Here's an overview of the most common types of diabetes:

Diabetes mellitus is defined as a fasting blood glucose of 126 milligrams per deciliter (mg/dL) or more. Prediabetes is a condition in which blood glucose levels are higher than normal (a fasting blood glucose level between 100 and 125 mg/dl) but not yet diabetic. Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) are intermediate states of abnormal glucose regulation between how a body normally uses glucose and diabetes.

Type 2 diabetes is the most common form of diabetes. It appears most often in middle-aged adults. Today, however, adolescents and young adults are developing type 2 diabetes at an alarming rate. It develops when your body doesn't make enough insulin or develops “insulin resistance” and can’t make efficient use of the insulin it makes.

Type 1 diabetes usually occurs in children and young adults. In type 1, the pancreas makes little or no insulin. Without daily injections of insulin, people with type 1 diabetes won't survive. 

Both type 1 and type 2 diabetes may be inherited in genes. A family history of diabetes can significantly increase the risk of developing diabetes. Untreated diabetes can lead to many serious medical problems. These include blindness, kidney disease, nerve disease, limb amputations and cardiovascular disease (CVD).

Treatment
Diabetes is treatable, but even when glucose levels are under control it greatly increases the risk of heart disease and stroke. In fact, most people with diabetes die of some form of heart or blood vessel disease.

Pre-diabetes and subsequent type 2 diabetes usually results from insulin resistance. When insulin resistance or diabetes occur with other CVD risk factors (such as obesity, high blood pressure, abnormal cholesterol and high triglycerides), the risk of heart disease and stroke rises even more.

When diabetes is detected, a doctor may prescribe changes in eating habits, weight control, exercise programs and medication to keep it in check. It's critical for people with diabetes to have regular check-ups.

Work closely with your healthcare provider to manage your diabetes and control any other risk factors. For example, blood pressure for people with diabetes should be lower than 130/80 mm Hg.

AHA Recommendation

Diabetes is a major risk factor for stroke and coronary heart disease, which includes heart attack. People with diabetes may avoid or delay heart and blood vessel disease by controlling the other risk factors.

It's especially important to control weight and blood cholesterol with a low-saturated-fat, low-cholesterol diet and regular physical activity. It's also important to lower high blood pressure and to not smoke.

Diabetes and Cardiovascular Disease

• high blood pressure
• lipid disorders
• high LDL (bad) cholesterol
• high triglycerides
• low HDL (good) cholesterol
• smoking
• obesity
• lack of physical activity
• poorly controlled blood sugars (too high) or out of normal range

Another emerging risk factor is insulin resistance, a core metabolic dysfunction of type 2 diabetes.

Understanding insulin resistance

Insulin resistance is a condition in which the body doesn't respond efficiently to the insulin it makes. According to Gene Therapy Weekly, it affects about 60 million people in the United States. One in four of them will develop type 2 diabetes when their body becomes unable to maintain normal insulin and glucose levels.

Here’s a list of conditions typically found in people with type 2 diabetes, and an explanation of how they contribute to a patient's risk for developing cardiovascular disease:

• Obesity is a major risk factor for cardiovascular disease and has been strongly associated with insulin resistance. Insulin resistance may be a mechanism by which obesity leads to cardiovascular disease.
  
  Weight loss can improve cardiovascular risk, decrease insulin concentration and increase insulin sensitivity. Obesity and insulin resistance also has been associated with other risk factors, such as high blood pressure. Learn how to manage your weight.
  
  
• Physical Inactivity is another modifiable major risk factor for insulin resistance and cardiovascular disease. Exercising and losing weight can prevent or delay the onset of type 2 diabetes, reduce blood pressure and help reduce the risk for heart attack and stroke.
  
  It's likely that any type of physical activity — whether sports, household work, gardening or work-related physical activity — is similarly beneficial. 
  
• Hypertension (high blood pressure) has long been recognized as a major risk factor for cardiovascular disease. Studies report a positive association between hypertension and insulin resistance. When a person has both hypertension and diabetes, a common combination, their risk for cardiovascular disease doubles. Learn more.
  
  
• Dyslipidemia  Atherogenic dyslipidemia, often called diabetic dyslipidemia in people with diabetes, is a condition associated with insulin resistance. This type of dyslipidemia is characterized by high levels of triglycerides (hypertriglyceridemia), high levels of small LDL particles and low levels of HDL. This lipid triad often occurs in patients with premature coronary heart disease.
  
  Growing evidence suggests that all of the components of the lipid triad can contribute to the development of atherosclerosis (fatty buildups in artery walls) and can be considered a risk factor. Even though most patients with diabetes don't have marked elevations of LDL cholesterol, their levels are high enough to support the development of atherosclerosis. Learn more about diabetes and cholesterol. 

Diabetes and Peripheral Artery Disease

Get a Leg Up on Peripheral Artery Disease
If you have diabetes, you're at higher risk of heart attack, stroke and peripheral artery disease (PAD).

PAD is a condition similar to coronary artery disease (clogged arteries that supply blood to the heart muscle) and carotid artery disease (clogged arteries leading to the brain). But it affects arteries leading to areas outside the brain and heart, most often in the legs and feet. In PAD, fatty deposits build up in the inner linings of the artery walls of the legs. This can cause pain in the legs, especially when walking. In extremely severe cases, limb amputation may be needed. This same buildup in the arteries of the heart and brain significantly increases your risk of heart attack and stroke.

What increases my risk?

• Smoking
• High blood pressure
• High cholesterol
• Overweight/Obesity
• Physical inactivity
• Poor control of blood glucose, or blood sugars that are not within a normal range 
• Family history of cardiovascular disease, stroke or PAD
• Previous history of coronary artery disease (heart attack, angina, angioplasty or bypass surgery) or stroke

What are the symptoms?
Symptoms include muscle cramps while walking, cold feet, decreased or absent pulses in the feet or legs, loss of fat under the skin of the calves, and hair loss on the lower legs. Typically, the pain caused by PAD goes away with rest and returns when you walk again. If you think you have PAD, consult your physician immediately.

What is the treatment for PAD?
Peripheral artery disease is treatable. The first step is usually to change your lifestyle such as by participating in a regular walking program, wearing special footwear and taking medications to help improve walking distance or to help prevent blood clots from forming.

A minority of patients may also need minimally invasive treatment or surgery, including angioplasty and stent placement or clot removal.

If a long part of an artery in your leg is completely blocked and you have severe symptoms, surgery may be necessary. Doctors can take a vein from another part of the body to bypass and reroute blood around the closed artery. Your healthcare professional will discuss options and help you choose the best procedure for you.

To reduce your risk of PAD:

• Keep your blood glucose levels as normal as possible. (If it's too high, this increases your risk of developing PAD). 
• Keep your blood pressure under 130/80 mmHg or lower, using medication if it's prescribed by your doctor.
• Get your cholesterol levels down, with medication if necessary.
• Control your weight.
• Ask your doctor if you should take an aspirin a day.
• Get regular physical activity as indicated by your doctor.
• Eat a heart-healthy diet low in saturated fat, cholesterol and salt.
• If you smoke, quit. If you don't smoke, don't start.

Taking these steps will reduce your risk of PAD, help reduce your chances of a heart attack or stroke and enhance your overall health and quality of life.

Diabetes Tests, Treatment and Medication

Your healthcare provider will often do periodic testing to assess whether you have developed other risk factors associated with cardiovascular diseases, such as high cholesterol, high blood pressure or peripheral artery disease.

Testing your heart
People with diabetes have a strong risk of cardiovascular complications such as heart attack and stroke, so it's good to know the different types of tests and treatments your healthcare provider may perform. Learn more.

Heart-healthy medications
High blood pressure and high cholesterol are both conditions that can greatly aggravate the vascular complications that arise from diabetes. They can also increase the risk of premature death.

There are many drug therapy choices, and your healthcare provider may choose several depending on the severity of your condition. Learn more about the medications for high blood pressure and cholesterol.

An aspirin a day: Will it keep a heart attack away?
Did you know that aspirin is a recommended line of defense against heart attack and stroke for people with diabetes? There are risks and side effects. Learn more before starting any new therapy.