Although there have been previous studies that have linked raised blood pressure in midlife to an increased risk of dementia in later life, the term 'midlife' has been poorly defined and ranged from 35 to 68 years. Participants in the study, who were aged between 35-55 in 1985, had their blood pressure measured in 1985, 1991, 1997 and 2003. Other medical information was also taken, such as age, sex, lifestyle behaviours (such as smoking and alcohol intake), and socio-demographic factors.
Among the 8,639 people analysed for this study, 32.5% of whom were women, 385 developed dementia by 2017. Those who had a systolic blood pressure of 130 mmHg or more at the age of 50 had a 45% greater risk of developing dementia than those with a lower systolic blood pressure at the same age. The link between high blood pressure and dementia was also seen in people who had no heart or blood vessel-related conditions (cardiovascular disease) during the follow-up period.
Professor Archana Singh-Manoux, research professor at INSERM and honorary professor at UCL, who led the research, said: "Our work confirms the detrimental effects of midlife hypertension for risk of dementia, as suggested by previous research. It also suggests that at age 50, the risk of dementia may be increased in people who have raised levels of systolic blood pressure below the threshold commonly used to treat hypertension. The analysis suggests that the importance of mid-life hypertension on brain health is due to the duration of exposure. Therefore, there is an increased risk for people with raised blood pressure at age 50, but not 60 or 70, because those with hypertension at age 50 are likely to be 'exposed' to this risk for longer.
Limitations of the study include the fact that diagnosis of dementia was made by linking to electronic medical records that might miss milder cases of dementia; the researchers were not able to examine whether the association of hypertension was stronger with Alzheimer's disease or vascular dementia because of the small numbers in the study affected by dementia, and this requires further research; and the researchers do not know whether effective management of high blood pressure in people in mid-life might weaken the risk of later dementia.
Category(s):Aging & Geriatric Issues, Cognitive Problems Amnesia / Dementia, Dementia
Source material from Science Daily
