Mental decline may shorten life

Older people with impaired thinking or cognitive function are at greater risk of dying within a few years than those with intact cognitive function.

One in five people aged 65 years and older are cognitively impaired. While cognitive impairment is known to reduce a person's likelihood of survival, several factors may be involved in the relationship such as smoking, poor health, and depression. And while older people who are more socially engaged have a lower risk of dying, social connectedness doesn't appear to influence the risk of death in people with cognitive impairment.

Researchers from United Kingdom studied 10,720 elderly men and women to examine the association between cognitive impairment and social support mortality. Cognitive function of all the participants was measured and their social engagements were also assessed using data like marital status, living situation, availability of assistance and frequency of social contact. At the study's outset, 13% had mild cognitive impairment, while 2% had moderate to severe cognitive impairment.

During follow-up lasting 6 to 10 years, the people with mild cognitive impairment were at 31% greater risk of dying than people with no cognitive trouble. The risk of dying was 64% greater for people with moderate to severe impairment.

The researchers also determined levels of social engagement among study subjects and found that people with a medium amount of social engagement were 18% more likely to die during follow up than those who were highly socially engaged, and the risk was 29% greater for those with low levels of social engagement. But there was no relationship between social engagement and death for people with impaired cognitive function.

The findings suggest that although social engagement and interventions to enhance it may improve the quality of life in older people with dementia, they may not affect mortality risk. The researchers concluded that social engagement had modest but significant effects on survival for the population as a whole, and efforts to help older people become more socially connected could benefit public health.