Diabetes: Symptoms, signs and causes
Diabetes has reached epidemic levels, and in fact is the seventh leading cause of death in the United States, but many people don't know exactly what it is, beyond the fact that is has something to do with sugar levels.
This week on “Take Care,” Dr. David Nathan discusses diabetes, how it’s caused and what symptoms to check for if you’ve developed it. Nathan is a professor of medicine at Harvard Medical School and director of the General Clinical Research Center and of the Diabetes Center at Massachusetts General Hospital.
More than 29 million people in the U.S. have diabetes, a very common chronic metabolic disease.
“By metabolic, I mean that it affects the endocrine system and it affects a number of different substances in the blood. The one that we think about most commonly, of course, is blood sugar or blood glucose.”
There are two types of diabetes – type 1 or juvenile diabetes and the most common one, type 2, also referred to as adult-onset diabetes.
Type 1 and type 2 diabetes both impact the way the body handles insulin – either there isn’t enough insulin or there isn’t enough sensitivity to insulin and blood levels increase.
Type 1 occurs most commonly occurs among youth. Type 1 is caused by an auto-immune attack to the pancreas, where insulin is produced. Therefore, those with Type 1 diabetes are unable to produce insulin, which causes an increase in blood sugar.
In Type 2 diabetes, the insulin-producing cells do not work as well as they should.
“For many people, they may have this tendency and it never expresses itself, it never causes a clinical problem,” Nathan says. “However, if one develops insulin resistance or a decreased sensitivity to insulin, the combination of not making enough insulin but needing more of it leads to the much more common Type 2 diabetes.”
Type 2 diabetes currently affects 10 percent of the adult population.
If a person has had diabetes for 10 to 20 years, they can develop complications that affect the eyes, kidneys and the heart.
“These are the complications that we most fear and worry about in diabetes but fortunately, ones that we actually know how to prevent or deal with if they develop,” Nathan says.
According to Nathan, diabetes is the single greatest cause of blindness and kidney failure and the largest cause of amputations in the U.S.
While diabetes has been a growing problem worldwide, Nathan says the U.S. has been seeing some recent declines in the number of people with the disease.
“Currently we have about 1.7 million new cases of diabetes in the U.S. every year,” Nathan says. “That’s a huge number of cases per year, but what we need to know is that about four years ago it was 2 million cases a year. So it actually looks like we may have hit the peak and it may be starting to decrease.”
According to Nathan, the reason so many people have diabetes is because of an obesity epidemic, a widespread discrepancy in caloric intake, or the energy we use versus the energy we take in.
“The real problem with the diabetes epidemic, what underlies it is the caloric imbalance which has led to overweight, obesity and a sedentary lifestyle,” Nathan says.
Many of the indicators that a person may have diabetes are non-specific, meaning it could be diabetes or it could be something else.
One warning sign is constant urination, which begins when the blood sugar levels rise to a high level.
If constant urination causes you to wake up frequently during the night to use the bathroom, it could be a symptom of diabetes. But it is something that can happen as you get older even without diabetes.
“When you urinate more you lose volume, you lose water in the urine and it makes you more thirsty and you’re actually finding you have to drink a lot more,” Nathan says. “People sometimes think they’re drinking more and that’s why they’re urinating more. In fact, it’s the opposite.”
Symptoms in diabetes are under-recognized, which is why Nathan recommends getting regular blood tests.
“A test that is done often is either just a blood sugar test or there’s another test called the hemoglobin A1C test, or A1C for short, and that measures average blood sugar over the previous three months,” Nathan says.
After age 45, these blood tests should become a standard part of a physical exam. However, if a person, at any age, is overweight, has a family history of diabetes or has hypertension, Nathan says a physician will become should order these blood tests.
Support for this story comes from the Health Foundation for Western and Central New York.