The beneficial and detrimental effects of prolactin hormone on metabolic syndrome: A double-edge sword.

The metabolic syndrome (MetS) is a clustering of abdominal obesity, hypertension, hyperglycaemia, hypertriglyceridemia and low high-density lipoprotein (HDL) level. MetS development is affected by endocrine hormones such as prolactin (PRL) hormone which induce insulin resistance and central obesity because PRL is implicated in the pathogenesis of MetS. Pituitary PRL controls mammary gland, however extra-pituitary PRL is highly intricate in the regulation of adipose tissue function. In addition, cAMP activators enhance expression and release of PRL which involved in the control of lipogenesis and energy homeostasis. Consequently, hyperprolactinaemia may be associated with the development of MetS. However, normal physiological level of PRL is essential for insulin sensitivity and regulation of adipose tissue function and energy metabolism. Therefore, PRL has dual effects on the components of MetS. Hence, the present review aims to discuss the modulatory mechanistic role of PRL on MetS regarding its beneficial and detrimental effects.