What is primarily responsible for the increase in blood pressure that accompanies age?

The primary factor responsible for the increase in blood pressure that accompanies age is left ventricular hypertrophy due to increased afterload. As people age, the arteries tend to become stiffer and less elastic, which elevates systemic vascular resistance. This increased resistance, referred to as afterload, forces the heart to work harder to pump blood against this higher pressure.

As a result of this increased workload, the heart muscle, particularly the left ventricle, undergoes hypertrophy, which is the thickening of the heart muscle. This hypertrophy allows the heart to effectively generate the additional pressure required to overcome the increased resistance in the arteries. Consequently, this can lead to sustained high blood pressure, a condition known as hypertension.

In contrast, while factors such as stress, fluid retention, and decreased physical activity levels can influence heart function and blood pressure, they do not primarily drive the age-related increase in blood pressure as significantly as left ventricular hypertrophy. The impact of structural changes in the heart and vasculature plays a more critical role in the cardiovascular changes observed with aging.