Mechanisms underlying the J-curve for diastolic blood pressure: Subclinical myocardial injury and immune activation

Non-linear association and benchmark dose of blood pressure on carotid artery intima-media thickening in a general population of southern China

Background and aims

This study aimed to evaluate whether there is a J-curve association between blood pressure (BP) and carotid artery intima-media thickening (CAIT) and estimate the effect of the turning point of BP on CAIT.

Methods and results

Data from 111,494 regular physical examinations conducted on workers and retirees (aged 18 years or older) between January 2011 and December 2016, exported from the hospital information system, were analyzed. Restricted cubic splines (RCS) logistic regression was employed to access the association of BP with CAIT, and Bayesian benchmark dose methods were used to estimate the benchmark dose as the departure point of BP measurements. All the pnon-linear values of BP measurements were less than 0.05 in the RCS logistic regression models. Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) had J-curve associations with the risk of CAIT at a turning point around 120/70 mmHg in the RCS. The benchmark dose for a 1% change in CAIT risk was estimated to be 120.64 mmHg for SBP and 72.46 mmHg for DBP.

Conclusion

The J-curve associations between SBP and DBP and the risk of CAIT were observed in the general population in southern China, and the turning point of blood pressure for significantly reducing the risk of CAIT was estimated to be 120.64/72.46 mmHg for SBP/DBP.

Association of low diastolic blood pressure with cardiovascular outcomes and all-cause mortality: A meta-analysis

BACKGROUND

Reduction of diastolic blood pressure (DBP) below 70 mmHg may decrease perfusion to the heart and worsen cardiovascular (CV) outcomes.

AIMS

Explore the association between low DBP and CV outcomes.

METHODS

We searched the online databases until August 2023 for studies reporting the risk of all-cause mortality (ACM) or CV outcomes in patients with low versus normal DBP (70-80mm Hg).

RESULTS

Inclusion of 10 studies (n = 1,998,223 patients) found that a mean achieved DBP < 60 mmHg was associated with an increased risk of all-cause mortality (HR 1.48; 95 % CI [1.26-1.74]), especially in patients with pre-existing CV disease. It was also associated to a higher risk of major adverse cardiovascular events (HR 1.84; [1.28-2.65]) and myocardial infarction (HR 1.49; [1.13-1.97]). A DBP of 60-69 mmHg was associated with an increased risk of all-cause mortality (HR 1.11; [1.03-1.20]).

CONCLUSION

Reduction of DBP, particularly below 60 mmHg, is associated with increased risk of ACM.

Unsolved Problem: (Isolated) Systolic Hypertension with Diastolic Blood Pressure below the Safety Margin

The problem of high systolic blood pressure (sBP) combined with low diastolic blood pressure (dBP) requires attention because sBP is directly and continuously related to the most important criterion, i.e., all-cause mortality, whereas dBP becomes inversely related to it after the age of 50-60 years. The European Society of Cardiology and European Society of -Hypertension (ESC/ESH) 2018 guidelines for hypertension (HTN) are helpful because they recommend a lower safety cut-off for in-treatment dBP. To prevent tissue hypoperfusion, these guidelines recommend that dBP should be ≥70 mm Hg during treatment. A patient with very elevated sBP (e.g., 220 mm Hg) and low dBP (e.g., 65 mm Hg) is difficult to treat if one strictly follows the guidelines. In this situation, the sBP is a clear indication for antihypertensive treatment, but the dBP is a relative contraindication (as it is <70 mm Hg, a safety margin recognized by the 2018 ESC/ESH guidelines). The dilemma about whether or not to treat isolated systolic hypertension (SH) patients with low dBP (<70 mm Hg) is evident from the fact that almost half (45%) remain untreated. This is a common occurrence and identifying this problem is the first step to solving it. We suggest that an adequate search and analysis should be performed, starting from the exploration of the prognosis of the isolated (I)SH subset of patients with a very low dBP (<70 mm Hg) at the beginning of already performed randomized clinical trials.

HIV and cardiovascular diseases risk: exploring the interplay between T-cell activation, coagulation, monocyte subsets, and lipid subclass alterations

Although rollout of combined antiretroviral treatment (cART) has blunted human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) onset, there is increased development of cardiovascular diseases (CVDs) in HIV-infected individuals. While most HIV-infected individuals on cART achieve viral suppression, this may not necessarily result in complete immunological recovery. This study therefore evaluated T-cell-mediated changes and coagulation markers in HIV-positive individuals to ascertain their potential to increase CVD risk. Eighty participants were recruited (Worcester, South Africa), and fasted blood was collected to evaluate: 1) immune activation (CD38 expression on CD4⁺ and CD8⁺ T cells) and thrombus formation [tissue factor (CD142)] on CD4⁺ and CD8⁺ T cells; 2) monocyte subpopulations (nonclassical, intermediate, and classical); and 3) classical regulatory T (Treg) cells with activation markers [glycoprotein A repetitions predominant (GARP) and special AT-rich sequence-binding protein 1 (SATB-1)]. High- and low-density lipoprotein subclasses (Lipoprint) were also determined. This study revealed four key findings for HIV-positive patients: 1) coexpression of the CD142 coagulation marker together with immune activation on both CD4⁺ and CD8⁺ T cells during chronic infection stages; 2) Treg cell activation and upregulated GARP and SATB-1 contributing to Treg dysfunction in chronic HIV; 3) proatherogenic monocyte subset expansion with significant correlation between T-cell activation and macrophage activation (marker: CD163); and 4) significant correlation between immune activation and lipid subclasses, revealing crucial changes that can be missed by traditional lipid marker assessments (LDL and HDL). These data also implicate lipopolysaccharide-binding protein as a crucial link between immune activation, lipid alterations, and increased CVD risk. NEW & NOTEWORTHY With combined antiretroviral treatment rollout, HIV-AIDS patients are increasingly associated with cardiovascular diseases onset. This study demonstrated the significant interplay between adaptive immune cell activation and monocyte/macrophage markers in especially HIV-positive individuals with virological failure and on second line treatment. Our data also show a unique link between immune activation and lipid subclass alterations, revealing important changes that can be missed by traditional lipid marker assessments (e.g., LDL and HDL).