Here's an editorial I just came across in this week's British Medical Journal....I thought it might interest Pryncess and other people interested in the prevention and management of type 2 diabetes:
Prevention and cure of type 2 diabetes
Weight loss is the key to controlling the diabetes epidemic
The Department of Health has published the first part of the national service framework defining standards of care for
people with diabetes. The substance of how these standards will be achieved is now awaited. Type
2 diabetes, however, is reaching epidemic proportions, and epidemics are seldom controlled unless their causes are
addressed. Obesity is strongly and causally linked to type 2 diabetes. Recent data suggest that the prevention of
diabetes is feasible if weight management is addressed adequately in individuals at high risk. More controversially,
weight management also has the potential to make a significant impact in those with established type 2 diabetes.
The most common definition of obesity is a body mass index greater than 30 kg/m2. In the nurses' health study the risk of type 2 diabetes in women with an index of
29-31 was 28-fold increased compared with women with an index lower than 22, and an index greater than 35 carried a 93-fold increased risk.1
The overall prevalence of self reported diabetes in the United States has reached 7.3%, and 15% in people over 60 years of age, driven by epidemic obesity.2 There
is no room for complacency in the United Kingdom. The prevalence of known and new type 2 diabetes, detected by oral glucose tolerance test, was 20% in
Europeans, 22% in Afro-Caribbeans, and 33% in Pakistanis in urban Manchester.3 Obesity and physical inactivity were the principal factors associated with
diabetes, and waist circumference, a measure of intra-abdominal fat, was the strongest predictor of glucose tolerance. Similarly, obesity related diabetes in childhood,
already common worldwide, has now reached the United Kingdom.4
So, could we prevent type 2 diabetes? In a prospective study of 84 941 female nurses followed for 16 years, a combination of five modifiable risk factors related to
dietary behaviour, physical activity, weight, and cigarette smoking was identified that was associated with a remarkable 91% reduction in the risk of developing
diabetes.5 Even with a family history of diabetes the risk reduction was 88%. In theory, therefore, most diabetes could be preventable, largely irrespective of genetic
background.
Two pioneering studies show that this is feasible. In the Finnish diabetes prevention study weight loss in overweight subjects with impaired glucose tolerance,
averaging just 3-4 kg over 4 years, led to a 58% reduction in incident diabetes.6 A similar result was achieved by the diabetes prevention programme in the United
States, in which lifestyle intervention involving exercise and dietary change in subjects with impaired glucose tolerance reduced incident diabetes by 58%.7
The mechanism of prevention of diabetes probably entails changes in both dietary behaviour and physical activity, for which weight loss is a surrogate indicator.
Whatever the mechanism the message is that much could be done to prevent diabetes in individuals at high risk. If theory is to be put into practice in the United
Kingdom, however, where few general practitioners see a role for primary care in the prevention of diabetes,8 a substantially increased awareness of risk factors
such as obesity and impaired glucose tolerance is needed. A bigger obstacle still is that lifestyle and body weight are far from being under voluntary control, and so
prevention of diabetes requires sustained cultural change.
The success of the diabetes prevention studies begs a controversial question: should we put greater emphasis on weight loss for patients with new diabetes? The
traditional dogma (not strongly evidence based) is that people with diabetes cannot lose weight and so this is futile. However, the regular support of a dietitian,
practical help with physical activity, and behavioural change at home and at work are the central tenets of successful weight management and are absent from
diabetes care. The most thought provoking data on improved glycaemic control, and sometimes remission of diabetes, through restriction of calories come from
morbidly obese individuals undergoing bariatric surgery.9 Although this remedy can hardly be advocated widely, the data show how diabetes can be controlled and
sometimes cured by major reductions in caloric intake. Weight loss, therefore, of at least 5-10% would be a logical goal, alongside standard glycaemic and
cardiovascular targets, for many overweight people with diabetes. This would slow progression, reduce insulin requirements, allow withdrawal of treatment for some,
and, most importantly, reduce mortality.10 Experience shows, however, that this is often beyond the reach of older patients; it may be more realistic for younger
newly diagnosed patients, given appropriate support, and perhaps judicious use of anti-obesity drugs. Much remains to be learned about the treatment of this disease.
Testing times lie ahead for this national service framework. Epidemic type 2 diabetes demands more than a reiteration of the established glycaemic and
cardiovascular targets on a grand scale. While the goal of a cure for type 2 diabetes remains some way off for most patients, prevention of diabetes and slowing of
the natural history of the disease are clearly feasible. We should act on this important new evidence.
Jonathan Pinkney, senior lecturer.
University Department of Medicine, Diabetes and Endocrinology Research Group, Clinical Sciences Centre, University Hospital Aintree, Liverpool L9 7AL
[email protected]
1.
Colditz G, Willett WC, Stampfer MJ, Manson JE, Hennekens CH, Arky RA, et al. Weight as a risk factor for clinical diabetes in women. Am J Epidemiol
1990; 132: 501-513[Abstract].
2.
Mokdad AH, Bowman BA, Ford ES, Vinicor F, Marks JS, Koplan JP. The continuing epidemics of obesity and diabetes in the United States. JAMA 2001;
286: 1195-2000[Medline].
3.
Riste L, Khan F, Cruickshank K. High prevalence of type 2 diabetes in all ethnic groups, including Europeans, in a British inner city: relative poverty, history,
inactivity, or 21st century Europe? Diabetes Care 2001; 24: 1377-1383[Abstract/Full Text].
4.
Drake AJ, Smith A, Betts PR, Crowne EC, Shield J. Type 2 diabetes in obese white children. Arch Dis Child 2002; 86: 207-208[Abstract/Full Text].
5.
Hu FB, Manson JE, Stampfer MJ, Colditz G, Liu S, Solomon CG, et al. Diet, lifetyle, and the risk of type 2 diabetes mellitus in women. N Engl J Med 2001;
345: 790-797[Abstract/Full Text].
6.
Tuomilehto J, Lindstrom J, Eriksson JG, Valle TT, Hamalainen H, Ilanne-Parikka P, Keinanen-Kiukaanniemi S, et al. 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; 344:
1343-1350[Abstract/Full Text].
7.
Diabetes Prevention Program Research Group. Reduction of the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002;
346: 393-403[Abstract/Full Text].
8.
Wylie G, Hungin APS, Neely J. Impaired glucose tolerance; qualitative and quantitative study of general practitioners' knowledge and perceptions. BMJ 2002;
324: 1190-1196[Abstract/Full Text].
9.
Pinkney JH, Sjostrom CD, Gale EAM. Should surgeons treat diabetes in severely obese people? Lancet 2001; 357: 1357-1359[Medline].
10.
Lean ME, Powrie JK, Anderson AS, Garthwaite PH. Obesity, weight loss and prognosis in type 2 diabetes. Diabet Med 1990; 7: 228-233[Medline].