Leptin

Been reading about leptin, the so-called satiety hormone. It
is coded for on the 'ob' gene, chromosone 7. Yes, the (in)famous
obesity gene. I am lucky to be able to read about it not only in English,
but in French and German. This adds vital elements, and gives a better
perspective.

Fom English I garner that leptin is a cytokine, produced from adipose
tissue. Its discovery occured in mice with genetic mutations that
made it ineffective, hence those mice became obese. These mutations
do not occur in humans. It targets the hypothalamus, the part of
the brain that regulates appetite.

Studies have shown that leptin regulation could be down after fasting, from
that could be used to aid weight loss. In the intestinal track, it favors protein absorption
at the expense of fat. It can be considered an antagonist to ghrelin, the appetite hormone
which is felt during waking hours so, not surprisingly, we find low leptin
with lack of sleep. It is a useful marker for the progression of osteoarthritis, in
overweight people.

From the German: leptin is a protein hormone (as opposed to a steroid one).
It activates certain processes in the blood such as thermogenesis. It reduces
the production of the harmful Alzheimer-inducing substances. It is a finer regulator
of glucagon than insulin and can be used in the treatment of diabetes-1.

Medical leptin is a 'rekombinantes Analogon'.

Interestingly, women produce three times as much leptin as men, from an otherwise
equal amount of subcutaneous fat.

Il semble qu’il existe une différence sexuée dans la sécrétion en leptine puisqu’à quantité de tissu sous-cutané égale, les adipocytes féminins sécrètent trois fois plus de leptine que les adipocytes masculins. 

https://www.news-medical.net/health/What-is-Leptin.aspx

source: English, French, German Wikipedia.