Diabetes and the elderly

Maxwell Adeyemi

THE PREVALENCE of type 2 diabetes, which represents about 90 per cent of all diabetes, increases with age and it affects roughly 20 per cent of people over the age of 65 years. In addition to the 20 per cent of the elderly population with frank diabetes, about another 25 per cent fit the criteria for the pre-diabetes state, characterised by impaired glucose tolerance and/or abnormal fasting glucose levels, which is not yet in the diabetic range but eventually will progress to become diabetes over time.

The elderly are generally defined as one in their sixth decade of life even though there is no definite consensus on the age, as there are variations from country to country.

The average life expectancy following a diagnosis of diabetes for a 65-year-old woman and man is 19 years and 15 years respectively, at age 75 it is 12 and nine years respectively, and because many older diabetic patients can be expected to live a decade or more after diagnosis, it is imperative that careful consideration be given to the risk and benefits of intervention on reducing the morbidity and mortality associated with diabetes.

Since nearly half of all type 2 diabetes cases are among individuals age 65 and older, management of type 2 diabetes in this age group requires numerous special considerations.

Because long-term complication of type 2 diabetes may still occur in the elderly, proper diagnosis and treatment are essential in this population. The older the patient gets and the longer the duration of the diabetes, the greater the risk of developing complications.

The long-term complications are related to small vessel-microvascular damage (retinopathy eye disease, nephropathy kidney disease), macrovascular (big vessel) disease or neuropathy nerve damage.

The macrovascular complications include coronary heart disease, peripheral vascular disease (poor circulation) and cerebrovascular accidents (strokes). These complications occur at a higher frequency in the elderly.

The elderly patient with diabetes also tends to have an increased prevalence of other cardiovascular risk factors such as hypertension and high cholesterol, which further predispose to a macrovascular disease.

Along with the above complications are:

* Elderly patients can have problems with fluid intake and are more prone to dehydration and hyperosmolar coma.

* They may not have adequate nutritional intake for a number of reasons including economic or psychological factors, physical disability due to associated medical illness or problems with food ingestion, which may lead to hypoglycemia.

* The elderly patients also have a reduced counter regulatory hormones response to hypoglycemia and often they have hypoglycemic unawareness.

* Changes in the body composition and decline in kidney function that is associated with ageing can also reduce the excretion rate of some diabetic medications, causing them to stay longer in the system and predispose the patient to hypoglycemia.

* Visual disturbances caused by ageing or related to diabetes eye disease can hinder appropriate dosing of medications (especially for those on insulin). Additionally, due to vision difficulties, elderly folks may not be able to visualise and inspect their feet effectively and if this is coupled with diabetic neuropathy, which impairs their ability to feel and perceive pain, they can have injuries, ulcers and infections that may not be detected or perceived early enough, which can lead to complications such as amputations.

* Ageing may also bring with it deterioration in brain function, and cognitive impairment becomes an issue. The cognitive impairment can result from hypoglycemia as well as hyperglycemia, and this may reduce treatment compliance.

Additionally, depression is closely associated with diabetes and is often undiagnosed. This may affect the elderly person’s ability to adhere to treatment regimes. The fact that some of the elderly often live by themselves can also increase the risk of loneliness and depression.

* Ironically, cognitive impairment, visual disturbances, as a result of hypoglycemia, may be mistaken for signs of dementia, hence careful evaluation of the elderly is necessary to avoid this confusion, so that they are differentiated and properly diagnosed.

* Many elderly people have coexisting medical conditions and therefore are on many types of medications, so polypharmacy/multiple prescription is a common scenario. If this is coupled with reduced kidney and liver function (due to ageing) it increases the risk of drug interaction in the patient. Dealing with multiple medical conditions is common in the elderly, and this can prove to be a daunting and frustrating scenario which needs support from friends and family members.

* The elderly person is also less physically active due to ageing, physical disabilities or concurrent illness. This puts them at risk of obesity, raises the risk of other cardiovascular diseases and diminishes the chance of good glucose control.

Because of all these factors, the treatment of elderly patients with diabetes must be individualised. Careful screenings for the complications of diabetes must be done and close attention should be paid to their glucose control, nutrition, medication compliance and general care.

It is also a good idea to have a network of support involving family, community and social groups for our elderly living with diabetes in order to help them manage their conditions, improve their coping skills and increase their resource base for help and assistance when needed.

Appropriate attention to these issues has the potential to improve the quality of life and increase life expectancy in our elderly patients with diabetes.

Contact Dr Maxwell at 3631807or 757541