How Type 2 Diabetes Develops

Insulin resistance results when the conditions are right.

Insulin is an important part of digestion because it plays a part in how the body digests food. The carbohydrate that we eat is broken down into glucose that then enters the bloodstream along with insulin so that the body can absorb glucose for energy. Insulin is very important in helping muscle, fat, and liver cells to absorb glucose from the bloodstream, which lowers blood sugar levels. Excess glucose is stored in the liver and muscle tissue as glycogen.

Another function of insulin is to lower blood glucose levels by reducing glucose production in the liver. In someone who does not have type 2 diabetes, these functions allow blood glucose and insulin to remain within the normal range.

Causes of Insulin Resistance

Scientists and doctors are still unsure of why insulin resistance develops, but they suspect that – along with genetic factors – excess weight and inactivity are causes. Extra weight in the form of belly fat is especially dangerous and is thought to contribute to resistance. This fat produces hormones that can cause insulin resistance and other health problems, such as cardiovascular disease, imbalanced cholesterol, and high blood pressure. Chronic inflammation develops and it can also allow the body to develop insulin resistance, type 2 diabetes, and cardiovascular disease.

Lack of physical activity is also associated with insulin resistance that usually leads to type 2 diabetes. The muscles of people who are active burn stored glucose and then refill with glucose taken from the bloodstream. This keeps glucose levels within normal ranges. Besides having more glucose remain in the body if a person is inactive, lack of muscle from not exercising means that muscles are not able to burn glucose to keep blood glucose levels within the normal range. The more muscle a body has, the better able it is to keep insulin levels normal.

Some of the other factors that contribute to insulin resistance are ethnicity, certain diseases, hormones, steroid use, certain medications, older age, sleep problems (especially sleep apnea) and cigarette smoking.

From Insulin Resistance to Diabetes

When a person develops insulin resistance, muscle, fat and liver cells are not able to absorb glucose from the bloodstream. In order for glucose to enter cells, the body then requires more insulin. In time, cells in the pancreas attempt to produce more insulin to overcome insulin resistance. As long as they can do this, blood sugar levels stay within the normal range. When insulin resistance has existed for some time, prediabetes and eventually type 2 diabetes can develop. Extra glucose accumulates in the blood, which leads to diabetes and can result in a variety of serious health disorders.

Source: National Diabetes Information Clearinghouse