Researchers found that the gene for kisspeptin (KISS1) is active in women's fat tissue, especially under the skin, and that higher levels in belly fat are linked to higher BMI. This suggests that kisspeptin isn’t just a brain hormone but may also be made by fat cells.

The current focus of kisspeptin research is an exploration of its key role in the hypothalamic control of human and animal fertility. Notwithstanding the importance of these studies, strong evidence exists that the gene encoding human kisspeptin, KISS1, is present in several peripheral sites, including the placenta. We also provided evidence that kiss1 is also expressed and regulated in rodent adipose tissue. This study describes a pilot investigation into the possibility that human female adipose tissue might also express the KISS1 gene. Samples of fat were taken from women undergoing open abdominal surgery, for example, during caesarian section. Two small samples of fat were obtained, one from subcutaneous tissue (n = 35) and one from the omentum (n = 32). RNA was isolated from all fat samples and KISS1 mRNA was detected by realtime RT-PCR. KISS1 gene expression was detected at varying levels in all samples of fat tissue but levels were significantly higher in subcutaneous fat. There was no significant correlation between KISS1 gene expression and body mass index (BMI) in subcutaneous fat (P = 0.43), but there was a significant positive correlation (P = 0.01) between KISS1 mRNA levels and BMI in omental adipose tissue. We have shown for the first time that human female adipose tissue may be a source of kisspeptins. Further studies are required to establish whether kisspeptins of adipose tissue origin might be correlated with some aspects of infertility.