Which age-related factor tends to affect blood pressure?

Narrowing of the arteries is a significant age-related factor that affects blood pressure. As individuals age, the arterial walls can become less elastic and may develop plaque buildup, leading to a condition known as atherosclerosis. This narrowing increases resistance to blood flow, which can result in elevated blood pressure. When arteries are tense and less able to accommodate the surge of blood with each heartbeat, the heart must work harder to pump blood through these narrower pathways, ultimately contributing to hypertension.

The other options, while related to overall vascular health, do not have the same direct impact on blood pressure as the narrowing of arteries. Increased flexibility of arteries is typically associated with lower blood pressure, as flexible arteries can more easily adapt to changes in blood flow. Decreased hormone levels generally do not lead to an increase in blood pressure; rather, some hormones that decline with age are responsible for regulating blood pressure. Increased elasticity of veins is also associated with better blood flow and lower blood pressure outcomes. Therefore, narrowing of the arteries stands out as the most critical factor among the options provided.