What additional roles does leptin have besides decreasing hunger?

Leptin is a hormone primarily produced by adipose (fat) tissue that plays a critical role in regulating energy balance and body weight. While its most well-known function is to decrease hunger by signaling the brain to reduce appetite, it also has additional roles, one of which is increasing insulin sensitivity.

Insulin sensitivity refers to how effectively the body responds to the hormone insulin, which is essential for glucose metabolism. Increased insulin sensitivity enables the cells to use glucose more effectively, lowering blood sugar levels and potentially reducing the risk of conditions like type 2 diabetes. Leptin has been shown to enhance insulin action, helping to regulate glucose homeostasis. This interaction is particularly important for managing energy balance in relation to obesity and metabolic health.

In contrast, the other options either do not reflect the primary functions of leptin or directly contradict its role. For instance, while leptin does not decrease muscle mass or stimulate carbohydrate storage, and it is specifically involved in reducing appetite rather than increasing it, these roles are not aligned with the physiological functions of leptin as understood in current medical research.