The physiology and pathophysiology of leptin and adiponectin in the elderly is only incompletely known. Age-related changes in body composition, as well as the decline in function of different hormonal axes with aging, may alter the physiology of leptin and adiponectin secretion in the elderly. It seems still not completely clear if aging may have an independent effect on leptin and adiponectin levels, if the association between these two adipokines and fat content and distribution may change with age, as well if a sexual dimorphism may be still present in old age. A growing amount of evidence seems to support a role for leptin and adiponectin in the pathophysiology of different disease states in the elderly and especially in alterations in glucose and lipid metabolism, widely prevalent in old age. Different studies reported very discordant results with some authors describing positive relation between adipokines and age, whereas others negative or even no significant association in unadjusted analyses. Moreover only a few longitudinal studies have been performed to study leptin and adiponectin changes with aging. Finally aging has been recently considered to be the one of the most common cause of impaired leptin sensitivity at both hypothalamic and peripheral levels, leading some authors to hypothesize for leptin resistance a causative role in the metabolic decline seen with aging. However only a few studies have been performed to investigate leptin-resistance in the elderly and its predictors. Therefore the main outcomes of this study were to evaluate the interrelationships between leptin, adiponectin and metabolic, anthropometric and body composition variables in elderly healthy subjects of both sexes. We also wanted to examine which of these variables was most closely related to adiponectin gene expression in a smaller group of women with a wide range of age, BMI and insulin-resistance. Moreover we sought to determine longitudinal changes in leptin and adiponectin levels with aging as well as the main predictors of these changes. Finally we studied the relationship between leptin-resistance, aging and body composition in a small group of women with a wide range of age and BMI.
Tipologia: Tesi di dottorato
Licenza: Accesso ristretto
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