General practice management of type 2 diabetes


Preventing type 2 diabetes
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☰ Table of contents


Recommendations

Reference

Grade*

Lifestyle modifications that focus on increased physical activity, dietary change and weight loss should be offered to all individuals at high risk of developing type 2 diabetes

Structured diabetes prevention programs are available

42
NHMRC, 2009

A

Bariatric surgery can be considered in selected morbidly obese individuals (based on weight alone or the presence of comorbidities) who are at high risk of type 2 diabetes

42

NHMRC, 2009

C

Individuals who are at high risk of diabetes should be identified through the use of risk assessment tools

42

NHMRC, 2009

C

*Refer to Summary, explanation and source of recommendations for an explanation of the level of evidence and grade of evidence


Clinical context


The dysglycaemic states (IFG, IGT) occur when blood glucose levels (BGLs) are elevated above normal, but are not high enough to be diagnosed as diabetes.

Intervention is warranted to prevent or delay progression to type 2 diabetes, and to reduce mortality associated with the metabolic condition itself.

Clinical trial evidence demonstrates that the metabolic progression to type 2 diabetes can be slowed or stopped with effective diet and lifestyle modification, as well as with some drug therapies. Studies demonstrating prevention of type 2 diabetes development by structured lifestyle behaviour change programs have been conducted in Finland, the US, China and India.43–46 These had intensive programs supporting the intervention group, with the goals of intervention between 5% and 7% weight reduction using a low-kilojoule and low-fat diet, and moderate intensity physical activity (eg brisk walking) for at least 150 minutes/week.

In patients with dysglycaemic states, structured lifestyle interventions can achieve a relative risk reduction (RRR) of up to 58% in the development of type 2 diabetes. In the Indian study, the numbers needed to treat was 6.4, to prevent one incident case of diabetes over three years using a lifestyle modification program. Longer term follow-up has revealed a 43% reduction in the rate of diabetes at 20 years in the Da Qing study, 43% reduction at seven years in the Finnish study, and 34% reduction at 10 years in the US Diabetes Prevention program. Notably, in the US study, the strongest determinant of reduced diabetes incidence was weight reduction, with each 1 kg loss leading to a RRR of 16%. Of the therapies, pharmacotherapy with metformin has been shown to achieve a RRR of 31%, particularly in obese individuals with BMI >35 kg/m2. This is, however, still less effective than successful lifestyle change.47 Of the trials that evaluated mortality benefits from interventions, lifestyle has not definitively shown clear benefits, except when mediated through diabetes prevention. Pharmacological interventions have not shown reduced CVD mortality benefit.48

Note: At the time of publication, metformin does not have Therapeutic Goods Administration (TGA) or Pharmaceutical Benefits Scheme (PBS) approval for this indication within Australia.


In practice


In addition to providing comprehensive risk assessment, screening, diagnosis and management for diabetes, GPs should consider systems for identifying and managing patients with IGT or IFG who are at high risk of diabetes. They should also include absolute CVD risk assessment, and chronic kidney disease risk assessment and management in this group. Referral to government-supported type 2 diabetes and CVD prevention programs should be considered where these exist. Programs and strategies for educating patients about diabetes to encourage lifestyle modification should also be considered.

Lifestyle modification

Lifestyle modification programs (refer to Chapter 6. Lifestyle modification) should be developed using a patient-centred approach. These should be individualised with realistic goals based on what the patient can and wants to achieve. Each plan should: focus on physical activity, dietary modification and weight control; be long term; and involve partners and other family members.

The main element of the programs was an intensive lifestyle modification aimed at helping participants achieve and maintain 7% weight loss and ≥150 minutes per week of moderate-intensity physical activity. The US study included 75 minutes per week of strength training, while the Finnish study provided strength training twice weekly. All studies with success had individual goal setting, and provided individualised and group counselling, predominantly on behavioural change and nutrition.49

Plans could involve other practice team members and may include referral to allied health professionals such as, APDs, CDEs and AEPs, physiotherapists and clinical psychologists. Consider structured goal-oriented programs and community resources.

Diabetes prevention programs are supported by different state and local health authorities. General practices may seek advice on local patient referral pathways for those with IGT or IFG, or those identified by risk assessment tools such as AUSDRISK by contacting their local state or territory organisation on 1300 136 588 or at Diabetes Australia.


Diabetes Australian and RACGP logo's
 
  1. Knowler WC, Barrett-Connor E, Fowler SE, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002;346(6):393–403.
  2. Pan XR, Li GW, Hu YH, 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.
  3. Ramachandran A, Snehalatha C, Mary S, Mukesh B, Bhaskar AD, 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.
  4. Tuomilehto J, Lindstrom J, Eriksson JG, 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.
  5. Khavandi K, Amer H, Ibrahim B, Brownrigg J. Strategies for preventing type 2 diabetes: an update for clinicians. Ther Adv Chronic Dis 2013;4(5):242–61.
  6. Emdin CA, Rahimi K, Neal B, Callender T, Perkovic V, Patel A. Blood pressure lowering in type 2 diabetes: A systematic review and meta-analysis. JAMA 2015;313(6):603–15.
  7. Sumamo E, Ha C, Korownyk C, Vandermeer B, Dryden D. Lifestyle interventions for four conditions. Type 2 diabetes, metabolic syndrome, breast cancer, and prostate cancer. Technology Assessment Report. Rockville, MD: Agency for Healthcare Research and Quality, 2011.