Nurse measuring blood pressure.

    Diabetes and high blood pressure increase Alzheimer’s risk

    10 August 2017

    People with vascular health problems, including diabetes and high blood pressure, have a greater chance of dementia later in life, according to new research published in JAMA Neurology.

    The researchers, from Johns Hopkins University in the US, analysed data from 15,744 people who participated in the Atherosclerosis Risk in Communities study. From 1987 to 1989, the participants, who were between 45 and 64 years of age, underwent a battery of medical tests during their initial examinations. Over the next 25 years they were examined four more times. Cognitive tests of memory and thinking were administered during all but the first and third exams.

    They found that 1,516 participants were diagnosed with dementia during an average of 23 follow-up years. Initially, when they analysed the influence of factors recorded during the first exams, the researchers found that the chances of dementia increased most strongly with age followed by the presence of APOE4, a gene associated with Alzheimer’s disease.

    In agreement with previous studies, an analysis of vascular risk factors showed that participants who had diabetes or high blood pressure, also called hypertension, had a higher chance of developing dementia. Diabetes was almost as strong a predictor of dementia as the presence of the APOE4 gene.

    In addition, the researchers discovered a link between dementia and prehypertension, a condition in which blood pressure levels are higher than normal but lower than hypertension.

    Rebecca Gottesman, the study’s lead author, said: ‘Our results contribute to a growing body of evidence linking midlife vascular health to dementia. These are modifiable risk factors. Our hope is that by addressing these types of factors early, people can reduce the chances that they will suffer from dementia later in life.’

    Instant analysis

    With an ageing population, dementia is becoming an increasingly severe problem but evidence continues to build showing that reducing risk factors in middle age can have a significant effect on the likelihood of dementia occurring in later life. This large, long-term American study analysing over 15,000 middle-aged people over 25 years shows that – as we already know -– diabetes and high blood pressure are strong risk factors in the future development of dementia.

    However, unlike other studies it showed a link between dementia and pre-hypertension, where blood pressure levels are slightly raised but not to a level of hypertension. This is further evidence that strictly controlling blood pressure in mid-life as well as other factors such as diabetes, obesity and smoking can impact on dementia risk when older. We should all be looking at our own lifestyles to ensure we do all we can ourselves to help reduce our risk now.

    Research score: 4/5