Effects of Diabetes on Blood Pressure, Pulse, & Pupil Size

Close-up of dialated pupil.
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Diabetes is a condition that affects a growing number of individuals. It is a condition characterized by the inability of the body to process blood glucose (sugar), which leads to numerous complications in almost every organ system. Diabetes has effects on blood pressure, pulse and pupil size.

Blood Pressure

Diabetes affects the blood vessels, accelerating the process of atherosclerosis (hardening of the arteries). This affects the fluid dynamics of the circulatory system and causes high blood pressure. In addition to the mechanical disruption of the circulation, atherosclerosis in the renal arteries supplying the kidneys causes a reflexive increase in the systemic blood pressure, because the renal arteries have special sensors to monitor blood pressure and flow. In an article for MERCK, George L. Bakris, M.D. explains that when these sensors are damaged, the body reflexively tries to increase the blood pressure to maintain perfusion of the kidneys.

Effect of Pulse

Pulse has two dimensions that are evaluated by medical professionals: pulse rate and pulse pressure. In diabetic patients, the pulse rate is not significantly related to long-term progress of the disease. Pulse rate, however, can increase greatly during a hypoglycemic episode when the individual's blood sugar drops below the normal range. Rapid pulse is one of the signs of hypoglycemia and should be recognized and treated immediately. Pulse pressure is a measure of the force of the pulse against the walls of the arteries. Diabetes damages the blood vessels, causing them to harden, which results in an increased pulse pressure. An article published in the Journal of Hypertension, September 2002, by researcher M.T. Schram, reported that the increased pulse pressure is positively associated with serious cardiovascular morbidity and mortality.

Pupil Size

Individuals with long-standing or poorly controlled diabetes tend to have smaller pupils than normal individuals or individuals in whom the condition had been carefully managed. The Institute of Child Health, Royal Hospital for Sick Children, Bristol, published an article in The Archives of Disease in Childhood, 1994, that reported the effect of diabetes on the pupil size is due to damage to the sympathetic nerves that cause the pupil to become larger. When these nerves are damaged, then the balance is disrupted and the pupil tends to constrict (shrink). The nerves are damaged directly by the disease process and secondarily by microvascular damage in the supplying blood vessels.

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