RESUMEN

BACKGROUND AND OBJECTIVE: An inverse relationship has been described between blood pressure and the prognosis in heart failure (HF). The characteristics of this relationship are not well unknown. The objective of this study was to determine if this relationship is maintained in a non-selected cohort of patients with HF and if it can be modified by treatment. MATERIAL AND METHODS: Prospective study of cohorts including patients hospitalized for decompensated HF in Internal Medicine departments and followed as outpatients in a monographic consultation. Patients were classified according to their levels of systolic (SBP) and diastolic blood pressure (DBP). Clinical characteristics, all-cause mortality and readmissions after the first, third and sixth month of follow-up were analysed. RESULTS: Two hundred and twenty-one patients were included after their admission to the hospital for acute HF. Mean patient age was 79.5 years(SD 8.09); 115 patients were male. No significant differences between SBP quartiles and basal characteristics were found. Patients with lower SBP (Q1) had higher mortality rates (20%, P<.05). No significant differences between mortality/readmissions and DBP were found. However, the Kaplan-Meier analysis showed higher all-cause mortality rates for the group of patients with lower SBP and DBP (log-rank=0.011 and 0.041, respectively). The pharmacological treatment did not differ significantly between both study groups. CONCLUSION: For non-selected patients suffering HF, higher SBP upon the admission is associated with significantly lower all-cause mortality rates during follow-up. Pharmacological treatment of HF does not seem to influence this inverse relationship between SBP at admission and patient mortality.

Asunto(s)

RESUMEN

La disminución de colesterol-LDL (c-LDL) se considera meta principal del tratamiento de pacientes con riesgo cardiovascular. Sin embargo, pacientes con Enfermedad Renal Crónica (ERC) en hemodiálisis presentan c-LDL menor de 100 mg/dL, aumentos moderados de triglicéridos y baja frecuencia de colesterol-HDL por debajo de valores deseables. Esta condición se encuadra dentro del fenómeno conocido como "epidemiología inversa", en la cual la conocida asociación prevalente entre hipercolesterolemia, hipertensión arterial, obesidad y morbimortalidad por eventos cardiovasculares no se encuentra y, por el contrario se invierte la estrecha relación de estos parámetros con eventos cardiovasculares propia de los pacientes no hemodializados. Por un lado el 35% de los pacientes con ERC presentan diabetes mellitus tipo 2 y por otra parte, existen otros factores patogénicos menos conocidos como la Lipoproteína asociada a Fosfolipasa A2, la Proteína C Reactiva, los remanentes lipoproteicos, la Lp(a) y enzimas y proteínas asociadas a la HDL, como la Paraoxonasa y Apo A-I. El conjunto de factores descritos podrían reemplazar, en pacientes con ERC en hemodiálisis, al colesterol-LDL (c-LDL), típico analito que en otros pacientes actúa como factor de riesgo y/o patogénico de aterosclerosis y no sólo como marcador circulante. Una explicación plausible respecto al c-LDL disminuído es la modificación cualitativa de LDL por oxidación, glicación, carbamilación, la presencia de LDL pequeñas y densas, fenómenos inflamatorios y malnutrición.(AU)

The decrease in LDL cholesterol (LDL-C) is considered the main goal in the treatment of patients with atherosclerotic cardiovascular risk. However, patients with chronic kidney disease (CKD) on hemodialysis have LDL-C below 100 mg/dL, moderate increases in triglycerides and low frequency of HDL cholesterol values below desirable.This condition fits into the phenomenon known as "reverse epidemiology", in which the normal relationship between hypercholesterolemia, high blood pressure, obesity and cardiovascular morbidity and mortality is not found; contrarily, there is a reversal in the close relationship of these parameters with cardiovascular events typical of non-hemodialyzed patients. On the one hand, 35% of CKD patients have Type 2 diabetes mellitus and on the other hand, there are other lesser known pathogenic factors such as lipoprotein-associated phospholipase A2, C-reactive protein, remnant lipoproteins, Lp(a) and enzymes and proteins associated to HDL such as paraoxonase and Apo A-I. The set of factors described could replace, in CKD patients on hemodialysis, LDL cholesterol, a typical analyte that, in other patients, acts as a risk and/or pathogenesis factor of atherosclerosis and not only as a circulating marker. A likely explanation for decreased C-LDL cholesterol is qualitative modification of LDL as a result of oxidation, glycation, carbamylation, occurrence of small and dense LDL, inflammatory phenomena and malnutrition.(AU)

A diminuiþÒo de colesterol-LDL (c-LDL) considera-se objetivo principal do tratamento de pacientes com risco cardiovascular. Entretanto, pacientes com Doenþa Renal Cr¶nica (ERC) em hemodiálise apresentam c-LDL menor de 100 mg/dL, aumentos moderados de triglicerídeos e baixa frequÛncia de colesterol-HDL inferior aos valores desejáveis. Esta condiþÒo se enquadra dentro do fen¶meno conhecido como "epidemiologia reversa", na qual a conhecida associaþÒo prevalente entre hipercolesterolemia, hipertensÒo arterial, obesidade e morbimortalidade por eventos cardiovasculares nÒo se encontra e, pelo contrário se inverte a estreita relaþÒo destes parÔmetros com eventos cardiovasculares própria dos pacientes nÒo hemodialisados. De um lado, 35% dos pacientes com ERC apresentam Diabetes Melito tipo 2 e do outro, existem diferentes fatores patogÛnicos menos conhecidos como a Lipoproteína associada a Fosfolipase A2, a Proteína C Reativa, os remanescentes lipoproteicos, a Lp(a) e enzimas e proteínas associadas O HDL, como a Paraoxonase e Apo A-I. O conjunto de fatores descritos poderia substituir, em pacientes com ERC em hemodiálise, o colesterol-LDL (c-LDL), típico analito que em outros pacientes age como fator de risco e/ou patogÛnico de aterosclerose e nÒo só como marcador circulante. Uma explicaþÒo plausível a respeito do c-LDL diminuído é a modificaþÒo qualitativa de LDL por oxidaþÒo, glicaþÒo, carbamilaþÒo, a presenþa de LDL pequenas e densas, fen¶menos inflamatórios e malnutriþÒo.(AU)

RESUMEN

La malnutrición calórico-proteica y la inflamación suelen ser condiciones comunes y concurrentes en pacientes con hemodiálisis crónica, asociándose ambas a mal pronóstico. La hiporexia y el hipercatabolismo son características comunes y frecuentes. Se ha sugerido que la primera es secundaria a la inflamación. Si bien la evidencia no es concluyente, se ha acuñado el término síndrome complejo de malnutrición e inflamación para englobar esta situación clínica, independientemente de la causa originaria. Posibles causas de este síndrome incluyen diferentes comorbilidades, estrés oxidativo, pérdida de nutrientes a través de la diálisis, hiporexia, toxinas urémicas, elevación de citoquinas inflamatorias, sobrecarga de volumen, hiperfosfatemia, subdiálisis, entre otros. Se cree que en este síndrome la resistencia a la eritropoyetina, promueve la enfermedad aterosclerótica, disminuyendo la calidad de vida e incrementando el tiempo de internación y la mortalidad. Este síndrome origina un bajo índice de masa corporal, hipocolesterolemia, sarcopenia e hipocreatininemia, e hipohomocisteinemia, paradójicamente incrementando el riesgo cardiovascular. A este fenómeno se lo ha denominado "epidemiología reversa". Por lo tanto, y dentro de ciertos límites, la obesidad, la hipercolesterolemia, el incremento de la creatinina y de la homocisteína jugarían un rol protector, asociándose a mejor pronóstico. No existe consenso sobre cómo determinar la gravedad del síndrome complejo de malnutrición e inflamación, su abordaje y su tratamiento. En este trabajo se discuten varias herramientas diagnósticas y modalidades de tratamiento. El correcto manejo de este cuadro podría disminuir en última instancia la enfermedad cardiovascular, principal causa de óbito en esta población.

Protein-energy wasting (PEW) and inflammation are usually common and concurrent conditions in maintenance dialysis patients and associated with poor prognosis. Low appetite and hypercatabolic states are common features. In dialysis patients, the former has been suggested to be secondary to inflammation; however, the evidence is not conclusive. Hence, the term malnutrition-inflammation complex syndrome (MICS) was coined to include this clinical entity, regardless the original causes. Possible causes of MICS include comorbid illnesses, oxidative stress, nutrient loss through dialysis, hyporexia, uremic toxins, decreased clearance of inflammatory cytokines, volume overload, increased blood phosphate and dialysis-related factors. MICS is believed to be the main cause of erythropoietin hypo-responsiveness, cardiovascular atherosclerotic disease, decreased quality of life, hospitalization and increased mortality in dialysis patients. Because MICS leads to a low body mass index, hypocholesterolemia, decrease in muscle mass, hypocreatininemia and hypohomocysteinemia, a "reverse epidemiology" phenomenon of cardiovascular risk factors can occur in dialysis patients. Therefore, obesity, hypercholesterolemia, and increased blood levels of creatinine and homocysteine, within certain limits, appear to be protective and paradoxically associated with a better outcome. There is no consensus about how to determine the degree of severity of MICS or how to manage it. Several diagnostic tools and treatment modalities are discussed in this paper. The correct management of MICS may diminish the cardiovascular disease, main cause of death in this population.

Asunto(s)

RESUMEN

A obesidade em termos epidemiológicos é um fator de risco de mortalidade da população em geral. Todavia, experimentos realizados com pacientesdialisados revelam que a obesidade (índice de massa corporal elevado) pode estar associada à maior sobrevida desses pacientes. Esse fenômeno temsido conceituado como “Epidemiologia Reversa”. Em outra direção, estudos indicam que o tecido adiposo é um órgão complexo com várias outras funçõesalém do armazenamento de energia, pois, secreta um número significante de adipocinas que podem estar envolvidas em processos inflamatórios. Destaforma, o aumento de tecido adiposo pode estar associado à inflamação subclínica e/ou sistêmica nesses pacientes. Se confrontarmos os dados dos estudos sobre obesidade em pacientes renais, percebemos que ainda há muitas controvérsias a respeito da “Epidemiologia Reversa”, pois estes estudos avaliam obesidade apenas pelo IMC, o que não distingue massa magra e massa gorda. Enquanto o efeito de um aumento do IMC determinado por aumento da massa muscular poderia ser protetor, o determinado por aumento do tecido adiposo, ao contrário, poderia associar-se a um maior processo inflamatório.Assim, fica evidente com esta revisão, a necessidade de mais estudos nesta área para se ter um consenso sobre o papel deste tecido na doença renalcrônica.

Although obesity confers an increased risk of mortality in the general population, observational reports on the dialysis population have suggested that obesityis associated with improved survival. Then, the association of high body mass index (BMI) with better survival in chronic kidney disease (CKD) has beenconsidered a "risk factor paradox" or "reverse epidemiology". Adipose tissue is a complex organ with functions far beyond the mere storage of energy and secretes a number of adipokines that could be involved with inflammatory process. It has been proposed that adipose tissue may be a significant contributorto increased systemic and/or low grade inflammation. Until now, there are many controversies about the "reverse epidemiology", because the diagnosis ofobesity in uremic patients is based in a high BMI (a parameter that does not differ between muscle mass or adipose tissue). A raise in BMI due to a musclemass increase could be protective while the one determined by an increase of adipose tissue could be adverse due to the associated low gradeinflammation. In conclusion, more studies are needed in this area before reaching a consensus as to the role of adipose tissue in the chronic kidney disease.

Asunto(s)