Leptin rhythmicity and its relationship with other rhythm markers

Leptin is a peptide hormone secreted by a number of tissues and has a multitude of functional implications like energy homeostasis, angiogenesis, bone formation, reproduction, neuroendocrine role, hematopoesis, lymphopoesis, glucose homeostasis and fatty acid metabolism. Its serum pattern has a circadian rhythm with sleep as a physiological modulator. Leptin pattern has important co-relationships with important rhythm markers like body temperature, melatonin, cortisol and catecholamine. Leptin has endocrine feedback loop dynamics with cortisol and catecholamine. It is implicated in a number of signaling cascades such as p42/44 MAPK, p38 MAPK, STAT 1, STAT 3, STAT 5, etc. This multidimensionality in the site of secretion, function, relation with other rhythm markers and signaling cascade means its serum pattern has implications in sleep disorders, cardiac myopathies, diabetes, obesity, polycystic ovary syndrome, etc. It is therefore imperative to understand the serum leptin dynamics and its relationship with the various facets of its multidimensionality.