The Metabolic Effects of Oestrogens and SERMs: Regulatory interactions with the GH-IGF-system in health and disease

点击翻译按钮获取中文摘要

This project extends work aimed at understanding how GH and sex hormones work together to optimise physical health in women and men. It addresses the benefits and safety of oestrogen compounds in relation to their effects on body fat and muscle (body composition). Oestrogen compounds are among the most widely used medicines and include tradition oestrogens (female hormone) and synthetic oestrogens called SERMs. Oestrogens are used in young women as oral contraception and in the postmenopause for replacement therapy. Body composition is an important determinant of fitness and health. Obesity reduces fitness and increases the risk of diabetes and heart attacks while muscle loss causes weakness and frailty. GH is a major regulator of body composition; it acts by breaking down fat and building muscle mass. We discovered that oestrogens, when taken as a tablet interferes with the action of GH and causes detrimental changes in body composition. On the positive side, we have exploited the GH blocking action to treat acromegaly. This is a debilitating disease of excessive GH production from a pituitary tumour and for which available drug treatments are very expensive and require injection. The effects of SERMs on body composition are unknown. SERMs are interesting compounds because they act like oestrogens in some but as oestrogen blockers in other tissues. These are widely used in the treatment of breast cancer and osteoporosis. The extent to which they interfere with the action of GH has not been studied. They may exert additional effects because they act on the pituitary gland to reduce the secretion of GH. They may also prove to be effective in acromegaly which could extend their usefulness to men. In summary, the work will provide important information on the long-term benefits of SERMs in patient groups that tend to be frail. It may also prove to be a simple and inexpensive treatment for acromegaly.