Diabetes prevention and self-management interventions
There is evidence from large clinical trials that modest changes in diet and physical activity reduce the incidence of type-2-diabetes in high risk people. A substantial challenge remains in translating these findings into routine clinical practice. Systematic reviews considering real-world diabetes prevention programmes indicate a wide variation in effectiveness, often with lower levels of weight loss than more intensive interventions used in efficacy trials. However, this more modest level of weight loss is still likely to have a clinically meaningful effect on diabetes incidence. Furthermore, effectiveness of real-world lifestyle-change interventions might also be improved with closer adherence to guideline recommendations.
The rising epidemic of type 2 diabetes is putting increasing pressure on healthcare systems globally. The implementation of primary prevention strategies aimed at promoting lifestyle behaviour change represents a key opportunity to substantially reduce the incidence of type 2 diabetes worldwide. Impaired glucose regulation is an intermediate condition between normal glucose regulation and type 2 diabetes, which confers an
Figure 1: Dose-response effects of lifestyle behaviour change on diabetes incidence (at a median 7 years) in people with impaired glucose tolerance. Based on data from the Finnish Diabetes Prevention Study.  *The program goals were: no more than 30% of daily energy from fat (1); no more than 10% of energy from saturated fat (2); at least 15 g per 1,000 kcal fibre (3); at least 30 min per day of moderate physical activity (4); and at least 5% weight reduction (5).increased risk of progression to type 2 diabetes. Large, randomised controlled trials show that, for people who have impaired glucose regulation, a reduction in incidence of type 2 diabetes by over 50% can be achieved by making relatively small lifestyle changes. Better adherence to health behaviours results in a greater risk reduction, in a dose-dependent manor (Figure 1); and seven year follow-up data indicate that for individuals who succeed in making five modest lifestyle changes the rate of progression to type 2 diabetes is reduced to almost zero. Evidence suggests that weight loss and physical activity are the main drivers for diabetes prevention. However, a major challenge is how to implement these findings into “real world” healthcare systems. The resource intensive interventions used in clinical efficacy trials need to be translated into pragmatic, more affordable, programmes, that can be delivered in routine clinical practice but also that retain their effectiveness.
Real world diabetes prevention programmes
Findings from the original diabetes prevention clinical efficacy trials (the US Diabetes Prevention Programme (DPP),3 the Finnish Diabetes Prevention Study (DPS), the Da-Qing Diabetes Study in China, and the Indian Diabetes Prevention Programme), were published between 1996 and 2001. Since then, a number of pragmatic or “real world” diabetes prevention studies, that focused on translating the evidence into community based lifestyle behaviour change programmes, have been conducted. Examples of translational programmes include: the US community based group intervention DEPLOY (Diabetes Education and Prevention with a Lifestyle Intervention Offered at the YMCA), based on the DPP; the GOAL study (Good Ageing in Lahti Region study) conducted in primary healthcare in Finland and translating evidence from DPS; and DEPLAN being implemented in centres across Europe.
Evidence of effectiveness of real-world prevention programmes
Evidence from systematic reviews on the effectiveness of translational diabetes prevention programmes, suggests that a mean weight reduction of around 2kg is achievable at 12 months of follow up.10 This level of weight loss is lower than the amounts achieved by the intervention arms of large randomised trials such as the Finnish DPS (∼4.2Kg) and the US DPP (∼6.7Kg), at the same time point. However, this amount of weight loss should still result in a clinically meaningful change in diabetes incidence; findings from the US DPP study suggest that future diabetes incidence can be reduced by around 16% for each kilogram of weight lost. Furthermore, a recent meta-analytic review of real-world lifestyle interventions found that the progression rate to type 2 diabetes was 34 per 1000 person-years. This compares favourably with a recently published study considering progression to diabetes in high risk individuals who received no intervention or treatment; the authors demonstrated that for people with impaired fasting glucose, impaired glucose tolerance or both, diabetes progression rates were 47, 56 and 76 per 1000 person-years respectively.
Beyond weight loss, there is also evidence that structured education can be used to promote health behaviour and reduce glucose levels. The PREPARE pragmatic group based structured education programme, incorporating pedometers, was effective at improving glucose tolerance in people at high risk of diabetes; furthermore, these improvements were sustained at 24 months. However, the challenge may be in improving the perceived need for self-management lifestyle intervention programmes for people who are identified as being at high future risk of type 2 diabetes. A recent study conducted in Finland found that only 36% of men and 52% of women, who were at high risk of type 2 diabetes, perceived the need for lifestyle change advice.
Recent evidence based guidelines for diabetes prevention, compiled by the UK’s National Institute for Health and Clinical Excellence (NICE) and the IMAGE project (Development and Implementation of a European Guideline and Training Standards for Diabetes prevention), make clearly defined recommendations for the essential components to include in any lifestyle programmes, in order to maximise their effectiveness (see Recommendations below). These recommendations were informed by robust reviews of the relevant literature, and supplemented by expert opinion. Specific recommendations include utilising behaviour change techniques that are well-established and known to increase effectiveness, and the use of group based programmes in order to decrease costs.
Recommendations for design and content of lifestyle-change programmes for preventing type 2 diabetes (taken from IMAGE and NICE guidance)
1. Lifestyle changes - aim to promote changes in both diet and physical activity:
- ≥ 150 minutes/week of moderate-intensity physical activity gradual
- weight loss to reach and maintain a ‛healthy’ body mass index
- increase consumption of dietary fibre
- reduce total amount of fat and eat less saturated fat|
2. Behaviour change techniques – utilise established, well defined techniques such as:
- Self-monitoring, goal-setting, problem solving, relapse prevention, motivational interviewing, prompting self-talk, prompting practice, individual tailoring, time management
3. Social support
- Facilitate/encourage social support (family, friends, colleagues) for the planned behaviour change
- Maximize the frequency or number of contacts (within the resources available)
- Provide at least 16 hours of contact time over the first 9 - 18 months
5. Self-regulatory techniques – utilise techniques such as:
- Specific goal setting, prompting self-monitoring, providing feedback on performance, review of behavioural goals
6. Group versus individual
- To balance cost and effectiveness - use a group size of around 10-15 people
7. Person centred approach
- Ensure programmes adopt an empathy-building approach. Supports person to become the expert and puts them in control
8. Time between sessions
- Ensure sessions are spread over a period of time - to allow people to make gradual changes to their lifestyle and reflect and learn from experiences
- Allow time during group sessions for people to share this learning with other
9. Information provision
- Raise awareness of the benefits of lifestyle changes (and changes needed)
10. Explore participants’ reasons and confidence to change
- Exploration and reinforcement of reasons for wanting to change and confidence about making changes
11. Setting of goals and graded tasks
- Start with specific achievable short term (proximal) goals to gradually build confidence (self-efficacy) and enhance motivation
There is also some evidence to suggest that closer adherence to guideline recommendations for diabetes prevention improves the effectiveness of interventions delivered in real world service delivery settings; a recent meta-regression demonstrated that adherence of intervention content and delivery to guideline recommendations was associated with a significantly greater weight loss.15 If we can identify the components of lifestyle interventions that are reliably associated with increased effectiveness, this will inform the design of more efficient (cost-effective) diabetes prevention programmes.
Implications and future directions
Evidence suggests that pragmatic lifestyle interventions are effective at reducing weight and promoting healthier behaviour, and could potentially reduce future incidence of diabetes and cardiovascular disease. However, the challenges in translating this evidence into routine care and ensuring guideline-based interventions are delivered as part of practice need to be addressed. Potential barriers to implementation at both a national and a local level include, a lack of funding for service provision, and difficulties engaging healthcare providers; in order to produce benefits in the longer term, diabetes prevention programmes need to be adequately resourced on a national level.6 Nevertheless, there continues to be an increase in the commissioning of services aimed at prevention of type 2 diabetes. Self-management lifestyle programmes are currently being implemented in a number of diverse health care settings globally , thus demonstrating compatibility to routine care. Ongoing research by our group and others will establish the longer-term effectiveness and cost-effectiveness of this approach.
^ American Diabetes Association. Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 2012;35(Supplement 1):S64-71.
^ Knowler W, Barrett-Connor E, Fowler S, Hamman R, Lachin J, Walker E, et al. Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin. N Engl J Med 2002;346(6):393-403.
^ Lindström J, Ilanne-Parikka P, Peltonen M, Aunola S, Eriksson JG, Hemiö K, et al. Sustained reduction in the incidence of type 2 diabetes by lifestyle intervention: follow-up of the Finnish Diabetes Prevention Study. The Lancet 2006;368(9548):1673-9.
^ Gillies CL, Abrams KR, Lambert PC, Cooper NJ, Sutton AJ, Hsu RT, et al. Pharmacological and lifestyle interventions to prevent or delay type 2 diabetes in people with impaired glucose tolerance: systematic review and meta-analysis. BMJ 2007;334(7588):299.
^ Schwarz PE, Greaves CJ, Lindstrom J, Yates T, Davies MJ. Nonpharmacological interventions for the prevention of type 2 diabetes mellitus. Nat Rev Endocrinol 2012; print;8(6):363-73.
^ Tuomilehto J, Lindström J, Eriksson JG, Valle TT, Hämäläinen H, Ilanne-Parikka P, et al. Prevention of Type 2 Diabetes Mellitus by Changes in Lifestyle among Subjects with Impaired Glucose Tolerance. N Engl J Med 2001;344(18):1343-50.
^ 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(4):537-44.
^ Ramachandran A, Snehalatha C, Mary S, Mukesh B, Bhaskar A, Vijay V. The Indian Diabetes Prevention Programme shows that lifestyle modification and metformin prevent type 2 diabetes in Asian Indian subjects with impaired glucose tolerance (IDPP-1). Diabetologia 2006;49(2):289-97.
^ Cardona-Morrell M, Rychetnik L, Morrell S, Espinel P, Bauman A. Reduction of diabetes risk in routine clinical practice: are physical activity and nutrition interventions feasible and are the outcomes from reference trials replicable? A systematic review and meta-analysis. BMC Public Health 2010;10:653.
^ Ackermann RT, Marrero DG. Adapting the Diabetes Prevention Program Lifestyle Intervention for Delivery in the Community. The Diabetes Educator 2007;33(1):69-78.
^ Absetz P, Valve R, Oldenburg B, Heinonen H, Nissinen A, Fogelholm M, et al. Type 2 Diabetes Prevention in the “Real World”. Diabetes Care 2007;30(10):2465-70.
^ Schwarz PEH, Lindström J, Kissimova-Scarbeck K, Szybinski Z, Barengo NC, Peltonen M, et al. The European perspective of type 2 diabetes prevention: diabetes in Europe: prevention using lifestyle, physical activity and nutritional intervention (DE-PLAN) project. Exp Clin Endocrinol Diabetes 2008;116(3):167-72.
^ Hamman RF, Wing RR, Edelstein SL, Lachin JM, Bray GA, Delahanty L, et al. Effect of Weight Loss With Lifestyle Intervention on Risk of Diabetes. Diabetes Care 2006;29(9):2102-7.
^ Dunkley A, Bodicoat DH, Greaves CJ, Russell C, Yates T, Davies MJ, et al. Diabetes Prevention in the Real World: Effectiveness of Pragmatic Lifestyle Interventions for the Prevention of Type 2 Diabetes and of the Impact of Adherence to Guideline Recommendations. A Systematic Review and Meta-analysis. Currently Under Review.
^ Morris DH, Khunti K, Achana F, Srinivasan B, Gray LJ, Davies MJ, et al. Progression rates from HbA1c 6.0 - 6.4% and other prediabetes definitions to type 2 diabetes: a meta-analysis. Diabetologia 2013; 56(7):1489-93.
^ Yates T, Davies MJ, Sehmi S, Gorely T, Khunti K. The Pre-diabetes Risk Education and Physical Activity Recommendation and Encouragement (PREPARE) programme study: are improvements in glucose regulation sustained at 2 years? Diabetic Med 2011;28(10):1268-71.
^ Salmela SM, Vähäsarja KA, Villberg JJ, Vanhala MJ, Saaristo TE, Lindström J, et al. Perceiving Need for Lifestyle Counseling: Findings from Finnish individuals at high risk of type 2 diabetes. Diabetes Care 2012; 35(2):239-41.
^ National Institute for Health and Clinical Excellence (NICE). Preventing type 2 diabetes: Risk identification and interventions for individuals at high risk. London: NICE; 2012.
^ Paulweber B, Valensi P, Lindström J, Lalic NM, Greaves CJ, McKee M, et al. A European Evidence-Based Guideline for the Prevention of Type 2 Diabetes. Hormone and Metabolic Research 2010;42:S3-S36.