Diabetes - Tests and diagnosis

Screening for diabetes

Because the symptoms of type 2 diabetes may be so subtle, they are often not noticed at all; many people who have type 2 diabetes are not aware of it. Screening can help to ensure that type 2 diabetes is diagnosed early, allowing careful control of bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. glucoseA simple sugar that is an important source of energy in the body., which can prevent or delay the complications of diabetes.

Screening programmes have not been implemented everywhere, and can vary from country to country. Recommendations for screening people who are at higher risk of type 2 diabetes have recently been produced in France and in the United States, for example.

In France, screening has been so effective that undiagnosed diabetes is now unusual in people with known risk factors such as a family history of the condition.[1]

The American Diabetes Association recommends three-yearly screening for people who are aged 45 years or older.

However, screening may be less effective in the USA than in France, because preventive action is often not taken as it should be in the light of abnormal findings.[2,3]

Studies have suggested that screening for type 2 diabetes and impaired glucose toleranceA level of insulin resistance that leads to high glucose levels, but not high enough for a diagnosis of diabetes. in people at risk who are aged 45 years and older is cost-effective. Targetting those known to have risk factors for diabetes therefore seems to be the most effective policy.[4,5]

Diagnosis and ongoing evaluation

If you think you may have any of the symptoms of diabetes, or that you may be at risk, it is strongly advised that you seek medical advice. Early diagnosisThe process of determining which condition a patient may have. and treatment can prevent or delay many of the complications of diabetes.

Blood tests that may be ordered if diabetes is suspected include:

  • Blood glucoseA simple sugar that is an important source of energy in the body. level
  • Oral glucose toleranceThe ability of the body to maintain a normal glucose level following the ingestion of glucose. test
  • Glycated haemoglobin, or HbA1cAn abbreviation for glycated haemoglobin, a measure of how well glucose levels have been controlled over the previous three months or so in a person with diabetes. It is expressed as a percentage. level
  • Cholesterol and other lipids levels.

Urine tests that may help to assess suspected diabetes include checks for:

  • Urine glucoseA simple sugar that is an important source of energy in the body.
  • Ketones
  • Protein.

More detail on:

Blood tests

Urine tests

Assessment for complications

References: 
  1. Assessment of diabetes screening by general practitioners in France: the EPIDIA Study. Cogneau J, Balkau B, Weill A et al. Diabet Med. 2006;23:803-7.
  2. Glucose testing and insufficient follow-up of abnormal results: a cohort study. Kern LM, Callahan MA, Brillon DJ et al. BMC Health Services Research. 2006;6:87-92.
  3. Opportunistic screening for diabetes in routine clinical practice. MW Ealovega, BP Tabaei, M Brandle et al. Diabetes Care. 2004;27:9-12.
  4. Different strategies for screening and prevention of type 2 diabetes in adults: cost effectiveness analysis. Gillies CL, Lambert PC, Abrams KR et al. BMJ. 2008;336:1180-5.
  5. Screening adults for type 2 diabetes: a review of the evidence for the U.S. Preventive Services Task Force. Norris SL, Kansagara D, Bougatsos C et al. Ann Intern Med. 2008;148:855-68.