The Effect of Mean Platelet Volume/Platelet Count Ratio on Dipper and Non-Dipper Blood Pressure Status

Platelet indices and the risk of pulmonary arterial hypertension: a two-sample and multivariable Mendelian randomization study

Background

Recent epidemiological studies have indicated a correlation between platelet indices and pulmonary arterial hypertension (PAH), yet the causality between them remains unclear. To explore the causal relationship between four platelet indices and PAH, with the aim of providing a theoretical basis for clinical prevention and treatment.

Methods

Single-nucleotide polymorphisms (SNPs) associated with platelet-related traits were selected as exposure factors from published genome-wide association studies (GWAS), including: platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV), and platelet distribution width (PDW). Summary-level data for PAH were obtained from the FinnGen study (248 cases and 289,117 controls). Two-sample and multivariable Mendelian randomization (MR) analyses were conducted to assess the causal relationship between exposure factors and the risk of outcomes. The inverse variance weighted (IVW) method was utilized as the primary MR analysis approach, supplemented by weighted median, mode-based estimation, MR-Egger regression, and the MR Pleiotropy Residual Sum and Outlier (MR-PRESSO) test to detect and adjust for pleiotropy, ensuring the reliability of the results through sensitivity analysis.

Results

(1) The IVW results from the two-sample MR analysis showed a positive causal association between PLT and the risk of developing PAH [(OR = 1.649, 95%CI: 1.206-2.256, P = 0.0017)], with the sensitivity analysis confirming the robustness of the causal relationship. The MR-Egger intercept analysis did not detect potential pleiotropy (P = 0.879). (2) The MVMR results showed no statistically significant causal relationship between these four markers and the risk of developing PAH. After adjusting for collinearity, a direct positive causal association was observed between PLT and the risk of developing PAH (OR = 1.525, 95%CI: 1.063-2.189, P = 0.022).

Conclusion

The positive correlation between PLT and the risk of PAH suggests that correcting elevated platelet levels may reduce the risk of developing PAH.

A diagnostic model for Parkinson's disease based on circadian rhythm-related genes

BACKGROUND

Circadian rhythm (CR) disturbance is intricately associated with Parkinson's disease (PD). However, the involvement of CR-related mechanisms in the pathogenesis and progression of PD remains elusive.

METHODS

A total of 141 PD patients and 113 healthy participants completed CR-related clinical examinations in this study. To further investigate the CR-related mechanisms in PD, we obtained datasets (GSE7621, GSE20141, GSE20292) from the Gene Expression Omnibus database to identify differentially expressed genes between PD patients and healthy controls and further selected CR-related genes (CRRGs). Subsequently, the least absolute shrinkage and selection operator (LASSO) followed by logistic algorithms were employed to identify the hub genes and construct a diagnostic model. The predictive performance was evaluated by area under the curve (AUC), calibration curve, and decision curve analyses in the training set and external validation sets. Finally, RT‒qPCR and Western blotting were conducted to verify the expression of these hub genes in blood samples. In addition, Pearson correlation analysis was utilized to validate the association between expression of hub genes and circadian rhythm function.

RESULTS

Our clinical observational study revealed that even early-stage PD patients exhibited a higher likelihood of experiencing sleep disturbances, nocturnal hypertension, reverse-dipper blood pressure, and reduced heart rate variability compared to healthy controls. Furthermore, 4 CR-related hub genes (AGTR1, CALR, BRM14, and XPA) were identified and subsequently incorporated as candidate biomarkers to construct a diagnostic model. The model showed satisfactory diagnostic performance in the training set (AUC = 0.941), an external validation set GSE20295 (AUC = 0.842), and our clinical centre set (AUC = 0.805). Additionally, the up-regulation of CALR, BRM14 and the down-regulation of AGTR1, XPA were associated with circadian rhythm disruption.

CONCLUSION

CR disturbance seems to occur in the early stage of PD. The diagnostic model based on CR-related genes demonstrated robust diagnostic efficacy, offering novel insights for future clinical diagnosis of PD and providing a foundation for further exploration into the role of CR-related mechanisms in the progression of PD.

Platelet Indices and Hypertension: Results from Shahedieh Cohort Study, Yazd, Iran

Introduction

Hypertension is one of the most important diseases worldwide. In this study, we aim to demonstrate the relationship between platelet indices and hypertension.

Materials and Methods

We studied 9448 people in the age range of 30 to 70 years. We assessed their hypertension status, platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), smoking, cardiovascular disease history, diabetes status, body mass index, and creatinine levels. Hypertension status was assessed qualitatively. All platelet indices were categorized by quartiles. We then used logistic regression to predict the relationship between these indices and hypertension.

Results

PDW index and hypertension had a statistically significant relationship in the second quartile (16.2 fL < PDW ≤ 16.7 fL) in 30 to 40 years old (AOR: 0.225, 95% CI: 0.063-0.806), in the fourth quartile in 50 to 60 years old (AOR = 1.532, 95% CI: 1.048-2.238), and in all the quartiles of the age range of over 60 years. PLT index had a positive relationship (AOR = 3.147, 0.95% CI: 1.163-8.516) in 30 to 40 years old in the fourth quartile vs. the first quartile. A positive relationship was obtained in the third and fourth quartiles of PLT and the age range of 40 to 50 years, respectively (AOR = 2.063, 0.95% CI: 1.162-3.662) and (AOR = 2.204, 0.95% CI: 1.220-3.981).

Conclusion

According to the results of this study, some platelet indices could be correlated with hypertension, so we may be able to reduce the burden of this disease.

Evaluation of Mean Platelet Volume in Children with Hypertension

Background

Childhood hypertension, a disease with increasing prevalence, can lead to severe health problems. With the increased pressure on the vascular endothelium in hypertension, lesions in the endothelium result in endothelial activation and a process of inflammation, which causes platelet activation and in the bone marrow the release of platelet precursor cells into the peripheral blood stream. During inflammation, changes in the number and size of platelets are observed. With the release of platelet precursors into the peripheral blood stream due to platelet activation, an increase in mean platelet volume (MPV) is also seen.

Aim

Our aim in this study is the evaluation of MPV changes in the hemogram of children suffering from hypertension, a condition causing severe cardiovascular problems. Material and Methods. This research is a descriptive retrospective cross-sectional study. It consists of a patient group diagnosed with hypertension and a control group of children presenting for routine check-ups with no diagnosed hypertension. Demographic characteristics, arterial pressure values, and hemogram parameters have been evaluated.

Results

A total of 90 cases were enrolled in the study, including a patient group of 45 cases with hypertension (19 females, 26 males) and a control group of 45 cases (27 females, 18 males). The median age was 15 years in the hypertension group and 13 years in the control group. In the hypertension cases, the thickness of the carotis intima media was statistically significantly greater than in the control group (p < 0.001). Echocardiographic findings (IVSd, LVDd, LVPWd, IVSs, LVDs, LVPWs, and LV mass) were significantly higher in the hypertension group compared to the control group (p < 0.001). A statistically significant difference in platelet count and MPV values between the groups was not found (p = 0.151, p = 0.405, respectively).

Conclusion

While MPV is hypothesized to be higher in hypertensive individuals, there was no statistically significant difference between the hypertensive and non-hypertensive groups in this study.

Are Differences in Inflammatory Markers between Patients with and without Hypertension-Mediated Organ Damage Influenced by Circadian Blood Pressure Abnormalities?

We aimed to explore the influence that the circadian blood pressure (BP) profile could exert on the correlation between some inflammatory markers and hypertension-mediated organ damage (HMOD). This was a cross-sectional study that included patients with primary arterial hypertension older than 18 years old. We included some parameters of 24 h ambulatory blood pressure monitoring collection and several inflammatory markers, as follows: platelet count (PTC), erythrocyte sedimentation rate (ESR), ultrasensitive C-reactive-protein, ferritin, fibrinogen, and uric acid. Myocardial hypertrophy, albuminuria, carotid intima-media thicknesses and ankle brachial index were assessed as HMOD presentations. Individuals were divided into two groups: patients with and without HMOD. We included 522 patients (47% women, mean age of 54 years). Multivariate logistic regression analysis showed that male patients older than 50 years old with uric acid levels above 7 mg/dL, ESR higher than 20 mm/h, fibrinogen greater than 320 mg/dL and PTC lower than 275 × 103/µL were associated with HMOD (p < 0.05). The circadian BP profile (dipper versus non-dipper pattern) did reach neither statistical significance nor influence the odds ratio of those inflammatory markers for HMOD. We found that differences in some inflammatory markers between patients with and without HMOD were not explained by a different circadian BP profile.

The relationship between mean platelet volume and reverse dipping blood pressure pattern in patients with essential hypertension

OBJECTIVE

An association between increased mean platelet volume (MPV) and cardiovascular events is well established. Recent studies suggest that a nondipper blood pressure pattern is closely related to increased MPV. Because little information has been revealed about the relationship between reverse dipper hypertension (RDHT) and MPV, we aimed to investigate this relation.

METHODS

A total of 317 patients were retrospectively evaluated by analyzing the records of ambulatory blood pressure monitoring (ABPM). Patients were categorized into three groups according to their ABPM values as RDHT (n = 63), non-dipper hypertension (NDHT) (n = 95), and dipper hypertension (DHT) groups (n = 159). MPV and biochemical analyses were recorded from the hospital database.

RESULTS

The largest MPV was found in patients with RDHT, followed by patients with NDHT and DHT group (9.1 ± 0.4 fl, 8.8 ± 0.6 fl, and 8.6 ± 0.5 fl, respectively, for all p < .05). MPV was positively correlated with mean 24-hour systolic blood pressure (SBP), mean 24-hour diastolic blood pressure (DBP), mean daytime SBP, mean nighttime SBP and mean nighttime DBP. In multivariate logistic regression analysis, MPV (OR 1.761, 95% CI 1.329 to 2.334, p = .001) and age (OR 1.065, 95% CI 1.019 to 1.113, p = .001) were found to be associated with RDHT. ROC curve analysis of MPV for prediction of RDHT showed that at the cutoff value of >9,1 fl with a sensitivity of 60% and specificity of 69%, respectively (AUC = 0.696 ± 0.035, 95% CI: 0.627-0.764). Our data show that the RDHT pattern is associated with increased MPV values in patients with essential hypertension.

Association between central non-dipping pattern and platelet morphology in adults with type 1 diabetes without cardiovascular disease: a cross-sectional study

The non-dipping pattern is nighttime systolic blood pressure (SBP) fall of less than 10%. Several studies showed that the non-dipping pattern, increased mean platelet volume (MPV), and platelet distribution width (PDW) are associated with elevated cardiovascular risk. Hypertensives with the non-dipping pattern have higher MPV than the dippers but this relationship was never investigated among people with type 1 diabetes mellitus (T1DM). This study aimed to investigate the association between the central dipping pattern and platelet morphology in T1DM subjects. We measured the central and brachial blood pressure with a validated non-invasive brachial oscillometric device—Arteriograph 24—during twenty-four-hour analysis in T1DM subjects without diagnosed hypertension. The group was divided based on the central dipping pattern for the dippers and the non-dippers. From a total of 62 subjects (32 males) aged 30.1 (25.7–37) years with T1DM duration 15.0 (9.0–20) years, 36 were non-dippers. The non-dipper group had significantly higher MPV (MPV (10.8 [10.3–11.5] vs 10.4 [10.0–10.7] fl; p = 0.041) and PDW (13.2 [11.7–14.9] vs 12.3 [11.7–12.8] fl; p = 0.029) than dipper group. Multivariable logistic regression revealed that MPV (OR 3.74; 95% CI 1.48–9.45; p = 0.005) and PDW (OR 1.91; 95% CI 1.22–3.00; p = 0.005) were positively associated with central non-dipping pattern adjusting for age, sex, smoking status, daily insulin intake, and height. MPV and PDW are positively associated with the central non-dipping pattern among people with T1DM.

Relationship between 25-hydroxyvitamin D and microalbuminuria in patients with newly diagnosed essential hypertension

Purpose: Vitamin D deficiency is known that associated with hypertension. Microalbuminuria (MAU) is associated with increased cardiovascular morbidity and mortality. This study aimed to evaluate the relationship between 25-hydroxyvitamin D (25(OH)D) and MAU in newly diagnosed essential hypertension (NDEH) patients. Methods: A total of 116 patients with a diagnosis of NDEH were enrolled in the study. The diagnosis of hypertension was based on ABPM. Patients were divided into 2 groups according to 25(OH)D levels: Group 1: (25(OH)D)>20 ng/mL was defined as Vitamin D sufficiently (VDS), while Group 2: (25(OH)D)<20 ng/mL was defined Vitamin D deficiently (VDD). The relationship between 25(OH)D and MAU was analyzed. The results were analyzed using the SPSS program version 21. Results: The mean age of the patients was 58.4 ± 14.7 years and 60 (51.7%) of them were female. The prevalence of MAU was 18.9% and Vitamin D deficiency was 61.2% in NDEH. Linear regression analysis showed that 25(OH)D was independently related to MAU [β 0.643, 95% confidence interval 1.173-1.631, p = .011]. Besides, male gender, C-reactive protein, non-dipper hypertension, and diastolic blood pressure were independent risk factors associated with MAU in the multivariate analysis (p < .05). Conclusion: Vitamin D deficiency is highly prevalent in NDEH patients. This study showed that the level of microalbuminuria was significantly higher in patients with 25(OH)D deficiency compared to patients with normal 25(OH)D levels. Vitamin D deficiency is independently related to microalbuminuria in NDEH.