Unlike last week’s paper from Exeter which focussed on the care of people who have developed dementia, this study from researchers based in Paris and London, looks at factors identifiable in middle age which are associated with the incidence of dementia before the age of 70, or death in the same follow up period.
Subjects – 10,095 aged 35-55- were drawn from the Whitehall ii study of civil servants with a baseline 1985-1988. Follow up was to 2019.
The take-home story is that ‘multi-morbidity’ in middle age (55) is associated with increased likelihood of developing dementia or dying in the follow up period.
Multi-morbidity is defined as having two or more chronic condition, severe Multi-morbidity – having three of more chronic conditions. The chronic conditions identified were: coronary heart disease, stroke, heart failure, diabetes, hypertension, cancer, chronic kidney disease, chronic obstructive airways disease, liver disease, depression, other mental disorders, Parkinson’s disease and arthritis.
Dementia was diagnoses using codes from the ICD: F00, F03, F05.1, G30, and G31
Data were drawn from Hospital Episode Statistics, Mental Health Data Set and the Mortality Register and linked with the UK NHS electronic health records.
639 new cases of dementia were identified in the follow up which had a median of 31.7 years
The most common chronic conditions amongst the people developing dementia were: hypertension, coronary artery disease, depression and diabetes – in that order
People with two or more chronic conditions at 55 were 3.86 more likely to develop dementia and 1.73 times as likely to have died.
People with three or more chronic conditions at 55 were 5.22 times as likely to develop dementia.
Other studies suggest that the characteristics of this large Civil Service sample are similar to those of the population, so that it is not unreasonable to feel that these findings can be applied more widely.
There are some other follow up series – but these include fewer people – less than 2,500 per study. They have focussed on older adults and provided shorter follow up. Their findings are in keeping with those of this study.
The analysis controlled for age, gender and social circumstances.
The message is clear - that for a healthier old age, with less risk of dementia, people should be adopting life-styles which reduce the development of chronic illnesses earlier in life – and be sure to get them treated if they occur. This is probably easier to do when you are fairly well off, but not impossible with prudence in any situation. Something to be acted on in education as well as health.The national newspapers carried reference to another study about dementia this week: Association between age at onset of multimorbidity and incidence of dementia: 30 year follow-up in Whitehall II prospective cohort study | The BMJ