[Primary care evaluation of the hypertensive patient management in specialized care after derivation (DERIVA-2 Study)]. / Valoración desde atención primaria del manejo del hipertenso en atención especializada (estudio DERIVA-DOS).

INTRODUCTION: To know the opinion/evaluation of the primary care physicians (PCPH) of the received information about patients that were attended in specialized care (SC). DESIGN: Cross-sectional study. LOCATION: Performed nationwide in primary care centers. PARTICIPANTS: Researchers from the primary care network. METHODS: We used the SEH-LELHA derivation criteria guidelines, plus an ad hoc survey that included demographic and anthropometric data, blood pressure levels, and the main reason for derivation to SC at the baseline and final (post-derivation) visit. In addition, time deployed for the study of every patient, changes in diagnosis and treatment, type of follow-up, issues throughout the derivation process and assessment of the medical referred to the PCPH were evaluated. RESULTS: With participation of 578 researchers from primary, the study included 1715 patients aged 60.7±13.3years, 62.7% male. Patients were taking 2.3±1.2 (range 0-10) antihypertensive drugs pre-referral and 2.5±1.2 (0-9) after derivation. Blood pressure levels changed from 166±21.6 /97.7±12.6mmHg to 143±14.4 /85.5±10.5mmHg. The number of controlled patients (BP<140 and <90mmHg) increased from 5.8% to 32.2%. Time between pre- and post-derivation visit was 72±64days (median 57days, IQ26-99). The PCPH received a medical report in 80.3% of cases, 76.9% with an explanation of the results of the complementary tests, 75.8% with additional information or a reasoning of treatment and in 71% of cases information about the patient future management. 63% of PCPH were fully agreed with the management of the specialist, 29% agree and 2% strongly disagree. The derivation was evaluated as effective or very effective in 86% of patients and no effective in 9%. CONCLUSIONS: Communication between AE and SC in HTA is valued satisfactorily by MAP. However there is still room for improvement in the process.

[Evaluation of referral process of the hypertensive patient in Spain: DERIVA study]. / Análisis del proceso de derivación del paciente hipertenso en España: Estudio DERIVA.

INTRODUCTION: An adequate communication between levels of medical attention is the key point for optimal treatment and outcomes of the hypertensive population. AIMS: The aim of this study was to evaluate the adequacy of the hypertensive patients' derivation from Primary Care to Specialized Care. As secondary objectives, the information registered on the derivation report was assessed and concordance between derivation reason and final diagnosis was analysed. DESIGN: This is an observational, descriptive, multicentre study. SITE: Study conducted at the national level. PARTICIPANTS: Specialty Care Physicians receiving hypertensive patients referred from primary care. PRINCIPAL MEASUREMENTS: On the baseline visit, the specialist physicians assessed the quality of the derivation records and attended the patient. After the study, final diagnosis and treatment is suggested on the final visit. RESULTS: 1769 subjects were included, mean aged 62,4 (13,6) years, 45% female. Time of diagnosis of hypertension was 8,0 (7,7) years. More than the half of the derivation records contained very good information (5,4%; CI4,3-6,5) or sufficient (50,7%; CI48,4-53,0). In 7,1% (IC5,9-8,3) derivation cause was not specified. 74,7% of the derivations were considered as appropriate, though 30% were late. Concordance between derivation reasons and final diagnosis was low (kappa index 0,208). CONCLUSIONS: A quarter of the hypertensive population is unnecessary derived to Secondary Care and 30% of the appropriately derived was late. We should improve the interrelation of attention in the hypertension and cardiovascular area between the both attention levels.

Are lead, cadmium and mercury risk factors for resistant hypertension?

BACKGROUND: Lead (Pb), cadmium (Cd) and mercury (Hg) are toxic trace elements that represent a public health problem as risk factors for cardiovascular disease and hypertension (HT) and could also contribute to the development of resistant hypertension (rHT) AIMS: To compare the blood concentrations of Pb, Cd and Hg in subjects with resistant and non-resistant HT and to define whether there is a relationship between its levels and rHT. METHODS: Cross-sectional study. Subjects aged ≥ 21 to ≤ 80 years with a body mass index < 40 kg/m2 were recruited on a discretionary basis from October 2001 to October 2004 in a hypertension unit of a tertiary hospital amongst those sent to the hypertension unit by their family physician. Resistant hypertension was defined according to the American Heart Association (AHA) criteria. Whole blood concentrations of Cd, Pb and Hg were measured by electrothermal atomic absorption spectrometry. RESULTS: 46 out of 73 included subjects (63%) suffered from rHT. Blood Pb median: HT 3.9 (IQR 2.7-5.2) vs. rHT 3.6 (IQR 2.8-6.0) µg/dL (p=0.941). Blood Cd median: HT 0.07 (IQR 0.07-0.80) vs. rHT 0.30 (IQR 0.07-0.65) µg/L (p=0.681). Blood Hg median: HT 7.9 (IQR 5.8-12.9) vs. rHT 7.3 (IQR 4.6-13.3) µg/L (p=0.611). Considering the 75th percentile of each element (Pb: 5.55 µg/dL, Cd: 0.75 µg/L, Hg: 13.15 µg/L), a multiple logistic regression analysis (adjusted for age, BMI, diabetes mellitus, clearance of creatinine and only for Cd the smoking habit) showed an OR = 3.44 (0.84-14.10, p=0.086) for Pb, OR = 1.80 (0.39-8.24, p=0.451), for Cd and OR = 2.31 (0.59-9.14, p=0.232) for Hg. Moreover, the stratified analyses showed that men with Pb ≥5.55 µg/dL have a 14 times higher risk of suffering from rHT (p=0.026). Interestingly, a 9-fold increased risk was found for non-obese subjects with elevated Pb levels, above 5.55 µg/dL (p=0.029). Also in men, the probability of suffering from rHT was more than 7 times higher if Cd levels were ≥ 0.75 µg/L (p=0.076). Most smokers had higher Cd levels, with a high risk of suffering from rHT (ORa 12.6 (0.8-200.2), p=0.072). CONCLUSION: A higher blood Pb levels, defined by the 75th percentile (Pb ≥ 5.55 µg/dL), is associated with a greater risk of suffering from rHT and to a lesser extent in the case of Cd and Hg.

Documento de consenso sobre tabaquismo y riesgo vascular.

Consensus statement on smoking and vascular risk About 22% of the Spanish population are daily smokers. Men are more likely to smoke than women. In Spain, women between 15-25 years of age smoke as much or more than men. Every smoker should be assessed for: physical dependence on nicotine (Fagerström test), social and psychological dependence (Glover Nilsson test), level of motivation to quit (Richmond test), probability of therapy success (Henri-Mondor and Michael-Fiore tests), and stage of behavioral change development (Prochaska and DiClementi). Advice on smoking cessation is highly cost-effective and should always be provided. Smoking is an enhancer of cardiovascular risk because it acts as a pathogen agent in the development of arteriosclerosis and is associated with ischemic heart disease, stroke, and peripheral artery disease. Smoking increases the risk of chronic lung diseases (COPD) and is related to cancers of the lung, female genitalia, larynx, oropharynx, bladder, mouth, esophagus, liver and biliary tract, and stomach, among others. Combined oral contraceptives should be avoided in women smokers older than 35 years of age due to the risk of thromboembolism. In smoking cessation, the involvement of physicians, nurses, psychologists, etc. is important, and their multidisciplinary collaboration is needed. Effective pharmacological treatments for smoking cessation are available. Combined treatments are recommended when smoker's dependence is high. For individuals who are unable to quit smoking, a strategy based on tobacco damage management with a total switch to smokeless products could be a less dangerous alternative for their health than continuing to smoke.

Consensus document for lipid profile testing and reporting in Spanish clinical laboratories.

Cardiovascular diseases (CVD) continue to be the main cause of death in our country. Adequate control of lipid metabolism disorders is a key challenge in cardiovascular prevention that is far from being achieved in real clinical practice. There is a great heterogeneity in the reports of lipid metabolism from Spanish clinical laboratories, which may contribute to its poor control. For this reason, a working group of the main scientific societies involved in the care of patients at vascular risk, has prepared this document with a consensus proposal on the determination of the basic lipid profile in cardiovascular prevention, recommendations for its realization and unification of criteria to incorporate the lipid control goals appropriate to the vascular risk of the patients in the laboratory reports.

Consensus document for lipid profile testing and reporting in Spanish clinical laboratories: What parameters should a basic lipid profile include?

Cardiovascular diseases (CVD) continue to be the main cause of death in our country. Adequate control of lipid metabolism disorders is a key challenge in cardiovascular prevention that is far from being achieved in real clinical practice. There is a great heterogeneity in the reports of lipid metabolism from Spanish clinical laboratories, which may contribute to its poor control. For this reason, a working group of the main scientific societies involved in the care of patients at vascular risk, has prepared this document with a consensus proposal on the determination of the basic lipid profile in cardiovascular prevention, recommendations for its realization and unification of criteria to incorporate the lipid control goals appropriate to the vascular risk of the patients in the laboratory reports.

Consensus document for lipid profile determination and reporting in Spanish clinical laboratories. What parameters should be included in a basic lipid profile? / Documento de consenso para la determinación e informe del perfil lipídico en laboratorios clínicos españoles: ¿Qué parámetros debe incluir un perfil lipídico básico?

Cardiovascular diseases (CVD) continue to be the main cause of death in our country. Adequate control of lipid metabolism disorders is a key challenge in cardiovascular prevention that is far from being achieved in real clinical practice. There is a great heterogeneity in the reports of lipid metabolism from Spanish clinical laboratories, which may contribute to its poor control. For this reason, a working group of the main scientific societies involved in the care of patients at vascular risk, has prepared this document with a consensus proposal on the determination of the basic lipid profile in cardiovascular prevention, recommendations for its realization and unification of criteria to incorporate the lipid control goals appropriate to the vascular risk of the patients in the laboratory reports.

Consensus document for lipid profile testing and reporting in Spanish clinical laboratories: what parameters should a basic lipid profile include?

Cardiovascular diseases (CVD) continue to be the main cause of death in our country. Adequate control of lipid metabolism disorders is a key challenge in cardiovascular prevention that is far from being achieved in real clinical practice. There is a great heterogeneity in the reports of lipid metabolism from Spanish clinical laboratories, which may contribute to its poor control. For this reason, a working group of the main scientific societies involved in the care of patients at vascular risk, has prepared this document with a consensus proposal on the determination of the basic lipid profile in cardiovascular prevention, recommendations for its realization and unification of criteria to incorporate the lipid control goals appropriate to the vascular risk of the patients in the laboratory reports.

[New therapeutic strategies to improve control of arterial hypertension and simplify the regimen of drug treatment]. / Nuevas estrategias terapéuticas para mejorar el control de la hipertensión arterial y simplificar la pauta de tratamiento farmacológico.

Hypertension is a public health problem of first magnitude, because of its high prevalence and the associated increase in cardiovascular and renal complications. For this reason, achieving adequate pressure control in a high percentage of patients is a priority for any health system. In our country there have been numerous studies examining the degree of control of hypertension. The percentage of patients achieving adequate control has increased progressively, but the margin of improvement is still very important. Among the factors that have contributed to this improved control is the use of antihypertensive drugs in combination, free or fixed. This article reviews the progress made in controlling hypertension, in which the combined use of antihypertensive drugs has played a key role and future therapeutic options to further improve the pressure control, with special attention to the fixed combination three antihypertensive drugs.

Renal denervation for the treatment of resistant hypertension in Spain. The Flex-Spyral Registry.

INTRODUCTION AND OBJECTIVES: Renal denervation is a percutaneous intervention for the treatment of resistant hypertension. Randomized studies have shown contradictory results on its efficacy. We present the results of a renal denervation registry for the treatment of resistant hypertension in real-life patients in Spain. METHODS: Multicenter registry of consecutive patients with resistant hypertension treated with renal denervation in Spain between 2009 and 2018. RESULTS: We included 125 patients (mean age, 56 years; 41% female; mean onset of hypertension 14±9 years previously). Office systolic and diastolic blood pressure and ambulatory blood pressure monitoring decreased 6 months after the intervention (166±20/95±16 to 149±22/87±16 mmHg and 151±14/89±12 to 143±15/84±11, both P <.0001). At 12 months, the blood pressure reduction was maintained and the number of antihypertensive drugs decreased from 4.9±1.2 to 4.4±1.5 (P=.0001). There were no significant procedure-related complications. The response rate to denervation at 1 year was 80%, but there were wide differences between centers. CONCLUSIONS: In patients with resistant hypertension, treatment with renal denervation was related to a decrease in office blood pressure and, more importantly, in ambulatory blood pressure monitoring, with a significant reduction in pharmacological treatment.

Effect of intensive multifactorial treatment on vascular progenitor cells in hypertensive patients.

BACKGROUND: Most hypertensive patients, despite a proper control of their cardiovascular risk factors, have cardiovascular complications, evidencing the importance of controlling and/or reversing target-organ damage. In this sense, endothelial dysfunction has been associated with the presence of cardiovascular risk factors and related cardiovascular outcomes. Since hypertension often clusters with other risk factors such as dyslipemia, diabetes and obesity, in this study we have investigated the effect of intensive multifactorial treatment on circulating vascular progenitor cell levels on high-risk hypertensive patients. DESIGN: We included108 hypertensive patients receiving intensive multifactorial pharmacologic treatment and dietary recommendations targeting blood pressure, dyslipemia, hyperglycemia and weight for 12 months. After the treatment period, blood samples were collected and circulating levels of endothelial (CD34+/KDR+, CD34+/VE-cadherin+) and smooth muscle (CD14+/endoglin+) progenitor cells were identified by flow cytometry. Additionally, plasma concentration of vascular endothelial growth factor (VEGF) was determined by ELISA. RESULTS: Most hypertensive patients (61±12 years, 47% men) showed cardiovascular parameters within normal ranges at baseline. Moreover, body mass index and the majority of the biochemical parameters (systolic and diastolic blood pressure, fasting glucose, total cholesterol, HDL-c, LDL-c, creatinine and hs-CRP) significantly decreased overtime. After 12 months of intensive treatment, CD34+/KDR+ and CD14+/endoglin+ levels did not change, but CD34+/VE-cadherin+ cells increased significantly at month 12 [0.9(0.05-0.14)% vs 0.05(0.02-0.09)% P<0.05]. However, VEGF plasma concentration decreased significantly overtime [89.1(53.9-218.7) vs [66.2(47.5-104.6) pg/mL, P<0.05]. CONCLUSIONS: Long-term intensive treatment in hypertensive patients further improves cardiovascular risk and increases circulating EPCs, suggesting that these cells could be a therapeutic target.

Documento de consenso para la determinación e informe del perfil lipídico en laboratorios clínicos españoles / Consensus document for lipid profile determination and reporting in Spanish clinical laboratories. What parameters should be included in a basic lipid profile?

Las enfermedades cardiovasculares (ECV) siguen siendo la principal causa de muerte en nuestro país. El control adecuado de las alteraciones del metabolismo lipídico es un reto clave en prevención cardiovascular que está lejos de alcanzarse en la práctica clínica real. Existe una gran heterogeneidad en los informes del metabolismo lipídico de los laboratorios clínicos españoles, lo que puede contribuir al mal control del mismo. Por ello, un grupo de trabajo de las principales sociedades científicas implicadas en la atención de los pacientes de riesgo vascular hemos elaborado este documento con una propuesta básica de consenso sobre la determinación del perfil lipídico básico en prevención cardiovascular, recomendaciones para su realización y unificación de criterios para incorporar los objetivos de control lipídico adecuados al riesgo vascular de los pacientes en los informes de laboratorio. (AU)

Cardiovascular diseases (CVD) continue to be the main cause of death in our country. Adequate control of lipid metabolism disorders is a key challenge in cardiovascular prevention that is far from being achieved in real clinical practice. There is a great heterogeneity in the reports of lipid metabolism from Spanish clinical laboratories, which may contribute to its poor control. For this reason, a working group of the main scientific societies involved in the care of patients at vascular risk, has prepared this document with a consensus proposal on the determination of the basic lipid profile in cardiovascular prevention, recommendations for its realization and unification of criteria to incorporate the lipid control goals appropriate to the vascular risk of the patients in the laboratory reports. (AU)

Documento de consenso para la determinación e informe del perfil lipídico en laboratorios clínicos españoles ¿Qué parámetros debe incluir un perfil lípido básico? / Consensus document to determine and report the lipid profile in spanish clinical laboratories. Which parameters should a basic lipid profile include?

Las enfermedades cardiovasculares (ECV) siguen siendo la principal causa de muerte en nuestro país. El control adecuado de las alteraciones del metabolismo lipídico es un reto clave en prevención cardiovascular que está lejos de alcanzarse en la práctica clínica real. Existe una gran heterogeneidad en los informes del metabolismo lipídico de los laboratorios clínicos españoles, lo que puede contribuir al mal control del mismo. Por ello, un grupo de trabajo de las principales sociedades científicas implicadas en la atención de los pacientes de riesgo vascular, hemos elaborado este documento con una propuesta básica de consenso sobre la determinación del perfil lipídico básico en prevención cardiovascular, recomendaciones para su realización y unificación de criterios para incorporar los objetivos de control lipídico adecuados al riesgo vascular de los pacientes en los informes de laboratorio.(AU)

Cardiovascular diseases (CVD) continue to be the main cause of death in Spain. Adequate control of lipid metabolism disorders is a key challenge in cardiovascular prevention that is far from achieved in real clinical practice. There is a major heterogeneity in the reports of lipid metabolism from Spanish clinical laboratories, which may contribute to its poor monitoring. For this reason, a working group of the main scientific societies involved in the care of patients at vascular risk, has drawn up this document with a consensus proposal on the determination of the basic lipid profile in cardiovascular prevention, recommendations for its implementation and combining the criteria to incorporate the lipid monitoring goals suitable for the vascular risk of the patients in the laboratory reports.(AU)

Should hypertension guidelines be changed for hypertensive patients with the metabolic syndrome?

The authors analyzed the impact of present guidelines for hypertension management on cardiovascular (CV) risk factors in hypertensive patients with and without the metabolic syndrome (MS). Results in 549 nondiabetic hypertensive patients with a mean follow-up of 3.8+/-1.2 years on usual recommended care were reviewed. At baseline, 231 (42.1%) patients had MS and, per the definition, showed significantly higher values of traditional CV risk factors than non-MS patients. At the end of follow-up, blood pressure levels were similar in both groups; the lipid profile tended to improve in MS patients. Eighteen MS patients (7.8%) and 7 non-MS patients (2.2%) developed diabetes (P<.001). Prevalence of microalbuminuria was reduced in both groups, but it remained significantly higher in MS patients. Usual care of hypertensive patients achieved similar blood pressure and low-density lipoprotein cholesterol goals, both in MS and non-MS patients. Global CV risk, however, remained higher in MS patients, as suggested by a 3-fold higher incidence of new-onset diabetes (absolute increase of 5.6%) and a 2-fold increase in microalbuminuria.

Consensus document on the prevention of methylmercury exposure in Spain: Study group for the prevention of Me-Hg exposure in Spain (GEPREM-Hg).

The beneficial effects of fish consumption in both children and adults are well known. However, the intake of methylmercury, mainly from contaminated fish and shellfish, can have adverse health effects. The study group on the prevention of exposure to methylmercury (GEPREM-Hg), made up of representatives from different Spanish scientific societies, has prepared a consensus document in a question and answer format, containing the group's main conclusions, recommendations and proposals. The objective of the document is to provide broader knowledge of factors associated with methylmercury exposure, its possible effects on health amongst the Spanish population, methods of analysis, interpretation of the results and economic costs, and to then set recommendations for fish and shellfish consumption. The group sees the merit of all initiatives aimed at reducing or prohibiting the use of mercury as well as the need to be aware of the results of contaminant analyses performed on fish and shellfish marketed in Spain. In addition, the group believes that biomonitoring systems should be set up in order to follow the evolution of methylmercury exposure in children and adults and perform studies designed to learn more about the possible health effects of concentrations found in the Spanish population, taking into account the lifestyle, eating patterns and the Mediterranean diet.

[Relevance of chronic kidney disease and cardiovascular prognosis in arterial hypertension]. / Relevancia de la insuficiencia renal en el pronóstico cardiovascular de los pacientes con hipertensión arterial esencial.

Recently published guidelines recognize the relevance of the finding of chronic kidney disease in the stratification of risk of the hypertensive patient. Determination of the presence of microalbuminuria and estimation of glomerular filtration rate are mandatory in order to ensure an adequate evaluation of global cardiovascular risks in the hypertensive patient. The presence of subtle elevations of serum creatinine concentrations and/or proteinuria are also potent predictors of a poor cardiovascular prognosis. Clustering of associated risk factors seems to justify the elevated cardiovascular risk observed in patients with essential hypertension and mild alterations of renal function.

[Methylmercury exposure in the general population; toxicokinetics; differences by gender, nutritional and genetic factors]. / Exposición al metilmercurio en la población general; toxicocinética; diferencias según el sexo, factores nutricionales y genéticos.

Mercury is an environmental toxicant that causes numerous adverse effects on human health and natural ecosystems. The factors that determine the existance of adverse effects, as well as their severity are, among others: the chemical form of mercury (elemental, inorganic, organic), dosis, age, period of exposure, pathways of exposure and environmental, nutritional and genetic factors. In the aquatic cycle of mercury, once it has been deposited, it is transformed into methylmercury due to the action of certain sulphate-reducing bacteria, which bioaccumulates in the aquatic organisms and moves into the food chain. The methylmercury content of large, long-lived fish such as swordfish, shark, tuna or marlin, is higher. Methylmercury binds to protein in fish and is therefore not eliminated by cleaning or cooking the fish. Fetuses and small children are more vulnerable to the neurotoxic effects of methylmercury from the consumption of contaminated fish. Methylmercury is absorbed in the gastrointestinal tract and crosses the blood-brain barrier and the placenta. The intake of certain dietary components such as polyunsaturated fatty acids, selenium, fiber, thiol compounds, certain phytochemicals and other nutrients can modify methylmercury bioaccesibility and its toxicity. Apart from environmental factors, genetic factors can influence mercury toxicity and explain part of the individual vulnerability.

El mercurio es un tóxico ambiental que causa numerosos efectos adversos en la salud humana y en los ecosistemas naturales. Los factores que determinan la aparición de efectos adversos y su severidad son entre otros: la forma química del mercurio (elemental, inorgánico, orgánico), la dosis, la edad, la duración de la exposición, la vía de exposición y los factores ambientales, nutricionales y genéticos. En el ciclo acuático del mercurio, una vez que se ha depositado, se transforma en metilmercurio por la acción de determinadas bacterias sulfato reductoras y se bioacumula en los organismos acuáticos incorporándose a la cadena trófica de alimentos. El contenido de metilmercurio es mayor en las especies depredadoras de mayor tamaño y que viven más años como el emperador, pez espada, tiburón, atún o marlín. El metilmercurio se halla unido a las proteínas del pescado por lo que no se elimina mediante la limpieza ni el cocinado del mismo. El feto en desarrollo y los niños pequeños son los más vulnerables a los efectos neurotóxicos del metilmercurio procedente de la ingesta de pescado contaminado. El metilmercurio se absorbe en el tracto gastrointestinal y atraviesa la barrera hematoencefálica y la placenta. Algunos componentes de la dieta como los ácidos grasos poliinsaturados, el selenio, la fibra, los compuestos tiol, algunos fitoquímicos y otros nutrientes pueden modificar la bioaccesibilidad del mercurio y su toxicidad. Además de los factores ambientales, los factores genéticos pueden influir en la toxicidad del mercurio y explicar parte de la vulnerabilidad individual.

[The effects of methylmercury on health in children and adults; national and international studies]. / Efectos sobre la salud del metilmercurio en niños y adultos; estudios nacionales e internacionales.

The benefit of fish consumption in children and adults is well-known. However, it has been pointed out that excessive methylmercury intake due to consumption of contaminated fish leads to neurological toxicity in children, affecting cognitive function, memory, visual-motor function and language. After the intoxications in Minamata and Iraq, wide-ranging epidemiological studies were carried out in New Zealand, the Faroe Islands and the Seychelles and international recommendations were established for fish consumption in pregnant women and small children. In Spain, the Childhood and Environmental project (INMA, its Spanish acronym) has studied the effects of diet and the environment on fetal and childhood development in different geographic areas of Spain. National and international sudies have demonstrated that mercury concentrations are mainly dependent on fish consumption, although there are variations among countries which can be explained not only by the levels of fish consumption, but also by the type or species of fish that is consumed, as well as other factors. Although the best documented adverse effects of methylmercury are the effects on nervous sytem development in fetuses and newborns, an increasing number of studies indicate that cognitive function, reproduction and, especially, cardiovascular risk in the adult population can also be affected. However, more studies are necessary in order to confirm this and establish the existance of a causal relationship.

Los efectos beneficiosos del consumo de pescado tanto en niños como en adultos han sido bien reconocidos. Sin embargo, se ha referido que la ingesta excesiva de metilmercurio procedente del pescado contaminado produce toxicidad neurológica en los niños afectando a la función cognitiva, la memoria, la función visual-motora y al lenguaje. Después de las intoxicaciones de Minamata e Iraq, se realizaron grandes estudios epidemiológicos en Nueva Zelanda, las islas Féroe y las islas Seychelles y se establecieron recomendaciones internacionales sobre el consumo de pescado y marisco en las mujeres embarazadas y niños pequeños. En España, el proyecto Infancia y Medio Ambiente (INMA) ha estudiado los efectos del medio ambiente y de la dieta sobre el desarrollo fetal e infantil en diversas zonas geográficas de España. Los estudios realizados nacionales e internacionales muestran que la concentración de mercurio depende principalmente del consumo de pescado, aunque existe una variabilidad entre los países que podría explicarse no solo por la cantidad de pescado consumida, sino también por el tipo o especies de pescados que se consumen, así como por otro tipo de factores. Aunque los efectos perjudiciales del metilmercurio mejor documentados son los que se producen sobre el desarrollo del sistema nervioso en el feto y en el recién nacido, cada vez hay más estudios que indican que también puede afectar a la función cognitiva, reproducción y especialmente al riesgo cardiovascular en la población adulta. Sin embargo, son necesarios más estudios para confirmarlo y establecer la existencia de una relación causal.

[Methylmercury: existing recommendations; methods of analysing and interpreting the results; economic evaluation]. / Metilmercurio: recomendaciones existentes; métodos de análisis e interpretación de resultados; evaluación económica.

The beneficial effects of fish consumption are well- known. Nevertheless, there is worldwide concern regard methylmercury concentrations in fish, which is why many countries such as the United States, Australia, New Zealand, Canada and numerous European countries have made fish consumption recommendations for their populations, particularly vulnerable groups, in order to México methylmercury intake. Blood and hair are the best biological samples for measuring methylmercury. The most widely-used method to analyse methylmercury is cold vapor atomic absorption spectrometry, although there are also direct methods based on the thermal decomposition of the sample. In recent years, the number of laboratories that measure mercury by inductively coupled plasma mass spectrometry has increased. In addition, the different kinds of mercury can be distinguished by coupling chromatography methods of separation. Laboratories that analyse mercury in biological samples need to participate in external quality control programmes. Even if mercury emissions are reduced, mercury may remain in the environment for many years, so dietary recommendations are fundamental in order to reduce exposure. It is necessary to propose public health measures aimed at decreasing mercury exposure and to evaluate the benefits of such measures from the economic and social standpoints.

Los efectos beneficiosos del consumo de pescado son bien reconocidos. Sin embargo, existe preocupación a nivel mundial sobre los niveles de metilmercurio en el pescado, por lo que muchos países como Estados Unidos, Australia, Nueza Zelanda, Canadá y muchos países europeos han realizado recomendaciones de consumo de pescado a la población , especialmente a los grupos vulnerables con el fin de reducir la ingesta de metilmercurio. La sangre y el pelo son las mejores muestras biológicas para medir el metilmercurio. El método de análisis más empleado ha sido la espectroscopia de absorción atómica con la técnica del vapor frío, aunque existen también métodos directos que se basan en la descomposición térmica de la muestra. En los últimos años han aumentado los laboratorios que miden el mercurio por espectrometría de masas con plasma acoplado por inducción. Además, se puede diferenciar las distintas especies de mercurio acoplando métodos de separación cromatográficos. Es necesario que los laboratorios que analizan mercurio en muestras biológicas participen en programas de garantía externa de la calidad. Aunque se logre reducir las emisiones de mercurio, el mercurio del medio ambiente todavía puede permanecer muchos años, por lo que es fundamental el consejo dietético para disminuir la exposición. No es aconsejable el uso de terapia quelante con fines diagnósticos o en pacientes asintomáticos. Es preciso proponer medidas de salud pública encaminadas a la disminución de la exposición al mercurio y que se evalúe también los beneficios de las mismas desde el punto de vista económico y social.