|A Decade Later, Lifestyle Changes or Metformin
Still Lower Type 2 Diabetes Risk
Study reports on persistence of benefits seen in the Diabetes
Intensive lifestyle changes aimed at modest weight loss reduced
the rate of developing type 2 diabetes by 34 percent compared with
placebo in people at high risk for the disease, researchers conclude
based on 10 years of data.
Participants randomly assigned to make lifestyle changes also
had more favorable cardiovascular risk factors, including lower
blood pressure and triglyceride levels, despite taking fewer drugs
to control their heart disease risk, according to the study.
Treatment with the oral diabetes drug metformin reduced the rate
of developing diabetes by 18 percent after 10 years compared with
placebo. Results of the Diabetes Prevention Program Outcomes Study
(DPPOS), which examines the persistence of the interventions tested
in the Diabetes Prevention Program (DPP), appear online in The
Lancet on Oct. 29, 2009.
"In 10 years, participants in the lifestyle changes group
delayed type 2 diabetes by about four years compared with placebo,
and those in the metformin group delayed it by two years. The benefits
of intensive lifestyle changes were especially pronounced in the
elderly. People age 60 and older lowered their rate of developing
type 2 diabetes in the next 10 years by about half," said
study chair David M. Nathan, M.D., of Massachusetts General Hospital.
In the United States, about 11 percent of adults — 24 million
people — have diabetes, and up to 95 percent of them have
type 2 diabetes. An additional 57 million overweight adults have
glucose levels that are higher than normal but not yet in the diabetic
range, a condition that substantially raises the risk of a heart
attack or stroke and of developing type 2 diabetes in the next
10 years. "The spiraling epidemics of obesity and type 2 diabetes
in United States and worldwide show no signs of abating," said
Griffin P. Rodgers, M.D., director of the National Institute of
Diabetes and Digestive and Kidney Diseases (NIDDK), part of the
National Institutes of Health. "Millions of people could
delay diabetes for years and possibly prevent the disease altogether
if they lost a modest amount of weight through diet and increased
The DPPOS is a continuation of the DPP, a large, randomized trial
in 3,234 overweight or obese adults with elevated blood glucose
levels. Researchers announced the initial findings of the DPP in
2001, a year earlier than scheduled because results were so clear:
after three years, intensive lifestyle changes reduced the development
of type 2 diabetes by 58 percent compared with placebo. Metformin
(850 milligrams twice a day) reduced it by 31 percent compared
Striking as the findings were, the researchers could not say how
long the benefit would endure, since the results were based on
just three years of data. After a bridge period from January to
July 2002, when all participants learned the results and were offered
a 16-session program explaining how to make intensive lifestyle
changes, the DPPOS began, with 88 percent of DPP volunteers taking
Intensive lifestyle changes consisted of lowering fat and calories
in the diet and increasing regular physical activity to 150 minutes
per week. Participants received training in diet, exercise (most
chose walking), and behavior modification skills. In the first
year of the DPP, this group lost 15 lbs. on average but regained
all but about 5 pounds over 10 years. The metformin group has maintained
a loss of about 5 pounds, and the placebo group lost less than
2 pounds over the decade.
About 5 to 6 percent of those in the lifestyle intervention group
developed type 2 diabetes annually, an incidence rate that remained
steady throughout the DPPOS. When the DPP ended in 2001, the metformin
and placebo groups were developing diabetes at the rate of 8 and
11 percent a year, respectively. In 10 years, however, the yearly
diabetes incidence rates for the drug and placebo groups had also
fallen to about 5 to 6 percent, and the lifestyle intervention
group's rate remained at this lower level.
The researchers are looking at a number of explanations for the
convergence of diabetes incidence rates for the three groups. One
may be that lifestyle changes adopted by the drug and placebo groups
after the DPP ended may have lowered their rate of type 2 diabetes
"Sustaining even modest weight loss with lifestyle changes
is highly challenging, but it produced major long-term health rewards
by lowering the risk of type 2 diabetes and reducing other cardiovascular
risk factors in people at high risk of developing diabetes," said
lead author and a principal investigator for the study, William
Knowler, M.D., Dr.P.H., of the NIDDK in Phoenix. "Once we
learned how dramatically this intervention reduced diabetes onset
in the DPP, we offered modified training in lifestyle changes to
all participants, which probably contributed to the falling diabetes
rates in the placebo and metformin groups."
At enrollment in the DPP, participants ranged from age 25 to 85
years, with an average age of 51. Their average body mass index
(BMI) was 34, which is in the obese range. BMI measures weight
in relation to height. Forty-five percent of participants were
from minority groups disproportionately affected by type 2 diabetes:
African-Americans, Hispanic/Latino Americans, American Indians,
and Asian-Americans and Pacific Islanders. The trial also recruited
other groups at higher risk for type 2 diabetes, including people
age 60 years and older, women with a history of gestational diabetes,
and people with a first-degree relative with type 2 diabetes.
Other studies have shown that diet and exercise delay type 2 diabetes
in at-risk people. However, the DPP, conducted at 27 centers nationwide
was the first major trial to show that lifestyle changes can effectively
delay diabetes in a diverse population of overweight American adults
at high risk of diabetes. Questions and Answers about the DPP/DPPOS
will be available at www2.niddk.nih.gov/Research/ClinicalResearch/DPPOS.
About 24 million people in the United States have diabetes. It
is the main cause of kidney failure, limb amputations, and new
onset blindness in adults and a major cause of heart disease and
stroke. Type 2 diabetes, which accounts for up to 95 percent of
all diabetes cases, becomes more common with increasing age. It
is strongly associated with obesity, inactivity, family history
of diabetes, history of gestational diabetes, impaired glucose
metabolism, and racial or ethnic background. The prevalence of
diagnosed diabetes has more than doubled in the last 30 years,
due in large part to the upsurge in obesity.
The National Diabetes Education Program, jointly sponsored by
the NIH, the Centers for Disease Control and Prevention, and 200
partner organizations, provides diabetes education to improve the
treatment and outcomes for people with diabetes, promote early
diagnosis, and prevent or delay the onset of diabetes. In its "Small
Steps. Big Rewards. Prevent Type 2 Diabetes" campaign, the
explains how people at risk can take steps to turn the tide against
The DPP is registered as NCT00004992, and the DPPOS is registered
as NCT00038727 in clinicaltrials.gov. The studies have been funded
by the National Institute of Diabetes and Digestive and Kidney
Diseases; Eunice Kennedy Shriver National Institute of Child Health
and Human Development; National Institute on Aging; National Eye
Institute; National Heart, Lung, and Blood Institute; National
Center on Minority Health and Health Disparities; National Center
for Research Resources; and Office of Research on Women's Health
within the NIH. Additional funding came from the Indian Health
Service, the Centers for Disease Control and Prevention, and the
American Diabetes Association. Lipha (Merck-Sante) provided medication.
LifeScan Inc.; Merck-Medco Managed Care, Inc.; and Merck and Co.
donated materials, equipment, or medicines.
NIDDK, part of the NIH, conducts and supports basic and clinical
research and research training on some of the most common, severe
and disabling conditions affecting Americans. The Institute's research
interests include diabetes and other endocrine and metabolic diseases;
digestive diseases, nutrition, and obesity; and kidney, urologic
and hematologic diseases. For more information, visit www.niddk.nih.gov.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and Centers
and is a component of the U.S. Department of Health and Human Services.
It is the primary federal agency for conducting and supporting basic,
clinical and translational medical research, and it investigates
the causes, treatments, and cures for both common and rare diseases.
For more information about NIH and its programs, visit www.nih.gov.
For Broadcast Media: A bites/b-roll package with sound bites from Dr. David Nathan, DPP/DPPOS study chair, Dr. Griffin P. Rodgers, NIDDK Director, and study participants will be available at http://multivu.prnewswire.com/broadcast/36430/press.html and fed via satellite as follows:
Wednesday, October 28th, 2009
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Wednesday, October 28th, 2009
6:30 PM - 6:45 PM ET
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For general questions regarding the newsfeed, contact MultiVu's Media Relations Office at 800-653-5313 x3.