Abstract: The main characteristics of the metabolic syndrome are visceral obesity, glucose
intolerance, raised blood pressure, dyslipidaemia, inflammation and thrombosis. Low testosterone levels are
associated with the metabolic syndrome closely. The metabolic syndrome is a clustering of risk factors
predisposing to diabetes mellitus, atherosclerosis and cardiovascular morbidity and mortality. Cross鄄sectional
epidemiological studies reported a direct correlation between plasma testosterone level and insulin sensitivity,
and low testosterone levels are associated with an increased risk of type 2 diabetes mellitus. Lower total
testosterone and sex hormone鄄binding globulin predict a higher incidence of the metabolic syndrome. There
were also some clinical trials showing improvements in insulin resistance and glycaemic control with
testosterone supplement therapy. Administration of testosterone to hypogonadal men reverses the unfavorable
risk profile for the development of diabetes and atherosclerosis. The lower serum T level should be an element
in the definition of the metabolic syndrome.

Key words: Testosterone, Metabolic syndrome X, Hypogonadism, Insulin resistance, Diabetes mellitus, type 2