Feature Article

Diabetes and dementia

Pat Phillips, Philip Y Popplewell



Erratic behaviour, confusion, incontinence, chronic ulceration and polypharmacy are all common problems in people with both diabetes and dementia. Targets for glycaemic control may have to be amended in these people to reduce the risks of hypoglycaemia in some cases and glycosuria in others.

Key Points

  • Concern about memory loss does not always point to a diagnosis of dementia.
  • Hypoglycaemia in the elderly may present with subtle changes and may be missed.
  • Nonmixed insulins are preferable to premixed insulins in most elderly people with diabetes.
  • Postprandial hyperglycaemia may be improved by using a very short acting aspart insulin or lispro insulin or a short acting insulin secretagogue such as repaglinide.
  • Metformin should be used cautiously in the elderly because of decreased renal function and therefore increased risk of lactic acidosis. The glitazones may be the drugs of choice in elderly people with diabetes because of low risk of hypoglycaemia.
  • The risk of an adverse drug reaction increases linearly with increasing numbers of medications. Medications that can be given once daily are preferable to those that need to be given thrice daily. NSAIDs and diabetes do not mix.