Mr. Chairman, I am Phillip Gorden, the Director of the National Institute of Diabetes
and Digestive and Kidney Diseases (NIDDK), which has lead responsibility for diabetes
research at the National Institutes of Health (NIH), within the Department of Health and
Human Services (DHHS).
I appreciate the opportunity to testify before the Congressional Hispanic Caucus about
NIH research to understand, treat, and prevent diabetes.
In both human and economic terms, diabetes is an extremely costly disease. It affects
an estimated 16 million Americans, including both genders, the young and the old, all
races and ethnic groups, the rich and the poor. According to the American Diabetes
Association, diabetes and its complications of the eye, kidney, nervous system, and heart
cost an estimated $98 billion annually. Consistent with the focus of today's hearing, I will
address my testimony toward diabetes in the Hispanic community.
Diabetes is a disease in which the body does not produce or properly use insulin, a
hormone that is needed to convert sugar, starches, and other food into energy essential
for daily life. The cause or causes of diabetes are unknown in most instances, although
both genetic and environmental factors appear to play a role. Type 2 diabetes, the form
most commonly seen in the Hispanic community, occurs at a rate approximately twice that in
the non-Hispanic Caucasian population. Formerly known as non-insulin-dependent diabetes
mellitus or adult-onset diabetes, type 2 diabetes is the most common form of the disease,
accounting for 90 to 95 percent of diabetes. Type 1 diabetes, formerly known as
insulin-dependent diabetes mellitus or juvenile-onset diabetes, most often occurs in
children, and accounts for 5 to 10 percent of all diabetes in the United States
.
Diabetes in Hispanics is a serious health challenge because of the increased
prevalence, the greater number of risk factors, and the greater incidence of
complications. In early 1999, data released by the Centers for Disease Control and
Prevention (CDC) indicated that six percent of Hispanic adults in the United States
and
Puerto Rico have been diagnosed with diabetes--twice the rate of Caucasian
Americans--while another six percent have undiagnosed diabetes. This is the first report
of diabetes prevalence among all Hispanics in the United States
and Puerto Rico. Most
previous studies that have focused on the Hispanic community have been conducted among
Mexican Americans and have found that approximately one out of every ten Mexican Americans
aged twenty years and older has diabetes.
The prevalence of diabetes among Hispanic adults increases with age and varies
according to geographic location. Hispanics in Puerto Rico and the West/Southwest are more
likely to have diabetes than Hispanics in the rest of the nation. Diabetes is two to three
times more common in Mexican American and Puerto Rican adults than in non-Hispanic
Caucasians. One in every four Mexican Americans and Puerto Ricans aged 45 or older has
diabetes. The prevalence of diabetes in Cuban Americans is lower, but still higher than
that in non-Hispanic Caucasians. One in every six Cuban Americans over the age of 45 has
diabetes.
The frequency of diabetes in Hispanic American adults is influenced by the same risk
factors that are associated with type 2 diabetes in other populations--age, obesity, and
genetics. Recent reports indicate an increase in the prevalence of type 2 diabetes among
Mexican American youth, especially among those who are overweight. Although Mexican
Americans have higher rates of kidney disease, eye disease, and peripheral vascular
disease due to diabetes, they have a decreased rate of heart attacks.
HIGHLIGHTS OF NIH-WIDE RESEARCH EFFORTS AND STRATEGIES
I would like to emphasize several points that are central to present and future efforts
to prevent and treat diabetes effectively. The many institutes and centers of the NIH have
a broad and multi-faceted research agenda to understand, treat, prevent, and cure
diabetes. Because the complications of diabetes affect so many parts of the body--the
heart, the eyes, the kidneys, and the nervous system--it is an important trans-NIH
research area. Efforts to reduce and eliminate health disparities among Americans are a
special area of concern within the NIH. Diabetes research at the NIH is complemented by
the activities of the CDC and other components of the DHHS.
We are witnessing rapid advances in the study of the patterns of inheritance of
specific traits (genetics) and the development and application of global experimental
approaches to assess gene function (genomics) that underlie our goal to find and eliminate
the cause of many diseases, including diabetes. Major new understandings of cell
communication are also critical to diabetes. Likewise, key advances in clinical research
are showing how the control of blood pressure, serum cholesterol, and other lipids, as
well as control of blood glucose, is important in the comprehensive care of patients with
diabetes.
To identify the most promising avenues of diabetes research, the NIH has a two-step
peer review process mandated by law to ensure high scientific standards among funded
projects. This process begins with an assessment of scientific and technical merit by an
initial review group of non-Federal scientists. Applications are then reviewed by the
National Diabetes and Digestive and Kidney Diseases Advisory Council, a group of eminent
scientists and lay individuals with expertise in NIDDK's areas of research, to
consider program needs and the relevance of grant applications to the mission of the
Institute.
In addition to the peer review system, the NIH also takes steps to guide and facilitate
the development of its programs through a variety of means. In diabetes, for example, we
have accelerated
and enhanced our efforts and have sought advice from a special trans-NIH workshop held
in September 1997, entitled "Diabetes Mellitus: Challenges and Opportunities" -- complemented by the
Strategic Plan of the Diabetes Research Working Group. We have already initiated research
projects from these processes and will continue to build upon them in the future. We are
also developing a new NIDDK Strategic Plan based on cross-cutting scientific themes, many
of which are highly relevant to type 2 diabetes.
I am pleased to share with you today some of our most recent efforts which relate to
diabetes in the Hispanic community. A number of these have been undertaken in partnership
with other NIH institutes, other agencies, and voluntary organizations.
EXAMPLES OF FUNDAMENTAL RESEARCH ADVANCES
IMPORTANT TO DIABETES IN HISPANICS
The NIDDK has a major research initiative on obesity, which is a serious risk factor
for type 2 diabetes. NIDDK funded the initial discovery of the obesity gene and its
protein product, leptin, the major energy regulator, in a mouse model of obesity. This led
to the discovery of multiple gene mutations, which control critical aspects of both eating
and energy regulation. These findings have now spearheaded the discovery of at least five
different genetic defects in humans that lead to obesity. Such important research advances
have relevance not only to our understanding of obesity, but also to the
inter-relationship of obesity and diabetes.
The National Task Force on Prevention and Treatment of Obesity was established by the
NIDDK in June 1991. This task force of leading obesity researchers and clinicians is
responsible for evaluating current scientifically-based information about the prevention
and treatment of obesity. The Task Force also advises the Institute on important research
needs and identifies concepts for future clinical studies of obesity. The NIDDK also
provides support for four Obesity/Nutrition Research Centers.
The International Type 2 Diabetes Linkage Analysis Consortium originated in 1997 as a
collaborative effort to map genes responsible for type 2 diabetes. This Consortium is
jointly funded by the NIH and the American Diabetes Association. Currently, the Consortium
includes investigators representing 23 different populations from eight countries.
Locations in San Antonio and Starr County (Texas), and San Luis Valley (Colorado) include
Mexican American families in the genetic linkage analysis.
Other investments in genetics and functional genomics research have led to the
discovery of at least six separate genetic defects in rare forms of type 2 diabetes.
Recently, a gene responsible for
type 2 diabetes has been identified in the Mexican American population from Starr
County, Texas. These studies have stimulated collaborative research to penetrate the
complexity of genetic abnormalities in both type 1 and type 2 diabetes. Expansion of these
studies is now under way, with an emphasis on the kidney complications of diabetes. Thus,
we are now making a major commitment to a large-scale study of the genetics of diabetes
and the genetic susceptibility to diabetic kidney disease.
EXAMPLES OF CLINICAL TRIALS
In type 2 diabetes, the importance of maintaining close control of blood sugar levels
throughout the day was conclusively demonstrated by the United Kingdom Prospective
Diabetes Study (UKPDS). In addition, the UKPDS demonstrated that good blood pressure
control produced a major benefit in decreasing complications of the large blood vessels.
This study confirmed the findings of the NIDDK-supported Diabetes Control and
Complications Trial (DCCT) in type 1 diabetes, which showed that any reduction in blood
glucose reduces the risk for developing the long-term complications of the small blood
vessels of the eye, kidney, and nervous system. These findings give new emphasis to the
value of early treatment in type 2 diabetes. They also reinforce the importance of our
Diabetes Prevention Program (DPP), a major, ongoing clinical trial designed to find out
whether type 2 diabetes can be delayed or prevented. This trial is comparing the current
standard regimen on diet and exercise to a more intense regimen of diet and exercise and
metformin--a medication approved for the treatment of type 2 diabetes. This trial is being
conducted at 27 medical centers located in Arizona, California, Colorado, the District of
Columbia, Florida, Illinois, Hawaii, Indiana, Louisiana, Massachusetts, Maryland,
Missouri, New Mexico, New York, Pennsylvania, Tennessee, Texas, and Washington. The DPP
has completed recruitment with a total of 3,819 participants--44.5 percent of whom are
minorities. Thus, we are making progress, but we need to do even more.
Another clinical trial of great significance to type 2 diabetes is the Study of Health
Outcomes of Weight Loss (SHOW), which we expect will begin shortly. This large,
multicenter trial is designed to study if interventions to produce sustained weight loss
in obese individuals with type 2 diabetes will improve health. The SHOW is expected to
recruit approximately 6,000 patients over a three-year period with four additional years
of treatment and follow-up. A goal of the trial is to have the overall ethnic and racial
composition of the recruited patient populations reflect the prevalence rates for diabetes
in the United States
. We anticipate that SHOW will include participants from a range of
Hispanic populations, including at least 360 Mexican Americans; however, the study
population mix at any one center may vary from this overall distribution based on local
demography. The NIDDK is sponsoring this trial along with the National Heart, Lung, and
Blood Institute (NHLBI), the National Institute of Nursing Research (NINR), the Office of
Research on Minority Health (ORMH), the Office of Research on Women's Health (ORWH), and the
CDC.
The major goal of basic fundamental research is to create targets for therapeutic
intervention. These basic discoveries provide the platform for drug testing by the
biotechnology and pharmaceutical industry. An important research goal is to extend the
therapeutic arsenal of safe and effective drugs to treat type 2 diabetes. In the United
States, five classes of oral medications, each of which works through a different
mechanism of action, are currently available to improve blood glucose control in patients
with type 2 diabetes. These oral agents complement, in an important way, a variety of new
insulin preparations that have been introduced for treatment, as well as multiple agents
for the treatment of lipid and blood pressure disorders.
TYPE 2 DIABETES IN CHILDREN, ADOLESCENTS, AND YOUNG ADULTS
Type 2 diabetes has traditionally been considered a disease of adults because the age
of onset is frequently after age 40 and it is often associated with obesity. Children with
diabetes are usually presumed to have type 1 diabetes, an autoimmune disease. In recent
years, however, an increasing number of children who appear with elevated blood glucose
levels actually have type 2 diabetes. In some studies, the percentage of children with
diabetes who have type 2 diabetes has risen from less than five percent prior to 1994, to
20 to 30 percent after 1994. Not surprisingly, one of the major risk factors for type 2
diabetes in children is obesity. The increase in reports of type 2 diabetes among children
parallels a similar rise in the adult population, as obesity has become a major public
health concern. In children, the alarming rise in the incidence of type 2 diabetes appears
to be occurring largely in minority populations--Hispanic Americans, African Americans,
and Native Americans.
The NIDDK recently convened a group of epidemiologists and pediatric endocrinologists
to address this issue. Based on data presented at that meeting, we plan to solicit
research on the pathophysiology, prevention and treatment of type 2 diabetes in children.
The National Diabetes Education Program (NDEP) also plans to develop a campaign to alert
pediatricians to this alarming trend.
MAJOR EPIDEMIOLOGICAL STUDIES OF DIABETES IN HISPANIC AMERICANS
A "Diabetes in America, 2nd Edition," is a compendium of data
about the impact of diabetes, which has been compiled by the National Diabetes Data Group
(NDDG) of the NIDDK. The NDDG was established in 1977 in response to recommendations of
the U.S. National Commission on Diabetes. Its purposes are to define needs for information
that can address the important scientific and public health issues in diabetes, facilitate
research on the epidemiological and clinical aspects of diabetes, and develop reliable and
accurate information on the scope and impact of diabetes in the U.S. population.
Through these efforts and other epidemiological research, a great deal has been learned
about diabetes in parts of the Hispanic community, particularly in Mexican Americans. Most
of this information has come from four studies: the San Antonio Heart Study (Texas), the
San Luis Valley Diabetes Study (Colorado), the Starr County Study (Texas), and the
Hispanic Health and Nutrition Examination Survey (HHANES). These studies have established
that the prevalence of type 2 diabetes is two to three times higher in Mexican Americans
than in non-Hispanic Caucasians. HHANES, conducted by the CDC's National Center for
Health Statistics with support from NIDDK for the diabetes component of the study, is the
only one of the four studies that included information on Cuban Americans in the Miami
area and on Puerto Ricans in the New York City area.
OUTREACH AND EDUCATION PROGRAMS
The NIDDK initiated the National Diabetes Education Program (NDEP) in 1995, with the
CDC, and with support from the NIH Office of Research on Minority Health (ORMH). A goal of
this program is to improve the treatment and outcome for people with diabetes in order to
reduce the illness and death associated with diabetes and its complications. Because
survey research showed that the level of awareness of diabetes among the public was low,
the program launched a media campaign aimed at people with diabetes in June 1998, with the
theme, "Control Your Diabetes. For Life." The aim of this campaign was to disseminate the findings from our
major clinical trial, which showed that close control of blood glucose levels can prevent
or reduce the complications of diabetes. In national and local media outlets across the
country, the message that diabetes is serious, common, costly, yet controllable, received
excellent coverage.
Because of the extremely high incidence of diabetes in all minority groups, the NDEP
quickly moved to target these audiences with culturally-sensitive public health messages
tailored by minority organizations (National Council on Aging and the National Council of
La Raza) who belonged to the NDEP Partnership. The Hispanic/Latino campaign recently won
an Award of Excellence from the Health Improvement Institute and the 1998 Silver Mercury
Award from the International Academy of Communications, Arts and Sciences/MerComm, Inc.
Print and broadcast news stories reached audiences of 12.5 million Hispanics and Latinos
in the United States
and Puerto Rico by September 1998. A new wave of campaign media
materials will include an English version, "Lightning and Thunder," for English-speaking Latinos. Complementing these education
campaigns are the efforts of the National Diabetes Information Clearinghouse (NDIC),
established to increase knowledge and understanding about diabetes among patients, health
care professionals, and the public. To carry out this mission, the Clearinghouse works
closely with the diabetes community to identify and respond to informational needs about
diabetes and its management. Many fact sheets and pamphlets about diabetes are available
in Spanish formats.
The NIDDK also funds research on the development of model education programs through
its Diabetes Research and Training Centers (DRTCs), as well as through research grants. A
major function of the DRTC program is to generate the most competent professional
personnel, and to identify ways through which advances in the field of diabetes research
can be translated as quickly as possible into improved care for the patient. Activities at
a number of NIDDK-supported Diabetes Centers have a focus on minority populations,
including Hispanics. The administrative guidelines for the Centers program state, "The NIDDK is concerned
with the disproportionate prevalence of diabetes in minority groups and the increased
susceptibility to the complications of diabetes in these groups. There is accordingly a
requirement for DRTCs to develop programs and/or materials directed at minority
populations." A DRTC that has had a major focus on diabetes in Hispanic populations is located at the
University of Chicago. Four major projects, the MidWest Clinicians' Network Project, the "For Your Health" Program, the Chicago
Hispanic Health Coalition Resource Guide, and the Neighborhood Clinic Diabetes Initiative
Project, are supported by the Chicago DRTC and are relevant to diabetes in the Hispanic
community. In addition to programs conducted through the DRTCs, the NIDDK also supports
regular research grants studying culturally-sensitive lifestyle interventions. An example
is at the University of Texas in Austin, where an NIDDK-funded investigator has designed
an education and support program for Hispanic diabetics. The purpose of this project is to
develop culturally-relevant, community-based interventions aimed at improving the health
of diabetic Mexican Americans and their families. The intervention is provided in Spanish
and is directed by Hispanic health care providers.
Mr. Chairman, I am grateful for the opportunity to share with you some examples of NIH
efforts focusing on type 2 diabetes, with emphasis on the Hispanic community. I have tried
to underscore today that we at the NIH understand the great burden diabetes places on
patients, families, and communities. At the same time, I want to share my feelings of
great encouragement and hope because of the pace at which diabetes research is moving. I
believe that our strong national research and educational programs hold the essential key
to reducing and removing the disparity with which diabetes affects the Hispanic community.
We have important efforts under way, but much more remains to be done. I am pleased to
answer any questions you may have.