The metabolic syndrome X and peripheral cortisol synthesis

The metabolic syndrome X and Cushing's syndrome show similar symptoms but one major difference: Plasma cortisol is not elevated in the metabolic syndrome. Evidence is presented, that by the action of 11beta-hydroxysteroid dehydrogenase 1 (11betaHSD1) higher intracellular cortisol concentration may be created that may be relevant to induce insulin resistance and metabolic disturbances. Regulation of 11betaHSD1 expression by hormones, growth factors, cytokines and transcription factors enables tissue specific adjustments of glucocorticoid receptor activation by cortisol. Specific inhibition of 11betaHSD1 would help to understand aspects of the pathogenesis of syndrome X and to develop new therapeutic perspectives.