Diabetes in people over 65

• Non-Insulin Dependent Diabetes Mellitus (NIDDM) often, but not always presents in older people.
• The prevalence of diabetes rises with increasing age and affects around 20% of those over 65 years in the UK, up to 50% in some ethnic groups and the obese. Of these, half will be unaware that they have diabetes.
• There are an increasing number of older insulin-dependent diabetics who were diagnosed when young; some have survived with few or no complications.
• Many older people with diabetes are recognised late for various reasons and diagnosis may be made as an incidental finding when routine screening tests are carried out. This is partly because the renal threshold for glucose is raised (so the classical symptoms of polyuria and glycosuria occur later) and the thirst mechanism is reduced (so the symptom of excessive drinking is delayed).
• The mortality rate for older people with diabetes is more than twice that of non-diabetic people of the same age mainly because of the increase in cardiovascular disease especially in those with Type 2 Diabetes.
• Older people, especially those who have had diabetes for more than 20 years have a reduced awareness of the symptoms of hypoglycaemia (if treated with insulin or sulphonurea medication) and therefore are at greater risk.
• Because of the development of complications with diabetes over time older person with diabetes are more likely to have complications than younger persons:
  • After 20 years, almost all patients with IDDM have some retinopathy
  • After 20 years, 30% develop nephropathy
  • Around 30% of diabetic patients develop neuropathy; it is related to the duration of the diabetes and the degree of control.

• Secondary diabetes is more common in older people.