Overview, Causes, & Risk Factors
Diabetes mellitus, often called diabetes, is a condition that makes it hardfor the body to control the level of glucose in the blood. This means it is hard for thebody to convert food into the energy that the body needs to work. Glucose is the mainform of sugar in the body.
What is going on in the body?
The pancreas, a long, thin organ located behind the stomach, makesinsulin. In most people, the pancreas makes extra insulin when they eat. It is thenreleased into the bloodstream. Insulin helps move glucose that is in the bloodstream tothe inside of cells in the body. Glucose is a key source of energy for the body. In aperson with diabetes, the pancreas cannot make enough insulin to keep up with thebody’s demand. So glucose cannot be moved into the cells and used. In some typesof diabetes, the body cells resist the insulin. As a result, glucose builds up in theblood. And that leads to a high blood glucose level, called hyperglycemia.
Some 17 million Americans have diabetes, according to the AmericanDiabetic Association, also known as ADA. There are three main types of diabetes.
- Type 1 diabetes.This type used to be known as insulin-dependent diabetes mellitus, IDDM, orjuvenile-onset diabetes. A person with this type makes little or no insulin. So he orshe needs to take insulin shots each day.
- Type 2 diabetes.This type used to be known as noninsulin-dependent diabetes mellitus, NIDDM, oradult-onset diabetes. This is by far the most common type of diabetes. Someone withtype 2 diabetes might make healthy or even high levels of insulin. Butobesitymakes his or her body resistant to its effect. Type 2 diabetes used to be rare inchildren. But with the increase in obesity in children, doctors are now finding that asmany as 1 out of each 20 children who have diabetes has type 2 diabetes. Of thesechildren, 85% are obese.
- Gestational diabetesor pregnancy-induced diabetes. This type of diabetes develops in a pregnantwoman. In most cases, this type of diabetes goes away after the woman’s child is born.
There are other types of diabetes that are less common. This categoryincludes diabetes caused by a genetic defect or pancreatic diseases. Other typesof diabetes are caused by hormonal problems or from being exposed to certaindrugs or chemicals.
- Diabetes caused by a hormonal imbalance. One example is Cushing syndrome,which involves high levels of adrenal hormones.
- Diabetes caused by medicines. These can include prednisone, oral contraceptives, or thiazidediuretics.
- Diabetes caused by other conditions. These include chronic inflammation,infection, or other damage to the pancreas.
What are the causes and risks of the disease?
Genetics may play a part in all types of diabetes mellitus. Othercauses and risks vary. They depend on the type of diabetes involved.
Type 1 diabetesdoes not always have a known cause. Experts believe it might be caused by anautoimmune disorder, in which the body makes antibodies that destroy pancreaticcells. Experts do know that type 1 diabetes is more common in whites than in othergroups.
Type 2 diabetesoccurs when the cells in the body are resistant to insulin. As a result, the bodycannot use blood glucose as well as it should. Risk factors for type 2 diabetes include:
- Obesity.This is the main cause of type 2 diabetes in both adults and children. A recentstudy showed a 33% increase in the number of Americans with type 2 diabetes overthe past 8 years. The increase was 70% in people ages 30 to 39 years old andwas linked to a sharp rise in obesity in this group.
- Race. This type of diabetes is more common in African Americans, HispanicAmericans, Asian Americans, Native Americans, and Pacific Islanders.
- Lack of physical exercise. A recent study showed that walking briskly for 30minutes a day at least 5 days a week reduces a woman’s risk of type 2 diabetes.
- High blood pressure.Experts define this as a blood pressure equal to or greater than 140/90.
- Low HDL level,known as the good cholesterol, and high triglyceride level. HDL levels equal to orless than 35 mg/dL and/or a triglyceride levelgreater than or equal to 250 mg/dL are considered unhealthy.
- Age of 45 or older.
- History of gestational diabetes,or having babies that weighed more than 9 pounds at birth.
- Hormonal changes linked to menopause.A recent study of 16,000 American women between the ages of 40 and 65 showedthat diabetes was one of the top six diseases diagnosed. A long-termstudy is under way to see if menopause and changes in hormone level arefactors in the development of type 2 diabetes.Gestational diabetesis considered when a woman has any abnormal glucose test result duringpregnancy.It may be the result of increased hormone levels during pregnancy, which workagainst insulin. Weight gain during pregnancy might also be a factor in causinggestational diabetes.
Almost all people who develop type 2 diabetes have a condition calledpre-diabetes first. Thiscondition used to be known as impaired glucose tolerance or impaired fastingglucose, and the ADA estimates that almost 16 million people over the age of 40have it. This condition occurs when blood glucose levels are higher than healthylevels but too low to be diagnosed as diabetes. Without lifestyle changes, mostpeople who have pre-diabetes will progress to type 2 diabetes within 10 years.
Symptoms & Signs
What are the signs and symptoms of the disease?
Symptoms partly depend on the type of diabetes a person has andhow long it has been untreated. Many patients with type 2 diabetes have nosymptoms at all. Any signs and symptoms are mostly related to high bloodglucose levels and include:
- bladder infections
- coma, which happens only if the diabetes gets too far out of control
- extreme hunger
- extreme thirst
- fatigue and weakness
- frequent urination in increased amounts
- nausea and vomiting
- skin infections, especially fungal or more serious bacterial infections
- visual problems, such as blurred vision
- weight loss despite increased hunger and thirst
A condition called ketoacidosismay occur in a person with type 1 diabetesif the person goes without enough insulin for too long. This is a severe complication andrequires medical attention right away. Symptoms include:
- deep rapid breathing, sometimes with a fruity odor to the breath
- extreme thirst
- frequent urination
- nausea andvomiting
- stomach pains
- upset stomach
Diagnosis & Tests
How is the disease diagnosed?
A doctor may suspect diabetes after taking a person’s health history anddoing a physical exam. Based on those results, the doctor may want to check for ahigh glucose level in the blood. There are several types of blood tests doctors canuse to diagnose diabetes, including:
- fasting plasma glucose test,which is the most common method to diagnose most cases of diabetes. In this test,a person is asked to fast overnight for at least 8 hours. In the morning, the level ofglucose in the blood is then checked. Healthy fasting plasma glucose levels areless than 110 milligrams per deciliter or mg/dL. A fasting plasma glucose level ofmore than 126 mg/dL usually suggests diabetes. Levels between 110 and 126 mg/dLare seen in pre-diabetes.
- oral glucose tolerance testwhich is the preferred way to diagnose gestational diabetes.It can also be used to diagnose type 2 diabetes and pre-diabetes. In this test, aperson is asked to drink a sweet liquid. Blood samples are then drawn at timedintervals. If a person does not have diabetes, the glucose levels will rise and thenfall quickly after drinking the sweet liquid. When a person has diabetes, glucoselevels will rise higher and fail to come down as fast as those in a person withoutdiabetes. If the blood glucose level is 140 to 199 mg/dL 2 hours after drinking theliquid, a diagnosis of pre-diabetes can be made.
- plasma glucose test,which can be done without fasting and is used as a screening tool. A level of200 mg/dL or higher suggests diabetes. If the level is above 200 mg/dL,a fasting glucose test or oral glucose tolerance testcan be done to confirm the diagnosis of diabetes.
Prevention & Expectations
What can be done to prevent the disease?
There is no way to prevent type 1 diabetes.But it may be possible to prevent type 2 diabetesin many cases! This is especially true once pre-diabetes is known. Even modestlifestyle changes can help prevent the onset of diabetes. This is why it is veryimportant to recognize pre-diabetes. The key is to:
- eat a healthy diet
- exercise 30 minutes a day at least 5 days a week
- maintain a healthy body weight
What are the long-term effects of the disease?
Over time, high blood sugar levels damage blood vessels, nerves, andother internal structures. Long-term effects of diabetes may include:
- Retinopathy, a disease in the retina of the eye that can cause blindness.Diabetes is the number one cause of blindness in adults who are younger thanage 40.
- Diabetic nephropathy,which is a disease of the kidneys. This disease can progress to a form of kidneyfailure known as chronic renal failure.Diabetes is the leading cause of chronic renal failure.
- Atherosclerosis,also known as hardening of the arteries. Artherosclerosis can lead toheart attacksand strokes.It can also cause poor circulation in the legs and feet.
- Diabetic neuropathy,which means damage to nerves in the arms and legs. This damage can cause numbness and pain inthe hands and feet. When combined with poor circulation, neuropathy can result indiabetic foot ulcersand leg infections that may require amputation.
- Autonomic neuropathy, which is a disorder that affects certain nerves. Itmay cause problems with digestion,diarrhea,erectile dysfunction, a rapid heartbeat,and low blood pressure.
Some of these long-term effects may begin even at the moderate-highlevels of blood glucose seen in pre-diabetes. This is why it is important to eat ahealthy diet, exercise 30 minutes a day, and keep body weight within ahealthy range. All of these actions can keep blood glucose withinhealthy levels. People with diabetes risk factors should also be screened forpre-diabetes on a regular basis.
What are the risks to others?
Diabetes is not catching and poses no risk to others. It does tend torun in families.
Treatment & Monitoring
What are the treatments for the disease?
Treatment depends on the type of diabetes that is present. A person withtype 1 diabeteswill most likely need insulin shots each day. These shots replace the insulinthat the pancreas cannot make on its own. A proper diet is also a key to staying healthy.
Gestational diabetes is also usually treated with diet and insulin shots as needed.
The most effective treatment available for type 2 diabetes is a change in lifestyle, including the following:
- Weight loss.Loss of as little as 10 to 15 pounds can help keep blood glucose under control.
- Healthy eating. A healthydiet can help with weight loss. And that can prevent the need for medicine.
- Regular exercise.Walking only 30 minutes a day can lead to better glucose control.
A person with type 2 diabetes may also be treated withoral medicines and/or insulin shots. Diabetes pills can work in four ways.
- They can stimulate the pancreas to make more insulin.
- They can help the cells in the body use insulin and glucose better.
- They can keep the starches that are eaten from being broken down into glucose inyour intestines.
- They can reduce the amount of glucose that is released from the liver.
Treating the underlying condition or stopping a certain medicine maycorrect diabetes that is caused by medicine or an illness. If this is not possible,diet, exercise, and pills or shots are used to control the blood glucose.
Careful monitoring and management help keep diabetes undercontrol and reduce the risk of long-term effects. A person with diabetes should:
- monitor his or her blood glucose levels at home
- take medicines as prescribed by the doctor
- know how to recognize and treat hypoglycemia,which is low blood glucose
- get regular eye checkups that include an examination of the retina after thepupil of the eye has been dilated with eye drops
- do thorough foot careon a daily basis
- follow a plan to monitor and treat changing blood glucose levels when sick orunder stress
- follow a healthy diet
- have regular checkups with the doctor
- get a pneumonia shot
- get a flu shot each fall
Treating the complications of diabetes may involve many differentspecialists. For example, a person with diabetes may need to see eye, heart, foot,hormone, and circulation specialists. Dieticians also help people with diabetes bydesigning a healthy eating plan. Dieticians can also suggest healthy calorie intake levelsand types of foods to eat.
What are the side effects of the treatments?
Side effects depend on the treatments used. If a personhas too much insulin in his or her body, the blood glucose levels can drop too low.This condition, called hypoglycemia,can cause the following symptoms:
The usual treatment for low blood glucose is to drink a sweet beverage or eat a sweetfood. If low blood glucose goes untreated, a person may pass out orhave seizures. Emergency medical care is crucial in this situation.
Some of the oral medicines used for type 2 diabetes may cause weightloss or gain,allergic reactions,or liver damage. Some may also cause low blood glucose levels.
What happens after treatment for the disease?
Diabetes generally cannot be cured, but it can be controlled withcareful management and treatment. A person with diabetes will need tohave close medical follow-up throughout his or her life to control blood glucoselevels and prevent serious complications.
How is the disease monitored?
A person with diabetes should keep all of his or her appointmentswith his or her primary doctor, as well as other scheduled specialists. Physical exams, blood tests, urine tests, foot and skin care, routine eye exams,and routine dental care are all part of basic care for a person with diabetes. Themain goal of treatment is to keep blood glucose levels as close to a healthy rangeas is safely possible. In general, ideal ranges of blood glucose levels are 80 to 120milligrams per deciliter (mg/dL) before meals and 100 to 140 mg/dL at bedtime. Anynew or worsening symptoms should be reported to the doctor.
Article type: xmedgeneral