Which hormone is most closely associated with signaling energy stores and can influence puberty onset?

Which hormone is most closely associated with signaling energy stores and can influence puberty onset?

• A. Leptin
• B. Insulin
• C. Ghrelin
• D. Melatonin

Answer: (A)

Leptin is the hormone most closely tied to signaling energy stores and can influence puberty onset. It is produced by fat tissue, and its circulating level rises as fat mass increases. This signal informs the brain about the body's energy reserves. When leptin levels are sufficient, they act on the hypothalamus to promote the release of GnRH (through pathways like kisspeptin), which sets puberty in motion. If energy stores are too low, leptin drops and puberty can be delayed or suppressed, while adequate leptin signals help initiate reproductive maturation. Insulin indicates short-term energy status but isn’t the primary signal for puberty timing. Ghrelin signals hunger and energy deficit, which can actually modulate reproductive function in opposite ways. Melatonin relates to circadian rhythms rather than energy stores.

Leptin is the hormone most closely tied to signaling energy stores and can influence puberty onset. It is produced by fat tissue, and its circulating level rises as fat mass increases. This signal informs the brain about the body's energy reserves. When leptin levels are sufficient, they act on the hypothalamus to promote the release of GnRH (through pathways like kisspeptin), which sets puberty in motion. If energy stores are too low, leptin drops and puberty can be delayed or suppressed, while adequate leptin signals help initiate reproductive maturation.

Insulin indicates short-term energy status but isn’t the primary signal for puberty timing. Ghrelin signals hunger and energy deficit, which can actually modulate reproductive function in opposite ways. Melatonin relates to circadian rhythms rather than energy stores.