Serum testosterone and cardiovascular disease in men

Cardiovascular diseases (CVD) represent the main cause of death in Brazil. Men die more of coronary artery disease and they have higher levels of testosterone than women. However, recent studies indicate that androgens can have beneficial and/or neutral effect in the male cardiovascular system. Low levels of endogenous testosterone have been involved with the presence of some components of the metabolic syndrome including dyslipidemia, visceral obesity, hypertension and thrombus formation process. Consistent data on the relationship between testosterone and vascular reactivity, atherosclerosis and cardiovascular mortality in men are rare, with the results of available studies presenting contradictions. Large randomized and prospective trials are needed to evaluate androgen-specific function in male CVD so that better conclusions can be established.As doenças cardiovasculares (DCV) representam atualmente o principal grupo de causa de morte no Brasil. Os homens morrem mais de doença arterial coronariana e possuem níveis mais elevados de testosterona do que as mulheres. No entanto, estudos recentes indicam que os andrógenos podem ter efeito benéfico e/ou neutro no sistema cardiovascular masculino. Baixos níveis de testosterona endógena têm sido relacionados à presença de vários componentes da síndrome metabólica, incluindo dislipidemia, obesidade visceral, hipertensão arterial sistêmica e estados pró-trombóticos. Os dados da relação entre testosterona e reatividade vascular, aterosclerose e mortalidade cardiovascular nos homens são escassos, com os resultados de estudos disponíveis apresentando contradições. Grandes estudos randomizados e prospectivos são necessários para avaliar a função específica dos andrógenos nas DCV masculinas, para que melhores conclusões possam ser estabelecidas.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM)Instituto Dante Pazzanese de CardiologiaUNIFESP, EPMSciEL

Associação entre globulina de ligação a hormônio sexual (SHBG) e síndrome metabólica em homens

CONTEXT AND OBJECTIVE:Metabolic syndrome consists of a set of factors that imply increased risk of cardiovascular diseases. The objective here was to evaluate the association between sex hormone-binding globulin (SHBG), sex hormones and metabolic syndrome among men.DESIGN AND SETTING:Retrospective analysis on data from the study Endogenous oestradiol but not testosterone is related to coronary artery disease in men, conducted in a hospital in São Paulo.METHODS:Men (aged 40-70) who underwent coronary angiography were selected. The age, weight, height, waist circumference, body mass index and prevalence of dyslipidemia, hypertension and diabetes of each patient were registered. Metabolic syndrome was defined in accordance with the criteria of the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (NCEP-ATPIII). Serum samples were collected to assess the levels of glucose, total cholesterol, HDL-cholesterol (high density lipoprotein), triglycerides, albumin, SHBG, estradiol and total testosterone (TT). The levels of LDL-cholesterol (low density lipoprotein) were calculated using Friedewald's formula and free testosterone (FT) and bioavailable testosterone (BT) using Vermeulen's formula.RESULTS:141 patients were enrolled in the study. The prevalence of metabolic syndrome was significantly higher in the first SHBG tercile than in the second and third terciles. A statistically significant positive association between the SHBG and TT values was observed, but no such association was seen between SHBG, BT and FT.CONCLUSION:Low serum levels of SHBG are associated with higher prevalence of metabolic syndrome among male patients, but further studies are required to confirm this association.CONTEXTO E OBJETIVO:A síndrome metabólica (SM) consiste em um conjunto de fatores que implicam risco elevado para doenças cardiovasculares. O objetivo foi avaliar a associação entre a globulina ligadora de esteroides sexuais (SHBG), hormônios sexuais e a SM em homens.TIPO DE ESTUDO E LOCAL:Análise retrospectiva de dados do estudo Estradiol mas não testosterona se correlaciona com doença arterial coronariana em homens, conduzido em um hospital em São Paulo.MÉTODOS:Foram selecionados pacientes do sexo masculino com idade entre 40 e 70 anos, submetidos a angiografia coronária. A idade, a prevalência de dislipidemia, hipertensão e diabetes, o peso, a altura, cintura e o índice de massa corpórea de cada paciente foram coletados. A definição de SM seguiu os critérios do NCEP-ATPIII. Amostras séricas foram coletadas para análises da glicose, colesterol total, colesterol-HDL (high density lipoprotein), triglicerídeos, albumina, SHBG, estradiol e testosterona total (TT). O colesterol-LDL (low density lipoprotein) foi calculado pela fórmula de Friedewald e as testosteronas livre (TL) e biodisponível (TB) pela fórmula de Vermeulen.RESULTADOS:Entraram no estudo 141 pacientes. A prevalência de SM foi significativamente maior no primeiro tercil de SHBG em comparação ao segundo e terceiro tercis. Foi verificada uma associação positiva e significativa ente os valores de SHBG e TT, porém essa associação não foi verificada entre SHBG e TB e TL.CONCLUSÃO:Baixos níveis séricos de SHBG estiveram associados com alta prevalência da SM em pacientes do sexo masculino. Faz-se necessário que estudos avaliem essa associação.Universidade Federal do CearáUniversidade Federal de São Paulo (UNIFESP)Instituto Dante Pazzanese de CardiologiaUNIFESPSciEL

Association between sex hormone-binding globulin (SHBG) and metabolic syndrome among men

CONTEXT AND OBJECTIVE: Metabolic syndrome consists of a set of factors that imply increased risk of cardiovascular diseases. The objective here was to evaluate the association between sex hormone-binding globulin (SHBG), sex hormones and metabolic syndrome among men. DESIGN AND SETTING: Retrospective analysis on data from the study "Endogenous oestradiol but not testosterone is related to coronary artery disease in men", conducted in a hospital in São Paulo. METHODS: Men (aged 40-70) who underwent coronary angiography were selected. The age, weight, height, waist circumference, body mass index and prevalence of dyslipidemia, hypertension and diabetes of each patient were registered. Metabolic syndrome was defined in accordance with the criteria of the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (NCEP-ATPIII). Serum samples were collected to assess the levels of glucose, total cholesterol, HDL-cholesterol (high density lipoprotein), triglycerides, albumin, SHBG, estradiol and total testosterone (TT). The levels of LDL-cholesterol (low density lipoprotein) were calculated using Friedewald's formula and free testosterone (FT) and bioavailable testosterone (BT) using Vermeulen's formula. RESULTS: 141 patients were enrolled in the study. The prevalence of metabolic syndrome was significantly higher in the first SHBG tercile than in the second and third terciles. A statistically significant positive association between the SHBG and TT values was observed, but no such association was seen between SHBG, BT and FT. CONCLUSION: Low serum levels of SHBG are associated with higher prevalence of metabolic syndrome among male patients, but further studies are required to confirm this association