How does hyperthyroidism affect total peripheral resistance to promote an increase in GFR?

The correct choice highlights that hyperthyroidism decreases total peripheral resistance, contributing to increased glomerular filtration rate (GFR). In hyperthyroidism, elevated levels of thyroid hormones enhance metabolic activity throughout the body, leading to a variety of cardiovascular effects.

When total peripheral resistance decreases, the blood vessels experience vasodilation, which lowers systemic vascular resistance. This reduction in resistance allows for increased blood flow, including to the kidneys. With enhanced renal perfusion, there is a rise in the hydrostatic pressure within the glomerular capillaries, which ultimately results in an increased GFR.

While other factors like enhanced cardiac output or increased blood volume may also play roles in kidney function, the direct relationship between decreased total peripheral resistance and increased GFR underlies the main mechanism by which hyperthyroidism promotes these changes. The condition is characterized by an overall state of heightened metabolism and circulation, further emphasizing the significance of this vascular adjustment.