The Association between Hypertension and Dementia in the Elderly

Coffee and tea consumption and dementia risk: The role of sex and vascular comorbidities

BACKGROUND

Coffee and tea consumption has been linked to dementia. However, it remained unknown how sex and vascular risk factors modify the association. We aimed to investigate the association of coffee and tea consumption with dementia and whether sex and vascular comorbidities modified the association.

METHODS

We included 278 elderly patients with Alzheimer's disease (AD) and 102 patients with vascular dementia (VaD) from three hospitals; controls (N = 468) were recruited during the same period. We collected the frequency and amount of coffee and tea consumption and the presence of vascular comorbidities. The multinomial logistic regression model was utilized to evaluate the association of coffee and tea consumption with dementia, stratified by sex and vascular comorbidities.

RESULTS

Different combinations and quantities of coffee and tea consumption protected against AD and VaD. Consumption of ≥3 cups of coffee or tea per day was protective against AD [adjusted odds ratio (aOR) = 0.42; 95% confidence interval (CI) = 0.22-0.78)] and VaD (aOR = 0.42; 95% CI = 0.19-0.94). Stratified analyses showed that the protective effects of a higher quantity of coffee and tea against AD were more pronounced among females and individuals with hypertension. Consumption of either coffee or tea was associated with a decreased risk of VaD among diabetic participants (aOR = 0.23; 95% CI = 0.06-0.98). Hyperlipidemia modified the association of coffee or tea consumption on the risk of AD and VaD (both Pinteraction < 0.01).

CONCLUSION

The risk of AD and VaD was lower with increased consumption of coffee and tea; the impact differed by sex and vascular comorbidities including hypertension, hyperlipidemia, and diabetes.

General anesthesia is not associated with dementia in older adults with osteoarthritis for hip/knee replacements, a national population-based nested case-control study

BACKGROUND

Dementia is a prevalent neurological condition, yet the relationship between dementia and general anesthesia remains uncertain. The study aimed to explore the association between general anesthesia and dementia using a nationwide population-based database.

METHODS

The study extracted data from Taiwan's national health insurance, which encompassed the records of one million insured residents. A total of 59,817 patients aged 65 years and above, diagnosed with osteoarthritis between 2002 and 2010, were included. Among these patients, 3277 individuals with an initial diagnosis of dementia between 2004 and 2013 were matched with non-dementia patients based on age, gender, and the date of osteoarthritis diagnosis. Following a 1:2 random matching, the case group included 2171 patients with dementia, while the control group consisted of 4342 patients without dementia. The data was analyzed using conditional and unconditional logistic regressions.

RESULTS

No significant differences in the odds of dementia were found between individuals exposed to general and regional anesthesia during hip/knee replacement surgeries (OR = 1.11; 95%CI: 0.73-1.70), after adjusting for age, sex, and co-morbidities. Similarly, there were no significant differences in the odds of dementia based on different durations of anesthesia exposure (General: <2 h: OR = 0.91, 95%CI = 0.43-1.92; 2-4 h: OR = 1.21, 95%CI = 0.82-1.79; >4 h: OR = 0.39, 95%CI = 0.15-1.01; compared to no exposure. Regional: <2 h: OR = 1.18, 95%CI = 0.85-1.62; 2-4 h: OR = 0.9, 95%CI = 0.64-1.27; >4 h: OR = 0.55, 95%CI = 0.15-1.96; compared to no exposure). Likewise, no significant differences were observed in the odds of dementia based on the number of replacement surgeries (twice: OR = 0.74, 95%CI = 0.44-1.23, compared to once).

CONCLUSION

Neither general anesthesia nor regional anesthesia in hip/knee surgery was associated with dementia. Different numbers and durations of anesthesia exposure showed no significant differences in the odds for dementia.

Neurodegenerative diseases and blood pressure variability: A comprehensive review from HOPE Asia

Asia has an enormous number of older people and is the primary contributor to the rise in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The therapy of many neurodegenerative diseases has not yet progressed to the point where it is possible to alter the course of the disease. Mid-life hypertension is an important predictor of later-life cognitive impairment and brain neurodegenerative conditions. These findings highlight the pivotal role of preventing and managing hypertension as a risk factor for neurodegenerative disease. Autonomic dysfunction, neuropsychiatric and sleep disturbances can arise in neurodegenerative diseases, resulting in blood pressure variability (BPV). The BPV itself can worsen the progression of the disease. In older people with neurodegenerative disease and hypertension, it is critical to consider 24-h blood pressure monitoring and personalized blood pressure therapy.

The Association Between Diet and Cardio-Metabolic Risk on Cognitive Performance: A Cross-Sectional Study of Middle-Aged Australian Adults

Adherence to different dietary patterns has been linked to the development of cognitive decline; yet little is known about whether this relationship is present in middle age. The current study aimed to explore the relationship between different dietary patterns, cognitive performance, and potential cardio-metabolic mechanisms for this relationship. Participants were recruited using a diet screening tool to ensure that the cohort had a range of diet quality ranging from relatively poor to relatively healthy. In a sample of 141 middle-aged adults (age: M = 52.84 years, SD = 6.87 years), multiple 24 h diet recalls were collected and used to score adherence to the Mediterranean diet, dietary approaches to stop hypertension (DASH) diet, and Mediterranean-DASH diet intervention for neurodegenerative delay (MIND) diet. Metabolic risk was assessed using the metabolic syndrome severity score (MetSSS) and arterial stiffness. Cognitive performance was assessed using the Swinburne University Computerized Cognitive Assessment Battery (SUCCAB). Adherence to the MIND diet was significantly related to Stroop Processing domain (β = 0.19, p = 0.035). None of the dietary patterns were significantly related to MetSSS or arterial stiffness. However, adherence to the DASH diet was significantly associated with two cardio-metabolic measures including lower augmentation index (β = -0.17, p = 0.032) and lowered cholesterol (β = -0.18, p = 0.041). Interestingly, two cardio-metabolic risk factors were also associated with better cognitive performance: MetSSS (β = 0.21, p = 0.010) and waist circumference (β = 0.22, p = 0.020). Together these findings suggest that diet in middle age may be important for cognitive functioning and cardio-metabolic risk. However, more research is needed in the form of randomized controlled trials to confirm the direction of these relationships.

Treatment of hypertension reduces cognitive decline in older adults: a systematic review and meta-analysis

OBJECTIVES

To systematically analyse the effect of pharmacological treatment of hypertension (HTN) on cognitive decline in older adults.

METHODS

Randomised, placebo-controlled trials with a prespecified quantitative outcome of cognition and a pharmacological intervention for at least 12 months to treat HTN in older adults (>60 years). Our primary outcome was change in cognition with pharmacological treatment of HTN. Standardised mean difference (SMD) was used to analyse different outcomes reported in the selected studies. We searched PubMed CENTRAL and the Cochrane Library from inception to 6 July 2020. Two independent reviewers assessed trial quality and extracted data. Internal and external validity of the studies was assessed.

RESULTS

Nine randomised controlled trials with 34 994 participants were included in the final analysis. The net SMD for change in cognition was -0.049 (CI: -0.078 to -0.019) indicating that treatment of HTN decreased cognitive decline. Heterogeneity was low with an I² of 6%.

DISCUSSION

Current evidence does not indicate worsening of cognition with treatment of HTN. Treatment of HTN in older adults may reduce cognitive decline. These results have important implications in clinical management of patients at risk for dementia.

PROSPERO REGISTRATION NUMBER

CRD42020139750.

Association of Late Life Depression, (Non-) Modifiable Risk and Protective Factors with Dementia and Alzheimer's Disease: Literature Review on Current Evidences, Preventive Interventions and Possible Future Trends in Prevention and Treatment of Dementia

The number of people living with dementia and Alzheimer’s disease is growing rapidly, making dementia one of the biggest challenges for this century. Many studies have indicated that depression plays an important role in development of dementia, including Alzheimer’s disease; depression, especially, during the late life may either increase the risk of dementia or even being its prodromal stage. Despite a notably large number of carried observational studies and/or clinical trials, the association between the late life depression and dementia remains, due to the complexity of their relationship, still unclear. Moreover, during past two decades multiple other (non-)modifiable risk and possibly protective factors such as the hypertension, social engagement, obesity, level of education or physical (in)activity have been identified and their relationship with the risk for development of dementia and Alzheimer’s disease has been extensively studied. It has been proposed that to understand mechanisms of dementia and Alzheimer’s disease pathogeneses require their multifactorial nature represented by these multiple factors to be considered. In this review, we first summarize the recent literature findings on roles of the late life depression and the other known (non-)modifiable risk and possibly protective factors in development of dementia and Alzheimer’s disease. Then, we provide evidences supporting hypotheses that (i) depressive syndromes in late life may indicate the prodromal stage of dementia (Alzheimer’s disease) and, (ii) the interplay among the multiple (non-)modifiable risk and protective factors should be considered to gain a better understanding of dementia and Alzheimer’s disease pathogeneses. We also discuss the evidences of recently established interventions considered to prevent or delay the prodromes of dementia and provide the prospective future directions in prevention and treatment of dementia and Alzheimer’s disease using both the single-domain and multidomain interventions.

Vitamin B6, B12, Asam Folat, Tekanan Darah dan Demensia pada Lanjut Usia

Background: Dementia is a multifactorial disease due to genetic and environmental influences. Lack of intake of vitamins B6, B12, folic acid and blood pressure are one of the environmental factors that cause dementia.Objective: To analyze the relationship between the adequacy of vitamins B6, B12, folic acid and blood pressure with dementia in the elderlyMethod: This research was a cross sectional study, which was carried out in Tulungagung Regency. The sampling technique was cluster random sampling and a sample size of 100 elderly from 7 elderly Posyandu in Tulungagung Regency, with independent variables such as adequacy of vitamin B6, B12, folic acid and blood pressure, while the dependent variable was dementia. Data were analyzed with chi square testResults: Respondents in this study were generally aged 60-74 years (70.0%), women (48.0%), were educated in elementary / junior high school (60.0%) and did not work (69.0%). Most respondents have insufficient vitamin B6, B12 and folic acid in the less category, with percentages of 57.0%, 54% and 64%, respectively. There was an association between the adequacy of vitamins B6, B12 and folic acid with dementia in the elderly (OR=2.302; 95% CI=1.011-5.241; p=0.045; OR=2.397; 95% CI=1.060-5.422; p=0.034; OR=2.516; 95% CI=1.015-6.238; p=0.043). Blood pressure is associated with dementia in the elderly (OR=3.000; 95% CI=1.288-6.988; p=0.010). The average consumption of vitamin B6, B12 and folic acid in the normal group was higher than the dementia group, with a difference of 0.16 ± 0.04 mg, 0.54 ± 0.05 mcg and 65.89 ± 4.95 respectively mcgConclusionABSTRAKLatar Belakang: Demensia merupakan penyakit multifaktorial karena pengaruh genetik dan lingkungan. Minimnya asupan vitamin B6, B12, asam folat dan tekanan darah menjadi salah satu faktor lingkungan yang menyebabkan demensia.Tujuan:  Tujuan penelitian ini adalah menganalisis hubungan antara kecukupan vitamin B6, B12, asam folat dan tekanan darah dengan demensia pada lanjut usiaMetode: Penelitian ini berupa penelitian cross sectional, yang dilakukan di Kabupaten Tulungagung. Teknik sampling dengan cluster random sampling dan besar sampel 100 lansia dari 7 posyandu lansia di Kabupaten Tulungagung, dengan variabel bebas berupa kecukupan vitamin B6, B12, asam folat dan tekanan darah, sedangkan variabel terikatnya adalah demensia. Data dianalisis dengan uji chi squareHasil: Responden penelitian ini umumnya berusia 60-74 tahun (70,0 %), wanita (48,0 %), berpendidikan terakhir SD/SMP (60,0 %) dan tidak bekerja (69,0 %). Kebanyakan responden memiliki kecukupan vitamin B6, B12 dan asam folat dalam kategori kurang, dengan persentase masing-masing  57,0 %, 54 % dan 64 %. Ditemukan hubungan antara kecukupan vitamin B6, B12 dan asam folat dengan demensia pada lanjut usia (OR=2,302, 95% CI=1,011-5,241, p=0,045; OR=2,397, 95% CI=1,060-5,422, p=0,034; OR=2,516,95% CI=1,015-6,238, p=0,043). Tekanan darah berhubungan dengan demensia pada lanjut usia (OR=3,000,95% CI=1,288-6,988,p=0,010). Rata-rata konsumsi vitamin B6, B12 dan asam folat kelompok normal lebih tinggi dibandingkan kelompok demensia, dengan selisih masing-masing sebesar 0,16±0,04 mg, 0,54±0,05 mcg dan 65,89 ±4,95 mcg.Kesimpulan: Terdapat hubungan antara kecukupan vitamin B6, B12, asam folat dan tekanan darah dengan demensia pada lanjut usia. 

Impact of Hypertension on Cognitive Decline and Dementia

Dementia reduces a person’s ability to perform their activities of daily living and is the leading cause of morbidity worldwide. While most preventive measures are ineffective in reducing dementia risk, active treatment of hypertension in middle-aged and older adults without dementia may reduce the incidence of dementia. Hypertension is associated with vascular dementia but may also affect the manifestations of Alzheimer disease. Observational studies support the association between hypertension and white matter lesions, hippocampal atrophy, and cognitive decline. Both increased and decreased blood pressure were related to the development of white matter lesions. Cohort studies showed that hypertension treatment and treatment duration were associated with lower cognitive decline. This review describes findings from randomized controlled studies on the effects of antihypertensives on cognitive decline. Only the Systolic Hypertension in Europe (Syst-Eur) trial using calcium-channel blockers demonstrated a significant reduction in dementia incidence. Further studies are required to evaluate the long-term benefits of antihypertensive treatment in dementia.

High blood pressure in dementia: How low can we go?

Hypertension is an important public health concern. The prevalence keeps increasing, and it is a risk factor for several adverse health outcomes including a decline in cognitive function. Recent data also show that the prevalence of hypertension and age-related dementia is rising in Asian countries, including in the oldest old group. This study aims to discuss possible treatments for high blood pressure in the elderly and propose an optimal target for BP relative to cognitive outcomes. This review discusses several studies on related blood pressure treatments that remain controversial and the consequences if the treatment target is too low or aggressive. Longitudinal, cross-sectional, and RCT studies were included in this review. An optimum systolic blood pressure of 120-130 mm Hg is recommended, especially in nondiabetic hypertensive patients with significant risk factors. In the oldest old group of patients, hypertension might have a protective effect. The use of calcium channel blockers (CCB) and angiotensin receptor blocker (ARB) is independently associated with a decreased risk of dementia in older people. However, personalized care for patients with hypertension, especially for patients who are frail or very old, is encouraged.

Hypertension and Dementia: A comprehensive review from the HOPE Asia Network

Approximately 365 million people in Asia were classified as elderly in 2017. This number is rising and expected to reach approximately 520 million by 2030. The risk of hypertension and cognitive impairment/dementia increases with age. Recent data also show that the prevalence of hypertension and age-related dementia are rising in Asian countries. Moreover, not many people in Asian countries are aware of the relationship between hypertension and cognitive impairment/dementia. Furthermore, hypertension control is poorer in Asia than in developed countries. Hypertension is known to be a major risk factor for damage to target organs, including the brain. Decreased cognitive function can indicate the presence of target organ damage in the brain. Twenty-four-hour blood pressure profiles and blood pressure variability have been associated with cognitive impairment and/or silent cerebral diseases, such as silent cerebral infarction or white matter lesions, which are predisposing conditions for cognitive impairment and dementia. Hypertension that occurs in midlife also affects the incidence of cognitive impairments in later life. Managing and controlling blood pressure could preserve cognitive functions, such as by reducing the risk of vascular dementia and by reducing the global burden of stroke, which also affects cognitive function.

T-Cell Accumulation in the Hypertensive Brain: A Role for Sphingosine-1-Phosphate-Mediated Chemotaxis

Hypertension is considered the major modifiable risk factor for the development of cognitive impairment. Because increased blood pressure is often accompanied by an activation of the immune system, the concept of neuro-inflammation gained increasing attention in the field of hypertension-associated neurodegeneration. Particularly, hypertension-associated elevated circulating T-lymphocyte populations and target organ damage spurred the interest to understanding mechanisms leading to inflammation-associated brain damage during hypertension. The present study describes sphingosine-1-phosphate (S1P) as major contributor to T-cell chemotaxis to the brain during hypertension-associated neuro-inflammation and cognitive impairment. Using Western blotting, flow cytometry and mass spectrometry approaches, we show that hypertension stimulates a sphingosine kinase 1 (SphK1)-dependent increase of cerebral S1P concentrations in a mouse model of angiotensin II (AngII)-induced hypertension. The development of a distinct S1P gradient between circulating blood and brain tissue associates to elevated CD3+ T-cell numbers in the brain. Inhibition of S1P₁-guided T-cell chemotaxis with the S1P receptor modulator FTY720 protects from augmentation of brain CD3 expression and the development of memory deficits in hypertensive WT mice. In conclusion, our data highlight a new approach to the understanding of hypertension-associated inflammation in degenerative processes of the brain during disease progression.

Screening for mild cognitive impairment in patients with cardiovascular risk factors

AIM

Cardiovascular risk factors are also risk factors for cognitive impairment. They have cumulative effect in target organ damage. The precise correlation between cardiovascular risk factors and cognitive impairment, as well as assessing the extent to which they may affect cognitive functioning, is difficult to ascertain in everyday clinical practice. Quick, specific, and sensitive neuropsychological tests may be useful in screening for, and the prophylaxis of, target organ damage in hypertensive patients.

METHODS

We gathered full anamnesis, performed physical examination, laboratory screening and echocardiography. These variables were observed at office and home for all patients, For half of the patients, 24-hour ambulatory blood pressure monitoring and neuropsychological testing using Montreal Cognitive Assessment (MoCA), Mini Mental State Examination (MMSE), Geriatric Depression Scale, and the 4-instrumental activities of daily living scale were undertaken.

RESULTS

For a period of 2 years, 931 patients were included after applying the inclusion and exclusion criteria. The mean age was 65.90±10.00 years. Two hundred and sixty three patients (85 [32.32%] males and 178 [67.68%] females) were reevaluated after a mean follow-up period of 12 months (6-20 months). The mean results of MoCA and MMSE were significantly lower (p<0.05) in the group of patients with poorly controlled blood pressure and cardiovascular risk factors. There was mild to intermediate negative correlation between Systematic Coronary Risk Evaluation (SCORE) and the neuropsychological tests' results.

CONCLUSION

Cardiovascular risk factors play an important role for the development of cognitive impairment in the eastern European population because of their high frequency and interaction. The use of easily applicable neuropsychological tests in everyday clinical practice of specialties other than neurology may help in stratifying the risk for development and progression of mild cognitive impairment in this high-risk group.

Increased dementia risk predominantly in diabetes mellitus rather than in hypertension or hyperlipidemia: a population-based cohort study

Background

The pathophysiology of insulin resistance-induced hypertension and hyperlipidemia might entail differences in dementia risk in cases with hypertension and hyperlipidemia without prior diabetes mellitus (DM). This study investigated whether incident hypertension, incident hyperlipidemia, or both, increased the dementia risk in patients with and without DM.

Methods

A nationwide retrospective cohort study was conducted. The study sample was obtained from the National Health Insurance Research Database. We enrolled 10,316 patients with a new diagnosis of DM between 2000 and 2002 in the DM cohort. For the same period, we randomly selected 41,264 patients without DM in the non-DM cohort (matched by age and sex at a 1:4 ratio with the DM cohort). Both cohorts were then separately divided into four groups on the basis of incident hypertension or incident hyperlipidemia status.

Results

In total, 51,580 patients aged between 20 and 99 years were enrolled. The dementia risk was higher in the DM cohort than in the non-DM cohort (adjusted hazard ratio (HR) = 1.47, 95% confidence interval (CI) = 1.30–1.67, p < 0.001). In the DM cohort, the dementia risk in patients with both hypertension and hyperlipidemia did not significantly increase compared with that in those without hypertension and hyperlipidemia (p = 0.529). Similar results were observed in those with either hypertension (p = 0.341) or hyperlipidemia (p = 0.189). In the non-DM cohort, patients with both hypertension and hyperlipidemia had a higher dementia risk (adjusted HR = 1.33, 95% CI = 1.09–1.63, p = 0.006). The results remained largely unchanged in patients with only hypertension (adjusted HR = 1.22, 95% CI = 1.05–1.40, p = 0.008). However, the dementia risk did not increase significantly in patients with only hyperlipidemia (p = 0.187).

Conclusions

The development of hypertension, hyperlipidemia, or both, following a diagnosis of incident diabetes is secondary to diabetes onset and likely mediated through insulin resistance associated with diabetes, which does not further accentuate dementia risk. DM itself (i.e., the systemic influence of hyperglycemia) might be the main driver of increased dementia risk.

Calcium-Channel Blockers and Dementia Risk in Older Adults - National Health Insurance Service - Senior Cohort (2002-2013)

BACKGROUND

Some disagreements surround the effects of calcium-channel blockers (CCBs) on the risk of dementia. The purpose of this study was to investigate the protective effects of CCBs on dementia among elderly hypertensive Koreans.

METHODS AND RESULTS

We conducted a large population-based cohort study using the senior cohort database of the Korean National Health Insurance Service (2002-2013). Subjects were elderly hypertensive Koreans older than 60 years of age. A total of 18,423 patients (CCB user group: 13,692 patients; non-CCB antihypertensive user group: 4,731 patients) were statistically analyzed using the Cox proportional hazard regression model to estimate the adjusted hazard ratio (aHR) and confidence intervals (CIs) of dementia associated with CCB use. There were 2,881 cases (21.0%) of dementia in the CCB user group and 1,124 cases (23.8%) in the non-user group. CCB use significantly reduced the risk of total dementia (aHR 0.81, 95% CI 0.75-0.87, P<0.0001), Alzheimer's dementia (aHR 0.80, 95% CI 0.72-0.88, P<0.0001), and vascular dementia (aHR 0.81, 95% CI 0.70-0.94, P=0.0067).

CONCLUSIONS

CCB use had a protective effect on the risk of dementia among elderly hypertensive Koreans. (Circ J 2016; 80: 2336-2342).

An integrative genome-wide transcriptome reveals that candesartan is neuroprotective and a candidate therapeutic for Alzheimer's disease

BACKGROUND

Alzheimer's disease is the most frequent age-related dementia, and is currently without treatment. To identify possible targets for early therapeutic intervention we focused on glutamate excitotoxicity, a major early pathogenic factor, and the effects of candesartan, an angiotensin receptor blocker of neuroprotective efficacy in cell cultures and rodent models of Alzheimer's disease. The overall goal of the study was to determine whether gene analysis of drug effects in a primary neuronal culture correlate with alterations in gene expression in Alzheimer's disease, thus providing further preclinical evidence of beneficial therapeutic effects.

METHODS

Primary neuronal cultures were treated with candesartan at neuroprotective concentrations followed by excitotoxic glutamate amounts. We performed genome-wide expression profile analysis and data evaluation by ingenuity pathway analysis and gene set enrichment analysis, compared with alterations in gene expression from two independent published datasets identified by microarray analysis of postmortem hippocampus from Alzheimer's disease patients. Preferential expression in cerebrovascular endothelial cells or neurons was analyzed by comparison to published gene expression in these cells isolated from human cortex by laser capture microdissection.

RESULTS

Candesartan prevented glutamate upregulation or downregulation of several hundred genes in our cultures. Ingenuity pathway analysis and gene set enrichment analysis revealed that inflammation, cardiovascular disease and diabetes signal transduction pathways and amyloid β metabolism were major components of the neuronal response to glutamate excitotoxicity. Further analysis showed associations of glutamate-induced changes in the expression of several hundred genes, normalized by candesartan, with similar alterations observed in hippocampus from Alzheimer's disease patients. Gene analysis of neurons and cerebrovascular endothelial cells obtained by laser capture microdissection revealed that genes up- and downregulated by glutamate were preferentially expressed in endothelial cells and neurons, respectively.

CONCLUSIONS

Our data may be interpreted as evidence of direct candesartan neuroprotection beyond its effects on blood pressure, revealing common and novel disease mechanisms that may underlie the in vitro gene alterations reported here and glutamate-induced cell injury in Alzheimer's disease. Our observations provide novel evidence for candesartan neuroprotection through early molecular mechanisms of injury in Alzheimer's disease, supporting testing this compound in controlled clinical studies in the early stages of the illness.

Heart failure and Alzheimer's disease

It has recently been proposed that heart failure is a risk factor for Alzheimer's disease. Decreased cerebral blood flow and neurohormonal activation due to heart failure may contribute to the dysfunction of the neurovascular unit and cause an energy crisis in neurons. This leads to the impaired clearance of amyloid beta and hyperphosphorylation of tau protein, resulting in the formation of amyloid beta plaques and neurofibrillary tangles. In this article, we will summarize the current understanding of the relationship between heart failure and Alzheimer's disease based on epidemiological studies, brain imaging research, pathological findings and the use of animal models. The importance of atherosclerosis, myocardial infarction, atrial fibrillation, blood pressure and valve disease as well as the effect of relevant medications will be discussed.

Prevalence of dementia in Colombian populations

With the gradual increase in the life expectancy of the population due to scientific progress and public health at the service of society, the prevalence of dementia has been increasing at different rates worldwide. Currently, the prevalence rates range between 5% and 7% (6.4% in the U.S. and up to 8.5 % in Latin America) in subjects older than 60 years. The lowest prevalence rate (2.1%) has been reported from sub-Saharan Africa, probably due to selective mortality under 60 years of age. By contrast, a very high prevalence of dementia (23.6% dementia in individuals >60 years) was observed in the city of Neiva, Southern Colombia. We believe that this high rate could be explained by the presence of several risk factors such as very low schooling, low socio-economic strata, chronic diseases, the inclusion of geriatric homes among others, and additional unknown factors.

Antihypertensive and neuroprotective effects of catestatin in spontaneously hypertensive rats: interaction with GABAergic transmission in amygdala and brainstem

The chromogranin A-derived peptide catestatin (CST) exerts sympathoexcitatory and hypertensive effects when microinjected into the rostral ventrolateral medulla (RVLM: excitatory output); it exhibits sympathoinhibitory and antihypertensive effects when microinjected into the caudal ventrolateral medulla (CVLM: inhibitory output) of vagotomized normotensive rats. Here, continuous infusion of CST into the central amygdalar nucleus (CeA) of spontaneously hypertensive rats (SHRs) for 15 days resulted in a marked decrease of blood pressure (BP) in 6-month- (by 37 mm Hg) and 9-month- (by 65 mm Hg)old rats. Whole-cell patch-clamp recordings on pyramidal CeA neurons revealed that CST increased both spontaneous inhibitory postsynaptic current (sIPSC) amplitude plus frequency, along with reductions of sIPSC rise time and decay time. Inhibition of GABAA receptors (GABAARs) by bicuculline completely abolished CST-induced sIPSC, corroborating that CST signals occur through this major neuroreceptor complex. Hypertension is a major risk factor for cerebrovascular diseases, leading to vascular dementia and neurodegeneration. We found a marked neurodegeneration in the amygdala and brainstem of 9-month-old SHRs, while CST and the GABAAR agonist Muscimol provided significant neuroprotection. Enhanced phosphorylation of Akt and ERK accounted for these neuroprotective effects through anti-inflammatory and anti-apoptotic activities. Overall our results point to CST exerting potent antihypertensive and neuroprotective effects plausibly via a GABAergic output, which constitute a novel therapeutic measure to correct defects in blood flow control in disorders such as stroke and Alzheimer's disease.

Impairment in preattentive processing among patients with hypertension revealed by visual mismatch negativity

Objective. Patients with hypertension show deficits in cognitive function. However, the neural mechanisms underlying the preattentive information processing in hypertensive patients are poorly understood. We seek to investigate whether hypertensive patients have impairments in preattentive information processing. Methods. We compared visual mismatch negativity (vMMN) between 15 hypertensive patients and 15 age-matched healthy controls, which was elicited by the change of visual duration randomly presented in both peripheral visual fields. In addition, the global cognitive function for all participants was assessed with Mini-Mental State Examination (MMSE). Results. The vMMN in deviant-standard comparison was observed at occipital-temporal regions. Compared with normal healthy controls, the amplitude of vMMN was significantly decreased in hypertensive patients (P < 0.05). Meanwhile, the vMMN peak latency was delayed in the hypertensive group (P < 0.05). However, the MMSE scores of patients with hypertension were not significantly different from those of controls (P > 0.05), and there was no significant correlation between the mean amplitude of vMMN and SBP, DBP, and MMSE in hypertensive individuals, respectively. Conclusions. These data indicate dysfunction of automatically change detection processing in patients with hypertension. Moreover, the changes of vMMN provide a more objective and reliable assessment for cognitive impairment in hypertensive patients.

Impaired cognitive executive dysfunction in adult treated hypertensives with a confirmed diagnosis of poorly controlled blood pressure

BACKGROUND

High blood pressure (BP) poses a major risk for cognitive decline. Aim of the study was to highlight the relationship between cognitive assessment scores and an effective therapeutic BP control.

METHODS

By medical visit and ambulatory BP monitoring (ABPM), we studied 302 treated hypertensives, subdivided according to office/daytime BP values into 120 with good (GC) and 98 poor (PC) BP control, 40 with "white coat hypertension" (WCH) and 44 a "masked-hypertension" phenomenon (MH). Patients underwent neuropsychological assessment to evaluate global cognitive scores at the Mini Mental State Examination (MMSE) and Frontal Assessment Battery (FAB) and attention/executive functions (Delayed Recall, Digit Span Forwards, Digit Span Backwards, Selective Attention, Verbal Fluency, Stroop Test and Clock Drawing). Carotid intima-media thickness (IMT) served as the index of vascular damage.

RESULTS

There were no differences among the groups in terms of gender, age, education, metabolic assessment, clinical history and hypertension treatment. GC presented lower office and ambulatory BP values and IMT. PC performed worse than GC on global executive and attention functions, especially executive functions. In PC, office systolic BP (SBP) was significantly associated to the MMSE and FAB scores and, in particular, to Verbal Fluency, Stroop Errors and Clock Drawing tests. Office diastolic BP (DBP) was associated to Selective attention, nocturnal SBP to Digit Span backwards and Verbal Fluency. Worse cognitive assessment scores were obtained in WCH than GC.

CONCLUSIONS

The findings showed that in adult treated hypertensives, a poor BP control, as both doctor's office and daytime scores, is associated to impaired global cognitive and especially executive/attention functions.

Antihypertensives, angiotensin, glucose and Alzheimer's disease

Evidence supporting a link between vascular disorders such as hypertension and Alzheimer's disease (AD) is increasing. Population studies have suggested an association between hypertension and an increased risk of developing AD. A potential role for antihypertensive medications in the management of cognitive disorders has also been suggested, although findings are mixed. However, it is of interest that evidence is now leaning towards the possibility that some of these antihypertensive medications may improve cognition independent of their blood pressure lowering effects. Many of these drugs cross the blood-brain barrier and may influence neurotransmitters involved in cognition. Increasing knowledge of the actions of antihypertensives in the brain and the vascular system could lead to better treatment and/or prevention options for AD.

Hypertension and vascular dementia in the elderly: the potential role of anti-hypertensive agents

BACKGROUND

Vascular dementia (VaD) - a severe form of vascular cognitive impairment - and cognitive decline are associated with hypertension and therefore it seems logical to consider that reducing BP with anti-hypertensive therapy may protect against the development/onset of cognitive function impairment or dementia.

SCOPE

This narrative, non-systematic review discusses the available evidence on the potential correlation between the use of anti-hypertensive agents and the risk of VaD and cognitive decline.

METHODS

MEDLINE was searched for inclusion of relevant studies. No limitations in time were considered.

RESULTS

A consensus on the potential effects of anti-hypertensive treatment in the reduction of VaD and associated cognitive decline has not been reached. A protective effect of anti-hypertensive agents has been observed in a number of studies although it is still unclear whether different classes of anti-hypertensive agents have a different effect on the development of VaD.

CONCLUSIONS

The protective effect of anti-hypertensive agents appears to depend on the specific drug used - positive effects have been observed with calcium channel blockers (CCBs), such as lercanidipine and nitrendipine, the combination perindopril-indapamide and telmisartan.

Increased risk of dementia in people with previous exposure to general anesthesia: a nationwide population-based case-control study

BACKGROUND

Dementia, which leads to disability, is one of the important diseases occurring among older populations. However, the exact mechanism of the disease remains unknown. The potential risk factor of general anesthesia (GA) in the development of dementia is a controversial topic. Therefore, this study aimed to evaluate the association between previous exposure to different GA types and the incidence of dementia.

METHODS

Using the claims data of 1 million insured residents covered by Taiwan's universal health insurance from 2005 to 2009, 5345 newly diagnosed dementia patients older than 50 years were eligible for the study group. The control group, which consisted of 21,380 individuals without dementia, was matched for age, gender, and index date. GA was categorized into three subtypes: endotracheal tube intubation general anesthesia (ETGA), intravenous injection general anesthesia (IVGA) or intramuscular injection general anesthesia (IMGA), and heavy sedation. The multiple logistic regression model was used for analyses.

RESULTS

Individuals exposed to surgery under ETGA (odds ratio [OR], 1.34; 95% confidence interval [CI], 1.25-1.44) and those exposed to surgery under IVGA or IMGA (OR, 1.28; 95% CI, 1.14-1.43) were at significantly higher risk of dementia in a dose-response relationship (P < .0001), whereas surgery under heavy sedation was not associated with increased risk of dementia (OR, 1.04; 95% CI, 0.68-1.59). The dementia risk for subjects with diabetes mellitus who received surgery under ETGA (OR, 1.59; 95% CI, 1.42-1.78), hypertension (OR, 1.98; 95% CI, 1.78-2.21), atherosclerosis (OR, 1.35; 95% CI, 1.22-1.50), or after having experienced a stroke (OR, 3.52; 95% CI, 3.13-3.97), but no interaction was found between surgery under ETGA and depression for the risk of dementia.

CONCLUSIONS

A history of previous exposure to surgery under GA might be associated with an increased risk of dementia, particularly in subjects who have undergone repeated exposure to GA. In addition, subjects who had received surgery under ETGA with comorbidities such as stroke, hypertension, diabetes mellitus, and atherosclerosis could have a potential relationship with dementia risk.

Intensive blood pressure lowering increases cerebral blood flow in older subjects with hypertension

Hypertension is associated with reduced cerebral blood flow (CBF). Intensive (<130/80 mm Hg) blood pressure (BP) lowering in older people might give greater reduction in cardiovascular risk, but there are concerns that this might produce hypoperfusion which may precipitate falls and possibly stroke. We determined the effect of intensive compared with usual BP lowering on CBF in hypertensive older subjects. Individuals aged >70 years with a history of systolic hypertension on 1 or no BP lowering drugs were recruited from primary care (n=37; age, 75±4 years; systolic BP, >150 mm Hg) and randomized to receive intensive (target BP, <130/80 mm Hg) or usual (target BP, <140/85 mm Hg) BP lowering for 12 weeks, with reviews every 2 weeks. CBF, determined using 3T arterial spin labeling MRI, and 24-hour ambulatory BP were performed at baseline and after 12 weeks of treatment. Baseline BP (ambulatory or in clinic) and baseline gray matter CBF were not significantly different between the groups. After treatment, BP was reduced significantly in both groups but fell more in the intensive group (26/17 versus 15/5 mm Hg; P<0.01). Over the same period, gray matter CBF increased significantly in the intensive group (7±11 mL/min per 100 g; P=0.013) but was unchanged in the usual BP target group (-3±9 mL/min per 100 g; P=0.23); P<0.01 for comparison. Intensive BP lowering in older people with hypertension increases CBF, compared with BP lowering to usual target. These findings suggest hypertension in older people shifts the autoregulatory CBF curve rightward and downward and is reversible with BP lowering.

Evidence for a detrimental relationship between hypertension history, prospective memory, and prefrontal cortex white matter in cognitively normal older adults

Hypertension affects many older adults and is associated with impaired neural and cognitive functioning. We investigated whether a history of hypertension was associated with impairments to prospective memory, which refers to the ability to remember to perform delayed intentions, such as remembering to take medication. Thirty-two cognitively normal older adult participants with or without a history of hypertension (self-reported) performed two laboratory prospective memory tasks, one that relied more strongly on executive control (nonfocal prospective memory) and one that relied more strongly on spontaneous memory retrieval processes (focal prospective memory). We observed hypertension-related impairments for nonfocal, but not focal, prospective memory. To complement our behavioral approach, we conducted a retrospective analysis of available structural magnetic resonance imaging data. Lower white matter volume estimates in the anterior prefrontal cortex were associated with lower nonfocal prospective memory and with a history of hypertension. A history of hypertension may be associated with worsened executive control and lower prefrontal white matter volume. The translational implication is that individuals who must remember to take antihypertensive medications and to monitor their blood pressure at home may be impaired in the executive control process that helps to support these prospective memory behaviors.

Heart disease as a risk factor for dementia

As life expectancy lengthens, dementia is becoming a significant human condition in terms of its prevalence and cost to society worldwide. It is important in that context to understand the preventable and treatable causes of dementia. This article exposes the link between dementia and heart disease in all its forms, including coronary artery disease, myocardial infarction, atrial fibrillation, valvular disease, and heart failure. This article also explores the cardiovascular risk factors and emphasizes that several of them are preventable and treatable. In addition to medical therapies, the lifestyle changes that may be useful in retarding the onset of dementia are also summarized.

Candesartan, an angiotensin II AT₁-receptor blocker and PPAR-γ agonist, reduces lesion volume and improves motor and memory function after traumatic brain injury in mice

Traumatic brain injury (TBI) results in complex pathological reactions, the initial lesion worsened by secondary inflammation and edema. Angiotensin II (Ang II) is produced in the brain and Ang II receptor type 1 (AT₁R) overstimulation produces vasoconstriction and inflammation. Ang II receptor blockers (ARBs) are neuroprotective in models of stroke but little is known of their effect when administered in TBI models. We therefore performed controlled cortical impact (CCI) injury on mice to investigate whether the ARB candesartan would mitigate any effects of TBI. We administered candesartan or vehicle to mice 5 h before CCI injury. Candesartan treatment reduced the lesion volume after CCI injury by approximately 50%, decreased the number of dying neurons, lessened the number of activated microglial cells, protected cerebral blood flow (CBF), and reduced the expression of the cytokine TGFβ1 while increasing expression of TGFβ3. Candesartan-treated mice also showed better motor skills on the rotarod 3 days after injury, and improved performance in the Morris water maze 4 weeks after injury. These results indicate that candesartan is neuroprotective, reducing neuronal injury, decreasing lesion volume and microglial activation, protecting CBF and improving functional behavior in a mouse model of TBI. Co-treatment with a peroxisome proliferator-activated receptor-gamma (PPARγ) antagonist significantly reduced some of the beneficial effects of candesartan after CCI, suggesting that PPARγ activation may contribute to part or to all of the neuroprotective effect of candesartan. Overall, our data suggest that ARBs with dual AT₁R-blocking and PPARγ activation properties may have therapeutic value in treating TBI.