Hepatitis B vaccine linked to a lower risk of developing diabetes

The hepatitis B vaccine seems to reduce the risk of developing diabetes, not only by preventing infection.

The vaccine is systematically offered to infants from most countries, generally by three doses. In the United States, this became part of the vaccination program in 1991, so only 30% of adults had full coverage in 2018.

Scientists have already discovered that the vaccine seems to reduce the risk of diabetes. This may be due to the hepatitis B virus – which infects the liver and spreads through blood, sperm and vaginal liquids – disturbing the ability of the organ to keep blood sugar. This could increase the risk of diabetes, where blood sugar is constantly too high.

But previous studies have not examined whether the vaccine could reduce the risk of diabetes among a group of immune and non -immunity people who have not contracted hepatitis B, which suggests that the effect acts independently of the simple prevention of infection.

To explore this, Nhu-Quynh Phan at the Medical University of Taipei in Taiwan and his colleagues analyzed health files of more than 580,000 people across the United States, Europe, Africa, Latin America, the Middle East and Asia-Pacific. On average, these files lasted almost four years for each individual between 2005 and 2023.

None of the participants, aged 18 to 90, had no type of diabetes or had been infected with the hepatitis B virus, according to their files and the absence of specific blood markers. About half of them had received a vaccine against hepatitis B, evaluated according to the levels of antibodies specific to the virus in their blood.

The team noted that vaccinated participants had a global rate of 15% diabetes – defined as they received a diagnosis, having a constant blood sugar level or prescribing diabetes drugs – that their non -vaccinated counterparts. The vast majority of cases were type 2 diabetes, the most common form of the condition. The results will be presented in the annual meeting of the European Association for the study of diabetes in Vienna, Austria.

Although it is observational research, scientists also found a dose-answer effect, where participants vaccinated with higher levels of specific antibodies of hepatitis B were less likely to develop diabetes than those with lower levels. Differences in antibody levels can reflect the number of vaccine doses that participants have received, to what extent they have been immune or the general variation of immune responses.

With regard to the mechanism, the fact that none of the participants had been knowingly infected with hepatitis suggests being immune reduces the risk of diabetes independent of the simple prevention of infection, explains Phan. A potential explanation is that it somehow reduces chronic inflammation that damages the liver and the pancreas, which release hormones that regulate blood sugar, like insulin, she says.

However, scientists cannot exclude the possibility that part of the protective effect of the vaccine has just warned infection, she said. They hope to explore the potential ways involved and how they can vary between different forms of diabetes, in studies in mice, explains Phan.

It is possible that people who are vaccinated are simply more likely to make lifestyle choices that reduce the risk of type 2 diabetes, such as eating a healthy diet and exercising regularly. “People who are inclined to be vaccinated are generally people who are more aware of living a healthy life,” explains Albert Osterhaus at the University of Hanover veterinary medicine in Germany.

The team has taken into account the factors that could affect results, such as the age of the participants, sexual relations and if they smoked or had other conditions, such as obesity and high blood pressure. But Osterhaus maintains that the influence of these factors cannot be excluded.