Effects of Diastolic Blood Pressure on Brain Structures and Cognitive Functions in Middle and Old Ages: Longitudinal Analyses

White matter microstructure alterations in type 2 diabetes mellitus and its correlation with cerebral small vessel disease and cognitive performance

Microstructural abnormalities of white matter fiber tracts are considered as one of the etiology of diabetes-induced neurological disorders. We explored the cerebral white matter microstructure alteration accurately, and to analyze its correlation between cerebral small vessel disease (CSVD) burden and cognitive performance in type 2 diabetes mellitus (T2DM). The clinical-laboratory data, cognitive scores [including mini-mental state examination (MMSE), Montreal cognitive assessment (MoCA), California verbal learning test (CVLT), and symbol digit modalities test (SDMT)], CSVD burden scores of the T2DM group (n = 34) and healthy control (HC) group (n = 21) were collected prospectively. Automatic fiber quantification (AFQ) was applied to generate bundle profiles along primary white matter fiber tracts. Diffusion tensor images (DTI) metrics and 100 nodes of white matter fiber tracts between groups were compared. Multiple regression analysis was used to analyze the relationship between DTI metrics and cognitive scores and CSVD burden scores. For fiber-wise and node-wise, DTI metrics in some commissural and association fibers were increased in T2DM. Some white matter fiber tracts DTI metrics were independent predictors of cognitive scores and CSVD burden scores. White matter fiber tracts damage in patients with T2DM may be characterized in specific location, especially commissural and association fibers. Aberrational specific white matter fiber tracts are associated with visuospatial function and CSVD burden.

Deciphering the causal relationship between blood pressure and regional white matter integrity: A two-sample Mendelian randomization study

Elevated arterial blood pressure (BP) is a common risk factor for cerebrovascular and cardiovascular diseases, but no causal relationship has been established between BP and cerebral white matter (WM) integrity. In this study, we performed a two-sample Mendelian randomization (MR) analysis with individual-level data by defining two nonoverlapping sets of European ancestry individuals (genetics-exposure set: N = 203,111; mean age = 56.71 years, genetics-outcome set: N = 16,156; mean age = 54.61 years) from UK Biobank to evaluate the causal effects of BP on regional WM integrity, measured by fractional anisotropy of diffusion tensor imaging. Two BP traits: systolic and diastolic blood pressure were used as exposures. Genetic variant was carefully selected as instrumental variable (IV) under the MR analysis assumptions. We existing large-scale genome-wide association study summary data for validation. The main method used was a generalized version of inverse-variance weight method while other MR methods were also applied for consistent findings. Two additional MR analyses were performed to exclude the possibility of reverse causality. We found significantly negative causal effects (FDR-adjusted p < .05; every 10 mmHg increase in BP leads to a decrease in FA value by .4% ~ 2%) of BP traits on a union set of 17 WM tracts, including brain regions related to cognitive function and memory. Our study extended the previous findings of association to causation for regional WM integrity, providing insights into the pathological processes of elevated BP that might chronically alter the brain microstructure in different regions.

Dietary and Non-Dietary Modulators of Cognitive Function

Manifold internal and external factors may influence brain function in the long run, including genetic predispositions as well as epigenetic and environmental factors [...].

Association of blood pressure with brain perfusion and structure: A population-based prospective study

PURPOSE

To explore the association of blood pressure (BP) measurements with cerebral blood flow (CBF) and brain structure in general population.

METHOD

This prospective study included 902 participants from Kailuan community. All participants underwent brain MRI and BP measurements. The association of BP indicators with CBF, brain tissue volume and white matter hyperintensity (WMH) volume were investigated. In addition, mediation analysis was used to determine whether significantly changed brain tissue volume explained associations between BP and CBF.

RESULTS

Elevated diastolic BP (DBP), but not systolic BP (SBP), was associated with lower CBF in the total brain (β [95 % CI]: -0.62 [-1.14, -0.10]), total gray matter (β [95 % CI]: -0.71 [-1.27, -0.14]), hippocampus (β [95 % CI]: -0.59 [-1.13, -0.05]), frontal (β [95 % CI]: -0.72 [-1.31, -0.13]), parietal (β [95 % CI]: -0.92 [-1.54, -0.3]), temporal (β [95 % CI]: -0.63 [-1.18, -0.08]), and occipital lobe (β [95 % CI]: -0.69 [-1.37, -0.01]). Higher SBP and DBP were associated with reduced total and regional brain tissue volume (all p < 0.05). Increased SBP and PP were associated with higher total and periventricular WMH volume (all p < 0.05). In addition, mediation analysis identified that significantly decreased brain volume did not mediate the associations of BP measurements and lower CBF in corresponding region (all p > 0.05).

CONCLUSIONS

Elevated BP level was associated with decreased total and regional CBF and brain tissue volume and increased WMH burden.

Extended-release metformin improves cognitive impairment in frail older women with hypertension and diabetes: preliminary results from the LEOPARDESS Study

BACKGROUND

Women have a high risk of frailty independently of age and menopause state. Diabetes and hypertension increase the risk of frailty and cognitive impairment. Metformin has been employed in post-menopausal women and some reports have shown encouraging effects in terms of attenuated frailty. However, the impact on cognitive performance of a recently introduced extended-release formulation of metformin has never been explored.

METHODS

We studied consecutive frail hypertensive and diabetic older women presenting at the ASL (local health authority of the Italian Ministry of Health) Avellino, Italy, from June 2021 to August 2022, who were treated or not with extended-release metformin. We included a control group of frail older males with diabetes and hypertension treated with extended-release metformin and a control group of frail older women with diabetes and hypertension treated with regular metformin.

RESULTS

A total of 145 patients successfully completed the study. At the end of the 6-month follow-up, we observed a significantly different cognitive performance compared to baseline in the group of frail women treated with extended-release metformin (p: 0.007). Then, we compared the follow-up groups and we observed significant differences between frail women treated vs. untreated (p: 0.041), between treated frail women and treated frail men (p: 0.016), and between women treated with extended-release metformin vs. women treated with regular metformin (p: 0.048). We confirmed the crucial role of extended-release metformin applying a multivariable logistic analysis to adjust for potential confounders.

CONCLUSIONS

We evidenced, for the first time to the best of our knowledge, the favorable effects on cognitive impairment of extended-release metformin in frail women with diabetes and hypertension.

Low diastolic blood pressure and adverse outcomes in inpatients with acute exacerbation of chronic obstructive pulmonary disease: A multicenter cohort study

BACKGROUND

Although intensively studied in patients with cardiovascular diseases (CVDs), the prognostic value of diastolic blood pressure (DBP) has little been elucidated in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study aimed to reveal the prognostic value of DBP in AECOPD patients.

METHODS

Inpatients with AECOPD were prospectively enrolled from 10 medical centers in China between September 2017 and July 2021. DBP was measured on admission. The primary outcome was all-cause in-hospital mortality; invasive mechanical ventilation and intensive care unit (ICU) admission were secondary outcomes. Least absolute shrinkage and selection operator (LASSO) and multivariable Cox regressions were used to identify independent prognostic factors and calculate the hazard ratio (HR) and 95% confidence interval (CI) for adverse outcomes.

RESULTS

Among 13,633 included patients with AECOPD, 197 (1.45%) died during their hospital stay. Multivariable Cox regression analysis showed that low DBP on admission (<70 mmHg) was associated with increased risk of in-hospital mortality (HR = 2.16, 95% CI: 1.53-3.05, Z = 4.37, P <0.01), invasive mechanical ventilation (HR = 1.65, 95% CI: 1.32-2.05, Z = 19.67, P <0.01), and ICU admission (HR = 1.45, 95% CI: 1.24-1.69, Z = 22.08, P <0.01) in the overall cohort. Similar findings were observed in subgroups with or without CVDs, except for invasive mechanical ventilation in the subgroup with CVDs. When DBP was further categorized in 5-mmHg increments from <50 mmHg to ≥100 mmHg, and 75 to <80 mmHg was taken as reference, HRs for in-hospital mortality increased almost linearly with decreased DBP in the overall cohort and subgroups of patients with CVDs; higher DBP was not associated with the risk of in-hospital mortality.

CONCLUSION

Low on-admission DBP, particularly <70 mmHg, was associated with an increased risk of adverse outcomes among inpatients with AECOPD, with or without CVDs, which may serve as a convenient predictor of poor prognosis in these patients.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trail Registry, No. ChiCTR2100044625.