Journal of Medical Sciences (2010); 3(2): 82-86
Review Article Open Access
Type 2 Diabetes Is a Preventable Disease - Lifestyle Is the Key Keywords: Controlled trials, lifestyle intervention, obesity, prevention, type 2
Jaakko Tuomilehto1,2,3 Institute, Department of Public Health, University of Helsinki, Helsinki, Finland
diabetes.
1Hjelt
2South
Ostrobothnia Central Hospital, Seinajoki, Finland 3Department
Medicin, Austria
of Clinical and Preventive Danube-University Krems, Krems,
Abstract Type 2 diabetes is increasing rapidly all over the world. Since it develops from an interaction between genes and lifestyle factors, it can also be prevented by influencing its modifiable risk factors. During the last two decades, several well-designed and properly conducted controlled trials have confirmed that lifestyle intervention is highly effective in preventing type 2 diabetes in high-risk individuals. Such trials have been carried out in many different populations and living environments – all of them producing similar beneficial effects. Moreover, long-term follow-up of the participants in such trials has revealed that these benefits are sustaining long after the actual intervention has been stopped. It is however likely that different people benefit from different interventions, and this may partly depend on their genetic constellations. The results from these trials must now be applied in the real-life settings in order to stop the pandemic of type 2 diabetes.
Correspondence JAAKKO TUOMILEHTO Mannerheimintie 172, 00014 University of Helsinki Helsinki, Finland Tel: +358 40 5016316 Fax: +358 20 6108661 E-mail:
[email protected]
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It is well known that obesity, unbalanced diet and physical inactivity are the major risk factors for type 2 diabetes (T2D).1 In genetically predisposed people the probability to develop T2D is very high once exposed to "unhealthy" lifestyles. The development of T2D is a slow process during which only subjects that carry a genetic predisposition may develop T2D. About half of individuals will develop T2D during their lifetime, and up to 30-35% will have impaired glucose tolerance (IGT).2,3 Even though genetic effects are important for the development of T2D4 and increasing number of T2D susceptibility genes are known,5 it is not possible to modify them. Until recently, evidence regarding the prevention of T2D based on proper randomized controlled trials (RCT) was virtually missing, but today this knowledge gap is filled and there is unequivocal and strong evidence that we can prevent the progression to T2D diabetes in high-risk individuals with lifestyle intervention. Lifestyle Trials in People with IGT to Prevent Progression to Type 2 Diabetes The feasibility of diet and exercise intervention in men with IGT was assessed in Swedish men.6 Since the reference group comprised of men who did not want to join the intervention, the groups were not randomly assigned. During the 5-year study 11% and 29% of the intervention and reference groups developed diabetes, respectively. In Da-Qing China subjects with IGT were assigned either to a control, or lifestyle intervention groups using a cluster-randomized trial design.7 The cumulative 6-year incidence of type T2D was lower in the three intervention groups (41-46%) than in the control group (68%).
TYPE 2 DIABETES IS A PREVENTABLE DISEASE
The Finnish Diabetes Prevention Study (DPS) provided the first convincing evidence from a proper RCT that T2D can be prevented by lifestyle modification.8 Persons with IGT were randomized to intensive lifestyle intervention had a 58% lower T2D incidence than the control group during an average 3.2-year followup,. The lifestyle intervention goals were l) reduction in weight of 5 %, 2) total fat intake
