The overriding aim of my thesis was to study the relationship between blood pressure (BP) and cognitive and psychological functioning in older persons. Observational studies indicate that lower BP... Show moreThe overriding aim of my thesis was to study the relationship between blood pressure (BP) and cognitive and psychological functioning in older persons. Observational studies indicate that lower BP increases risk for cognitive decline in older persons. Older persons are at risk for impaired cerebral autoregulation, and lowering their BP may compromise cerebral blood flow and cognitive function. Contradictory to our hypothesis, the Discontinuation of Antihypertensive Treatment in Elderly people (DANTE) Study Leiden, a community-based randomized clinical trial in older persons (aged ≥75 years) with mild cognitive deficits, did not show that discontinuation of antihypertensive treatment improves cognitive functioning. The lack of the effect of this trial may be due to the unintentional inclusion of persons with a relatively intact cerebral autoregulation. Furthermore, we demonstrated that older persons with mild cognitive deficits and with orthostatic hypotension, who discontinued all their antihypertensive medication had an increased probability of being free from orthostatic hypotension 4 months later, compared to persons who continued their medication. Finally, in the DANTE MRI sub study, the relationship between BP and both conventional features of small vessel disease (SVD) and microstructural damage was explored, as well as the relation between microstructural damage and cognitive and psychological dysfunction. Show less
With the increase in life expectancy, the prevalence of cognitive disorders is expected to rise the coming years. In this thesis we studied the association between blood pressure, cardiac... Show moreWith the increase in life expectancy, the prevalence of cognitive disorders is expected to rise the coming years. In this thesis we studied the association between blood pressure, cardiac biomarkers and cognitive function in 5800 people with mean age of 75 years. Furthermore, we investigated the feasibility to use smartphone technology to measure home blood pressure in 151 people during a 6 months follow-up period. We show that higher variability in blood pressure is associated with increased microdamage of the brain and worse cognitive function, independent of average blood pressure and use of blood pressure lowering medication. Furthermore, increased levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT), both markers of cardiac disease, are associated with worse cognitive function and steeper cognitive decline, independent of cardiovascular diseases or risks. Finally, we show that smartphone-based technology is a reliable and promising method with good adherence to measure blood pressure at home. This provides a possibility for implementation in large-scale studies and can potentially contribute to blood pressure reduction, eventually helping to prevent cognitive impairment. Show less
With increasing age the prevalence of hypertension rises. High blood pressure at midlife is associated with cognitive impairment. Nevertheless, in older persons a lower rather than a higher... Show more With increasing age the prevalence of hypertension rises. High blood pressure at midlife is associated with cognitive impairment. Nevertheless, in older persons a lower rather than a higher blood pressure is associated with incident dementia. The main purpose of the work in this thesis was to explore the role of blood pressure in relation to cerebral structure, neurocognitive functioning and hemodynamics of the brain in old age. Therefore, we sought to determine whether discontinuation of antihypertensive therapy in persons aged 75 years and over with mild cognitive deficits and using antihypertensive medication (the Discontinuation of ANtihypertensive Treatment in Elderly people [DANTE] population) would improve their cognitive and psychological functioning. The assumption was that the increase in blood pressure after the discontinuation of antihypertensives would lead to a direct increase in cerebral blood flow and, as a consequence, to an improvement in cerebral functioning. An additional objective was to investigate possible underlying mechanisms in the relation between blood pressure and neurocognitive functioning. To enable this, brain MRI was used to determine whether (lower) blood pressure was associated with (micro)structural damage, cerebral small vessel disease and blood flow in the brain, and also whether the presence of cerebral (micro)structural damage was related to neurocognitive functioning. Show less
Current evidence on older adults is derived from population-based cohort studies and randomized controlled trials, which may not include frail individuals. Data are lacking on older outpatients, a... Show moreCurrent evidence on older adults is derived from population-based cohort studies and randomized controlled trials, which may not include frail individuals. Data are lacking on older outpatients, a potentially diverse population. Therefore, we initiated the Milan Geriatrics 75+ Cohort Study, a prospective hospital-based outpatient cohort study. Chapter 1 of this thesis provides a background on the controversies regarding the homeostasis of older adults. Chapter 2, 3 and 4 report findings from the Milan Geriatrics 75+ Cohort Study. Chapter 2 explores the association between blood pressure and cognition, and whether it varies according to age and functional status. Chapter 3 examines the relationship between blood pressure and mortality risk, and whether it varies according to functional and cognitive status. Chapter 4 investigates the association between thyroid status and mortality risk in euthyroid older adults, and whether it differs by sex and age. Chapter 5 and 6 report findings from the PROSPER cohort, which includes older adults at high cardiovascular risk. Chapter 5 presents new evidence on the association of heart rate and heart rate variability with functional decline. Chapter 6 analyses the relationship between blood pressure variability and functional decline. Chapter 7 summarises and discusses the main findings of this thesis. Show less
The main objective of this thesis was to clarify the observed reversal of effect of classical risk factors for dementia and mortality with increasing age and to gain better insight in the... Show moreThe main objective of this thesis was to clarify the observed reversal of effect of classical risk factors for dementia and mortality with increasing age and to gain better insight in the biological mechanism behind the relation between both phenotypic and genetic variation in apolipoprotein E (apoE) and cognitive function. Although high cholesterol levels in midlife associate with worse cognitive function and dementia in late-life, this association attenuates and even reverses with increasing age. In memory outpatient clinic patients high blood pressure associated with better cognitive function, only in patients with structural brain damage. In the Leiden 85-Plus Study, a decline in global cognitive function preceded declines in total cholesterol levels, HDL cholesterol levels, and blood pressure, and not vice versa. Moreover, mortality was associated with larger declines in body mass index, total cholesterol levels, HDL cholesterol levels, and blood pressure. High plasma apoE levels associated with worse cognitive function, whereas offspring from Alzheimer__s disease patients had lower plasma apoE levels when measured in midlife compared to offspring from cognitively intact controls. Finally, high serum calcium levels were strongly associated with worse cognitive function in APOE _3_4 carriers, to a lesser extent in _3_3 carriers, but not in _2_3 carriers. Show less
