What role does BDNF play in blood sugar?

BDNF (Brain-Derived Neurotrophic Factor) is a protein primarily expressed in the brain that supports neuronal survival and plasticity. Regarding blood sugar, BDNF plays a key role in glucose metabolism: it acts on the hypothalamus to regulate energy balance, enhances insulin sensitivity, and promotes glucose uptake in skeletal muscle. Human studies have found that lower circulating BDNF levels are associated with insulin resistance and type 2 diabetes. However, the evidence is largely observational, and causal mechanisms are not fully established. Lifestyle factors such as exercise and diet can increase BDNF, which may indirectly improve glycemic control. Currently, genetic tests for BDNF variants (e.g., Val66Met) have limited clinical utility for blood sugar management because the effects are small and context-dependent. In summary, BDNF is a relevant but not definitive marker; its role in blood sugar is best understood as part of a complex network involving neural and metabolic signaling.