Marine debris on a tropical coastline: Abundance, predominant sources and fate in a region with multiple activities (Fortaleza, Ceará, northeastern Brazil).

The aim of the present study was to perform the first assessment of the abundance and classification of marine debris as well as determine the sources, transport and fate of this debris on an urbanized coast with multiple human activities. More than 80% of the marine debris was composed of synthetic materials. The beached marine debris was classified according to size. Meso-debris accounted for the highest portion of contamination (55%), followed by macro-debris (25.1%) and small debris (19.9%). Contamination by debris, such as cotton swabs (31%) and lollipop sticks (36.8%) accounted for the largest portion of the small debris class. Human recreational activities were the predominant source of debris, followed by navigation/fishing activities, domestic activities and industrial/port activities. The assessment of the predominance of human activities and the results of the model revealed a larger contribution of debris from recreational activities on nearby beaches on the small to larger scale and that rivers exert less of an influence due to the fact that they do not flow the entire year.

The Suspended Sediment and Metals Load from the Mariana's Tailing Dam Failure to the Coastal Sea.

We present an assessment on the sediment flux caused by the tailing dam failure at Mariana, Minas Gerais Estate, Brazil. Field data of water level, water flow, and suspended sediment concentrations (SSCs) were obtained during the period from 21 November to 5 December 2015, when the muddy waters reached the coast. A rating curve of the coastal tidal signal was built, allowing a robust estimate of the flow at the mouth of the Doce River. Together with SSC data, early sediment delivered to the coastal sea was of 15 × 104 t, what may account for only 0.5% of the total material remobilized at the accident site. This accounted for >25 000 t of Fe and between 1 and 4 t of other trace metals, such as Co, Ni, and Zn. Integr Environ Assess Manag 2020;16:661-668. © 2020 SETAC.

É apresentada uma avaliação do fluxo de sedimentos causado pela ruptura da represa de resíduos em Mariana, MG. Dados de campo de nível da água, fluxo e concentração de sedimentos em suspensão (CSS) foram obtidos durante o período de 21-Novembro até 5-Dezezembro, 2015, quando as águas barrentas chegaram na costa. Uma curva chave de descarga resolvendo o nível da maré costeira foi elaborada permitindo uma estimativa robusta da descarga fluvial na desembocadura do Rio Doce. Com valores de descarga e CSS, obtivemos que a exportação inicial de sedimentos para a costa foi de 15 × 104 ton, o que contabiliza por somente 0,5% do total de material remobilizado no local do acidente. Isto contabiliza >25,000 tons de Fe e entre 1 e 4 toneladas de outros metais traço, tais como Co, Ni e Zn. Integr Environ Assess Manag 2020;16:661-668.

Use of Tisbe biminiensis nauplii in ecotoxicological tests and geochemical analyses to assess the sediment quality of a tropical urban estuary in northeastern Brazil.

An approach pooling geochemical analyses and ecotoxicological tests has been applied to assess the sediment quality of the Capibaribe River Estuary, Brazil. Toxicity tests were performed to compare a well-established, labor-intensive protocol using ovigerous females to a new, easier and faster protocol using nauplii of the epibenthic marine copepod Tisbe biminiensis. The endpoints of the nauplii toxicity test were comparable to those of the female test. Nauplii proved to be more sensitive than females as a biological model for indicating sediment toxicity. All sediments collected had at least one contaminant above the threshold effects level (TEL) proposed in the literature. Furthermore, more than one-third of samples exhibited contaminants above the probable effects level (PEL). The PCA revealed that nauplii mortality was associated with metals in October 2014, which was confirmed by the Spearman correlation factor. In contrast, no strong association among contaminants and toxicological endpoints in May 2015 was found.

Sources and distribution of aromatic hydrocarbons in a tropical marine protected area estuary under influence of sugarcane cultivation.

Goiana estuary is a well preserved marine protected area (MPA) located on the northeastern coast of Brazil. Despite its current state, human activities in the watershed represent a potential threat to long term local preservation. Dissolved/dispersed aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were investigated in water and sediments across the estuarine salt gradient. Concentration of aromatic hydrocarbons was low in all samples. According to results, aromatic hydrocarbons are associated to suspended particulate matter (SPM) carried to the estuary by river waters. An estuarine turbidity maximum (ETM) was identified in the upper estuary, indicating that both sediments and contaminants are trapped prior to an occasional export to the adjacent sea. PAHs distribution in sediments were associated with organic matter and mud content. Diagnostic ratios indicated pyrolytic processes as the main local source of PAHs that are probably associated with sugarcane burning and combustion engines. Low PAH concentrations probably do not cause adverse biological effects to the local biota although their presence indicate anthropogenic contamination and pressure on the Goiana estuary MPA.

Determination of geochemical background values on a tropical estuarine system in a densely urban area. Case study: Capibaribe estuary, Northeastern Brazil.

This study aims to infer the background values of several metals in the Capibaribe estuary and to identify the likely impact of anthropic activities during 200-years of sedimentation. Two cores were sampled, with subsamples at intervals of 2cm. Sedimentation rates and metal concentrations were analyzed. The Al-normalized method was used to infer the background values, and to identify anthropic influences, the enrichment factor, the contamination factor and the geoaccumulation index were employed. The background values showed concentrations for Mn of 292.2, for Co of 10.4, for Ni of 22.3, for Cu of 60.8, for Zn of 105.5, for As of 106.0, for Pb of 52.9 (all in mgkg-1) and for Fe of 2.7%, The higher values, mainly for As, Zn and Pb, are associated with the influence of the Barreiras Formation. The geogenic inputs are significantly greater than the anthropic activities, masking the contamination.

The environmental impacts of one of the largest tailing dam failures worldwide.

The impacts of the SAMARCO iron tailing spill along more than 650 km, between the dam and the plume of the Doce River in the Atlantic, were assessed by the determination of toxic metals. The tailing spill caused a substantial increase in suspended sediment loads (up to 33,000 mg L-1), in addition to large depositions of waste along the Doce basin. The highest estimated transport of dissolved metals was observed for Fe (58.8 µg s-1), Ba (37.9 µg s-1) and Al (25.0 µg s-1). Sediments reached the highest enrichment factors (EFs) for Hg (4,234), Co (133), Fe (43), and Ni (16), whereas As (55), Ba (64), Cr (16), Cu (17), Mn (41), Pb (38) and Zn (82) highest EFs were observed for suspended particulate matter (SPM). Iron, As, Hg, Mn exceeded sediment quality guidelines. Therefore, the risk of occurrence of adverse effects is highly possible, not only due to the dam failure, but also due to the Fe mining and the artisan Au mining. Heavy rain episodes will likely cause enhanced erosion, remobilization, and transport of contaminated particles, sustaining high inputs of SPM and metals for the years to come and threatening the ecosystem services.

Hydrocarbons in sediments along a tropical estuary-shelf transition area: Sources and spatial distribution.

Estuaries generally act as sediment traps and may retain a range of contaminants associated to this matrix. Aliphatic hydrocarbons (AHs) were investigated in Capibaribe Estuarine System and adjacent shelf, Northeast of Brazil, to evaluate the contamination and to better understand its functionality related to the coast. Fourteen sediment samples were analyzed, using gas chromatography with flame ionization detection. Total AHs concentrations ranged from 7.5 to 190.3µgg-1 and n-alkanes ranged from below detection limit (

Tidal and sub-tidal sea level variability at the northern shelf of the Brazilian Northeast Region.

A characterization of the sea level variability at tidal and sub-tidal frequencies at the northern shore of the Brazilian Northeast shelf for the period 2009-2011 is presented. The sea level data used was obtained from the Permanent Geodetic Tide Network from the Brazilian Institute of Geography and Statistics for the Fortaleza gauge station. Local wind data was also used to assess its effects on the low-frequency sea level variability. The variability of the sea level was investigated by classical harmonic analysis and by morphology assessment over the tidal signal. The low frequencies were obtained by low-pass filtering. The tidal range oscillated with the highest value of 3.3 m during the equinox and the lowest value of 0.7 m during the solstice. Differences between the spring and neap tides were as high as 1 m. A total of 59 tidal constituents were obtained from harmonic analysis, and the regional tide was classified as semi-diurnal pure with a form number of 0.11. An assessment of the monthly variability of the main tidal constituents (M2, S2, N2, O1, and K1) indicated that the main semi-diurnal solar S2 presented the highest variability, ranging from 0.21 to 0.41 m; it was the main element altering the form number through the years. The low frequency sea-level variability is negligible, although there is a persistent signal with an energy peak in the 10-15 day period, and it cannot be explained by the effects of local winds.

Circulation and suspended sediment dynamics in a tropical estuary under different morphological setting.

Estuarine processes are directly related to the interaction of its forcing conditions with the local morphology. In this study we assess the implications of the opening of a new inlet on the hydrodynamics and suspended sediment concentration (SSC). A set of physical parameters have been measured in the Itanhém river estuary, a small, shallow and mangrove fringed tropical estuary in Northeastern Brazil. Field surveys have been conducted in August 2007 and January 2008, separated by an important morphological change. Our observations show that even shortening the lower estuary channel in 2 km, the inlet opening did not imply in changes in the estuarine circulation. However, SSC increased after the inlet opening. General estuarine circulation showed synodical modulation of tidal asymmetry and residual suspended sediment transport. The estuary showed flood dominance at spring tide and ebb dominance at neap tide. Although not directly changing the estuarine hydrodynamics, the morphological change resulted in an important increase in SSC. This increase might be related to a facilitated import of inner shelf sediment through a shorter channel, having important implications for the estuarine sedimentation processes.

Spatial changes in the water quality of Itajaí-Açú Fluvial-Estuarine System, Santa Catarina, Brazil.

This study was carried out with the aim of evaluating the spatial variation of the water quality in the Itajaí-Açú River estuary. Seven stations along the estuary were monitored on a weekly basis, from October 2003 to December 2004, plus two stations in tributaries (Itajaí-Mirim River, the main tributary, and one reference station). This monitoring included measurements of salinity, pH, dissolved oxygen, temperature, nutrients(NH+4,NO3-2,NO-3,PO3-4,H4SiO4) Biochemical Oxygen Demand (BOD), total phosphorous and dissolved organic phosphorus (TP and DOP), particulate organic carbon (POC), suspended particulate matter (SPM) and chlorophyll-a (Cla). Multivariate analyses demonstrated the compartmentalization of the system based on the deterioration in water quality and marine influence. Urban development was the main factor responsible for the spatial variation of the monitored variables, resulting in increases in the indicators for organic matter and a progressive decrease in O2. Despite the effect of dilution by marine influence, there was an increase in ammonium, attributed to the influence of the municipal districts of Itajaí and Navegantes, close to the river mouth.

Spatial changes in the water quality of Itajaí-Açú Fluvial-Estuarine System, Santa Catarina, Brazil

This study was carried out with the aim of evaluating the spatial variation of the water quality in the Itajaí-Açú River estuary. Seven stations along the estuary were monitored on a weekly basis, from October 2003 to December 2004, plus two stations in tributaries (Itajaí-Mirim River, the main tributary, and one reference station). This monitoring included measurements of salinity, pH, dissolved oxygen, temperature, nutrients(NH+4,NO3-2,NO-3,PO3-4,H4SiO4) Biochemical Oxygen Demand (BOD), total phosphorous and dissolved organic phosphorus (TP and DOP), particulate organic carbon (POC), suspended particulate matter (SPM) and chlorophyll-a (Cla). Multivariate analyses demonstrated the compartmentalization of the system based on the deterioration in water quality and marine influence. Urban development was the main factor responsible for the spatial variation of the monitored variables, resulting in increases in the indicators for organic matter and a progressive decrease in O2. Despite the effect of dilution by marine influence, there was an increase in ammonium, attributed to the influence of the municipal districts of Itajaí and Navegantes, close to the river mouth.

Esse estudo foi realizado com o intuito de avaliar a variação espacial da qualidade de água no Estuário do Rio Itajaí-Açú. Sete estações ao longo do estuário foram monitoradas semanalmente, de outubro de 2003 a dezembro de 2004, além de duas outras estações em tributários (o Rio Itajaí-Mirim, principal tributário e uma estação de referência). Esse monitoramento incluiu medidas de salinidade, pH, oxigênio dissolvido, temperatura, nutrientes (NH+4,NO3-2,NO-3,PO3-4,H4SiO4), demanda bioquímica de oxigênio (DBO), fósforo total e fósforo orgânico dissolvido (PT e POD), carbono orgânico particulado (COP), material particulado em suspensão (MPS) e clorofila-a. Análises multivariadas demonstraram a compartimentação do sistema em função da deterioração da influência marinha e da qualidade da água. A ocupação urbana foi o principal fator responsável pela variação especial das variáveis monitoradas, resultando em aumentos dos indicadores de matéria orgânica e uma progressiva diminuição no oxigênio dissolvido. Próximo à desembocadura do estuário, mesmo com o efeito de diluição provocado pela intrusão da água marinha, foi observado aumento nas concentrações de amônio, atribuído à influência de municípios de Itajaí e Navegantes.

Predicción de eventos coronarios a nueve años mediante el score de Framingham en Uruguay / Prediction of coronary events nine years using the Framingham score in Uruguay

Fundamento: el score de Framingham permite estimar el riesgo de cardiopatía isquémica a diez años a partir de la edad, sexo, niveles de colesterol, presión arterial, y presencia o no de diabetes y tabaquismo. El presente estudio tiene como finalidad evaluar la capacidad predictiva de ese score en nuestro país. Metodología: entre 1995 y 1998 se seleccionó al azar una muestra de asociados con características similares a las de los participantes del estudio de Framingham. Se calculó su riesgo cardiovascular mediante el score y se pesquisó el desarrollo de cardiopatía isquémica hasta 2007. Se analizó la capacidad de discriminación del score mediante el cálculo del área bajo la curva ROC y su calibración mediante la prueba de Hosmer-Lemeshow. Resultados: entre los 1.110 participantes, el riesgo cardiovascular promedio estimado fue 12,4% en hombres y 6,3% en mujeres. La incidencia de cardiopatía isquémica a los nueve años fue 12,1% en hombres y 3,3% en mujeres. La discriminación del score fue 0,76 (IC 95% 0,69 a 0,83) en hombres y 0,63 (IC 95% 0,56 a 0,78) en mujeres y su calibración fue 6,82; p=0,56 en los hombres y 5,09; p=0,64 en las mujeres. Conclusiones: el score de riesgo de Framingham es adecuado para discriminar el riesgo de cardiopatía isquémica en los hombres, pero no en las mujeres de nuestro país. La calibración del mismo, ajustándolo de acuerdo a la prevalencia de factores de riesgo y la incidencia de eventos observada de nuestro medio, podría mejorar su capacidad de predicción.

Predicción de eventos coronarios a nueve años mediante el score de Framingham en Uruguay / Prediction of coronary events nine years using the Framingham score in Uruguay

Fundamento: el score de Framingham permite estimar el riesgo de cardiopatía isquémica a diez años a partir de la edad, sexo, niveles de colesterol, presión arterial, y presencia o no de diabetes y tabaquismo. El presente estudio tiene como finalidad evaluar la capacidad predictiva de ese score en nuestro país. Metodología: entre 1995 y 1998 se seleccionó al azar una muestra de asociados con características similares a las de los participantes del estudio de Framingham. Se calculó su riesgo cardiovascular mediante el score y se pesquisó el desarrollo de cardiopatía isquémica hasta 2007. Se analizó la capacidad de discriminación del score mediante el cálculo del área bajo la curva ROC y su calibración mediante la prueba de Hosmer-Lemeshow. Resultados: entre los 1.110 participantes, el riesgo cardiovascular promedio estimado fue 12,4% en hombres y 6,3% en mujeres. La incidencia de cardiopatía isquémica a los nueve años fue 12,1% en hombres y 3,3% en mujeres. La discriminación del score fue 0,76 (IC 95% 0,69 a 0,83) en hombres y 0,63 (IC 95% 0,56 a 0,78) en mujeres y su calibración fue 6,82; p=0,56 en los hombres y 5,09; p=0,64 en las mujeres. Conclusiones: el score de riesgo de Framingham es adecuado para discriminar el riesgo de cardiopatía isquémica en los hombres, pero no en las mujeres de nuestro país. La calibración del mismo, ajustándolo de acuerdo a la prevalencia de factores de riesgo y la incidencia de eventos observada de nuestro medio, podría mejorar su capacidad de predicción.

Background: Framingham risk score allows to estimate the 10 years risk of ischemic heart disease taking into account age, gender, cholesterol and blood pressure levels, and diabetes and smoking presence or not. This study was performed to evaluate the predictive capacity of that score in our country. Methods: between 1995 and 1998 an associate’s random sample with similar characteristics to Framingham study participants was selected. Its cardiovascular risk was estimated with the Framingham score and the development of coronary heart disease was investigated until 2007. The scores discrimination capacity was analyzed with the area under the ROC curve and its calibration with the Hosmer-Lemeshow test. Results: among 1.110 participants, average cardiovascular risk was estimated in 12,4% for men and 6,3% for women. At 9 years, coronary heart disease occurs in 12,1% of men and 3,3% in women. The score discrimination was 0,76 (95% CI 0,69 to 0,83) in men and 0,63 (95% CI 0,56 to 0,78) in women, and its calibration was 6.82, p=0.56 in men and 5,09, p=0,64 in women. Conclusions: the Framingham risk score is adequate to discriminate the risk of coronary heart disease risk among men, but it is not adequate to do it in the women of our country. Its calibration taking into account local prevalence of risk factors and events incidence could improve its predictive capacity.

Menos uso de fármacos antihipertensivos en hipertensos con cifras menores de presión arterial

RESUMEN Fundamento: la hipertensión arterial (HTA) es el factor de riesgo más frecuente de mortalidad y morbilidad cardiovascular y presenta un pobre grado de control. Ante la percepción de que el tratamiento de los hipertensos podría relacionarse a las cifras halladas de presión arterial (PA), evaluamos el grado de tratamiento antihipertensivo en función de las cifras medidas de PA. Método: se dividió a los 700 hipertensos con PA ³ 140/90 mmHg del relevamiento epidemiológico de HTA en tres grupos de acuerdo a la PA sistólica (140-149 mmHg, 150-159 mmHg y ³ 160 mmHg), y en tres grupos de acuerdo a la PA diastólica (90-94 mmHg, 95-99 mmHg y ³ 100 mmHg). Se analizó el tratamiento antihipertensivo recibido en cada uno de estos seis grupos y en función de que el médico hubiera tomado la PA en la última consulta o no diabéticos o no, coronarios o no y mayores o menores de 65 años. Resultados: 45,8% de los hipertensos analizados recibía tratamiento antihipertensivo, cifra que subió a 65,3% en los pacientes con enfermedad coronaria. El 54,1% de los pacientes con PA sistólica ³ 160 mmHg recibía antihipertensivos, lo que disminuyó a 34,7% en el grupo de PA sistólica 150-159 mmHg y bajó a 27,1% en el grupo de PA sistólica 140-149 mmHg (p<0,00001). No hubo diferencia estadísticamente significativa en el tratamiento en relación con las cifras de PA diastólica. Conclusiones: comprobamos que en la práctica asistencial existe subtratamiento de la HTA en todos los rangos de PA sistólica y de PA diastólica, siendo menor el porcentaje de hipertensos tratados cuando menores son las cifras de PA sistólica, a pesar de que este grupo constituye dos tercios del total de los hipertensos analizados. Los pacientes con enfermedad coronaria están tratados en mayor porcentaje, al igual que a los que el médico les midió la PA en la última consulta, pero también en estos dos grupos de hipertensos se observa mayor subtratamiento ante cifras más bajas de PA sistólica. En necesario vencer la inercia clínica mediante educación médica continua, auditorías y otras estrategias de gestión para aumentar el porcentaje de pacientes hipertensos tratados y así reducir la pesada carga que esta enfermedad impone a nuestra sociedad.

SUMMARY Background: elevated blood pressure (BP) is the most prevalent cardiovascular mortality and morbidity risk factor and it is poorly controlled. We evaluated the degree of antihypertensive treatment in relation to level of elevated BP because we presumed that the antihypertensive therapy could be related to that fact. Methods: the 700 hypertensive of our hypertension survey with BP ³ 140/90 mmHg were divided in three groups according to systolic BP (140-149 mmHg, 150-159 mmHg and ³160 mmHg), and in three groups according to diastolic BP (90-94 mmHg, 95-99 mmHg and ³100 mmHg). The antihypertensive treatment in each one of these six groups was analyzed, and also in several groups: BP measured in the last consultation or not, and diabetic or not, coronary heart disease or not and older or younger than 65 years. Results: 45,8% of the analyzed hypertensive was under antihypertensive treatment, numbers that raised 65,3% in the patients with cardiovascular disease. 54,1% of the patients with SBP ³160 mmHg were receiving antihypertensive, figures that drops to 34,7% in the group of 150-159 mmHg SBP and lowered to 27,1% in the group of 140-149 mmHg SBP (p <0,00001). There was no statistically significant difference in the treatment in relation to the numbers of DBP. Conclusions: we verify that in the practice hypertensive therapy in underused in all ranges of SBP and DBP, being minor the percentage of treated hypertensive at lowers values of SBP, although this group constitutes 2/3 of all analyzed hypertensive. Higher percentage of therapy was observed in patients with coronary heart disease and in patients that the doctor had measured the BP in the last consultation. But also in these two groups of hypertensive antihypertensive therapy was underused with lower values of SBP. It is necessary to overcome the clinical inertia by continuing medical education, audits and other management strategies to increase the percentage of hypertensive treated and this way to reduce the load that this illness imposes our society.

Prevalencia del síndrome metabólico en una población adulta

RESUMEN Objetivo: determinar la prevalencia de síndrome metabólico en la población adulta y su asociación con variables de estilo de vida potencialmente modificables. Métodos: se estimó la prevalencia de síndrome metabólico de acuerdo a la definición del Programa Nacional de Educación en Colesterol (ATP III) de Estados Unidos, entre 1.411 participantes del estudio epidemiológico que se desarrolla desde 1995 en una muestra representativa de los asociados adultos de la institución. Se realizó ajuste por edad y por sexo de acuerdo a la composición de la población uruguaya. Resultados: la prevalencia no ajustada de síndrome metabólico fue 27,7% y la prevalencia ajustada fue 19,7%. En hombres la prevalencia ajustada fue 23,1% y en mujeres 18,1%. La obesidad o el sobrepeso estuvieron presentes en 93% de los portadores de síndrome metabólico. El 75% de quienes presentan la entidad no realizan actividad física regular. La prevalencia de acuerdo al nivel educativo fue 35,9%, 30,6% y 17,9% (p<0,0001) entre quienes tenían <=6 años, 6 a 12 y >12 años de estudio. La prevalencia entre individuos activos fue 25,2%, siendo de 32,3% y de 30,0% en jubilados y en desocupados (p =0,02). Conclusiones: el síndrome metabólico tiene alta prevalencia en la población estudiada, la que es particularmente elevada en los hombres. El sedentarismo, el sobrepeso y la obesidad son altamente prevalentes entre los portadores de esta entidad. Es necesario identificar a los pacientes con síndrome metabólico y optimizar su estilo de vida para prevenir el desarrollo de enfermedad coronaria. Las estrategias para promover el cambio de estilo de vida deben poner especial énfasis en los grupos de mayor prevalencia.

SUMMARY Objective: to determine prevalence of the metabolic syndrome in an adult population and its association with varying lifestyles. Methods: prevalence of the metabolic syndrome was estimated following the National Cholesterol Education Program (ATP III), United States, among 1 411 adult users of a health-center since 1995. Age and sexe adjustments were done according to the Uruguayan population. Results: unadjusted prevalence of the metabolic syndrome was 27,7% and adjusted prevalence was 19,7%. Adjusted prevalence among men was 23,1%, among women, 18,1%. Obesity and overweight were seen in 93% of the metabolic syndrome carriers. Regular physical activity was practiced by 25%. Prevalence according to educational level was 35,9%, 30,6% y 17,9% (p<0,0001) among those with 6 years, 6 to 12 and >12 years of education. Prevalence among active adults was 25,2%, while among retired and unemployed people, 32,3% and 30,0% respectively (p=0,02). Conclusions: prevalence of the metabolic syndrome was high among the studied population, particularly among men. Sedentarism, overweight and obesity are particularly prevalent among metabolic syndrome carriers. Carriers of metabolic syndrome should be identify in order to optimize their lifestyles and consequently to prevent coronary disease.

Nifedipina de liberación sostenida & atenolol: correlación entre niveles plasmáticos y eficacia clínica / Sustained release nifedipine & atenolol: correlation between plasma levels and clinical efficacy

La combinación de antagonistas de los canales lentos del calcio y agentes de bloqueo betaadrenérgico presentan una serie de ventajas para el tratamiento de la hipertensión.Existen, sin embargo, algunos inconvenientes farmacocinéticos de los componentes que han sido estudiados ampliamente en voluntarios sanos, pero no en pacientes hipertensos.Para dilucidar este punto se ha diseñado el presente estudio.Se estudiaron 26 pacientes hipertensos durante 3 meses a los cuales se les administró la combinación: atenolol 50 mg (ATL) más nifedipina de liberación sostenida 20 mg (NLS).Se realizó el seguimiento clínico, de laboratorio y de niveles plasmáticos de los fármacos.Se correlacionaron estos niveles con diferentes parámetros clínicos y metabólicos.La combinación fija de ATL+NLS presentó una eficacia similar a la ya comunicada por diversos autores y niveles plasmáticos al estado de equilibrio que permiten un adecuado control recíproco de los efectos colaterales cardiovasculares.La falta de efecto sobre los lípidos de la sangre es un elemento favorable, a confirmar, de esta combinación