients aged 55 years or more was carried out in a primary care setting. Blood pressure was measured using the standard method. Cardiovascular history was determined from medical records and LVH was assessed electrocardiographically using Cornell's criteria. Results. In total, 15 798 patients (mean age 68.0 years, 55.3% women, and 30.4% with diabetes mellitus) were evaluated. Of these, 3207 (20.3%) had electrocardiographic signs of LVH. The prevalence was higher in males, diabetics, smokers, and patients with high blood pressure or renal or cardiovascular disease. Compared to patients without LVH, those with the condition were older, were more often male, and were more likely to have diabetes or renal or cardiovascular disease. Multivariate analysis showed that LVH was independently associated with advanced age, male gender, diabetes, smoking, poor blood pressure control, and the presence of cardiovascular or renal disease. Blood pressure control was poorer in patients with LVH than in those without it. Conclusions. The prevalence of electrocardiographic LVH is high, with affected patients being more likely to have diabetes or renal or cardiovascular disease. Moreover, blood pressure control is poor in these patients, and more aggressive pharmacological management is needed