The Blood Type That Predicts Early Stroke Risk

 Well, I'm O negative and still had an early stroke at age 50.

The Blood Type That Predicts Early Stroke Risk

Your blood type might signal whether you are prone to have an early stroke or not.

Besides lifestyle and environment, genes have a big impact on a person’s state of health.

One example is a person’s blood group, which is inherited from genes passed down by the parents.

A meta-analysis of genetic studies reveals that our blood type can determine whether we are at risk of an early stroke or not.

They found that people with blood type A are more at risk of an early stroke.

Also, those with blood type B were more likely to experience a stroke before the age 60 and later on.

The review is based on 48 genetic studies related to ischemic strokes, the most common type of strokes.

Ischemic strokes are life-threatening conditions caused by a blockage of an artery that supplies blood to the brain.

Professor Steven Kittner, the study’s senior author, said:

“The number of people with early strokes is rising.

These people are more likely to die from the life-threatening event, and survivors potentially face decades with disability.

Despite this, there is little research on the causes of early strokes.”

The research team compared genetic data from 17,000 stroke patients with nearly 600,000 healthy adults (non-stroke controls) who were between 18- and 59-years-old.

The team studied the ABO gene located on certain chromosomes in order to find out if there is any link between common genetic variants with the risk of having a stroke before age 60.

Their analysis showed that participants with early stroke were less likely to have blood type O and most likely to have blood type A.

Participants with blood group A were more likely to have an early stroke and those with blood type O had a lower risk of developing strokes.

Those with blood type B were at higher risk of having an early stroke and later in life.

Professor Braxton Mitchell, study co-author, said:

“Our meta-analysis looked at people’s genetic profiles and found associations between blood type and risk of early-onset stroke.

The association of blood type with later-onset stroke was much weaker than what we found with early stroke.”

Compared to people with other blood types, those with blood type A had a 16 percent higher risk of an early stroke.

The authors acknowledged that the increased risk of an early stroke for people with blood type A is small and so they don’t need to worry or do any additional health check and medical tests.

Professor Kittner said:

“We still don’t know why blood type A would confer a higher risk, but it likely has something to do with blood-clotting factors like platelets and cells that line the blood vessels as well as other circulating proteins, all of which play a role in the development of blood clots.”

Past studies have found that people with blood type A are at a slightly increased risk of experiencing deep vein thrombosis.

The study was published in the journal Neurology (Jaworek et al., 2022).

Non-O blood groups at increased risk for CV events

Rather useless to know since we can't change our blood type, pretty much a fucking waste of research dollars. I'm O-negative so that didn't save me from having a CV event.
http://www.healio.com/cardiology/vascular-medicine/news/online/%7Bb27e3ce3-1a44-49d8-93b7-9195bd08b8be%7D/non-o-blood-groups-at-increased-risk-for-cv-events?
Individuals with non-O blood groups were at an increased risk for coronary events and combined CV events, according to findings presented at Heart Failure 2017 in Paris.

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American College of Cardiology Annual Scientific Session

“It has been suggested that people with non-O blood groups (A, B, AB) are at higher risk for [MI] and overall [CV] mortality, but this suggestion comes from case-control studies, which have a low level of evidence,” Tessa Kole, a master’s degree student at the University Medical Centre Groningen in the Netherlands, said in a press release. “If this was confirmed, it could have important implications for personalized medicine.”
Kole and colleagues conducted a meta-analysis of prospective studies with more than 1.3 million participants combined. The researchers looked at associations between blood type and all coronary events, combined CV events and fatal coronary events.
There were 23,154 CV events in total. In the analysis of coronary events, 1.5% (n = 11,437) of people with non-O blood had a coronary event vs. 1.4% (n = 7,220) of participants with O blood (OR = 1.09; 95% CI, 1.06-1.13).
For combined CV events, 2.5% (n = 17,449) of participants with non-O blood had an event vs. 2.3% (n = 10,916) of those with O blood (OR = 1.09; 95% CI, 1.06-1.11).
There was no significant association between risk for fatal coronary event and blood type (OR = 1; 95% CI, 0.85-1.18).
“More research is needed to identify the cause of the apparent increased [CV] risk in people with a non-O blood group,” Kole said in the release. “Obtaining more information about risk in each non-O blood group (A, B and AB) might provide further explanations of the causes.”
Possible mechanisms include higher concentration of von Willebrand factor and increased rates of dyslipidemia in individuals with non-O blood, Kole and colleagues wrote in an abstract. – by Cassie Homer
Reference:
Kole T, et al. Abstract 697. Presented at: Heart Failure 2017 and the 4th World Congress on Acute Heart Failure; April 29-May 2, 2017; Paris.

Well having type O- didn't seem to lower my cardiovascular risk enough to prevent my stroke, maybe it will prevent cancer.
http://www.biomedcentral.com/1741-7015/13/7

Journal App

Commentary

The intriguing relationship between the ABO blood group, cardiovascular disease, and cancer

Massimo Franchini^1* and Giuseppe Lippi²

• * Corresponding author: Massimo Franchini massimo.franchini@aopoma.it

Author Affiliations

¹ Department of Hematology and Transfusion Medicine, C. Poma Hospital, Strada Lago Pajolo 10, Mantova, 46100, Italy
² Laboratory of Clinical Chemistry and Hematology, Academic Hospital of Parma, Via Gramsci 14, Parma, 43100, Italy

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BMC Medicine 2015, 13:7  doi:10.1186/s12916-014-0250-y
The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/13/7

Received:	17 November 2014
Accepted:	9 December 2014
Published:	16 January 2015

© 2015 Franchini and Lippi; licensee BioMed Central.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Abstract

Other than being present at the surface of red blood cells, the antigens of the ABO blood group system are efficiently expressed by a variety of human cells and tissues. Several studies recently described the involvement of the ABO blood group in the pathogenesis of many human disorders, including cardiovascular disease and cancer, so that its clinical significance extends now beyond the traditional boundaries of transfusion medicine. In a large cohort study recently published in BMC Medicine and including over 50,000 subjects, Etemadi and colleagues reported that nearly 6% of total deaths and as many as 9% of cardiovascular deaths could be attributed to having non-O blood groups, a condition that was also found to be associated with increased risk of gastric cancer. In this commentary, the clinical implications of ABO blood groups are critically discussed and a possible common pathogenic mechanism involving the von Willebrand factor is described.

Please see related article http://dx.doi.org/10.1186/s12916-014-0237-8 webcite.

Keywords:

ABO blood group; Cancer; Cardiovascular disease; Mortality; von Willebrand factor

Background

The antigens of the ABO blood group system (i.e., A, B, and H antigens), discovered more than one century ago [1], are complex carbohydrate molecules expressed on the extracellular surface of red blood cell membranes [2]. The A and B alleles encode slightly different glycosyltransferases that add N-acetylgalactosamine and D-galactose to a common precursor side chain, the H determinant, which is then converted into A- or B-antigens, respectively (Figure 1). The O alleles do not encode a functional enzyme, so that OO carriers lack these transferase enzymes and express the unaltered H structure, with a solitary terminal fucose moiety attached to the precursor oligosaccharide chain, which represents the phenotypic marker of the O blood group [3]. In addition to the expression on red blood cell surfaces, the ABO antigens are also present in a variety of human cells and tissues, including epithelium, sensory neurons, platelets, and vascular endothelium [4],[5]. Therefore, it is not surprising that the clinical significance of the ABO blood group extends now beyond the traditional boundaries of immunohematology and transfusion medicine, wherein this antigen system is seemingly involved in the pathophysiology of a wide range of human diseases, the most important being represented by cancers and infectious and cardiovascular disorders [6]-[9].

Figure 1. The intriguing relationship between ABO blood group system, von Willebrand factor (VWF), cancer and cardiovascular disease.

Discussion

A number of studies conducted in the past 50 years have consistently described the existence of an association between ABO blood type and cardiovascular disease [10]-[12]. In particular, a recent systematic review and meta-analysis documented that having a non-O blood group carries an approximately two-fold increased risk of venous thrombosis [10]. A weaker but still significant association was found in another systematic review conducted by the same group of authors between non-O blood type and arterial thrombosis (odds ratio [OR] of 1.28 for myocardial infarction and 1.17 for ischemic stroke) [11]. In addition to the effect of the ABO blood group on low-density lipoprotein and total serum cholesterol levels [13], the leading underlying mechanism that has been put forward to explain this association involves the profound influence that the ABO blood group system exerts on hemostasis, particularly on the von Willebrand factor (VWF) and, consequently, on coagulation factor VIII (FVIII) plasma levels, which are both well recognized prothrombotic risk factors [14]. Indeed, it is now clearly acknowledged that individuals of non-O blood group status have plasma levels of both VWF and FVIII that are approximately 25% higher than O blood group subjects [15]. The molecular basis of this phenomenon has been precisely identified with the presence of ABH antigenic structures on circulating VWF, which modulate the activity of this multifunctional protein through different degrees of glycosylation [12].

Another interesting field that has been extensively studied over the past five decades is that of the association between ABO blood group types and cancer [8],[9]. The most consistent association has been found with pancreatic and gastric cancers [8]. For instance, in the Nurses’ Health Study and Health Professionals Follow-up Study, Wolpin et al. [16] found that participants with blood groups A, AB, or B were more likely to develop pancreatic cancer compared with those with blood group O (adjusted hazard ratio [HR]: 1.44; 95% CI: 1.14–1.82). The higher prevalence of blood group A in patients with gastric cancer formerly observed by several studies [9] has also been recently confirmed in a large prospective population-based study involving more than one million of Scandinavian blood donors followed for up to 35 years [17]. The strength of this association was similar to that previously reported (OR: 1.20; 95% CI: 1.02–1.42). Although the underlying mechanisms linking the ABO blood group system and cancer are still largely unknown, one plausible explanation involves the ABO blood group-driven regulation of circulating levels of several proinflammatory and adhesion molecules (i.e., soluble E-selectin, P-selectin, and intercellular adhesion molecule-1), which play a key role in the tumorigenesis process [9]. Moreover, the recent discovery that VWF is an important modulator of angiogenesis and apoptosis provides an alternative, particularly intriguing, hypothesis to unify the mechanisms by which non-O blood group influences the onset of cardiovascular and neoplastic diseases (Figure 1) [18]. A significant advance in this field has now been provided by the Golestan Cohort Study, recently published in BMC Medicine[19]. This large epidemiological trial analyzed the association between ABO blood groups and overall and cause-specific mortality in over 50,000 people recruited between 2004 and 2008. Notably, the authors found that non-O blood groups were associated with a significantly increased risk of total death (HR: 1.09; 95% CI: 1.01–1.17) and mortality for cardiovascular disease (HR: 1.15; 95% CI: 1.03–1.27). Although no significant association was found with ABO-related cancer mortality, an aspect that was investigated for the first time in this study, an increased risk of developing gastric cancers was still observed in individuals with blood groups A and B. This latter finding is particular intriguing, and is also in keeping with the results from another recent study conducted by our group, in which a negative association between B blood group and life expectancy in a large cohort (n = 28,129) of subjects was found [20]. Although the analysis was only limited to overall mortality in our study, this evidence may be attributable to the association between B blood type and some aging associated conditions, including neurological and neoplastic disorders. Although additional research is needed to corroborate these preliminary findings, the attractive data that have emerged from these studies raise a new and intriguing scenario linking the ABO blood group with cardiovascular disease and cancer (Figure 1).

Conclusions

Despite being studied for more than half a century, the complex interplay between the ABO blood group system and human health is far from being definitely elucidated. In particular, if the association between non-O blood type and cardiovascular disease mortality is confirmed by further trials like that recently published by Etemadi et al. [19], non-O blood group status may be included in cardiovascular risk scores to better estimate the individual thrombotic risk profile. Further experimental studies are also needed to unravel the molecular mechanisms linking ABO blood type, VWF, and cancer development. Intuitively appealing, ABO blood typing may hence become part of a multifaceted strategy for cancer risk assessment.
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From a more readable source:

Cardiovascular Perks

Alexander says that it does look as though blood type O is protective in the setting of cardiovascular disease. “There is no reason to think that particular molecules on red blood cells would have anything to do with cardiovascular disease, but those same molecules attach molecules to a protein that is important in blood clotting, called the Von Willebrand factor,” she says. People with type O blood have lower Von Willebrand factor levels. That’s good for the heart because ”it means your blood is a little less likely to clot. And more heart attacks and strokes are caused by blood clots, so anything that can have a part in reducing that risk is beneficial.”