|Nieschlag E, Zitzmann M|
Testosterone and the Metabolic Syndrome in Men: Current Knowledge
Journal für Reproduktionsmedizin und Endokrinologie - Journal of Reproductive Medicine and Endocrinology 2006; 3 (6): 382-386
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Keywords: Androgensubstitution, Diabetes mellitus Typ 2, Hypogonadismus, Metabolisches Syndrom, Testosteron, androgen subsitution, diabetes mellitus type 2, hypogonadism, metabolic syndrome, testosterone
Circumstances of life and food supply have changed in developed countries, resulting in an increasing prevalence of overweight. As a consequence, a complex disorder consisting of visceral obesity, dyslipidemia, insulin resistance and hypertension emerges: the so-called metabolic syndrome leads to the manifestation of diabetes type 2 and cardiovascular disease. In men, testosterone deficiency contributes to the generation of the metabolic syndrome, as demonstrated by epidemiological and interventional approaches. Correspondingly, testosterone substitution in hypogonadal men is able to invalidate the mechanisms of the metabolic syndrome by various pathways. It has reciprocal effects on the generation of muscle and visceral fat tissue by exerting influence on the commitment of pluripotent stem cells. In addition, testosterone inhibits further development of pre-adipocytes. It also enhances insulin sensitivity of muscle cells by augmenting mitochondrial capacity and fostering expression of oxidative phosphorylation genes. Testosterone is also able to break the vicious circle of leptin resistance and generation of new adipose tissue. These effects are exerted by androgen receptor-mediated mechanisms. As epidemiological studies indicate, testosterone substitution is especially helpful in preventing or attenuating the metabolic syndrome in aging men with late-onset hypogonadism and in Klinefelter patients.