What is the connection between the endocrine system and the cardiovascular system?
The cardiovascular and endocrine systems are intimately related, and the endocrine system influences blood pressure, heart rate, and blood sugar levels. Insulin and glucagon, both hormones secreted by the pancreas, respectively increase and decrease the levels of glucose in the blood. This helps to regulate energy levels during and after exercise, eating, and rest. Levels of lipids (fats) are also tightly regulated by hormones in the body.
Glucocorticoids are stress hormones (cortisol is the most well known) that also strongly influence blood pressure and blood sugar. Epinephrine (commonly called adrenaline), a stress hormone that is secreted by the adrenal glands next to the kidneys and that is largely responsible for the "fight or flight" response, also strongly impacts blood pressure and blood sugar.
Because of this relationship, disorders of the endocrine system, such as hyperthyroidism and hypothyroidism (excessive and deficient thyroid activity), diabetes (disordered sensitivity to insulin or poor insulin production), and chronic stress (excess cortisol) can all have very negative effects on blood pressure, free lipids in the arteries (which can cause atherosclerosis), and blood sugar (which can also damage the arteries in excess), and therefore massively impact cardiovascular health.