Resistance-induced hyperinsulinemia can provoke leptin-resistant hyperleptinemia with a significant upregulation of white lipid synthesis and storage in adipose tissue, a characteristic of Metabolic Syndrome X. Furthermore, a relationship between the rate of leptin secretion and intracellular ATP concentration appears to exist in adipocytes from obese animals, which results in a positive correlation between leptin and percent body fat. This evidence concerns the gene LEP and hyperinsulinism.