Diabetes

Diabetes is a chronic condition characterised by high levels of glucose in the blood. It is caused either by the body’s inability to produce insulin (a hormone produced by the pancreas to control blood glucose (sugar) levels), or by the body not being able to use insulin effectively [8]. There are 3 main types of diabetes:

  • Type 1 diabetes is a non-preventable autoimmune disease that develops when the immune system destroys the insulin-producing cells of the pancreas. Although type 1 diabetes can occur at any age, it mainly develops during childhood and adolescence. Insulin replacement is an essential treatment for type 1 diabetes. Type 1 diabetes requires a careful balance of diet, exercise and management of insulin throughout the day using insulin injection or insulin pump.
  • Type 2 diabetes is largely associated with modifiable lifestyle risk factors, but also has genetic and family related risk factors. This condition occurs when the body becomes resistant to the insulin being produced by the pancreas and/or the amount produced is inadequate to meet the body's needs. When first diagnosed with type 2 diabetes, blood glucose levels can often be maintained at normal levels through lifestyle modification and/or oral glucose lowering medication, although insulin may eventually be required as the condition progresses.
  • Gestational diabetes is a condition marked by high blood sugar levels appearing for the first time during pregnancy that usually disappears once the baby is born. Gestational diabetes can be treated with a combination of lifestyle modifications and medication [8].

Prevalence

Based on the Australian Bureau of Statistics (ABS) 2014–15 National Health Survey (NHS), around 1 in 6 people aged over 65 reported having diabetes—just over 574,000 people [2]. The rate of diabetes tends to increase with age, with the highest prevalence (19.4%) reported in people aged 85 and over. Men reported slightly higher rates of diabetes than women, accounting for 55% of cases in people aged 65 and over. Consistent with the wider population, the most common type of diabetes reported by people aged 65 and over was type 2 diabetes—accounting for more than 9 in 10 cases (90%) (Figure 1) [2].

The rate of self-reported diabetes for people aged 65 and over has doubled over the last 2 decades—from 8.5% in 1995 to 17.4% in 2014–15 (Figure 2). This increase is likely due to a number of factors including: an increased prevalence of risk factors, improved public awareness, better detection techniques, improved survival through management techniques, and an ageing population [8].

Causes and complications

The cause of type 1 diabetes is unknown, although it is believed to result from genetic predisposition and environmental factors. Type 2 diabetes also has a strong genetic component, and is more likely to affect people with a family history of the condition. Certain lifestyle risk factors also increase the risk of developing this condition, such as a high body mass index (BMI) and high blood pressure, and this risk increases with age [9]. Further information on the prevalence of some of the main lifestyle risk factors in the older population is given in Healthy ageing.

Diabetes can result in a number of acute and chronic health conditions, including heart attack and stroke, kidney damage, vision loss, nerve damage (neuropathy) and delayed wound healing, which can lead also to lower limb amputation. Early and intensive management of blood sugar levels can delay the onset or slow the progression of these complications [10].

Type 2 diabetes pharmacological management in older people

Management of type 2 diabetes in older people using medication is more complex. For older people, the benefits of intensive glucose control need to be weighed against the associated risks, such as the impact of medications on the kidneys and the risk of interaction with other medicines used for managing multiple conditions (polypharmacy) [7].

In 2012, the pharmacological management of type 2 diabetes in a concessional population of people aged 65 and over was examined, and the following key findings were made [7]:

  • 8 in 10 (85%) were supplied with glucose lowering medicines
  • 2 in 10 (20%) were supplied with insulin
  • 4 in 10 (40%) were supplied with medicines as a monotherapy (a single medication)
  • 3 in 10 (33%) were supplied with dual therapy
  • 1 in 10 (11%) were supplied with triple therapy.

Hospitalisations

Diabetes was recorded as a diagnosis for over 1 million hospitalisations in 2015– 16—representing 10% of all hospitalisations that year. There were 59,900 hospitalisations related to type 1 diabetes, and 980,000 hospitalisations related to type 2 diabetes [8].

Hospitalisation rates for type 2 diabetes increased with age, with the majority (87%) of hospitalisations recorded in people aged 55 and over. The hospitalisation rate is highest in people aged 75–84, at 22,500 per 100,000 population (Figure 3).

Deaths

In 2016 diabetes was the seventh leading cause of death in Australia. A total of 16,500 deaths were related to diabetes, accounting for 10.4% of all deaths that year. Diabetes mellitus was the underlying cause for 4,770 of these deaths (29% of all diabetes deaths) and an associated cause of death for a further 8,330 deaths [3].

Diabetes mellitus death rates increase with age (Figure 4). In 2014–16, the death rate for people aged 85–94 was almost 3 times as high as those aged 75–84 [8].

Aboriginal and Torres Strait Islander people

Diabetes is an important health issue for older Aboriginal and Torres Strait Islander people, based on data from the ABS 2011–13 Australian Aboriginal and Torres Strait Islander Health Survey. Just under 2 in 5 (38%) Indigenous people aged 55 and over were diagnosed with diabetes (based on HbA1c testing), compared with 12% of non-Indigenous Australians [6].

There were more than 52,000 hospitalisations related to diabetes for Indigenous people in 2013–14, and 90% of these hospitalisations had either a principal or additional diagnosis of type 2 diabetes. The type 2 diabetes hospitalisation rate was 4 times the rate of non-Indigenous Australians, and the rate of hospitalisation increased with age (Figure 5). The highest rate was observed for people aged 65–74 (around 40,000 per 100,000) [5].

According to the ABS, diabetes was the second leading cause of death in Aboriginal and Torres Strait Islander people in 2016. The standardised death rate was 5.0 times the rate in non-Indigenous people (81.2 and 16.4 deaths per 100,000 people, respectively) [3].

References

  1. Australian Bureau of Statistics (ABS) 2013. Australian Health Survey: First Results, 2011-2012. ABS cat. no. 4364.0.55.003. Canberra: ABS.
  2. Australian Bureau of Statistics (ABS) 2015. National Health Survey: first results, 2014–15—Australia. ABS cat. no. 4364.0. Canberra: ABS.
  3. ABS 2018. Causes of Death, Australia, 2016. ABS cat. no.3303.0. Canberra: ABS.
  4. Australian Institute of Health and Welfare (AIHW) 2007. Older Australia at a glance: 4th edition. Cat. no. AGE 52. Canberra: AIHW.
  5. AIHW 2015a. Cardiovascular disease, diabetes and chronic kidney disease—Australian facts: Aboriginal and Torres Strait Islander people. Cardiovascular, diabetes and chronic kidney disease series no. 5. Cat. no. CDK 5. Canberra: AIHW.
  6. AIHW 2015b. The health and welfare of Australia’s Aboriginal and Torres Strait Islander peoples: 2015. Cat. no. IHW 147. Canberra: AIHW.
  7. AIHW 2016. Use of medicines by older people with type 2 diabetes. Cat. no. CVD 76 Department of Health 2015. Diabetes. Viewed 11 August 2016.
  8. AIHW 2017. Diabetes compendium. Viewed 7 March 2018.
  9. Diabetes Australia 2017. Type 2 Diabetes. Viewed 18 June 2018.
  10. Diabetes Australia 2017. Preventing complications. Viewed 18 June 2018.