The Diabetes Prevention Program For Type 2 Diabetes-The Preliminary Results ARE IN!

  

The Diabetes Prevention Program is a randomized clinical trial testing strategies to prevent or delay the development of type 2 diabetes in high-risk individuals with elevated fasting plasma glucose concentrations and impaired glucose tolerance. 

The 27 clinical centers in the U.S.  recruited at least 3,000 participants of both sexes, approximately 50% of whom are minority patients and 20% of whom are > or = 65 years old, to be assigned at random to one of three intervention groups: an intensive lifestyle intervention focusing on a healthy diet and exercise and two masked medication treatment groups--metformin or placebo--combined with standard diet and exercise recommendations. 

Participants are being recruited during a 2 2/3-year period, and all will be followed for an additional 3 1/3 to 5 years after the close of recruitment to a common closing date in 2002. The primary outcome is the development of diabetes, diagnosed by fasting or post-challenge plasma glucose concentrations meeting the 1997 American Diabetes Association criteria. The 3,000 participants will provide 90% power to detect a 33% reduction in an expected diabetes incidence rate of at least 6.5% per year in the placebo group. 

Secondary outcomes include cardiovascular disease and its risk factors; changes in glycemia, beta-cell function, insulin sensitivity, obesity, diet, physical activity, and health-related quality of life; and occurrence of adverse events. A fourth treatment group--troglitazone combined with standard diet and exercise recommendations--was included initially but discontinued because of the liver toxicity of the drug. This randomized clinical trial will test the possibility of preventing or delaying the onset of type 2 diabetes in individuals at high risk.

If you want to know the results of the Diabetes Prevention Study for Type 2 Diabetes, all we have to do is look at the results from similar studies that have been completed.  Do we need to wait to the final results are in?  Should we waste the time  and see thousands of people suffer or should we be addressing the issues of how to implement lifestyle changes to prevent the major chronic disease of our time, DIABETES! 

Let us know your suggestions on how best to implement these changes, TODAY!

Send your responses to diabetesincontrol@home.com 

New study from Finland shows that lifestyle changes can be made to work

Almost three decades ago the Finnish led the way for prevention of coronary heart disease by successfully implementing the community based North Karelia project.¹ With the recent publication of their randomized controlled clinical trial of prevention of type 2 diabetes, Tuomilehto et al have now shown that effective lifestyle changes can prevent another major chronic disease of our time. ^{2 3}

Type 2 diabetes has long been linked with behavioral and environmental factors such as overweight, physical inactivity, and dietary habits.⁴ The findings from the Finnish trial confirm this link. Major lifestyle changes resulting from industrialization are contributing to a rapid rise in diabetes worldwide, but especially in industrializing countries. An estimated 135 million people worldwide had diagnosed diabetes in 1995, and this number is expected to rise to at least 300 million by 2025.⁴ Between 1995 and 2025 the number of people with diabetes will increase by 42% (from 51 to 72 million) in industrialized countries and by 170% (from 84 to 228 million) in industrializing countries.

Diabetes exerts a huge toll in illness, death, loss of quality of life, and economic consequences at societal and individual levels.⁴ Several treatments are effective in preventing the devastating complications of diabetes, but these are sub optimally used, and the disease itself is chronic, progressive, and degenerative.⁴ Thus, the prospect that diabetes may be prevented through lifestyle changes is a call to action. Indeed, as Ovid recommended in Remedia Amoris, we should "Stop it at the start; it's late for medicine to be prepared when disease has grown strong through long delays."

In a randomized trial of 522 middle aged, overweight people with impaired glucose tolerance Tuomilehto et al showed that lifestyle changes can reduce the risk of progression to diabetes by a striking 58% over four years.² Each person in the intervention group received individualized counseling aimed at reducing weight, improving diet (by reducing intake of total fat and saturated fat and increasing intake of dietary fiber), and increasing physical activity. The net weight loss at the end of two years was modest: 3.5 kg in the intervention group and 0.8 kg in the control group. However, the cumulative incidence of diabetes after four years was 11% in the intervention group and 23% in the control group. The reduction in the incidence of diabetes was directly associated with the changes in lifestyle. One case of diabetes was preventable for every five subjects with impaired glucose tolerance treated for five years or for every 22 subjects treated for one year.

Two earlier studies from Sweden and China showed that lifestyle interventions may delay progression from impaired glucose tolerance to diabetes.^5-7 However, the Swedish study was not randomized and the Chinese study was randomized by clinic rather than by individual. Thus, the Finnish study offers us the best evidence so far that lifestyle modification can indeed prevent diabetes. Another major study, the diabetes prevention program is currently underway in the United States and is expected to finish next year.⁸ As the evidence for primary prevention of diabetes accumulates, we must begin thinking about how these findings can be translated into practice.

The compelling evidence that modest lifestyle changes can prevent type 2 diabetes is an enormous shot in the arm for chronic disease prevention and health promotion. Nevertheless, translating these findings into effective intervention programs both at clinical and public health levels may be challenging. Yet this challenge pales next to that of sustaining the lifelong implementation of complex, expensive medical and therapeutic regimens to control diabetes and its complications, a challenge faced daily by ever increasing numbers of people. The appeal of lifestyle interventions is that they are inexpensive, they have few side effects, and they actually reverse the proximal factors associated with diabetes for example, overweight, central obesity, physical inactivity, high fat and high energy diets. In the process, they also promote health in general (reduce blood pressure and lipids), empower people, make them less reliant on medicine, and as the Finnish study showed they also improve quality of life. Thus, focusing on lifestyle interventions truly shifts the paradigm from preventing disease to promoting health and well-being. Need we ask for more?

Current pandemic patterns of diabetes adversely affect the quality of people's lives and the economies of individuals, families, and nations. The Finnish study tells us unequivocally that diabetes, a devastating disease that has largely risen out of the lifestyle excesses of contemporary civilization, can be prevented through healthy lifestyle. Nevertheless, there remain many questions: how to apply these findings in a variety of countries and settings; how to efficiently identify and target people who will benefit most from these interventions; how best to sustain these changes; and what are the appropriate roles for the clinical and public health sectors.

The clinical setting is often not sufficiently effective in delivering lifestyle changes, and many actions at the community level affect lifestyle. Thus the next step may be to test lifestyle changes through a combination of clinical and community based strategies. The challenge of planning and implementing such comprehensive community based demonstration programs for diabetes prevention similar to those the Finnish established for heart disease in North Karelia¹ is one that we must all strive to meet.

Other examples:

1.      Effects of diet and exercise in preventing NIDDM in people with impaired glucose tolerance. The Da Qing IGT and Diabetes Study.

CONCLUSIONS: Diet and/or exercise interventions led to a significant decrease in the incidence of diabetes over a 6-year period among those with IGT.

2.      Prevention of type 2 (non-insulin-dependent) diabetes mellitus by diet and physical exercise. The 6-year Malmo feasibility study.

CONCLUSIONS: From a previously reported 5-year screening program of 6,956 47-49-year-old Malmo males, a series of 41 subjects with early-stage Type 2 (non-insulin-dependent) diabetes mellitus and 181 subjects with impaired glucose tolerance were selected for prospective study and to test the feasibility aspect of long-term intervention with an emphasis on life-style changes. A 5-year protocol, including an initial 6-months (randomized) pilot study, consisting of dietary treatment and/or increase of physical activity or training with annual check-ups, was completed by 90% of subjects. Body weight was reduced by 2.3-3.7% among participants, whereas values increased by 0.5-1.7% in non-intervened subjects with impaired glucose tolerance and in normal control subjects (p less than 0.0001); maximal oxygen uptake (ml.min-1.kg-1) was increased by 10-14% vs decreased by 5-9%, respectively (p less than 0.0001). Glucose tolerance was normalized in greater than 50% of subjects with impaired glucose tolerance, the accumulated incidence of diabetes was 10.6%, and more than 50% of the diabetic patients were in remission after a mean follow-up of 6 years. Blood pressure, lipids, and hyperinsulinemia were reduced and early insulin responsiveness to glucose loading preserved. Improvement in glucose tolerance was correlated to weight reduction (r = 0.19, p less than 0.02) and increased fitness (r = 0.22, p less than 0.02). Treatment was safe, and mortality was low (in fact 33% lower than in the remainder of the cohort)

We should be preparing for the final results and answer the question, HOW DO WE IMPLEMENT A PROGRAM OF LIFESTYLE INTERVENTIONS.

       K M Venkat Narayan, chief, diabetes epidemiology section. 

Barbara A Bowman, epidemiologist. 
Michael E Engelgau, chief, epidemiology and statistics branch. 

Division of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Mailstop K-68, 4770 Buford Highway NE, Atlanta, GA 30341, USA

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1.	Puska P, Tuomilehto J, Nissinen A, Vartiainen E. The North Karelia project: 20 year results and experiences. Helsinki: National Public Health Institute (KTL), 1995.
2.	Tuomilehto J, Lindstorm J, Eriksson JG, Valle TT, Hamalainein H, Ilanne-Parikka P, et al, for the Finnish Diabetes Prevention Study Group. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med 2001; 333: 1343-1350[Medline].
3.	Tataranni PA, Bogardus C. Changing habits to delay diabetes. N Engl J Med 2001; 333: 390-392[Full Text].
4.	Narayan KMV, Gregg EW, Fagot-Campagna A, Engelgau MM, Vinicor F. Diabetes: a common, serious, costly, and potentially preventable public health problem. Diabetes Res Clin Pract 2000; 50: 77-84[Medline].
5.	Eriksson K-F, Lindgarde F. Prevention of type 2 (non-insulin-dependent) diabetes mellitus by diet and physical exercise: the 6-year Malmo feasibility study. Diabetologia 1991; 34: 891-898[Medline].
6.	Pan X, Li G, Hu Y, Wang J, Yang W, An Z, et al. Effects of diet and exercise in preventing NIDDM in people with impaired glucose tolerance: the Da Qing IGT and diabetes study. Diabetes Care 1997; 20: 537-544[Medline].
7.	Knowler WC, Narayan KMV, Hanson RL, Nelson RG, Bennett PH, Tuomilehto J, et al. Preventing non-insulin-dependent diabetes mellitus. Diabetes 1995; 44: 483-488[Medline].
8.	Diabetes Prevention Program Research Group. The diabetes prevention program: design and methods for a clinical trial in the prevention of type 2 diabetes. Diabetes Care 1999; 22: 623-634[Medline].