Biological or Clinical Significance:
Leptin is synthesized in adipocytes as a 16 kD molecule. The circulating level is directly proportional to the total amount of fat in the body, but it is primarily associated with the subcutaneous fat depot. It binds to its receptors in the hypothalamus and plays an active role in regulation of food intake, energy expenditure and reproductive function. Serum leptin levels show a moderate circadian variation, with a peak at about 2 AM. The values at this time may be 30-100% higher than later in the morning or early afternoon. This variation and the influence of food intake need to be taken into account when collecting blood samples for leptin analysis.
Principle of Test Method:
The leptin assay is a solid-phase ELISA designed to measure human Leptin in serum and plasma. It employs the quantitative sandwich enzyme immunoassay principle.