Growth hormone, lipoprotein(a) and cardiovascular disease

Growth hormone, lipoprotein(a) and cardiovascular disease Pituitary growth hormone is a potent metabolic hormone introduced into clinical practice by Raben in 1958 [1]. In the following years, pituitary extracted growth hormone has been used exclusively to stimulate linear growth of growth hormone deficient children [2]. The biosynthesis of recombinant human growth hormone (hGH) in 1985 made this hormone available in unlimited amounts and enabled the initiation of clinical trials in conditions other than growth hormone deficiency, such as short children with normal growth hormone secretion, osteoporosis, ageing etc. [3]. The findings that growth hormone deficient patients have a small sized heart [4] and an impaired cardiac output and that hGH administration to such patients increased the thickness of the cardiac muscle and normalized cardiac performance [5] , as well as the common knowledge of cardio-megaly in acromegaly [6] , led to the use of growth hormone in experimental heart disease in animals. Duerr et al. [7] and Yang et al. [8] reported that insulin-like growth factor-I (IGF-I) and growth hormone, respectively, improved cardiac function in experimental heart failure. Fazio et al. [9] followed by treating patients with dilated cardiomyopathy with hGH. These authors reported significant improvement in the left ventricular ejection fraction and an increase in left ventricular muscle mass during 3 months of hGH treatment. All the above findings will undoubtedly lead to an extended use of growth hormone in cardiac diseases. The increasing use of hGH since 1985 to adult growth hormone deficient patients as well as elderly subjects [10] , has shown that adults are more sensitive to this hormone than children and their need for replacement is approximately one third the dose administered to children to stimulate [11]. If higher doses were used, water and electrolyte retention was registered causing oedema and arthralgia [11] presenting an overload to the heart. Reacting to the report by Fazio et al. [9] , Turner and Wass [12] drew attention to the fact that the pharmacological use of hGH to adults may increase the risk of insulin resistance and colon cancer and enhance mortality from cardiovascular and respiratory disease, to which Frustaci et al. [13] added the possibility of arrhythmia. In addition to its biological effects on protein metabolism, including muscle mass and function, as well as nervous tissue, which are mediated by IGF-I, growth hormone acts on the carbohydrate and lipid metabolism. In relation to the latter, recent studies …