PDF

Monitoring diabetes in people over 75

In the March 2012 issue of Best Tests, bpacnz published an article discussing testing for CVD, diabetes and renal disease in elderly people. This article suggested that many laboratory tests become more difficult to interpret in elderly people because of the effects of medicines and declining general health. However, monitoring diabetes remains important for elderly people due to its long-term degenerative nature and associated co-morbidities and complications.

Recommendations for monitoring diabetes
in people aged over 75 years

It is recommended that patients with diabetes receive an annual diabetes review including testing of HbA1c and microalbumin to calculate an albumin/creatinine ratio.1 This report will discuss whether these tests are being requested at an appropriate rate for elderly people (aged over 75 years) with diabetes. The data in this report is for all patients dispensed either oral medication or insulin for diabetes, and the HbA1c and microalbumin tests requested for those patients. The data in this report was sourced from the Ministry of Health National Collections.2,3

National data by ethnicity

Appropriate testing of HbA1c

In elderly people with diabetes, HbA1c should be tested annually as part of an annual diabetes review.1 Some patients may need to be tested more often; however more frequent testing is not necessary in patients with stable, well controlled diabetes.

Ongoing HbA1c testing is important for monitoring glycaemic control and predicting the risk of further complications.

fig1 % of people ≥75 years with diabetes who received at least one HbA1c test in 2011
Testing for microalbuminuria

Diabetic nephropathy is one of the most common forms of chronic kidney failure in the developed world and occurs in more than 30% of people with diabetes.4 Diabetic nephropathy generally takes six to 15 years to develop and therefore is more prevalent in older people with a long history of diabetes.4

Microalbuminuria is the first sign of nephropathy, but not all people with microalbuminuria will progress to full nephropathy. If detected early, microalbuminuria can be reversible with good glycaemic control and management of blood pressure.

Nationally, the rate of microalbumin testing in elderly patients is lower than we would expect. In older patients, the specifity of the albumin:creatinine ratio is reduced,5 however it remains the best way to detect early stage microalbuminuria and regular monitoring is important in people with diabetes, regardless of their age.

fig2 % of people ≥75 years with diabetes who received at least one microalbumin test in 2011
  1. Diabetes New Zealand. Annual diabetes check-up. Available from: www.diabetes.org.nz (Accessed May, 2012).
  2. Ministry of Health. Pharmaceutical Collection. (Accessed May, 2012).
  3. Ministry of Health. Laboratory Claims Collection. (Accessed May, 2012).
  4. Philips A. Diabetic nephropathy. Medicine 2011;39(8):470-4.
  5. Houlihan C, Tsalamandris C, Akdeniz A, Jerums G. Albumin creatinine ratio: a screening test with limitations. Am J Kid Dis 2002;38(6):1183-9.
  • National data excludes Nelson Marlborough DHB and South Canterbury DHB areas due to laboratory data recording discrepancies in these areas.