Hormonal and cytokine implications in the pathophysiology of osteoporosis occurring in chronic liver diseases.

IN THE LAST YEARS THERE HAS BEEN AN INCREASED AWARENESS REGARDING THE ALTERATIONS OF BONE METABOLISM AS A COMMON COMPLICATION OF CHRONIC LIVER THAT OCCURS REGARDLESS OF THE ETIOLOGY: alcoholic, viral, autoimmune, whether or not associated with cholestasis.The aim of this paper was to summarize the current understanding of bone metabolism and to point out the new discoveries that have been made in this field.Bone density is maintained constant due to the equilibrium between bone formation bone resorbtion, under the control of hormonal and proinflammatory cytokines. The influence of sex hormones, parathyroid hormone, growth hormone, and insulin-like growth factor-1 and 2 on bone metabolism is discussed. The role of proinflammatory cytokines, CSF1-RANKL system, leptin and oncofetal fibronectin are also discussed.Although the physiological mechanism of bone metabolism has been established, when it comes to pathological conditions, the hormones and cytokines have different new roles, or are associated with other factors having different influences.