Blood pressure variability and the development of hypertensive organ damage in the general population

The relation between body mass index and target organ damage and the mediating role of blood pressure

BACKGROUND/OBJECTIVES

The relationship between obesity and blood pressure (BP) is well known, but limited data exists regarding its relationship with target organ damage (TOD). Therefore, this study aimed to examine the relationship between body mass index (BMI) and TOD and the mediating role of BP.

SUBJECTS/METHODS

2555 adults (52.0% women) who visited a local Hypertension Unit with valid measures on weight, height, 24 h ambulatory BP monitoring, office BP measurements, echocardiography, carotid ultrasonography and blood creatinine levels, included in this cross-sectional study. BMI was used to categorize participants as having normal weight (< 25 kg/m2), overweight (25-29.9 kg/m2) or obesity (≥ 30 kg/m2). The intima-media thickness (IMT) of the common (CCA) and the internal (ICA) carotid artery, left ventricular mass (LVM), LVM index (LVMI) and estimated glomerular filtration rate (eGFR) were estimated and used as TOD indices. Linear regression models were used to examine the relationship between obesity and BP measurements or TOD, while structural equation modeling (SEM) for mediation analysis.

RESULTS

Obesity was significantly related to 24-hour systolic BP (b = 3.72, 95%CI: 2.24-5.21, p < 0.001), CCA-IMT (b = 0.04, 95%CI: 0.02-0.05, p < 0.001), ICA-IMT (b = 0.03, 95%CI: 0.01-0.05, p = 0.020), and LVMI (b = 7.54, 95CI%: 4.25-10.83, p < 0.001). The mediation analysis revealed that 24-hour systolic BP mediated by 27.9% the relationship between BMI and CCA-IMT, by 31.3% the relationship between BMI and ICA-IMT, and by 18.1% the relationship between BMI and LVMI.

CONCLUSIONS

These results indicate that obesity is associated with indices of asymptomatic cardiac remodeling and vascular atherosclerosis, and systolic BP mediates these relationships.

Association of blood pressure variability with target organ damage in older patients with essential hypertension

Background

Although multiple measures of blood pressure variability (BPV) have been proposed, whether they are better than mean blood pressure in predicting target organs is unclear. We aimed to determine the relationship between short term BPV and target organ injury.

Methods

This study was a retrospective study, and 635 inpatients in the Department of Cardiology from 2015 to 2020 were selected. We divided participants into four groups on the basis of the quartiles of BPV. One-way analysis of variance was used to compare the differences between the groups, and linear regression was used to analyze the relationship between BPV and target organ damage.

Results

The average age of 635 patients was 74.36 ± 6.50 years old. Among them, 354 of 627 patients had diminished renal function (56.5%), 221of 604 patients had associated left ventricular hypertrophy (36.6%), and 227 of 231 patients had carotid plaque formation (98.3%). The baseline data indicated significant differences in fasting glucose, total cholesterol, low-density lipoprotein, creatinine, glomerular filtration rate, sex, calcium channel blocker use, and the rate of diminished renal function. Multiple linear regression analysis showed that BPV was negatively correlated with renal injury (creatinine: r = 0.306, p < 0.01; estimated glomerular filtration rate: r = 0.058, p < 0.01), and BPV is positively correlated with cardiac injury (r = 0.083, p < 0.01). Elevated BPV was not found to be associated with vascular injury.

Conclusion

Renal function decreases with increasing BPV and left ventricular mass increases with increasing BPV.

Association between vascular endothelial dysfunction and stroke incidence in the general Japanese population: Results from the tohoku medical megabank community-based cohort study

Background

Flow-mediated dilation (FMD) measures vascular endothelial function by evaluating the vasodilatory response of blood vessels to increased blood flow. Nevertheless, the association between FMD and stroke incidence in a general population remains unclear. This study investigated the association between vascular endothelial function and stroke incidence in the general Japanese population.

Methods

Based on cohort data from the Tohoku Medical Megabank Community-based Cohort Study, participants aged ≥18 years were recruited from Iwate Prefecture, with the final sample comprising 2952 subjects.

Results

The FMD level was 0.5%-27.1%, with a median of 5.0% (interquartile, 4.2%-11.3%). The mean follow-up period was 5.5 ± 1.8 years (range, 0.6-6.9 years). After dividing the participants into two subgroups according to the median FMD value, a multivariate Cox regression analysis adjusting for gender, age, smoking, alcohol consumption, systolic blood pressure, low-density lipoprotein cholesterol, estimated glomerular filtration rate, N-terminal pro-brain natriuretic peptide, high-sensitivity cardiac troponin T and hemoglobin A1c revealed that a lower FMD value was strongly associated with incidences of total stroke (hazard ratio[HR] = 2.13, 95% confidence interval[CI] = 1.48-3.07, p < 0.001), ischemic stroke (HR = 3.33, 95%CI = 2.00-5.52, p < 0.001), nonlacunar stroke (HR = 2.77, 95%CI = 1.49-5.16, p = 0.001), and lacunar stroke (HR = 5.12, 95%CI = 1.74-16.05, p = 0.003).

Conclusions

This study showed that a low FMD value might reflect vascular endothelial dysfunction and then was associated with ischemic stroke incidence in the general Japanese population, suggesting that FMD can be used as a tool to identify future stroke risk.

Analysis of the relationship between blood pressure variability and subtle cognitive decline in older adults

BACKGROUND

Blood pressure variability (BPV) has been shown to be related to mild cognitive impairment and Alzheimer's disease in a number of studies. However, the relationship between BPV and subtle cognitive decline (SCD) has received minimal attention in this field of research to date and has rarely been reported.

AIM

To examine whether SCD is independently associated with changes in BPV in older adults.

METHODS

Participants were selected based on having participated in cognitive function evaluation and ambulatory blood pressure measurement at the Shanghai Sixth People's Hospital Affiliated with Shanghai Jiao Tong University School of Medicine between June 2020 and August 2022. The participants included 182 individuals with SCD as the experimental group and 237 with normal cognitive function as the control group. The basic data, laboratory examinations, scale tests, and ambulatory blood pressure test results of the two groups were analyzed retrospectively, and the relationship between SCD and BPV was subsequently evaluated.

RESULTS

Significant differences were observed between the two groups of participants (P < 0.05) in terms of age, education level, prevalence rate of diabetes, fasting blood glucose level, 24-h systolic blood pressure standard deviation and coefficient of variation, 24-h diastolic blood pressure standard deviation and coefficient of variation. The scale monitoring results showed significant differences in the scores for memory, attention, and visual space between the experimental and control groups. Logistic regression analysis indicated that age, education level, blood sugar level, and BPV were factors influencing cognitive decline. Linear regression analysis showed that there was an independent correlation between blood pressure variation and SCD, even after adjusting for related factors. Each of the above differences was still significant.

CONCLUSION

This study suggests that increased BPV is associated with SCD.