Embargoed by US Dept. of Health and Human Services
For 2:30 p.m. ET, Wednesday, Aug. 8, 2001
160 San Diegans
Participated in UCSD Portion of Nationwide Clinical Trial At least 10 million Americans at high risk for type 2
diabetes can sharply lower their chances of getting the disease with diet and
exercise, according to the findings of a major clinical trial announced today at
the National Institutes of Health by U.S. Department of Health and Human
Services Secretary Tommy G. Thompson. Diabetes afflicts more than 16 million people in the United
States and is the main cause of kidney failure, limb amputations and new onset
blindness in adults, as well as a major cause of heart disease and stroke. Type 2 diabetes, a metabolic disorder resulting from the body’s
inability to produce insulin, accounts for up to 95 percent of all diabetes
cases and is most common in adults over age 40. UCSD was one of 27 sites participating in the clinical
trial. The UCSD Diabetes Prevention
Program, located at the Whittier Institute in La Jolla, enrolled 160 San Diegans
in the 3-year study that enrolled 3,234 overweight individuals with impaired
glucose tolerance, a condition that often precedes diabetes. The same study found that treatment with the oral diabetes
drug metformin (Glucophage®) also reduces diabetes risk, though less
dramatically, in people at high risk for type 2 diabetes. On the advice of the national Diabetes Prevention
Program’s (DPP) external monitoring board, the trial ended a year early
because the data had clearly answered the main research question regarding the
effectiveness of medication, diet and exercise in preventing diabetes. Participants randomly assigned to intensive lifestyle
intervention reduced their risk of getting type 2 diabetes by 58 percent. On average, this group maintained their physical activity at 30 minutes
per day, usually with walking or other moderate intensity exercise, and lost 5-7
percent of their body weight. Participants randomized to treatment with
metformin reduced their risk of getting type 2 diabetes by 31 percent. Smaller studies in China and Finland have shown that diet
and exercise can delay type 2 diabetes in at-risk people, but the DPP is the
first major trial to show that diet and exercise can effectively delay diabetes
in a diverse American population of overweight people with impaired glucose
tolerance. “Every year a person can live free of diabetes means an
added year of life free of the suffering, disability and the medical costs
incurred by this disease,” said Jerrold Olefsky, M.D., director of the UCSD
portion of the study. “The Diabetes Prevention Program findings represent a
major step toward the goal of containing and ultimately reversing the epidemic
of type 2 diabetes in this country.” Of the 3,234 participants in the DPP trial, 45 percent are
from minority groups that suffer disproportionately from type 2 diabetes: African Americans, Hispanic Americans, Asian Americans, Pacific Islanders
and American Indians. The trial also recruited other groups known to be at higher
risk for type 2 diabetes, including individuals age 60 and older, who have a
nearly 20 percent prevalence of diabetes, reducing the development of diabetes
by 71 percent. Metformin was also effective in men and women and in all the
ethnic groups, but was relatively ineffective in the older volunteers and in
those who were less overweight,” said David Nathan, M.D., Massachusetts
General Hospital, Boston, and the DPP national study chairman. DPP volunteers were randomly assigned to one of the
following groups: The latter two groups also received information on diet and
exercise. A fourth arm of the study, treatment with the drug
troglitazone combined with standard diet and exercise recommendations, was
discontinued in June 1998 due to the potential for liver toxicity. DPP participants ranged from age 25 to 85, with an average
age of 51. Upon entry to the study,all had impaired glucose tolerance as measured by an oral glucose tolerance
test, and all were overweight, with an average body mass index (BMI) of 34. About 29 percent of the DPP standard group developed diabetes during the
average follow-up period of 3 years. In
contrast, 14 percent of the diet and exercise arm and 22 percent of the
metformin arm developed diabetes. Volunteers
in the diet and exercise arm achieved the study goal, on average a 7 percent –
or 15 pound – weight loss, in the first year and generally sustained a 5
percent total loss for the study’s duration. Participants in the lifestyle intervention arm received training in diet,
exercise (most chose walking), and behavior modification skills. Can the interventions prevent diabetes altogether? “We simply don’t know how long, beyond the 3-year
period diabetes can be delayed,” Nathan said. “We hope to follow the DPP
population to learn how long the interventions are effective.” The researchers will analyze the data to determine whether
the interventions reduced cardiovascular disease and arteriosclerosis, major
causes of death in people with type 2 diabetes. Type 2 diabetes affects 8 percent of the U.S. population
age 20 and older. It is strongly
associated with obesity (more than 80 percent of people with type 2 diabetes are
overweight), inactivity, family history of diabetes, and racial or ethnic
background. Compared to whites,
black adults have a 60 percent higher rate of type 2 diabetes and Hispanic
adults have a 90 percent higher rate. The
prevalence of type 2 diabetes has tripled in the last 30 years, and much of the increase is
due to the dramatic upsurge in obesity. People with a BMI of 30 or greater have a 5-fold greater risk of diabetes than people
with a normal BMI of 25 or less. The $174.3 million DPP is funded by the National Institute
of Diabetes and Digestive Kidney Disease, the National Institute of Child Health
and Human Development, the National Institute on Aging, the National Center on
Minority Health and Health Disparities, the National Center for Research
Resources, the Office of Research on Women’s Health, and the Office of
Behavioral and Social Science Research within the National Institutes of Health. Additional funding and support was provided by the Centers for Disease
Control and Prevention, the Indian Health Service, and the American Diabetes
Association. The study also is funded in part through a Cooperative Research Development Agreement (CRADA) with
Bristol Myers Squibb. Other sources of corporate support include Merck and Company, Merck Medco, Hoechst Marion
Roussell, Lifescan, Slimfast, Nike, and Health-O-Meter. # # # Media Contact: Sue Pondrom UCSD Health Sciences Communications HealthBeat: http://health.ucsd.edu/news/Diet and Exercise
Dramatically Delay Type 2 Diabetes
“In view of the rapidly rising rates of obesity and
diabetes in America, this good news couldn’t come at a better time,” said
Thompson. “So many of our health problems can be avoided through diet, exercise and making sure we
take care of ourselves. By promoting healthy lifestyles, we can improve the quality of life for all
Americans, and reduce health care costs dramatically.”
619-543-6163 spondrom@ucsd.edu