Introduction
The massive rise in type 2 diabetes in recent years, the serious health risks and healthcare costs associated with the condition, and the fact that several risk factors for the disease are modifiable, have created great interest in whether diabetes can be prevented. The importance of diabetes prevention cannot be underestimated. Unless significant efforts are made to stem the rise in diabetes, healthcare services across the world will soon be crippled by the costs of treating the diseases and its complications.
Most programmes aimed at preventing diabetes have focused on high-risk groups, particularly people whose blood glucose is already moderately raised. Recent studies have shown that lifestyle advice can be extremely effective at reducing diabetes risk in these groups.
Prevention studies
Finnish Diabetes Prevention Study (1)
This study involved 522 middle-aged, overweight people with impaired glucose tolerance (IGT). The study subjects were divided into two groups:
- an intervention group that received individual counseling aimed at helping them lose weight, reduce fat intake, and increase physical activity, for seven sessions in the first year and then every three months.
- a control group that received general diet and exercise advice once a year. After the subjects had been followed up for an average of 3.2 years, the incidence of diabetes was 58% lower in the intervention group than in the control group.
USA Diabetes Prevention Program (2)
This study involved 3,234 overweight people with Impaired Glucose Tolerance (IGT), 45% of whom were from an ethnic minority group at increased risk of diabetes. The study subjects were divided into three groups, that received:
- general lifestyle advice once a year, plus the daily administration of an oral drug
- general lifestyle advice once a year, plus a daily placebo
- intensive lifestyle advice (16 sessions over 24 weeks) aimed at achieving weight loss and increased physical activity
The subjects were followed up on for an average of 2.8 years. Compared to the placebo group, the incidence of diabetes was 58% lower in the group that had received intensive lifestyle advice, and 31% lower in the group that had been administered metformin.
Lessons learned
These studies show that frequent lifestyle advice, given by a trained health professional, is effective in reducing the development of diabetes in people at high risk. What remains a subject of debate is how applicable these findings are to the population at large, who are not as motivated to make lifestyle changes as people who choose to join clinical trials. Debate also surrounds how feasible it would be to offer time-intensive and expensive lifestyle intervention programmes to all those at high risk of diabetes, or even to whole populations.
Even the most effective lifestyle advice will not work for everyone. As diabetes carries such serious health risks, there is a growing feeling that people who are at high risk of developing diabetes and its complications (particularly cardiovascular disease), and who have not responded to lifestyle advice, should be given drugs to reduce their risk. A number of large clinical trials are in progress to investigate whether drugs that improve insulin secretion or insulin sensitivity reduce risk of diabetes and cardiovascular disease in people at high risk.
References
1. Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. The New England Journal of Medicine 2002; 346: 393-403.
2. Tuomilehto J, Lindstrom J, Eriksson JG, Valle TT, Hamalainen H, Ilanne-Parikka P, Keinanen-Kiukaanniemi S, Laakso M, Louheranta A, Rastas M, Salminen V, Uusitupa M. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. The New England Journal of Medicine 2001; 344: 1343-50.
Print this page
Send to friend