Type 2 Diabetes
- Chris Woolston, M.S.
- Posted March 11, 2013
Type 2 diabetes used to be rare, the kind of disease that doctors saw only once in a long while. Today, diabetes afflicts over 20 million Americans -- an increase of roughly 14 percent in just the past few years -- and almost everyone knows at least one person who has it. But that doesn't mean it's well understood by most people. One out of three people with type 2 diabetes isn't aware that they have the condition, and even those who know they have it often aren't sure how to control it. As a result, many people needlessly suffer diabetic complications, including nerve damage, blindness, and amputations.
As you might expect, the rise in diabetes means a greater financial impact on the health care system as well. A report released at a conference of the International Diabetes Federation in Paris estimates that worldwide annual health care costs for people aged 20 to 79 with the disease are at least $153 billion -- and they may rise to as much as $396 billion by the year 2025. In fact, in some countries, the IDF says, diabetes is a greater financial strain on the health care system than the AIDS epidemic.
The good news is that while type 2 diabetes isn't curable, in some cases it is preventable -- and it's always manageable. If your doctor says you have the disease or are at risk of developing it, it's time to take action. By learning everything you can about diabetes, and following your doctor's instructions, you have a good chance of controlling your diabetes and leading a healthy life.
What is type 2 diabetes?
The story of diabetes starts with sugar (more specifically glucose). Sugar isn't found just in candy or other sweets. It livens up many other foods, from broccoli to bread. Starchy foods like mashed potatoes and pasta also contain large amounts of carbohydrates that can quickly turn into sugar. Whenever you eat something containing glucose, the sugar quickly enters your bloodstream and gives you a quick boost of energy. So far, so good.
Your blood doesn't really need any extra sugar, but many cells throughout the body require glucose for energy. Whenever sugar levels in the blood start to rise, the body goes on "alert," causing the pancreas to release insulin -- a hormone that signals cells to start taking in the glucose and burning it for energy. If all goes well, cells get some much-needed fuel and the body's blood sugar level drops back to normal.
However, when you have diabetes, this balance between sugar and insulin is out of kilter, depending on which form of diabetes -- type 1 or type 2 -- you have. (People with type 1 diabetes produce little or no insulin on their own. As a result, they need frequent insulin injections just to keep their blood sugar under control.) At least 90 percent of all people with diabetes have the type 2 variety. People with this condition can make insulin, but it doesn't work very well. For someone with type 2 diabetes, there are two basic problems: First of all, the pancreas doesn't produce enough insulin relative to how much the body needs. Second, cells don't respond to insulin the way they should. (In other words, the cells don't always heed the signal to start burning sugar.) This is called insulin resistance.
The magnitude of these two problems varies from person to person. Some people have a shortage of insulin but don't have much insulin resistance. Others make near-normal amounts of insulin, but have a high level of resistance. Either way, it adds up to trouble if left untreated.
What are the potential complications of type 2 diabetes?
A little excess sugar in the blood is harmless, but sugar levels that stay too high for too long can damage blood vessels and nerves throughout the body. Diabetics have a higher risk of developing heart disease, kidney failure, blindness, impotence, and amputations of toes, feet, or lower extremities. Amputations can become necessary because of very poor circulation.
What causes type 2 diabetes?
Nobody knows exactly why type 2 diabetes develops, but experts agree that it probably takes a combination of genes and lifestyle to set the disease in motion. For instance, inactivity and obesity can lead to insulin resistance. If an overweight, inactive person also happens to have a genetic defect that slows down the production of insulin or creates insulin resistance that could mean diabetes is just around the corner.
Who is at risk for type 2 diabetes?
People who fall into one or both of the two biggest risk categories -- obesity and inactivity -- are especially susceptible because these factors can keep your body from burning sugar properly. Extra fat around the midsection is especially likely to lead to insulin resistance.
Obesity, in fact, has long been statistically linked with type 2 diabetes, but exactly why millions of overweight people develop type 2 diabetes is still a medical mystery. Some research shows that a hormone called resistin, which is produced by fat cells, incites tissues to resist insulin.
Other research suggests that fat and skeletal hormones together, along with signals from the sympathetic nervous system, may work in concert to regulate sugar. Fat produces a hormone called leptin which acts as a regulator of bone metabolism, and bone produces a hormone called osteocalcin. The sympathetic nervous system, which regulates the body in stressful situations, controls the amount of leptin the body produces. In animal studies, scientists have shown that higher levels of osteocalcin make mice more sensitive to insulin, increasing insulin production and slimming down fat mice.
Type 2 diabetes follows other patterns as well. It's especially common in people with a family history of the disease, and it seems to single out certain ethnic groups, including African Americans, Latinos, Native Americans, and Pacific Islanders. Type 2 diabetes is most common in people over 45, but the ranks of younger patients (including teenagers) with the disease have grown dramatically in recent years. Notably, women who have gestational diabetes during pregnancy are at increased risk for type 2 diabetes later in life.
What are the different stages of type 2 diabetes?
Type 2 diabetes doesn't just appear out of nowhere. Most people go through a few distinct steps on the way to developing the full-blown disease. In the earliest stage, the pancreas produces extra insulin to try to keep high blood sugar under control. This condition is called hyperinsulinemia. At this point people may not show any symptoms.
Over time, the cells in the body often become increasingly resistant to insulin's signal to burn sugar. As the pancreas works overtime to produce more and more insulin, sugar levels start to climb higher, especially after meals. This starts a vicious cycle because the extra sugar in the blood damages cells in the pancreas, further slowing down the flow of insulin. As insulin levels drop, blood sugar rises even further. Eventually, high sugar levels will linger even when the stomach is empty. This is diabetes.
A few people with insulin resistance manage to compensate by making extra insulin and never go on to develop full-fledged diabetes. However, even though their blood sugar is normal, their health may still be in danger. They often develop a group of conditions -- including high blood pressure, low levels of HDL (good) cholesterol, and high triglycerides (blood fat) -- that puts them at high risk for heart disease. Doctors call this metabolic syndrome or "syndrome X".
What are the symptoms of type 2 diabetes?
People in the early stages of type 2 diabetes often have no symptoms at all. But over time, the body will start to show signs of trouble. Possible symptoms of diabetes include the following:
- Increased thirst
- Frequent urination during the day or night
- Increased hunger
- Blurry vision
- Frequent infections of the skin, gums, or bladder
- Extremely dry, itchy skin
- Unexplained weight loss
- Numbness or tingling in the feet
- Slow healing of cuts or bruises
How is type 2 diabetes diagnosed
If you have symptoms of diabetes or are at high risk for the disease, your doctor will do one of two tests to measure the amount of glucose in your blood. The measurements are usually conducted at two different times. One reading is taken right after you've fasted for at least eight or nine hours, and the other is taken on a day when you have had regular meals. If the fasting reading is more than 126 milligrams of glucose per deciliter of blood (mg/dL), or if the non-fasting reading is over 200 mg/dL along with symptoms of diabetes, you probably have diabetes. Your doctor may want to repeat the tests to confirm the results, especially if you don't show any symptoms of the disease.
What is the treatment for type 2 diabetes
Recent guidelines from diabetes specialists suggest that everyone with type 2 diabetes should start on medicine in addition to a healthy diet and regular exercise, like walking, cycling, or swimming. A low-fat, balanced diet with lots of fruit, fiber, and vegetables helps many people keep their blood sugar under control. Diet and exercise are especially important for overweight patients. According to a report in the journal Nursing Clinics of North America, losing just 12 to 30 pounds can greatly reduce a person's need to take medication for diabetes.
The basics of a healthy diabetic diet are the same as those of a healthy regular diet. It should be low in fat (less than 30 percent of calories from fat), high in fiber, and rich in fruits and vegetables. Of course, people with diabetes have to be extra cautious. No food is off-limits, but indulging in sugary or high-carbohydrate foods, whether it's candy or pasta, can send blood sugar soaring. Anyone with diabetes should plan meals carefully with the help of a registered dietitian (RD) or an experienced certified diabetes educator (CDE).
How much exercise should I do to help control my diabetes?
Researchers have long known that exercise helps people with type 2 diabetes, but until recently no one knew how much was actually needed. But an Italian study published in Diabetes Care reported exactly how much you need to both improve your health and lower your medical costs: Walk at least three miles a day.
The Italian researchers found the greatest improvements in health and medical costs resulted by increasing physical activity by about 83 minutes a day (walking 5.3 miles, or 10,600 steps). But researchers found that people with type 2 diabetes who increased their exercise by just 38 minutes a day (2.2 miles, or 4,400 steps) over a two-year period significantly reduced their blood sugar, triglycerides, total cholesterol, and blood pressure, resulting in a two-fold decrease in the risk of heart disease. (Annual medical costs also dropped by $288.) Study participants who stayed inactive over the two-year period, on the other hand, showed a decline in their health and higher medical expenses.
If going to the gym or taking a hike intimidates you, remember, any kind of exercise is better than none. The American Diabetes Association recommends 150 minutes of moderate-intensity activity a week.
What kinds of drugs are used to treat diabetes?
Unfortunately, diet and exercise alone may not be enough to rein in high blood sugar and your doctor may prescribe a pill that lowers it. Among the major types of oral diabetes drugs:
- biguanides (Glucophage)
- thiazolidinediones (Actos)
- sulfonylureas (Glucotrol, Micronase, DiaBeta)
- glucosidase inhibitors (Precose, Glyset)
- glinides (Prandin, Starlix)
Whichever drug (or drug combination) your doctor prescribes, follow the instructions exactly, and ask your doctor about potential side effects. Some of these drugs have serious safety warnings. In fact, citing concerns about an increase in heart attack risk, the U.S. Food and Drug Administration in September 2010 significantly restricted the use of Avandia.
Pills are not the only option for type 2 diabetics. Some patients may need insulin injections to achieve good control of their blood sugar level. Whether a doctor recommends pills or injections depends on many factors. For some people, pills along with diet and exercise may be enough to lower blood sugar. Some patients may also need insulin or other medicines that are injected, like Byetta or Symlin, to achieve good control of their blood sugar level. Insulin is sometimes prescribed right away, but most often it is used when oral drugs alone fail to do the job.
Whatever the approach to managing your diabetes, the overall goal is the same: Keeping your blood sugar, blood pressure, and lipids (cholesterol and triglycerides) within a healthy range. By controlling these, you can dramatically reduce your risk of heart disease, blindness, kidney disease, amputations, and other diabetic complications.
Can type 2 diabetes be prevented
Few people are predestined to have type 2 diabetes. In fact, up to 90 percent of cases may be preventable through diet and exercise, according to a study published in the New England Journal of Medicine. Researchers from the Harvard School of Public Health surveyed 85,000 female nurses about their health habits. Over the next 16 years, 3,300 of these women developed type 2 diabetes. After comparing the lifestyles of women who became diabetic with those who did not, the researchers concluded that 91 percent of all cases "could be attributed to habits and forms of behavior."
Diet and exercise are especially crucial for anyone at high risk for diabetes. The Diabetes Prevention Program, a three-year study involving more than 3,200 high-risk patients, found that people who adopted a low-fat diet and exercised for 150 minutes each week cut their odds of type 2 diabetes by 58 percent.
If you are at high risk of developing type 2 diabetes, are obese, and under 60 years of age, or if you have pre-diabetes, your doctor will likely recommend a special diet and exercise regimen, in addition to taking the diabetes drug metformin.
Type 2 diabetes is a potentially devastating disease, but the key word is "potentially." It can be controlled, and it may be prevented. Millions of people have gained control over this disease, and you can, too.
Food and Drug Administration. FDA significantly restricts access to the diabetes drug Avandia. Sept. 23, 2010
American Diabetes Association. Clinical Practice Recommendations 2009. Diabetes Care. Volume 32, Supplement 1. January 2009. http://care.diabetesjournals.org/cgi/content/full/32/Supplement_1/S13#SEC4
Food and Drug Administration. FDA Approves First Ever Inhaled Insulin Combination Product for Treatment of Diabetes. January 2006. http://www.fda.gov/bbs/topics/news/2006/NEw01304.html
Food and Drug Administration. FDA Issues Safety Alert on Avandia. May 2007. http://www.fda.gov/bbs/topics/NEWS/2007/NEW01636.html
Lee NK et al. Endocrine regulation of energy metabolism by the skeleton. Cell. 130 (3):456-69. August 2007.
Hinoi E et al. The sympathetic tone mediates leptin's inhibition of insulin secretion by modulating osteocalcin bioactivity. The Journal of Cell Biology. 183(7):1235-42. December 2008.
American Academy of Family Physicians. Metabolic Syndrome. November 2006. http://familydoctor.org/online/famdocen/home/common/heartdisease/basics/826.html
American Diabetes Association. Clinical Practice Recommendations 2008. Diabetes Care. Volume 31, Supplement 1. January 2008. http://care.diabetesjournals.org/cgi/content/full/31/Supplement_1/S12
National Diabetes Education Program. Diabetes Medications Supplement. http://www.ndep.nih.gov/diabetes/pubs/Drug_tables_supplement.pdf
American Association of Clinical Endocrinologists. Medical Guidelines for Clinical Practice for the Management of Diabetes Mellitus. Endocrine Practice. Volume 13, Supplement 1. May/June 2007. http://www.aace.com/pub/pdf/guidelines/DMGuidelines2007.pdf
Quinn L. Type 2 diabetes: Epidemiology, pathophysiology, and diagnosis. Nursing Clinics of North America. June 2001. 36(2): 175-192.
Conlon PC. A practical approach to Type 2 diabetes. Nursing Clinics of North America. June 2001. 36(2): 193-202.
US Department of Health and Human Services. Diet and exercise dramatically delay Type 2 diabetes. August 6, 2001.
Managing Type 2 diabetes. Journal of the American Medical Association (patient page). January 12, 2000. 283(2): 288.
Hu FB et al. Diet, lifestyle, and risk of Type 2 diabetes mellitus in women. New England Journal of Medicine. September 13, 2001. 345(11): 790-797.
Emery, G. Study finds adult diabetes is 90% preventable. New England Journal of Medicine. September 13, 2001.
Khan, NM, Hershey, CO. Update on screening for Type 2 diabetes. Postgraduate Medicine, February, 2001 109(2)
World Facing Diabetes Catastrophe: Experts. Emelia Sithole. August 25, 2003 Reuters Health Information.
National Diabetes Fact Sheet. American Diabetes Association.
Newly-released CDC Study on Diabetes Reflects Growing Diabetes Epidemic; Illustrates Need for Heightened Research and Prevention and Improved Health Care for Diabetes-20.8 Million Americans Now Have Diabetes, Up 14 Percent Since 2003. American Diabetes Association. October 26, 2005
More Exercise Produces Bigger Benefits for Diabetics. Food and Fitness Advisor, Weill Medical college of Cornell University. Volume 8, Number 8. August 2005.
Ohio University. NIH Study to Probe Impact of Growth Hormone on Body Fat. April 2005. http://news.research.ohiou.edu/news/index.php?item=153