Assessing cardiovascular disease risk in people with type 2 diabetes

The NPS program Type 2 diabetes: priorities and targets focusses on the role of drug treatments in reducing cardiovascular risk for people with type 2 diabetes, recognising that lifestyle changes are the foundation of management.

Blood pressure and cholesterol management are priorities

Improved management of cholesterol and blood pressure is clearly effective in reducing cardiovascular risk for people with type 2 diabetes. Assess cardiovascular risk to guide the intensity of treatment.

  • Guidelines1 recommend a combination of management goals. In addition to hyperglycaemia, address lipids, blood pressure, and lifestyle factors (weight, smoking, alcohol intake and physical inactivity). Assess patients for their cardiovascular risk and offer assistance in managing their risk.1
  • Tight glycaemic control helps prevent long-term cardiovascular events in people newly diagnosed with type 2 diabetes2 but has a limited effect on cardiovascular outcomes in the short term (3–5 years).3,4 Lowering blood pressure or low-density lipoprotein (LDL) cholesterol levels appears to be more effective in the short term for reducing cardiovascular risk than intensifying glycaemic control.4

Manage according to cardiovascular risk

  • Assess absolute cardiovascular disease risk to determine how intensively to manage blood pressure, cholesterol and lifestyle factors.5 People at high cardiovascular risk (>15% risk of a cardiovascular event in the next 5 years) benefit from a statin and an antihypertensive, regardless of cholesterol level and blood pressure.5,6,7 The benefits are similar for people with and without diabetes.8,9
  • Treat blood pressure and cholesterol targets as a guide, not goals that everyone must achieve.5 For individuals who are close to target, assess whether the drug-related risks of intensifying drug therapy are worth the small added benefit.5

Individualise glycaemic targets

  • The benefits of tight glycaemic control on cardiovascular outcomes are small in the short term and do not outweigh the risks for people with long-standing diabetes.3,4,10,11
  • Use a target HbA1c ≤ 53 mmol/mol (≤ 7%) for most people with type 2 diabetes.13
  • Select a lower HbA1c target (≤ 48 mmol/mol [≤ 6.5%]) for people recently diagnosed with type 2 diabetes who do not have cardiovascular disease and who are not using insulin.12
  • Use the general HbA1c target ≤ 53 mmol/mol (≤ 7%) for people with longstanding diabetes, cardiovascular disease or other comorbidities.12
  • Recommend self-monitoring when the benefits to the individual are clear. Blood glucose monitoring can help people with diabetes to understand hypoglycaemic episodes and can help achieve glycaemic control by teaching patients how to adjust their treatment schedule according to blood glucose levels. Targets for self-monitored blood glucose levels are 6–8 mmol/L preprandial and 6–10 mmol/L 2 hours postprandial.13

References

  1. Diabetes Australia and The Royal Australian College of General Practitioners. Diabetes management in general practice. Guidelines for Type 2 Diabetes. 2011/12. 2011. http://www.diabetesaustralia.com.au/PageFiles/763/Diabetes%20Management%20in%20General%20Practice%202011-12.pdf (accessed 25 July 2012).
  2. Holman RR, Paul SK, Bethel MA, et al. 10-year follow-up of intensive glucose control in type 2 diabetes. N Engl J Med 2008;359:1577–89. [PubMed]
  3. Turnbull FM, Abraira C, Anderson RJ, et al. Intensive glucose control and macrovascular outcomes in type 2 diabetes. Diabetologia 2009;52:2288–98. [PubMed]
  4. Yudkin JS, Richter B, Gale EA. Intensified glucose lowering in type 2 diabetes: time for a reappraisal. Diabetologia 2010;53:2079–85. [PubMed]
  5. National Vascular Disease Prevention Alliance. Guidelines for the management of absolute cardiovascular disease risk. 2012. http://strokefoundation.com.au/site/media/AbsoluteCVD_GL_webready.pdf (accessed 25 July 2012).
  6. Law MR, Morris JK, Wald NJ. Use of blood pressure lowering drugs in the prevention of cardiovascular disease: meta-analysis of 147 randomised trials in the context of expectations from prospective epidemiological studies. BMJ 2009;338:b1665. [PubMed]
  7. Heart Protection Study Collaborative Group. MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: a randomised placebo-controlled trial. Lancet 2002;360:7–22. [PubMed]
  8. Turnbull F, Neal B, Algert C, et al. Effects of different blood pressure-lowering regimens on major cardiovascular events in individuals with and without diabetes mellitus: results of prospectively designed overviews of randomized trials. Arch Intern Med 2005;165:1410–9. [PubMed]
  9. Kearney PM, Blackwell L, Collins R, et al. Efficacy of cholesterol-lowering therapy in 18,686 people with diabetes in 14 randomised trials of statins: a meta-analysis. Lancet 2008;371:117–25. [PubMed]
  10. Boussageon R, Bejan-Angoulvant T, Saadatian-Elahi M, et al. Effect of intensive glucose lowering treatment on all cause mortality, cardiovascular death, and microvascular events in type 2 diabetes: meta-analysis of randomised controlled trials. BMJ 2011;343:d4169. [PubMed]
  11. Hemmingsen B, Lund SS, Gluud C, et al. Intensive glycaemic control for patients with type 2 diabetes: systematic review with meta-analysis and trial sequential analysis of randomised clinical trials. BMJ 2011;343:d6898. [PubMed]
  12. Cheung NW, Conn JJ, d’Emden MC, et al. Position statement of the Australian Diabetes Society: individualisation of glycated haemoglobin targets for adults with diabetes mellitus. Med J Aust 2009;191:339–44. [PubMed]
  13. Colagiuri S, Dickinson S, Girgis S, Colagiuri R. National Evidence Based Guideline for Blood Glucose Control in Type 2 Diabetes. Diabetes Australia and the National Health and Medical Research Council, 2009. http://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/di19-diabetes-blood-glucose-control.pdf (accessed 26 July 2012).