| People with type 1 diabetes (also called insulin-dependent diabetes mellitus or
IDDM) don't produce insulin and need regular shots of it to keep their blood
glucose levels normal. Type 1 diabetes was once called juvenile-onset diabetes,
but that name has been dropped because type 1 diabetes also strikes young and
older adults alike. Type 1 diabetes accounts for about 5% to 10% of those who
have the disease.Risk factors A family history of the disease increases risk.
Diabetes happens in people of every race, but it's most common among whites.
Half of those diagnosed with type 1 are under 20. Being age 20 or younger
increases your risk. What causes it?Most children of parents with diabetes do
not develop the disease. However, scientists have long suspected that heredity
plays a role because type 1 diabetes tends to run in families. Researchers have
identified several genes that appear to increase risk of type 1 diabetes. But
they haven't yet found a single gene that causes the disease. Type 1 diabetes
has many hallmarks of an auto-immune condition. In auto-immune diseases, the
immune system, which protects you from disease by killing invading germs,
mistakes the body's own cells for germs and destroys them. In the case of type 1
diabetes, the immune system kills the cells in the pancreas that produce insulin
(beta cells). Type 1 diabetes often strikes shortly after a viral infection, and
doctors sometimes notice a sharp jump in type 1 diabetes diagnoses after viral
epidemics. Which viruses? Candidates include those that cause mumps, German
measles, and a close relative of the virus that causes polio. |
Approximately 95 percent of people with diabetes have type 2 disease (also
called non-insulin-dependent diabetes mellitus or NIDDM). Those with type 2
produce insulin, but the cells in their bodies are "insulin resistant" -- they
don't respond properly to the hormone, so glucose accumulates in their blood.
Some people with type 2 diabetes must inject insulin, but most can control the
disease through a combination of weight loss, exercise, a prescription oral
diabetes medication, and tight control.Risk factors Like type 1 diabetes, type 2
disease also runs in families. Most people diagnosed with type 2 are age 30 or
older. Half of all new cases are age 55 and older. Compared with whites and
Asians, type 2 diabetes is more common among Native Americans,
African-Americans, Latinos, and Hispanics. Insulin resistance worsens as weight
increases and physical activity decreases. Many people with type 2 diabetes have
sedentary lifestyles and are obese; they weigh at least 20 percent more than the
recommended weight for their height and build. Lack of exercise, especially in
those who are overweight, increases risk. If you developed gestational diabetes
during pregnancy, you're at a higher risk of type 2 diabetes later. Women who
have given birth to babies weighing 9 pounds or more are at an increased risk.
These include thiazide diuretics (used to manage high blood pressure) and
steroids (used to help with inflammatory conditions). What causes it?Scientists
are not certain, but type 2, like type 1 diabetes, runs in families, which
suggests some genetic connection. In fact, a genetic link seems even stronger in
type 2 diabetes than in type 1. Scientists have not yet put their finger on a
single gene that causes the disease, but they are finding errors in several that
may contribute to the disease. Researchers also suspect a genetic susceptibility
to obesity.Obesity is the single most important cause of type 2 diabetes.
Definitions of obesity differ, but in general, you're obese if you weigh at
least 20 percent more than what's recommended for your height and build.
Three-quarters of people with type 2 diabetes are overweight. For reasons that
remain unclear, carrying excess body fat somehow causes insulin resistance.
That's why type 2 diabetes is usually treated with diet and exercise.Losing
weight and gaining muscle helps the body use insulin more efficiently. Where you
carry your weight is as important as how much you carry. People who carry their
fat above their hips have a greater risk of developing type 2 diabetes than
those who carry it on their hips Age also plays a role in type 2 diabetes. Half
of all new diagnoses are in people age 55 and above, and nearly 11 percent of
Americans ages 65 to 74 have type 2 diabetes. However, researchers don't know if
age is a cause of type 2 diabetes or simply a reflection of the fact that people
tend to gain weight and become less physically active as they grow older. |
Gestational diabetes develops only in pregnant women with no previous history of
diabetes. Nearly 135,000 U.S. women develop gestational diabetes each
year.Typically, gestational diabetes clears up on its own after women have
delivered their babies. But studies show that about 40% of women with
gestational diabetes go on to develop type 2 diabetes within 15 years. All
pregnant women should be tested for gestational diabetes between their 24th and
28th weeks of pregnancy.Keeping a healthy weight, eating healthy food and
regular exercise during pregnancy may help prevent insulin resistance and
gestational diabetes.Risk factors Diabetes tends to run in families. Too many
pounds increases insulin resistance. Native Americans, African-Americans, and
people of Hispanic or Latino descent are at increased risk. Whites and Asians
have a lower risk.What causes it? Hormones may play a role. Pregnant women
produce various hormones essential to their baby's growth. However, these
hormones may interfere with the mother's body's ability to properly use insulin,
causing insulin resistance.All pregnant women have some degree of insulin
resistance. But if this resistance becomes full-blown gestational diabetes, it
usually appears around the 24th week of pregnancy. That's why all pregnant women
should be screened for gestational diabetes around that time. |
