The prevalence of dementia is much higher among older people with Down syndrome, according to a new report.

It also revealed that among older people with any type of intellectual disability (ID), osteoporosis rates are higher, but heart attack and high blood pressure rates are lower.

The report was launched by the Intellectual Disability Supplement (IDS) to TILDA (The Irish Longitudinal Study on Ageing), which is an ongoing study of Irish people over the age of 50.

This marks the first time in history that people in Ireland with an ID are growing old in big numbers. The IDS-TILDA report, Advancing Years, Different Challenges, focuses on how the ageing process is affecting the physical and mental health of the 30,000 people in Ireland with such a disability.

The report reveals a big increase in the number of people with Down syndrome developing dementia. In the three-year period since the first IDS-TILDA study was conducted in 2010, the prevalence of this disease has nearly doubled in people with Down syndrome - from 15% to just under 30%.

These are much higher levels of dementia than those seen in the general population.

The report noted that the average age of onset of dementia among people with Down syndrome was 55, with some cases presenting in their early 40s. The majority of people without Down syndrome who develop dementia do so after the age of 65.

Meanwhile, the report also found that rates of osteoporosis among people with an ID had doubled since the 2010 study - from 8% to 16%. However, measurements taken during the current study reveled that almost 70% of older people with an ID had poor bone health. This suggests that poor bone health is largely under-diagnosed within this population.

On a positive note, the report revealed that rates of high blood pressure were 50% lower among people with an ID compared to the general population - 15% versus 37%. Rates of heart attack were also three times higher among people without an ID.

The report also found that:
-At least seven in 10 older people with an ID took part in only low levels of physical activity that were unlikely to lead to any health benefits
-Two in three were overweight or obese, although the majority of these thought that they were in the healthy weight range
-The prevalence of epilepsy increased from 30% in the 2010 study to almost 36% in this study. Among people with Down syndrome, it rose from 19% to 27%
-Almost half of those aged 65 and older had chronic constipation
-The rate of cataracts had increased by 50% since the 2010 study and the rate of the eye disease, macular degeneration, had also doubled. These are higher rates than within the general population
-Almost six in 10 older people with an ID had been diagnosed with an emotional, nervous or psychiatric disorder

"This is the first time in history we have ever had a population of people with an intellectual disability who have reached old age and this is something that we should celebrate. However, there are a number of very serious health concerns that we need to better understand in this population. Unless we can address some of these challenges, older people with ID are likely to live a poor quality of life as they grow older, and ageing in poor health is an empty prize," commented IDS-TILDA principal investigator, Prof Mary McCarron.

The report also looked at the level of social participation and connectedness among older people with an ID. It found that they tended to be single without children or grandchildren, and were very reliant on siblings and extended family to provide family networks, especially when their parents had passed away.

However, most family members lived in different areas than the person with an ID.

Meanwhile, two in three of those with an ID had problems with reading, writing, numeracy and money management, with 62% admitting they could not read their own name.

Prof McCarron said that there is a ‘planned movement' in Ireland to get people with intellectual disabilities away ‘from larger more self-contained settings to greater community living'.

"Such a movement to the community is intended to improve the quality of people's lives. However, unless the community is truly organised and resourced to support ageing people with ID when there are complex health issues, their experience may instead be one of social isolation, loneliness and new forms of institutionalisation,' she insisted.

She said that local medical and healthcare providers ‘must partner with intellectual disability service providers to ensure that needed healthcare is available, prepared and welcoming of this population of Irish citizens'.

Prof McCarron added that it is not only important to add years to life, ‘but also critically, that we add life to years'.

For more information on dementia, see our Alzheimer's Clinic here