INS and metabolic syndrome: Leptin production and expression are also influenced by a number of other factors, includingas sleep, body temperature, gender, circadian rhythm, fast or excessive meal consumption and other hormones like insulin, growth hormone,glucocorticoids, testosterone and thyroid hormone [11-12].One characteristic of obesity and abdominal adiposity, which is a risk factor for metabolic syndrome, is elevated serum leptin levels.Despite not being one of the diagnostic criteria for metabolic syndrome, high blood leptin is elevated in individuals with metabolicsyndrome [13].