Type 2 Diabetes
Diabetes Type 2
Diabetes is a condition in which the body cannot properly store and use fuel for energy. The body’s main fuel is a form of sugar called glucose, which comes from food (after it has been broken down). Glucose enters the blood and is used by cells for energy. To use glucose, the body needs a hormone called insulin that’s made by the pancreas. Insulin is important because it allows glucose to leave the blood and enter the body’s cells.
Diabetes develops when the body can’t make any or enough insulin, and/or when it can’t properly use the insulin it makes. For some people with diabetes, the body becomes resistant to insulin. In these cases, insulin is still produced, but the body does not respond to the effects of insulin as it should. This is called insulin resistance. Whether from not enough insulin or the inability to use insulin properly, the result is high levels of glucose in the blood, or hyperglycemia.
There are two main types of diabetes: type 1 diabetes and type 2 diabetes. About 90% of people with diabetes have type 2 diabetes, which used to be called adult onset diabetes. However, more and more children are being diagnosed with type 2 diabetes due to the rise in obesity.
Some people do not have diabetes but also do not handle glucose as well as normal. This is called impaired glucose tolerance (IGT). Up to 40% of people with IGT will eventually develop type 2 diabetes.
In type 2 diabetes, either the pancreas does not make enough insulin and/or the body does not use it properly. No one knows the exact cause of type 2 diabetes, but it’s more likely to occur in people who:
- are over 40 years of age
- are overweight
- have a family history of diabetes
- developed gestational diabetes during a pregnancy
- have given birth to a baby that is more than 4 kg (9 lbs)
- have high blood pressure
- have high cholesterol
- have IGT or impaired fasting glucose
- are of Aboriginal, Hispanic, Asian, South Asian, or South African descent
Symptoms and Complications
People with type 2 diabetes may not have symptoms for years or decades, but as the disease progresses and blood sugar levels rise, symptoms develop. People with type 2 diabetes may have the following signs and symptoms:
- blurred sight
- decreased sensation or numbness in the hands and feet
- dry, itchy skin
- frequent bladder and vaginal infections
- frequent need to urinate
- increased thirst and hunger
- male impotence (erectile dysfunction)
- slow healing of cuts or sores
Unfortunately, many people with type 2 diabetes go undiagnosed for several years and are not diagnosed until they go to the doctor with symptoms or complications of diabetes.
High blood sugar levels (hyperglycemia) can lead to a condition called glucose toxicity. This leads to further damage to the pancreas, and the body is less able to produce insulin. Without insulin, glucose levels continue to rise to levels that can cause damage to organs such as the eyes, nerves, and kidneys. These problems are similar to the complications associated with type 1 diabetes.
People with diabetes are at greater risk for problems that involve damage to small blood vessels and nerves due to high levels of glucose in the blood. They are also at a greater risk of developing hardening of large arteries (atherosclerosis), which can result in a heart attack, stroke, or poor blood flow to the legs.
Damage to small blood vessels can affect the eyes, kidneys, and nerves. Damage to eyes, specifically the retina, is called diabetic retinopathy and is the leading cause of blindness. Damage to the kidneys, called diabetic nephropathy, can lead to kidney failure and the need for dialysis. Damage to the nerves that supply the legs and arms and gastrointestinal tract is called diabetic neuropathy. Some people with diabetes who develop peripheral neuropathy (damage to the nerves in the legs) and have poor blood flow to the legs may eventually need an amputation.
If blood glucose levels become very high, especially when there are other stresses such as an infection, people with type 2 diabetes may become confused, dizzy, and have seizures. This can lead to a condition called non-ketonic hyperglycemia-hyperosmolar coma and requires immediate medical attention.
Fortunately, the complications of diabetes can be prevented, delayed, or slowed by controlling blood glucose levels to as close to the normal range as possible.
Making the Diagnosis
To diagnose diabetes, doctors will take a medical history (ask you about symptoms) and ask for blood and urine samples. Finding protein and sugar in the urine are signs of type 2 diabetes. Increased glucose and triglyceride (a type of lipid or fat) levels in the blood are also common findings. In most cases, blood glucose levels are checked after a person has been fasting for 8 hours.
If the fasting blood glucose level is 7.0 mmol/L (126 mg/dL) or higher, a diagnosis of diabetes is made. If the fasting blood glucose level is between 6.1 mmol/L and 6.9 mmol/L, the person has impaired fasting glucose and is at risk for developing type 2 diabetes.
Diabetes can also be diagnosed if a blood glucose level taken any time of the day without regards to meals is 11.1 mmol/L or higher, plus you have symptoms characteristic of diabetes (e.g., increase thirst, increase urination, unexplained weight loss). A doctor may also examine the eyes for signs of damage to the blood vessels of the retina (back of the eye). Finally, diabetes mellitus is diagnosed if the 3-month cumulative blood sugar average test, known as hemoglobin A1C or glycated hemoglobin, is 6.5% or higher.
Treatment and Prevention
The main goal of diabetes management is to maintain blood glucose levels within the normal range as much as possible. Weight control, diet, and exercise are all important components of management. The most important and main treatment for type 2 diabetes is nutritional.
Although some people with this type of diabetes are thin, the majority of people (90%) are overweight. Losing weight, even 2 kg to 5 kg (5 lbs to 10 lbs) can help lower blood glucose levels. For many people, following a healthy diet and an exercise program may be all that is needed to help control glucose levels. For others, healthy eating and exercise alone aren’t enough to lower blood glucose levels.
They may need to take medications in order to keep glucose levels within a healthy range. Medications for type 2 diabetes are usually taken by mouth in the form of tablets and should always be taken around meal times and as prescribed by the doctor. However, if blood glucose is not controlled by oral medications, a doctor may recommend insulin injections.
There are several types of oral diabetes medications, also called oral hypoglycemics, which work to lower blood glucose:
- sulfonylureas: This family of medications includes gliclazide, glimepiride, and glyburide. These medications are widely recommended for type 2 diabetes and work by stimulating the pancreas to release insulin. However, these medications don’t work for type 1 diabetes.
- biguanides: These medications include metformin and work to improve insulin sensitivity and to reduce the glucose produced by the liver.
- acarbose: This type of medication prolongs the absorption of carbohydrates after a meal. For these pills to work, they must be taken with or after a meal.
- thiazolidinediones: This family of medications includes pioglitazone and rosiglitazone and they work to improve insulin sensitivity.
- meglitinides: This family of medications includes repaglinide and nateglinide. They lower postprandial (after meals) glucose levels by stimulating the pancreas to release insulin.
- dipeptidyl peptidase-4 inhibitors: This class of medications includes sitagliptin and saxagliptin. They help improve insulin release from the pancreas and decrease liver release of glucose.
- GLP-1 analogs: This class of medications includes liraglutide, which is a synthetic form of the hormone GLP-1. It helps the body release insulin when blood sugar levels are high, and also reduces the release of sugar from the liver. It is taken as a daily injection under the skin.
- SGLT-2 inhibitors: this class of medication promotes the excretion of glucose via urination to lower blood glucose levels. In addition to lowering blood sugar, this class has shown effectiveness in promoting weight loss, as well as a modest drop in blood pressure.
Doctors may recommend one or more types of medications to help control diabetes. While taking medications, it’s important for people with diabetes to regularly test their blood glucose levels at home. There are many different blood glucose meters available on the market. Speak to a doctor or pharmacist about these meters to help you select the best meter for your needs.
As part of proper diabetes management, it is important to be aware of the symptoms of abnormal blood glucose levels and know how to properly monitor your blood glucose levels using a home glucose meter. You should remember to always keep glucose tablets or candies containing sugar with you at all times to manage low blood glucose levels (hypoglycemia). Symptoms of low blood glucose include:
- cold, clammy skin
- rapid heart rate
To prevent complications, it’s important to follow your diabetes management plan with a well-balanced diet and exercise. If you take medications for your diabetes, it is important to take them exactly as prescribed by your doctor.
Here are some tips to help you stay healthy and prevent some of the long-term complications:
Foot care: Poor circulation and nerve damage caused by diabetes reduce sensitivity in the feet. It’s important to check your feet regularly, looking for any blisters, cuts, or sores. Always keep your feet clean and dry and protect them by wearing socks and comfortable shoes.
Eye care: Eye problems (retinopathy) due to diabetes can lead to blindness. Therefore, have your eyes checked by an eye doctor (ophthalmologist) at least once a year. By treating problems early, serious complications can be avoided.
Skin care: High blood glucose and poor circulation can lead to skin problems such as slow healing after an injury or frequent infections. Make sure to wash every day with a mild soap and warm water, protect your skin by using sunscreen, take good care of any cuts or scrapes with proper cleansing and bandaging, and see your doctor when cuts heal slowly or if an infection develops.
Education: People with diabetes should learn as much as possible about this condition and how to manage it. The more you know about your condition, the better prepared you are to manage it on a daily basis. Many hospitals offer diabetes education programs and many nurses and pharmacists have been certified to provide diabetes education. Contact a local hospital, doctor, or pharmacist to find out about programs and diabetes educators in your area.
*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.