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Abstract(s)
Durante muitos anos, a maior incidência e mortalidade das doenças cardiovasculares
(CV) no sexo masculino em relação ao feminino foi sempre associada a uma maior concentração
da hormona testosterona nos homens. O pensamento dominante era de que a testosterona teria
efeitos sistémicos negativos, que aumentavam o risco CV, pelo que a sua maior concentração
nos homens seria um dos principais fatores que explicavam o maior impacto das doenças CV no
sexo masculino. No entanto, um número cada vez maior de evidências sugere que níveis
plasmáticos baixos de testosterona, em vez de elevados, estarão relacionados com um maior
risco CV nos homens. Alguns estudos apontam para uma associação entre níveis baixos de
testosterona e a Síndrome Metabólica (SMet), enquanto outros estabeleceram uma relação
inversa entre o nível de testosterona nos homens e a frequência e gravidade de síndromes
coronários agudos e acidente vascular cerebral (AVC).
O objetivo deste estudo consistiu em fazer uma extensa revisão da bibliografia
disponível sobre a relação entre baixos níveis plasmáticos de testosterona em homens e o
aumento do risco CV, para determinar se existe fundamento na hipótese da hormona ser um
fator de proteção do sistema CV.
Para este estudo, foram utilizadas pesquisas na internet e nas bases de dados da
PUBMED. Inicialmente foram selecionados 68 artigos usando o termo de pesquisa
“Testosterone” e cada um dos seguintes: “Cardiovascular”, “Coronary Artery Disease”;
“Stroke” e “Metabolic”. Dos 68 artigos, 63 foram selecionados para análise. Os restantes artigos
foram excluídos por não conterem informação relevante para o presente estudo.
A grande maioria dos estudos sugere um efeito protetor da hormona na saúde CV dos
homens. Alguns estudos demonstraram uma associação epidemiológica entre níveis plasmáticos
baixos de testosterona e maior risco de doenças CV, nomeadamente síndromes coronários
agudos e AVC. Os mecanismos propostos para o efeito protetor da hormona no sistema CV
consistem principalmente na promoção da vasodilatação, prevenção da aterosclerose e no
atraso do desenvolvimento de SMet.
A informação disponível atualmente sugere um efeito protetor da hormona contra
eventos CV nos homens. No entanto, mais estudos são necessários para determinar se baixos
níveis de testosterona constituem um fator de risco CV independente, ou se aumentam o risco
CV de uma forma indireta. Por outro lado, são também necessários estudos para determinar o
papel que a Terapia de Reposição de Testosterona (TRT) poderá ter na prevenção de eventos
CV nos homens com hipogonadismo. Por fim, a confirmação de que a testosterona tem um
efeito protetor no sistema CV dos homens não implica que a falta da hormona seja o único fator
responsável pelo maior impacto das doenças CV no sexo masculino. O mais provável é que a
maior incidência e mortalidade dos eventos CV nos homens se deva a uma conjugação de fatores
biológicos, comportamentais e psicossociais.
For many years, the greater incidence and mortality of cardiovascular (CV) diseases in males compared to females was attributed to a higher concentration of testosterone hormone in men. The dominant idea was that testosterone had negative systemic effects, which would lead to a rise of the CV risk, and therefore, the higher concentration of the hormone in men would be a key factor to explain the greater impact of CV diseases in this gender. However, there is growing evidence that suggests that low plasma levels of testosterone, rather than high, are related to a higher CV risk in men. Some studies demonstrated an association between low testosterone levels and Metabolic Syndrome (SMet), while other studies established an inverse relation between testosterone levels in men and the frequency and severity of acute coronary syndromes and stroke. The objective of this study was to perform an extensive revision of the available bibliography concerning the relationship between low plasma testosterone levels in men and high CV risk, to determine whether there is support for the hypothesis of the hormone being a CV system protection factor. For this study, a literature research on the internet and PUBMED databases was used. Initially, 68 articles were selected using the research term “Testosterone” and each of the following: “Cardiovascular”, “Coronary Artery Disease”, “Stroke” and “Metabolic”. Of the 68 articles, 63 were selected for analysis. The remaining articles were excluded for not having relevant information for this study. The great majority of the studies suggest a protective effect of the hormone on male CV health. Some studies demonstrated an epidemiological association between low plasma levels of testosterone and high risk of CV diseases, like acute coronary syndromes and stroke. The proposed mechanisms for the protective effect of the hormone on CV system consist mainly on promotion of vasodilation, prevention of atherosclerosis and delay of SMet development. The available information suggests a protective effect of the hormone against CV events in men. However, more studies are necessary to determine whether low testosterone levels are an independent CV risk factor, or if they raise CV risk in an indirect way. On the other hand, more studies are also necessary to determine what role Testosterone Replacement Therapy (TRT) could have on the prevention of CV events in men with hypogonadism. Finally, the confirmation that testosterone has a protective effect on the male CV system does not imply that the lack of the hormone is the only factor responsible for the greater impact of CV diseases in males. It is more likely that the greater incidence and mortality of CV events in men is due to a conjugation of biological, behavioral and psychosocial factors.
For many years, the greater incidence and mortality of cardiovascular (CV) diseases in males compared to females was attributed to a higher concentration of testosterone hormone in men. The dominant idea was that testosterone had negative systemic effects, which would lead to a rise of the CV risk, and therefore, the higher concentration of the hormone in men would be a key factor to explain the greater impact of CV diseases in this gender. However, there is growing evidence that suggests that low plasma levels of testosterone, rather than high, are related to a higher CV risk in men. Some studies demonstrated an association between low testosterone levels and Metabolic Syndrome (SMet), while other studies established an inverse relation between testosterone levels in men and the frequency and severity of acute coronary syndromes and stroke. The objective of this study was to perform an extensive revision of the available bibliography concerning the relationship between low plasma testosterone levels in men and high CV risk, to determine whether there is support for the hypothesis of the hormone being a CV system protection factor. For this study, a literature research on the internet and PUBMED databases was used. Initially, 68 articles were selected using the research term “Testosterone” and each of the following: “Cardiovascular”, “Coronary Artery Disease”, “Stroke” and “Metabolic”. Of the 68 articles, 63 were selected for analysis. The remaining articles were excluded for not having relevant information for this study. The great majority of the studies suggest a protective effect of the hormone on male CV health. Some studies demonstrated an epidemiological association between low plasma levels of testosterone and high risk of CV diseases, like acute coronary syndromes and stroke. The proposed mechanisms for the protective effect of the hormone on CV system consist mainly on promotion of vasodilation, prevention of atherosclerosis and delay of SMet development. The available information suggests a protective effect of the hormone against CV events in men. However, more studies are necessary to determine whether low testosterone levels are an independent CV risk factor, or if they raise CV risk in an indirect way. On the other hand, more studies are also necessary to determine what role Testosterone Replacement Therapy (TRT) could have on the prevention of CV events in men with hypogonadism. Finally, the confirmation that testosterone has a protective effect on the male CV system does not imply that the lack of the hormone is the only factor responsible for the greater impact of CV diseases in males. It is more likely that the greater incidence and mortality of CV events in men is due to a conjugation of biological, behavioral and psychosocial factors.
Description
Keywords
Acidente Vascular Cerebral Aterosclerose Cardiovascular Doença Arterial Coronária Endocrinologia Síndrome Metabólica Testosterona Vasodilatação