Recently, Yang Guangyu of Shanghai Jiaotong University, Wang Xinghuan of Wuhan University and others published a research paper online on the pre-printed platform medRxiv that compared with non-A blood, people with blood type A have a significantly increased risk of contracting the new coronavirus; compared with non-O blood In comparison, people with blood type O have a significantly lower risk of contracting the new coronavirus.
The most common classification method of blood group system is the ABO system. Those with A or B type agglutinogen (antigen) on the red blood cell are type A or B blood; if both types of agglutinogen are present, it is type AB blood; if there are none, It is type O blood. When the virus invades the human body, it usually needs to bind to the cell surface antigen in the body to invade the inside of the cell, continue to multiply and cause disease. Zhang Qun, director of the Department of Infectious Diseases at the Zhongda Hospital of Southeast University, said that different viruses may be more inclined to bind to different antigens. Taking hepatitis B virus as an example, studies have shown that people with blood type A or B have A antigen or B antigen on the surface of red blood cells, which helps prevent hepatitis B virus infection; while people with blood type O do not contain A and B antigens on their red blood cells. The positive rate of HBsAg (hepatitis B surface antigen) is relatively high.
The oligosaccharide molecules on the surface of red blood cells of different blood types are different. The same oligosaccharide molecules on red blood cells will also appear on the surface of small intestinal cells. Some viruses will tend to bind to certain oligosaccharide molecules on small intestine cells, resulting in viral infection. For blood type preference. Norovirus uses this principle to cause differences in infection rates among people of different blood types. According to Zhang Qun’s analysis, according to research reports at home and abroad, similar to SARS (atypical pneumonia virus), the new coronavirus may mainly infect cells through the angiotensin-converting enzyme II receptor, but type O blood anti-A antibodies will interfere with its binding. Thereby reducing the infection rate to a certain extent.
Zhang Qun said that the difference between viral infections among different blood types of ABO has always been a hot spot for domestic and foreign scholars. The research on the distribution of new coronavirus infection in different blood types of ABO is very timely, but there are also shortcomings: 1. The sample size is limited. The study involved only 2173 patients in some hospitals in Wuhan and 3 hospitals in Shenzhen. If the sample size can be expanded to More regions and centers, the results will be more meaningful; 2. If the research can also include mild and asymptomatic infections, the results may be more comprehensive. Finally, Zhang Qun reminded that there are many factors that affect the infection of the new crown virus. No matter what blood type, everyone must do standard protection, and there should be no chances.
Obese women are susceptible to cardiomyopathy
Cardiomyopathy is a common cause of heart failure in young people, and the incidence has increased in the past few decades. Previous studies have shown that there is a correlation between adolescent weight and future cardiomyopathy in men; for women, it is not known whether this correlation holds. To understand this, the University of Gothenburg in Sweden recently conducted a study.
The study included more than 1.38 million women of childbearing age (18 to 45 years old), followed up for 33 years. The initial data collected by the researchers included body mass index, smoking status, education level, and past medical history. During the follow-up period, a total of 1699 cases of cardiomyopathy were diagnosed. The average age of the subjects at diagnosis was 46.2 years. Among them, 481 cases were dilated cardiomyopathy, 246 cases were hypertrophic cardiomyopathy, and 61 cases were alcohol/drug-induced cardiomyopathy. The rest are other types. The analysis results show that when the body mass index [BMI=weight (kg) ÷ height (m) squared] is 21, the risk of diagnosed cardiomyopathy is the lowest; as the body mass index increases, the risk of cardiomyopathy will gradually increase, especially It is dilated cardiomyopathy. Compared with women with a body mass index between 20 and 22.5, women with severe obesity (body mass index ≥ 35) have a nearly 5-fold increase in the risk of developing dilated cardiomyopathy.
Researchers believe that body weight is closely related to cardiomyopathy, especially young women should pay more attention to reasonable exercise, weight control, and a healthy diet.