Study: Diet, exercise can prevent diabetes
Changing lifestyle cuts in half chance of becoming diabetic
By Mark E. Heckathorn
At 68, Robert Huber of Cheverly, Md., was pre-diabetic and facing the possibility of having to take daily insulin shots and other medications for the rest of his life.
Weighing about 215 pounds and with a family history of diabetes, he was at risk of developing full-blown diabetes.
“My mother had diabetes,” Huber said. “As a matter of fact, she had her leg amputated as she got older because of the disease.”
What is type 2 diabetes?
Diabetes is a disease in which blood glucose levels are above normal. People with diabetes have problems converting food to energy.
After a meal, food is broken down into a sugar called glucose, which is carried by the blood to cells throughout the body. Cells use the hormone insulin, made in the pancreas, to help them process blood glucose into energy.
People develop type 2 diabetes because the cells in the muscles, liver and fat do not use insulin properly.
Eventually, the pancreas cannot make enough insulin for the body’s needs. As a result, the amount of glucose in the blood increases while the cells are starved of energy.
Over the years, high blood glucose damages nerves and blood vessels, leading to complications such as heart disease, stroke, blindness, kidney disease, nerve problems, gum infections and amputation.
Source: National Institutes of Health
By just changing his diet and exercising 150 minutes a week, Huber still has not developed diabetes eight years later.
Huber is a participant in the Diabetes Prevention Program sponsored by the National Institutes of Health.
He stumbled onto the clinical trial at a Howard University Hospital Health fair where he had a free diabetes screening. A few days later he received a call confirming that he was pre-diabetic and offering him a chance to participate in the study.
Study follows 169 local participants
The Diabetes Prevention Program and the follow-up Diabetes Prevention Program Outcomes Study by the NIH have been following 3,234 patients, including 169 people in the Washington area, for 10 years.
Participants were divided into four groups: one group was given a placebo, the second was given metformin, the third was given troglitazone and the final group took no medication but modified their lifestyle.
“We had to reduce our fat intake to 30 grams a day and calories to 1,200,” Huber said. “We were given extensive training in diet and exercise.”
The first year, participants kept a food diary and meet weekly with a nutritionist who went go over the diary and suggested changes. Huber also joined a gym and exercised 30 minutes five times a week.
“It was very difficult at first,” Huber said.
"Just think: just by exercising three times a week and losing 7 percent of your body weight, individuals could achieve almost 60 percent avoidance of the onset of diabetes," said Dr. Wayman Cheatham, who was a doctor at Howard University Hospital and one of the two local principal investigators.
Lifestyle changes prevent diabetes
“Those in the intensive lifestyle modification group who used diet and exercise had a 58 percent reduction in the occurrence of diabetes over three years versus placebo only,” said Cheatham, who is now assistant vice president and medical director at the Medstar Research Institute in the district.
There are 20.8 million children and adults in the United States who have diabetes, according to the American Diabetes Association. While an estimated 14.6 million have been diagnosed with diabetes, the association said 6.2 million people are unaware that they have the disease.
An estimated 41 million more people in the U.S. are pre-diabetic, or at risk of developing type 2 diabetes. Type 2, or adult-onset, diabetes results from insulin resistance when the body fails to properly use insulin, combined with relative insulin deficiency.
All study participants received general lifestyle information, said Sue Shapiro, the current program manager of the Diabetes Prevention Program Outcomes Study. Those in the intensive lifestyle modification group met weekly with a nutritionist and were offered lifestyle classes on various topics such as exercise, cooking and yoga.
Exercise programs and diets were tailored to the individuals according to their lifestyle, Shapiro said.
“People in the so-called intensive modification group lost on average 7 percent of what their weight was when they came into the program,” Cheatham said. Someone who weighed 300 pounds and lost 21 pounds or someone who weighed 200 pounds and lost 14 pounds were able to reduce their risk of developing type 2 diabetes 58 percent.
The people given metformin had a 31 percent reduction in diabetes while those on troglitazone saw a 70 percent reduction, Cheatham said. However, the troglitazone arm of the study was discontinued when the drug was shown to cause liver damage.
Type 2: signs and symptoms
More than 6 million people in the United States have type 2 diabetes and do not know it. Many have no signs or symptoms. Symptoms can also be so mild that you might not even notice them.
Here is what to look for:
- increased thirst
- increased hunger
- fatigue
- increased urination, especially at night
- weight loss
- blurred vision
- sores that do not heal
Many people do not find out they have the disease until they have diabetes complications, such as blurry vision or heart trouble. Finding out early if you have diabetes is important because treatment can prevent damage to the body from diabetes.
Source: National Institutes of Health
Study ended early to get word out
Because the results were so significant an external monitoring board recommended that the program be halted a year early. The researchers published their findings in the February 7, 2002, issue of the New England Journal of Medicine. A follow up report was published in the September 2006 issue of the journal Diabetes Care.
“No one had ever shown before that you could prevent type 2 diabetes,” Cheatham said. “A person who is overweight doesn’t have to become normal weight. It gives anyone who hasn’t developed type 2 diabetes a chance not to develop type 2.”
Since the original findings were published, a Finnish study was able to achieve the same results with diet and exercise, Cheatham said.
Today Huber is 76 and healthy. He weighs 190 pounds, still goes to the gym three days a week, plays golf twice a week and walks 5,000 to 10,000 steps every evening with his wife.
Diet, exercise can also help manage diabetes
The study also found that diet and exercise can also help people who do develop diabetes keep it under control.
Stan Levy, 81, of New Carrollton, Md., was the first participant to sign up for the study nationwide.
“When I hit 189, that scared me,” he said. He now weighs 165 pounds.
He was in the troglitazone group that was removed from the study early.
Although he developed diabetes, Levy said he is able to control it without insulin shots or other medicines just by using diet and exercise alone.
“Through exercise and diet I’ve been able to control my diabetes,” Levy said. “The program made me aware of my problem. It made me aware of my diet and it made me aware of my exercise.”
Levy still belongs to a gym, rides the stationary bicycle and uses the weight machines two to three times a week. He also walks 30 to 45 minutes every other day and eats mostly vegetables, fruits and fish.
“I can’t emphasize how valuable this program is,” Levy said. “It makes me concentrate from the time I get up until the time I go to bed on my condition.”
The outcomes study will follow the original participants for 10 years to see if the results carry through, Shapiro said.
The 133 local participants in the follow up study are checked twice a year and offered quarterly lifestyle classes, she said.
