Effects of low energy availability on female reproductive function

Area of Science:

• Neuroendocrinology
• Reproductive Biology
• Metabolic Regulation

Background:

• Metabolic and nutritional disturbances are known to cause reproductive dysfunction in females.
• Reduced secretion of gonadotrophin-releasing hormone (GnRH) from the hypothalamus is a primary cause of these reproductive alterations.
• The underlying mechanisms linking metabolic status to reproductive function are increasingly understood.

Purpose of the Study:

• To review current knowledge on the impact of nutrition and metabolism on female reproductive functions.
• To specifically focus on the regulation of the GnRH system in response to nutritional and metabolic changes.

Main Methods:

• This study is a comprehensive review of existing scientific literature.
• It synthesizes findings on the neuroendocrine regulation of GnRH secretion.
• Focus is placed on the interplay between metabolic factors and reproductive control.

Main Results:

• GnRH secretion is regulated by various central and peripheral factors, including satiety-related hormones (leptin, insulin, alpha-MSH) that stimulate it, and orexigenic factors (neuropeptide Y, Agouti-related protein, orexin, ghrelin) that inhibit it.
• Metabolic and nutritional disturbances lead to reduced expression of kisspeptin, a critical positive regulator of GnRH.
• Alterations in these regulatory factors collectively impact GnRH neuron activity.

Conclusions:

• The observed neuroendocrine adaptations may function as defensive mechanisms.
• These mechanisms allow organisms to survive adverse conditions by temporarily suppressing reproductive processes.
• This highlights a crucial survival strategy linking energy balance to reproduction.