Type 2 diabetes takes many years to develop and most people are unaware of their illness. People often get diagnosed when complications of diabetes have already developed. Up to 50% of people who have diabetes, or who are prediabetic, are not aware.
Type 2 diabetes accounts for up to 95% of all diabetes in high-income countries. In Singapore, the prevalence of type 2 diabetes in the 18-69 age group is 8.2%.
WHAT IS TYPE 2 DIABETES?
At diagnosis, type 2 diabetics are unable to make enough insulin to meet the body’s needs for sugar. The body’s insulin requirements are dependent upon food intake, weight and exercise levels.
Insulin is a hormone that allows the cells of the body to use sugar. Insulin is produced by certain cells called islet cells in the pancreas. The pancreas is an organ deep in the abdominal cavity.
Without enough insulin, sugar cannot be used by the body’s cells and they will fail to function properly. The sugar that is digested ends up floating around in the blood instead of going into the cells, causing high levels of blood sugar.
Over a long enough time or high enough sugar level, diabetes will damage the eyes, kidneys, nerves and blood vessels.
WHY DOES TYPE 2 DIABETES DEVELOP?
The pancreas’ ability to produce insulin is limited. Beyond a certain amount, the islet cells of the pancreas are stretched beyond what they can produce and this stretch will damage them. They become weaker, or even shut down entirely if they are stretched too much.
Over time, a poor diet high in sugar and carbohydrates (which are digested into sugars) stresses the insulin-producing cells (islet cells). A lack of exercise makes the islet cells weaker and reduces their insulin production as well. Weight gain (including time being obese) and smoking also make the cells weaker.
With a poor lifestyle (lack of exercise, eating too much carbohydrates and sugar, gaining weight, staying obese, and smoking), more islet cells shut down permanently (doctors call this insulin deficiency) and the remaining ones don’t work as well and weaken (also known as insulin insensitivity). The cells weaken via glucotoxicity and lipotoxicity. This is the hallmark of type 2 diabetes.
There comes a point where there just isn’t enough islet cells that work well to provide insulin for even basic functions of the body. People get diabetes at this point. Studies have put the estimated residual function of the islet cells at diagnosis to be around 20% compared to the 100% function that one is born with.
Because every available cell is working at their hardest now, when someone crosses the threshold of diabetes, this will accelerate the decline of the remaining good islet cells.
There are no symptoms when someone just develops diabetes, so it is important to do testing so that treatment is started as early as possible.
Without treatment, the decline of the remaining islet cells can be as quick as 5 years, after which the patient would have no islet cells left that can produce insulin, and he/she will require insulin injections.
QUICK FACTS: Risk Factors for Type 2 diabetes.
Age above 40
Being overweight, or large abdominal girth
Lack of exercise, or being sedentary.
Poor diet ( high sugars AND/OR carbohydrates)
Family History ( can be genetic, or cultural)
Smoking
Pacific Islanders ( strong genetic risk in Hawaiians, Filipinos, etc), Pima Indians
Maturity-Onset Diabetes in the Young (MODY) or Latent Autoimmune Diabetes of Adults (LADA) is uncommon, and is outside the scope of this article as the information cannot apply to everyone.
