Efeitos da suplementação de magnésio sobre a pressão arterial, cationtes intracelulares, resistência à insulina em pacientes hipertensos em uso de hidroclorotiazída

• Ano de defesa: 2009
• Autor(a) principal: Maluly, Valter Gabriel
• Orientador(a): Sanjuliani, Antonio Felipe
• Banca de defesa: Francischetti, Emílio Antonio , Abreu, Virgínia Genelhu de , Soares, Eliane de Abreu
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Fisiopatologia Clínica e Experimental
• Departamento: Centro Biomédico::Faculdade de Ciências Médicas
• País: BR
• Palavras-chave em Português: Hipertensão; Magnésio; Sódio; Diuréticos
• Palavras-chave em Inglês: Hypertension; Magnesium; Sodium; Diuretics
• Área do conhecimento CNPq: CNPQ::CIENCIAS DA SAUDE
• Link de acesso: http://www.bdtd.uerj.br/handle/1/12796

Context: there are many scientific evidences that magnesium plays a very important role in the physiologic regulation of the blood pressure and glucose metabolism. The alterations of the intracellular homeostasis of this cation, could participate in a very important way in the physiopathologic mechanisms that contribute to the development of arterial hypertension and insulin resistance. Magnesium can influence the blood pressure by modulating the tonus and vascular structure and many effects in biochemical reactions that can control the vascular contractility, the inflammation and the insulin sensibility. Many trials aim that a long term use of diuretic in the treatment of hypertension can induce a depletion of intracellular magnesium. Objectives: to evaluate the effect of oral supplementation of magnesium in hypertension, the intra-erythrocyte concentration of magnesium and sodium and the insulin resistance in primary hypertensive patients treated with thiazidic diuretic. Study design: a randomized, double blind clinical trial was performed. Thirty nine primary hypertensive patients in first stage were distributed in two groups. One group received 20 patients and the other 19. After a period of wash out of two weeks one group received thiazidic diuretic (25mg) and magnesium (240mg of element magnesium) and the other group received thiazidic diuretic (25mg) and placebo during 16 weeks. The patients were evaluated once a month. In the visit 1 (after wash out) and visit 5 (final of the study), they were evaluated in their blood pressure by AMBP (ambulatory monitoring of blood pressure), the intracellular concentration of magnesium and sodium and of the insulin sensibility. In the visit 2 and visit 4, the patients were clinically evaluated and the blood pressure was measured by auscultatory method. Methods: the blood pressure evaluation was made by auscultatory method and AMBP (ambulatory monitoring of blood pressure by space labs). The intra-erythrocyte concentration of magnesium was made by atomic absorption and the concentration of sodium by flame photometer. The plasmatic insulin was measured by radioimmunoassay and the index of insulin resistance by the formulae of homeostatic model evaluation (HOMA). Results: after 16 weeks using diuretic plus magnesium or diuretic plus placebo we observed significative reduction of the blood pressure evaluated by auscultatory method and by ambulatory monitoring blood pressure (AMBP) during 24 hour in the two groups; although there was no significative difference between the reductions of the blood pressure when we compare the two groups. In the group with diuretic plus placebo the reduction of the blood pressure was of 22,30 ±2,44mmhg (p<0,001) e 12,25±1,54mmhg (p<0,001)of the systolic and diastolic blood pressure respectively and in the group with diuretic plus placebo the reduction was of 21,53±1,64mmhg (p<0,001) e 10,79±1,27mmhg (p<0,001) of the systolic and diastolic blood pressure respectively. The intracellular concentration of magnesium did not change significatively in the group with diuretic plus magnesium (-3,77±2,86mEq/L/cel) however in the group diuretic plus placebo the reduction was of significative form (- 16,29±4,12mEq/L/cel; p=0,001) The amount of the intra-erythrocyte sodium was reduced in both groups; in the group diuretic plus magnesium was (-0,97±0,25 mEq/L/cel; p=0,001) and in the group diuretic plus placebo was (-0,88±0.20 mEq/L/cel; p=0,001) any significative difference between the two groups was found. The intracellular concentration of sodium at the end of the study had a positive correlation with the levels of the blood pressure evaluated by AMBP: systolic blood pressure in a period of 24h was (r=0,31 and p=0,05) and diastolic blood pressure in a period of 24h was (r=0,34 and p=0,04). We did not register correlation between the reduction of the blood pressure in both groups and the levels of the intra-erythrocyte magnesium. At the final visit the sensibility to insulin evaluated by HOMA was not changed significatively in group diuretic plus magnesium was (0,31±0,23) and in the group diuretic plus placebo was (0,37±0,40). The others variable data of this research did not changed significative in both groups of treatment. Conclusions: the data of this trial demonstrated that the thiazidic diuretic reduced significatively and equally the blood pressure in the two groups of treatment. Any additional effects on the reduction of the blood pressure in the group magnesium plus diuretic was found. In spite of the reduction in the level of intracellular magnesium in the group diuretic plus magnesium any hypotensive effect of this treatment was registered. The reduction of the intracellular concentration of sodium seems to have influenced in the reduction of the blood pressure in the two groups of treatment. Any interference in the sensibility of insulin was found in the two groups of treatment.