This is the most common form of diabetes. Type 2 diabetes occurs when the body does not have enough insulin and/or is unable to use it properly. In early stages, the pancreas produces extra insulin to make up for this deficiency. Over time the body is unable to keep up and cannot make enough insulin to maintain normal blood glucose levels.
Type 2 diabetes usually takes many years to develop, and it all starts with insulin resistance. By insulin resistance, we mean that cells throughout the body require higher amounts of insulin in order to respond to insulin’s signal.
Insulin resistance develops under the right set of circumstances, which include genetic factors and environmental factors (see figure below). While we cannot chance genetic factors, Environmental factors are a focus of diabetes prevention and treatment.
Figure 1: factors involved in developing insulin resistance
To overcome insulin resistance, the beta cells of the pancreas must work harder to make more insulin. Early on in the disease process, the beta cells will get multiply in order to keep up with the demand (beta cell hyperplasia). However, over time this strain eventually results in some of the beta cells failing to work properly. We call this early beta cell failure, because enough of the cells are functioning to keep the metabolism functioning mostly normal. During this phase, blood glucose levels are seen to be modestly higher than normal, which is called prediabetes. As more time passes, more of the beta cells lose function. It is estimated that around the point where about 80% of beta cell function is lost, the person transitions from prediabetes to diabetes. It takes years of insulin resistance to cause enough beta cell damage to cause diabetes. Once someone has enough insulin resistance and beta-cell failure to develop diabetes, there is not enough insulin production to overcome resistance, and glucose levels in the bloodstream be highly abnormal.
Figure 2: pancreatic beta cell failure leads to diabetes
Insulin resistance impacts organs throughout the body, disrupting normal metabolic function. Insulin resistance is associated with at least 8 metabolic defects that eventually lead to the development of diabetes, but this takes years to happen.
Figure 3: Insulin resistance causes widespread metabolic dysfunction
Because the foundation of type 2 diabetes is insulin resistance, treating insulin resistance is the foundation of treating type 2 diabetes. Proper nutrition and weight loss are critically important treatments for insulin resistance.
Type 1 diabetes is an autoimmune disease, like lupus, hashimoto disease, or rheumatoid arthritis. In autoimmune diseases, your immune system attacks the body. In type 1 diabetes, the immune system targets and destroys the cells of the pancreas. There is no cure for type 1 diabetes, and eventually enough cells are destroyed so that the pancreas can no longer produce insulin.
About 5% of people with diabetes have type 1 diabetes. While type 1 diabetes is usually diagnosed in children and young adults, it can occur at any age.
Type 1 diabetes must be treated with insulin. However, nutrition is also critically important to treating this condition as well.
LADA is similar to type 1 diabetes as it is an autoimmune disease that destroys the beta cells of the pancreas. Many researchers think of it as a subtype of Type 1 diabetes. However, it can take between two and six years for a person with LADA to become insulin-deficient and require insulin. This is much slower than type 1 typically progresses. During this transition period, the blood sugars will be high, but can be controlled with diet and non-insulin medications.
Because of this slow progression, patients with LADA are often misdiagnosed as having type 2 diabetes.
Specialized blood testing can differentiate between type 2 diabetes and LADA.
There is no cure for LADA, but there are some interventions that may slow the destruction of the pancreas. You can search for clinical trials here, or ask your doctor.
Gestational diabetes occurs during pregnancy. If uncontrolled, it can cause the baby to grow very large, leading to problems with the baby’s delivery. Gestational babies are more likely to become overweight or obese during childhood or adolescence, which can, in turn, lead to type 2 diabetes.
Women who develop gestational diabetes have up to a 60% chance of subsequently developing type 2 diabetes as they age, though this risk can be substantially decreased with diet and exercise.