Central pulse pressure is a determinant of heart and brain remodeling in the elderly: a quantitative MRI and PET pilot study

Interactions Between Brain 18F-FDG PET Metabolism and Hemodynamic Parameters at Different Ages of Life: Results From a Prospective Cross-Sectional Study

Brain 18F-FDG PET imaging is useful to characterize accelerated brain aging at a pre-symptomatic stage. This study aims to examine the interactions between brain glycolytic metabolism and hemodynamic parameters in different age groups.

Methods: A total of 72 patients (from 23 to 88 years of age, 38 women) without any cerebral diseases but with available cardiac, arterial peripheral, and central blood pressure measurements as well as arterial stiffness parameters obtained from brachial pressure and applanation tonometry and a brain 18F-FDG PET scan were prospectively included into this study. Quantitative voxel-to-voxel analyses were carried out to test for negative associations between brain glycolytic metabolism and individual hemodynamic parameters (p-voxel of <0.001 for the whole population and <0.005 for age groups).

Results: The heart rate parameter of the whole population showed the most extensive associations with brain metabolism (15,857 mm3, T-score: 5.1), predominantly affecting the frontal and temporal regions (69% of the volume). Heart rate for the younger age group, systolic and pulse pressure for the 41–60-year-old group, and diastolic pressure for the older group were most extensively associated with brain metabolism and mainly involved the fronto-temporal lobes (respective involvement of 52.8%, 60.9%, and 65.5%) which are also the regions implicated in accelerated brain aging.

Conclusion: This cross-sectional prospective study identified extensive associations between cerebral metabolism and hemodynamic parameters, indicating common aging mechanisms. Heart rate throughout adult life, systolic and pulse pressure parameters around middle age, and diastolic pressure parameters in older patients, suggest the existence of potentially therapeutic targets to prevent accelerated brain aging.

Evaluating Impact of Pulse Pressure on Indexes of Myocardial Work by Speckle-Tracking Echocardiography in Normotensive, Prehypertensive and Newly Diagnosed Hypertensive Patients

Background

The impact of pulse pressure (PP) on indexes of myocardial work (MWIs). This study aims to explore the potential association of high PP with myocardial work (MW).

Hypothesis

PP had an association with four indexes of MW in a mixed population of normotensive, prehypertensive and newly diagnosed hypertensive individuals.

Methods

The study was a single-center, cross-sectional, observational study. A total of 204 participants (66 normotensive, 35 prehypertensive and 103 newly diagnosed hypertensive individuals) were evaluated by speckle-tracking echocardiography (STE) and blood pressure measurement. According to the PP tertiles, the participants were divided into three groups: Group I (<44 mmHg, n=67), Group II (44–52 mmHg, n=68) and Group III (≥52 mmHg, n=69).

Results

In Group II and Group III, the proportion of males was higher than that in Group I (median 46 vs 30 (P=0.002)). With increasing PP, the three indexes of MW, namely, GWI, GCW and GWW, increased, and the differences among the three groups were statistically significant (P<0.001). PP was positively related to GWI, GCW and GWW and negatively correlated with GWE. After adjusting for E/e’, LVMI, LAVI and GLS, PP was still significantly correlated with the four MW indexes (both P<0.001).

Conclusion

PP had a strong association with four indexes of MW in a mixed population of normotensive, prehypertensive and newly diagnosed hypertensive individuals. The evaluation of PP and MWIs might be valuable for identifying very early diastolic impairment of the heart.

Cross-sectional variations of white and grey matter in older hypertensive patients with subjective memory complaints

Mild cognitive impairment and Alzheimer's dementia involve a grey matter disease, quantifiable by ¹⁸F-Fluorodeoxyglucose positron emission tomography (FDG-PET), but also white matter damage, evidenced by diffusion tensor magnetic resonance imaging (DTI), which may play an additional pathogenic role. This study aimed to determine whether such DTI and PET variations are also interrelated in a high-risk population of older hypertensive patients with only subjective memory complaints (SMC).

Sixty older hypertensive patients (75 ± 5 years) with SMC were referred to DTI and FDG-PET brain imaging, executive and memory tests, as well as peripheral and central blood pressure (BP) measurements. Mean apparent diffusion coefficient (ADC_mean) was determined in overall white matter and correlated with the grey matter distribution of the metabolic rate of glucose (CMRGlc) using whole-brain voxel-based analyses of FDG-PET images.

ADC_mean was variable between individuals, ranging from 0.82 to 1.01.10^− 3 mm² sec^− 1, and mainly in relation with CMRGlc of areas involved in Alzheimer's disease such as internal temporal areas, posterior associative junctions, posterior cingulum but also insulo-opercular areas (global correlation coefficient: − 0.577, p < 0.001). Both the ADC_mean and CMRGlc of the interrelated grey matter areas were additionally and concordantly linked to the results of executive and memory tests and to systolic central BP (all p < 0.05).

Altogether, our findings show that cross-sectional variations in overall white brain matter are linked to the metabolism of Alzheimer-like cortical areas and to cognitive performance in older hypertensive patients with only subjective memory complaints. Additional relationships with central BP strengthen the hypothesis of a contributing pathogenic role of hypertension.

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Changes in grey and white matter are interrelated in elderly hypertensive patients.

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They can be documented in the absence of any objective memory complaint.

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These interrelationships are associated with cognitive test results.

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The interrelated grey matter areas are likely to define an Alzheimer-like pattern.

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These interrelationships are linked to the level of central blood pressure.