Carolinas HealthCare System
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Understanding Type 2 Diabetes: How Does This Blood Sugar Thing Work?

By Dr. Michael Richardson

The incidence of diabetes has dramatically increased in the past three decades, attributed to increased obesity, decreased physical activity, and the increased consumption of prepared, highly dense foods (especially fast food). Because symptoms of diabetes usually do not appear until the patient has had the disease more than 10 years, it is only detected in its early stages by screening laboratory tests.

Take the prediabetes risk assessment test.

Getting Sugar into the Cells for Energy

Red blood cells
Normally, the gastrointestinal tract breaks down carbohydrates in foods (grains, fruits, vegetables, dairy products) into glucose, which is transported into the bloodstream. Insulin is a hormone produced by the pancreas that transfers glucose from the bloodstream into cells, where it is either burned up for energy or stored. When food is not available in the gastrointestinal tract for processing, the liver produces glucose through a process called gluconeogenesis.

This provides a steady source for the body’s energy needs.

When Insulin Doesn’t Work Right

In diabetes, insulin doesn’t function normally. The muscle and fat cells, among others, appear to be resistant to the effects of insulin. This leads to higher levels of glucose than normal in the bloodstream. The liver cells do not seem to recognize insulin or glucose levels and continue to produce excessive amounts of glucose. The pancreas recognizes the higher sugar levels and pumps out more insulin to try to lower it.

Elevated Insulin Levels

This extra insulin triggers a variety of metabolic problems—it increases the risk for atherosclerosis, elevates triglycerides, lowers healthy HDL cholesterol, increases blood pressure, and increases blood-clotting tendencies. Elevated insulin levels may also fuel tumor growth, possibly accounting for the increased incidence of breast, colon, liver, and prostate cancer seen in diabetics.

A Buildup of Sugar in the Bloodstream

Eventually, the pancreas cannot keep up with the need for extra amounts of insulin, sugars continue to rise, and damage occurs to tiny blood vessels. This leads to damage to the structures that these tiny blood vessels supply - affecting nerves, kidneys, the eye, the heart, and the brain and increasing the risk for infection.

Symptoms of advanced diabetes include fatigue, weight loss, frequent urination, excessive thirst or hunger, changes in vision, numbness or burning in the feet, and the slow healing of wounds.

Dr. Richardson is an internal medicine physician at Charlotte Medical Clinic-Mint Hill.