The Problem Diabetes
The Problem Diabetes
The dramatic increase in newly diagnosed cases of type 2 diabetes has developed into
a major public health concern in this century [1]. Having diabetes means having a significantly reduced quality of life and reduced
life expectancy [2]. Furthermore, diabetes and impairment of glucose tolerance is increasingly appearing
amongst the elderly and recently also in younger people with a most sudden increase
in the age group of below 30 years [3]. This results in an increasing number of people being affected by diabetes mellitus
in their working age making diabetes to an economic factor. The continuously decreasing
age of diagnosis makes a longer and intensified medical treatment necessary due to
the increase in medical standards [4]
[5]
[6].
Recent large meta-analysis shows that more than half of all Europeans will suffer
from hyperglycemia and diabetes during their lifetime [4]
[5]
[6]. This increase in incidence has resulted in dramatically escalating rates of complications
of the disease, especially cardiovascular complications [6]. Recent data from the Framingham study show that the proportion of cardiovascular
disease due to diabetes has increased over the past 50 years, and the increasing prevalence
of diabetes could reverse the decreasing trend in coronary heart disease mortality
[11]. Hence, the increased costs due to diabetes are a significant burden for society.
All of the described factors increase the economical, medical and social burden of
diabetes mellitus exponentially. After diagnosis of diabetes mellitus there is - by
now - no cure of the disease - only treatment. The real cure of diabetes is the effective
primary prevention.
Risk factors are known
Risk factors are known
Type 2 diabetes is a complex metabolic disease developing in genetically susceptible
individuals as a result of environmental and lifestyle risk factors [8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]. These risk factors are well-known: obesity, central adiposity, physical inactivity,
and unhealthy diet. The more prevalent sedentary lifestyle and the globalization of
“fast” and overly rich nutrition, the more people will develop risk factors for diabetes
mellitus [20]. Therefore, diabetes is giving rise to excessive rates of heart disease, stroke,
peripheral vascular disease, renal and eye diseases, neurological and mental problems
[21]. While the age at onset of diabetes is lower, its complications will appear earlier
[22]. Due to this excessive rate of complications diabetes is a major cause of morbidity
and contributes significantly to premature mortality in all European countries.
Lifestyle modification to prevent diabetes
Lifestyle modification to prevent diabetes
The most efficient way to manage diabetes and its complications is to prevent diabetes
from developing. Fortunately, recent studies have convincingly demonstrated that prevention
of type 2 diabetes is possible [19]
[20]
[21]
[22]. The best method of intervention for preventing diabetes is still not clear, but
there is overwhelming evidence that diabetes can be prevented or delayed in high risk
population through lifestyle modification or pharmacological interventions.
A study from Da Qing, China, looked at the effects of diet and exercise in preventing
diabetes in Chinese patients with impaired glucose tolerance (IGT). Risk reductions
in diabetes were 31% with diet, 46% with exercise, and 42% with diet plus exercise
[26].
In the Diabetes Prevention Study (DPS) in Finland, significant reduction in progression
to diabetes was observed as 522 middle-aged obese subjects with IGT were randomized
to receive either diet and exercise counseling (control group) or intensive individualized
instruction on weight reduction, food intake, and guidance on increasing physical
activity (intervention group) [24]. After an average follow-up of 3.2 years, there was a 58% relative reduction in
the incidence of diabetes in the intervention group compared with the control subjects.
Interestingly strong correlation was also seen between the progression to diabetes
and the ability of the participants to achieve one or more of the following core goals
to lose weight (goal of 5.0% weight reduction), reduce fat intake (goal of <30% of
calories), reduce saturated fat intake (goal of <10% of calories), increase fiber
intake (goal of ≥15 g/1000 kcal), and exercise (goal of >150 min/week) [27]. Recently it was shown that the lifestyle intervention resulted in sustained lifestyle
changes and a reduction in diabetes incidence, which were maintained for years after
the individual lifestyle counseling was stopped [28].
The largest study up to now has been the Diabetes Prevention Program (DPP) [23]. This study examined 3234 patients with IGT and followed them for an average of
2.8 years. The risk reduction from lifestyle modification was identical to that seen
in the Finnish study: 58%. The lifestyle intervention consisted of a minimum of 150
minutes of physical activity per week, and resulted in a 7% reduction in weight. The
DPP also included a group that was assigned to metformin 850 mg twice daily reaching
a significant risk reduction of 31%. On average, 50% of the lifestyle group achieved
the goal of ≥7% weight reduction, and 74% maintained at least 150 min/week of moderately
intense activity. No serious side effects were seen in any group [29].
In the Indian Diabetes Prevention Program, the effect of lifestyle intervention alone,
metformin, or a combination of both was tested to be effective to prevent diabetes
in persons with IGT [30]. Interestingly the effect of all three strategies was very similar. The relative
risk reduction was 28.5% with lifestyle intervention, 26.4% with metformin and 28.2%
with the combination of both compared with the control group.
Drug treatment to prevent diabetes
Drug treatment to prevent diabetes
Other studies tested primary or secondary drug therapy to prevent or delay diabetes.
In the STOP-NIDDM trial participants with IGT were randomized to receive either acarbose
or a placebo. After a mean follow-up of 3.3 years, a 25% relative risk reduction in
progression to diabetes was observed in the acarbose-treated group compared with the
placebo group [25]. In the Troglitazone in Prevention of Diabetes (TRIPOD) study the thiazolidinedione
troglitazone treatment was associated with a 56% relative reduction in progression
to diabetes. Furthermore it was shown in the XENDOS trial that orlistat [31] significantly decreased progression of impaired glucose tolerance to diabetes by
52%. In the recently finished DREAM Study with over 5000 patients rosiglitazone reduced
the risk of developing type 2 diabetes by 62% relative to placebo among people at
high risk of developing type 2 diabetes [32], but the ACE inhibitor ramipril, however, did not reduce the likelihood of progression
to diabetes [33]. Other secondary studies showed that ACE inhibitors and angiotensin receptor blockers
were associated with reductions in the incidence of newly diagnosed diabetes by 27%
and 23%[34] as well as pravastatin by 30% and estrogen/progesterone by 35%[35]. For some people, medication is part of an overall plan for diabetes prevention
but it appears to be that drug therapy to prevent or delay diabetes is less beneficial
than lifestyle changes.
This information now has to be translated into well-defined strategies for screening
and treating high risk population in clinical practice. While these findings offer
the evidence-base for the development of community-based prevention strategies [36], it is necessary to develop and implement prevention programs into clinical practice
considering scientific aspects and practical requirements during implementation [37].
While translating the scientific evidence into population based intervention strategies
more and more questions arise, mostly related to economic and structural requirements
during implementation. At the end giving the right answers to these questions will
decide about the success of implemented prevention strategies.
What are the management aims in diabetes prevention?
What are the management aims in diabetes prevention?
The prevalence of diabetes is increasing in epidemic proportion worldwide and it is
becoming a major burden for the health care system. With a better understanding of
the pathogenesis of type 2 diabetes, the concept of primary prevention has emerged
and we have overwhelming evidence that we can prevent or delay the progression to
diabetes. Prevention of the disease is our only chance to alleviate the ever growing
burden of diabetes mellitus. Knowing this, our first aim is to reduce the incidence
of diabetes among those who are at high risk. Further, the effect should be maintained
over a long time, and this should ultimately reduce the associated burden of the disease
in terms of micro- and macrovascular complications.
To achieve these goals it is necessary to answer the following questions: 1. Who is
at risk for diabetes; 2. How do people at risk receive the necessary information and
motivation to change lifestyle - and what intervention is the best one; and 3. What
is the best way to maintain lifestyle changes over a long time [38]? Additionally the potential intervention should be accessible with acceptable effort
in the general population on a national level reaching people at risk for diabetes.
Based on this we can define 3 management aims in diabetes prevention in the following
way:
-
Persons with increased diabetes risk are found before disease onset;
-
Persons at risk for diabetes are getting an intervention to prevent diabetes; and
-
These persons will not develop diabetes or in case of developing the disease, diabetes
is detected early and treated with adequate therapy (secondary prevention).
Additionally the management concept should be accessible with acceptable effort in
the general population on a national level reaching people at risk for diabetes. Furthermore
it is necessary to take into consideration the reimbursement system in Germany and
issues of professionalism - to decide who is the professional to carry out the lifestyle
intervention [34]
[35].
It is unrealistic to believe that the increasing trend in the prevalence of diabetes
can be stopped focusing solely on high risk subjects. A realistic model of action
is a program that achieves over time a proportionally slower increase of diabetes
incidence with the intervention, and is able to maintain metabolic changes after discontinuation
of the intervention [39]. In addition, a population strategy aiming at promoting health of the entire population
by means of healthy diet and physical activity is required to reduce the number of
high risk subjects most likely to develop diabetes.
Which intervention concept is necessary?
Which intervention concept is necessary?
For the implementation of a prevention program it is necessary to find a way to translate
lessons learned from the prevention studies into a management concept which reaches
similar efficiency in lifestyle changes as in the mentioned studies and still being
practical to manage also a large number of participants. In the mentioned studies
the intervention followed a curricular intervention and was finished after a certain
time. The final success in reaching a lifestyle change was related to the degree the
participants were able to successfully include lifestyle changes in the daily routine.
Knowing this, future prevention management concepts should follow a 3-step intervention
plan:
-
Identification of the individuals at high risk to develop type 2 diabetes;
-
Intensive intervention based on individual choice; and
-
Continuous intervention for motivation maintenance and evaluation.
It is an important option to focus the prevention management on group interventions.
The intention is to motivate the person at risk to self-manage the diabetes risk and
the lifestyle changes with assistance. Whether group interventions are more cost-effective
than individualized interventions remains to be shown.
Whom to intervene?
Whom to intervene?
It is important to address as exactly as possible regarding who should receive an
intervention. It is not only a financial issue but also part of our medical responsibility
to treat persons who trust the medical professional. The major question is how many
false positive screened individuals one accepts to receive an intervention. This discussion
should be focused on the kind and the intensity of the intervention. More false positives
(for diabetes risk) are accepted with more general a lifestyle advice. If someone
accumulates risk factors like adiposity or high blood pressure he will benefit from
the intervention, even if he was not considered as with diabetes risk. On the other
hand interventions which have sometimes potential serious side effects like drug intervention,
and false positive cases in the screening are not acceptable. For diabetes prevention
programs the discussion focuses on persons with IGT/IFG or also persons with increased
diabetes risk before they have IGT/IFG. Potentially, the preventive effect of interventions
aimed at persons with elevated risk while they still are normoglycemic might be higher
than for people who already have IGT/IFG. This has implications on who is eligible
for intervention.
How to find the persons at risk?
How to find the persons at risk?
Strategies to identify persons at high risk for type 2 diabetes were issues of controversy
in the past [40]. The effort performed to identify subjects which fulfill inclusion criteria for
the larger prevention studies consumes large scale resources and is difficult to realize
for a large number of persons. Aiming at including not only persons with elevated
diabetes risk but also persons with IGT/IFG made it necessary to use a test that identifies
persons at disease risk. An efficient test should also recognize persons having a
predictive diabetes risk with a good ratio between specificity and sensitivity, should
be simple to handle, transparent to both sides (physician and the affected person),
widely accessible, and basically cost free. Furthermore the test should intend an
empowerment as feeling “being at risk” and not “being sick”.
The Finnish Diabetes Risk Score (FINDRISC) fulfils the above criteria [41] and can be an ideal tool to find person with increased diabetes risk. The FINDRISC
can be used as a self-administered test to screen subjects at high risk for type 2
diabetes. It can also be used in the general population and clinical practice to identify
undetected T2D, AGT and the metabolic syndrome [42]. This questionnaire comprises validated eight items [41] and it is easy to make the score available widely via the internet, distribute information
material by the health care and social institution, and maintaining occupational health
care and public health. At the end of the questionnaire a contact opportunity is given
using a local telephone or internet address for contacting a prevention manager. Even
if the resonance of a single screening shot is low (0.5%) it is very easy to increase
the redundancy of placing the FINDRISC for screening.
Of the tools currently available, FINDRISC is perhaps the most accurate and widely
used. It is the ideal tool to be used in primary prevention programs, because it is
simple to understand for lay people, does not require laboratory data and can be applied
on population level. FINDRISC is playing a central role in the Finnish Diabetes Prevention
Program, which was initiated in 2003 and is due to run until 2010 [42]. Individuals with a FINDRISC score between 7 and 14 receive advice on lifestyle
changes, while those with scores greater than 15 are given an OGTT to identify any
who have undiagnosed type 2 diabetes requiring more intensive intervention. The FINDRISC
is also used as the screening instrument in the German National Diabetes Prevention
Program [43]. Individuals with a score below 11 will receive written information about healthy
diet and exercise benefits. Subjects with a score between 11 and 20 will be encouraged
to participate in an intervention program performed in group sessions. Persons having
a score of 21 or greater get the recommendation to visit a medical doctor for diabetes
diagnosis or exclusion. If diabetes is excluded these persons can participate in the
intervention program. The differences in the scoring for diabetes are based on the
reimbursement system and the structural implementation. The intervention is much more
light in Finland so that the people are earlier (score 15) transferred to the medical
system as in Germany where the people can receive a structured intervention, which
makes a later referral possible.
In addition, FINDRISC will also be used in “Diabetes in Europe: Prevention using Lifestyle,
physical Activity and Nutrition intervention (DE-PLAN)”, an EU-funded public health
project to develop a European diabetes prevention management strategy. FINDRISC will
form the basis of a low-cost screening program to identify individuals with high diabetes
risk. The presence of pre-diabetes or undiagnosed type 2 diabetes can then be confirmed
by administering an OGTT [40].
How to deliver intervention?
How to deliver intervention?
Another key question to implement a nationwide prevention program of type 2 diabetes
is: Who should deliver the intervention? Addressing risk factors for a disease like
insulin resistance and obesity is a medical responsibility, but addressing physical
inactivity and dietary changes in persons who are still “healthy” is not primarily
physicians’ responsibility [39]. Furthermore even motivated physicians typically have limited experience in training
lifestyle intervention, and often they have inadequate access to the resources needed
to support lifestyle intervention. Therefore primary prevention of type 2 diabetes
raises several issues related to integration of lifestyle intervention into clinical
or preclinical practice. Fortunately in most countries providers for exercise, nutritional
and motivational counseling exist with high professionalism [44]. They can be used after a short additional training to deliver the intervention
if adequate quality control and evaluation is established. Another concept is the
implementation of “prevention managers” who work as specialized providers and coordinators
of the intervention [38]. Currently the EU public health research project “IMAGE “Development and Implementation
of a European Guideline and Training Standards for Diabetes Prevention” is developing
structures for a European prevention management concept including a curriculum for
the training of prevention managers funded by the Commission of the European Communities,
Directorate C - Public Health. The prevention managers can be recruited from existing
health care providers like psychologists, dieticians, diabetes educators, physical
trainers, physiotherapists, and persons attending an additional training to become
a prevention manager if they accept a continuous quality control and evaluation of
their work. The advantage is that an existing infrastructure can be used to spread
the intervention. Following this concept the physician works as a supervising partner
of the prevention manager if a professional diagnosis (diabetes, CHD) is needed [38]. The prevention manager will be a new category of health interventionist to deliver
and manage long term lifestyle intervention in the large number of persons who would
be eligible for these services [44]. As coordinating centre a central institution for prevention management should manage
the program and organize the quality control [38].
What intensity of the intervention is necessary?
What intensity of the intervention is necessary?
The prevention studies known today [19]
[20]
[21]
[22]
[26] were performed with different study designs and intervention procedures, different
observation time and also the initial hypothesis followed different hypothetical action
models [45] and intervention protocols with various intensities [38]. In the DPP an enormous effort was taken to prevent diabetes [23], but the result was very similar to the less intensive intervention performed in
the Diabetes Prevention Study from Finland [24]. Furthermore in the Finnish study the intervention resulted in sustained lifestyle
changes and a reduction in diabetes incidence, even after the individual lifestyle
counseling was stopped. Finally the intervention success in diabetes prevention was
related to the success in achieving the intervention goals of weight loss, reduced
intake of total and saturated fat and increased intake of dietary fiber, and increased
physical activity in the DPS and weight loss and increased physical activity in the
DPP [46]. This could lead to the conclusion that the intervention time is secondary - intervention
quality focusing on sustained achievement of intervention goals would be the primary
goal [28]. Then there is a good chance that less intensive lifestyle programs also are effective
in changing lifestyle [44]. One example for less intensive intervention is the example of Finland where the
FINDRISC itself is seen already as a minimal intervention. The score has information
about diabetes risk factors and possibilities to prevent the disease, and thus it
serves as a method to increase the awareness of the disease.
How to control quality of the intervention?
How to control quality of the intervention?
The key factors in performing high quality intervention are continuous evaluation
and quality control [47]. Therefore a continuous system of quality management and reporting is necessary
to install. This can become a key criterion for the success or failure of the intervention.
If a program is implemented on nationwide basis the individual success of the participating
persons and a long term success of the intervention needs to be reported. To establish
such a health reporting in the medical system can easily consume all resources provided.
Therefore the long term measurement of blood pressure and waist circumference could
be chosen for quality control and an independent evaluation and quality control. Prevention
of diabetes and the metabolic syndrome means reduction of metabolic risk factors like
blood pressure and waist circumference. In the mentioned prevention studies they were
associated with the intervention effect and they are easy to standardize and measure
without costly laboratory diagnostics. Collected on a regular basis, both parameters
can give a good evaluation about the risk and lifestyle changes [48]
[49]. With such a procedure a transparent feedback is possible both to the person receiving
the intervention and the prevention manager. The advantages of the quality control
based on the intervention effect will make a successful individual evaluation for
the participating persons possible, so that nonresponders can be identified early,
who are then eligible for a booster intervention [38].
How to maintain the effect?
How to maintain the effect?
Several investigations in the past have shown that, time-limited intervention to change
lifestyle fail to reach a continuous lifestyle change [34]
[35]. It is typically human to be activated and motivated for a short period of time,
even with a high personal involvement, but failing to maintain further [45]. Still, in the extended follow-up of the Finnish Diabetes Prevention Study, beneficial
lifestyle changes and the corresponding reduction in diabetes risk were sustained
over a long period of time [42]. Establishing a long term motivation to maintain lifestyle changes to prevent diabetes
needs to be the core part of the prevention management concept. Therefore, after the
initial intervention it is necessary to establish a bundle of interventions providing
a regular contact with a minimum of 4 weeks intervals to strengthen motivation of
the participating persons. This can include written “newsletters”, telephone counseling
and boostering, assisted problem management, continuous support including websites,
regular interactive email newsletters, optional booster sessions, and assistance to
explore the environment for physical activity. Furthermore, a regular quality control
including blood pressure and waist circumference measurement is ideal for personal
feedback assisting a sustained lifestyle change [34]
[35].
Conclusion
Conclusion
The only way to reduce the personal and socio-economic burden of diabetes and its
associated complications is the prevention of diabetes. The compeling scientific evidence
supports primary prevention of diabetes by lifestyle intervention and translations
of the study strategies into national prevention programs. Still, it is currently
not clear how to implement these intervention methods with maintained effectiveness
into primary health care system where resources are scarce. The implementation of
diabetes prevention programs will require an integrated, international approach if
we are to see significant reduction in the premature morbidity and mortality it causes.
We must accept that diabetes risk is not a disease; it is a symptom of a much larger
problem - the adaptation of our metabolism to sedentary globalization [51]. Diabetes is likely to remain a huge threat to public health in the years to come.
Therefore affordable strategies and quality controlled programs are needed for primary
prevention. The health intervention may not be limited to diabetes alone, it should
have a potential to prevent a great number of health conditions, not only for those
related to the metabolic syndrome but also for diseases like cardiovascular disease,
certain cancer types, and osteoporosis. Integration of lifestyle intervention into
current health care systems will require a simple network of prevention managers and
physicians to provide effective programs of lifestyle intervention and to implement
quality controlled prevention strategies. An urgent priority is therefore to establish
guidelines for the prevention of type 2 diabetes, including lifestyle and pharmaco-prevention.
