Ambulatory arterial stiffness index and its role in assessing arterial stiffness in dialysis patients

The Relationship Between Ambulatory Arterial Stiffness Index and Cardiovascular Outcomes in Women

Background

The ambulatory arterial stiffness index (AASI) obtained during ambulatory blood pressure monitoring (ABPM) has been cited as an independent predictor of major adverse cardiovascular events (MACEs) including cardiovascular death, stroke and worsening chronic kidney disease (CKD) among mixed-sex adult populations. This study aimed to determine the relationship between AASI and MACE and its predictive precision in women.

Methods

This work follows the guidelines of the STROBE initiative for cohort studies. This was a retrospective single-center observational study of adult women (aged 18 - 75 years), who underwent 24-h ABPM for the diagnosis of hypertension or its control. The primary endpoint was a composite MACE of cardiovascular death, acute limb ischemia, stroke, acute coronary syndrome (ACS), or progression to stage V CKD.

Results

A total of 219 women aged 57.4 ± 13.3 years were followed up for a median (interquartile range (IQR)) of 25.5 (18.3 - 31.3) months. Overall, 16 (7.3%) patients suffered one or more MACE events. AASI was significantly higher in patients with known coronary artery disease (CAD), diabetes mellitus, peripheral vascular disease (PVD), heart failure, previous stroke, or transient ischemic attack (TIA). AASI was a significant predictor of MACE (area under the curve: 0.78; P < 0.001) with an optimal cut-off of ≥ 0.56. On Kaplan-Meier analysis AASI ≥ 0.56 was significantly associated with MACE (log-rank test, P < 0.001). The only independent predictors of MACE on Cox proportional hazard analysis were diabetes mellitus, low high-density lipoprotein (HDL) levels, cumulative AASI values, or AASI ≥ 0.56.

Conclusions

An AASI of ≥ 0.56 is an independent predictor of MACE in women. A further validation study in a larger cohort of women is recommended.

Noninvasive markers of arterial stiffness and renal outcomes in patients with chronic kidney disease

Our study aimed to explore the intercorrelations of brachial‐ankle pulse wave velocity (baPWV), ankle‐brachial index (ABI), ambulatory arterial stiffness index (AASI), 24‐hour mean pulse pressure (24‐h   PP), and augmentation index (AIx, AIx@75, the AIx standardized to a heart rate of 75) and compare the effectiveness of these markers for predicting renal outcomes. A total of 117 patients with chronic kidney disease (CKD) who received noninvasive arterial stiffness examinations were enrolled. We used correlation analysis and linear regression to explore the correlations between these five arterial stiffness markers and the Cox proportional hazards model and receiver operator characteristic (ROC) curve to assess the associations of markers with kidney disease outcomes. The median (interquartile range) of age and eGFR were 61 (49‐65) years and 50.5 (35.5‐84.1) ml/min/1.73 m², respectively. In Pearson correlation analysis, baPWV was significantly associated with 24‐h  PP (r = .531, p < .001), AIx@75 (r = .306, p < .001). Additionally, 24‐h  PP was associated with AASI (r = .507, p < .001) and AIx@75 (r = .217, p = .019). During follow‐up for a median of 25 months, 26.5% (n = 31) of patients had a composite outcome; of these, 10 initiated dialysis, 17 had 40% eGFR loss, and 4 died. Increased AASI, 24‐h  PP, and baPWV were associated with poor renal outcomes in a univariate Cox analysis. After adjusting for age, sex, MAP, eGFR, and 24 hours proteinuria, 1‐SD increase in AASI and 24‐h  PP was associated with renal outcomes. The ROC analysis yielded the largest area under the curve (AUC) of 0.727 (95% CI: 0.624 to 0.831; p < .001) for 24  ‐h PP. When the Youden's index was at its maximum, the 24‐h PP value was 52 mmHg. In conclusion, 24‐h  PP, baPWV, and AIx@75 were linked well to one another. Arterial stiffness is a target for delaying the decline in kidney function. The use of 24‐h  PP as an arterial stiffness marker should be valued in CKD clinical practice.

Relationship between A1166C polymorphism of angiotensin II type 1 receptor gene and arteriosclerosis: A protocol for systematic review and meta-analysis

BACKGROUND

Arteriosclerosis has genetic correlation. Many studies have shown that angiotensin II type 1 receptor (AT1R) gene A1166C polymorphism is highly associated with arteriosclerosis, but there is no evidence-based basis. The purpose of this study is to systematically evaluate the relationship between AT1R gene A1166C polymorphism and arteriosclerosis.

METHODS

The search time is set from the establishment of the database in December 2020 in this study. The search database include China National Knowledge Infrastructure (CNKI), Wanfang, VIP and China Biology Medicine disc (CBM), PubMed, EMBASE, Web of Science, and the Cochrane Library. The subjects are observational studies on the relationship between AGTR1 A1166C polymorphism and arteriosclerosis (including case-control study, cross-sectional study, and cohort study). The language is limited to English and Chinese. The data of the included study are extracted and the literature quality is evaluated by 2 researchers independently. The data are statistically analyzed by Stata 16.0 software.

RESULTS

This study will use pulse wave velocity as an index to evaluate arteriosclerosis to explore the relationship between AT1R gene A1166C polymorphism and arteriosclerosis.

CONCLUSION

This study will provide evidence-based medicine for elucidating the genetic tendency of arteriosclerosis.

ETHICS AND DISSEMINATION

Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval will not be required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/V6E2Y.

Association of betaine with blood pressure in dialysis patients

Mechanisms underlying elevated blood pressure in dialysis patients are complex as a variety of non-traditional factors are involved. We sought to explore the association of circulating betaine, a compound widely distributed in food, with blood pressure in dialysis patients. We used baseline data of an ongoing cohort study involving patients on hemodialysis. Plasma betaine was measured by high performance liquid chromatography in 327 subjects. Blood pressure level was determined by intradialytic ambulatory blood pressure monitoring. The mean age of the patients was 52.6 ± 11.9 years, and 58.4% were male. Average interdialytic ambulatory systolic and diastolic blood pressure were 138.4 ± 22.7 mm Hg and 84.4 ± 12.5 mm Hg, respectively. Mean plasma betaine level was 37.6 μmol/L. Multiple linear regression analysis revealed significant associations of betaine with both systolic blood pressure (β = -3.66, P = .003) and diastolic blood pressure (β = -2.00, P = .004). The associations persisted even after extensive adjustment for cardiovascular covariates. Subgroup analysis revealed that the association between betaine and blood pressure was mainly limited to female patients. Our data suggest that alteration of circulating betaine possibly contributes to blood pressure regulation in these patients.