The management of older adults with type 2 diabetes requires careful consideration of the effects that advancing age and changes in health status can have on the competing risks and benefits of therapeutic interventions.
Dementia and diabetes are chronic illnesses. The prevalence of both these conditions is rising in the UK with our ageing population. Approximately 20% of individuals over 65 years of age have diabetes, which is often undiagnosed and under treated.1 800,000 people in the UK have dementia. The cost of treating diabetes and its complications to the NHS is an estimated £14 billion per year.2 In total, dementia is estimated to cost the UK £23 billion per year.3
In addition, 64% of those living in care homes have a form of dementia3 and as many as 25% of older people in residential and nursing care will have diabetes. Diabetes is associated with disability and functional decline.4 The number of people living in care homes is currently estimated to be 450,000 which may increase to 1,130 000 in the next 50 years.5
Good clinical practice guidelines from the Diabetes Society suggest that care home residents with diabetes are a highly vulnerable and neglected group; demonstrated by high susceptibility to infection, high prevalence of macrovascular complications and increased hospitalisation rates.5
When treating older patients with diabetes, clinicians should minimise complications by maintaining adequate blood sugar control.6 Poor glycaemic control may lead to worsening neuropathy, malaise, urinary incontinence and malnutrition.4 However, target blood glucose ranges may need to be individualised to avoid too strict control1 as this may result in more frequent hypoglycaemia and falls leading to functional decline.4 Therefore, for older patients the British Geriatrics Society recommend a target HbA1c of less than 7.0%. For frail patients this target should be less than 8.0%.7 This is supported by a study by Yau et al which found maintaining HbA1c within the range of 8.0-8.9% for diabetic nursing home residents was associated with less functional decline and less death at two years, than for residents with HbA1c levels lower than this.4
Blood sugar regulation for diabetic patients with dementia has numerous challenges due to variation in exercise, oral intake, disorientation, dietary patterns and stress levels as a result of the dementia process.
Dementia patients often cannot explain their symptoms, have difficulty remembering instructions and may resist therapy such as refusing oral hypoglycaemics or insulin.6 Many patients with dementia lose weight in the middle to later stages of the disease.6 Weight loss increases the chance of hypoglycaemia for patients taking sulphonylurea or insulin therapy.1 Complications of poor glycaemic control such as urinary incontinence or painful neuropathy can cause agitation for the patient with dementia and may be misinterpreted as part of the dementia process.
All patients with diabetes should undergo annual review of glycaemic control.5 Monitoring of diabetic control using HbA1c is a simple blood test that can be conducted at the point of care during a routine medical visit.8 HbA1c is a good blood test for dementia patients as it avoids the problem of day-to-day variability in blood glucose values and avoids the need for the patient to fast.
An audit was conducted in October 2012 to observe whether patients living in care homes in Swindon who have comorbid dementia and diabetes are receiving adequate monitoring for their diabetes. This was assessed by monitoring frequency of HbA1c blood tests, and recording whether patients have required hospital admission for possible complications of their diabetes within the last 12 months.
The audit identified 39 patients with diabetes (17.5%) from the cohort of 223 dementia patients living in care homes. Of these 61.5% had HbA1c monitoring within 12 months meeting the required standard of monitoring, 7.7% had never had an HbA1c checked and 51.3% required admission to hospital with complications possibly related to diabetes.
Despite evidence that mortality risk and kidney injury is increased if patients have HbA1c levels below 6% or above 9%,9 this audit demonstrated that abnormally high or low HbA1c levels did not equate to more frequent monitoring of glycaemic control.
Patients with raised HbA1c levels had increased hospital admissions for hyperglycaemia and infections. Patients with low HbA1c levels had a higher percentage of hospital admissions due to falls, perhaps due to hypoglycaemia. With increasing age and advancing dementia, renal and liver function is impaired resulting in decreased gluconeogenesis and reduced renal clearance of oral hypoglycaemics, making this patient group more prone to hypoglycaemia.9 Low HbA1c levels suggest diabetic control may be too strict in this elderly population. Dementia further increases vulnerability to hypoglycaemia as patients may miss meals due to poor memory or disorientation.8 Hypoglycaemia can cause cerebral damage leading to further cognitive loss, cardiac arrhythmia and death.10 These complications could be avoided if early detection of low or high HbA1c is acted upon.
Dementia appears to have a negative impact on the quality of diabetes care that care home residents receive, resulting in a high incidence of diabetic complications and hospital admissions.1 HbA1c monitoring could be improved in this patient group in order to optimise the quality of diabetic care. Improvement will require focused education of healthcare professionals with an emphasis on the importance of good glycaemic control in order to minimise the risk of diabetic complications.
Rita Vieira Alves, Laura Smith, Simon Manchip
Conflict of interest: none declared
2. Cost of Diabetes. Diabetes.co.uk. Document on the Internet. http://www.diabetes.co.uk/cost-of-diabetes.html
3. Statistics. Alzheimers Society. Document on the Internet. [Cited October 2012 Last Accessed October 2012] Available from http://www.alzheimers.org.uk/site/scripts/documents_info.php?documentID=341
4. Yau et al. Glycosylated Hemoglobin and Functional Decline in Community-Dwelling Nursing Home Eligible Elderly Adults with Diabetes Mellitus. Journal of American Geriatrics Society. 2012; 60: 1215-21
6. Medical Care for the Dementia Patient. www.alzbrain.org/pdf/handouts/8007.%20MEDICAL%20CARE%20FOR%20THE%20DEMENTIA%20PATIENT-NEW.pdf
10. Sjoblom P, Tengblad A, Lofgren U, et al. Can diabetes medication be reduced in elderly patients? An observational study of diabetes drug withdrawal in nursing home patients with tight glycaemic control. Diabetes Research and Clinical Practice 2008; 82: 197-202