Herpes virus may increase risk of developing diabetes, study finds – 05/12/2022

The herpes virus is extremely common in the population as it is easily transmitted. With different types, it is latent (asleep) after the first infection and can manifest at any time in life, especially when there is some impact on the person’s immunity.

According to a new study published in the journal Diabetologyfrom the European Association for the Study of Diabetes, this Wednesday (11), these viruses can contribute to the development of pre-diabetes and type 2 diabetes.

The mechanisms are still unclear, according to the study authors. However, they explain that the herpes virus can affect metabolism, especially glucose – which would result in diabetes. But all this without concluding causality and, yes, an association.

How the study was done

The research was based on health data from 1,967 individuals from southern Germany, by the research platform called Kora (Cooperative Health Research in the Augsburg Region).

Participants underwent detailed health examinations between 2006 and 2008 and, 7 years later, a medical follow-up between 2013 and 2014.

This included tests for oral glucose tolerance and measurement of glycated hemoglobin, which shows blood sugar control over the past three months, as well as tests to detect the presence of 7 types of herpes virus:

The study group had an average age of 54 years at baseline: 962 (49%) were men and 999 (51%) were women.

Among the participants, 1,257 had normal glucose tolerance at baseline, with possible risk for prediabetes.

Variables associated with diabetes risk were also evaluated at baseline, such as gender, age, BMI (body mass index), years of schooling, smoking (yes/no), leisure-time physical activity (active/inactive), diabetes (yes/no) and hypertension (yes/no, defined as blood pressure greater than 140/90 mmHg).

It is important to mention that pre-diabetes is a state in which the glucose level is already altered, but still does not meet the criteria for type 2 diabetes (DM2). And, according to the study authors, previous research has found that the incidence rate of type 2 diabetes is much higher in people with prediabetes than among individuals with normal glucose tolerance.

Os main findings of the study

The prevalence of prediabetes was 27.5% at baseline and 36.2% at follow-up, while type 2 diabetes was present in 8.5% of participants at baseline and 14.6% at follow-up.

Of the 1,257 volunteers with normal glucose tolerance at baseline, 364 developed prediabetes and 17 developed T2DM during the median follow-up period of 6.5 years.

The authors found that age, BMI, smoking and years of schooling were associated with an individual’s risk of developing prediabetes and T2DM.

Blood tests at baseline found Epstein-Barr virus (EBV) to be the most prevalent type of herpes, with 98% of the seropositive group, followed by HSV1 (88%), HHV7 (85%), VZV (79%). %), CMV (46%), HHV6 (39%) and HSV2 (11%).

About a third (34%) tested positive for more virus at the end of the follow-up period, 54% had the same number, and only 12% tested positive for less virus than at baseline.

Among the seven types of herpes examined, HSV2 and CMV were most associated with the incidence of prediabetes among subjects with normal glucose tolerance at baseline.

Individuals with HSV2 were 59% more likely to develop prediabetes than those who were seronegative, while CMV infection was associated with a 33% increase in the incidence of prediabetes.

The study found that both herpes type 2 and cytomegalovirus contributed consistently and complementary to the development of prediabetes, even considering gender, age, BMI, education, smoking, physical activity, parental diabetes, hypertension, lipid levels. , insulin resistance and fasting glucose.

Herpes are not always detected by antibodies in the blood

According to the authors, infection with the virus usually occurs in early childhood but can occur later in life. Therefore, one of the barriers of the survey is that, although the seroconversions observed may be new cases, they are more likely to occur due to an immune response to a previously undetected virus.

In the same way, they conclude, a person who loses his seropositivity cannot be considered virus-free and is much more likely to be in a latent state undetectable.

Importance of the study

The mechanisms by which these viruses may contribute to the development of prediabetes or type 2 diabetes remain to be discovered. According to the authors, both herpes type 2 and cytomegalovirus cause chronic infections that can modulate the immune system, either stimulating or suppressing its activity — which, in turn, can influence the function of the endocrine (hormonal) system.

Ultimately, the authors conclude that more research is needed to understand the relationship between herpes and diabetes. However, the result is important for evaluating public health viral prevention strategies, possibly including the development of effective herpes vaccines.