LEP and lipodystrophy: Since then, leptin-based therapies have been mainly developed for the treatment of congenital leptin deficiency [129,130], leptin deficiency in lipodystrophy patients [304] and hypothalamic amenorrhea [305,306] leading to the improvement of their phenotypes, including normalization of endocrine axes, decrease in insulin resistance and improvement of lipid profile and hepatic steatosis [307].