According to a new study from the University of Gothenburg, men who have a history of obesity in adolescence may be at a higher risk for a blood clot later in life. The risk of the blood clot (thrombus) in a leg or lungs rises successively and is shown to be highest in those who were severely obese in their late teens.
The study published in the Journal of Internal Medicine is based on data for 1,639,838 men who were enlisted for military service in Sweden between 1969 and 2005. Participants had an average age of 18 years and were followed up using patient and cause-of-death registers.
Researchers found that during the 28 year follow-up period, a blood clot in the leg or lung was registered in just over one percent of the study participants. A clear link was found between thrombus risk and body mass index (BMI) at the time of enlistment.
Results showed a successive rise in the risk of venous thromboembolism (VTE) in the group in the middle and the upper part of the normal BMI range (20-25) compared with the lower part of the normal range (18.5-20). The risk continued to rise in the two higher BMI groups—those with obesity and severe obesity.
In participants with obesity (BMI 30-35), the risk was 2.93—over twice as high compared to the reference group in the study. For those with severe obesity, the risk was 4.95, which accounted for a nearly fivefold risk of blood clots in the leg or lung.
Katarina Glise Sandblad, the first author of the study, said: “Up to now, the association between VTE and obesity has been studied mainly in populations where BMI is measured relatively late in life. By then, the study participants may have developed obesity-related diseases, such as certain forms of cancer, that also affect their thrombus risk. Consequently, there’s a danger of underestimating the risk from obesity. As obesity and severe obesity become more prevalent among children and adolescents, it’s increasingly important to study the long-term risks involved.”
A venous thromboembolism (VTE) is one of the most common cardiovascular diseases with a risk that increases with age. Previous studies have shown five-to-ten percent of the population are affected at some time during their lives.
This current study may have only analyzed data from men, but researchers believe that the patterns and associations found are probably similar for women. The research team has previously conducted similar studies of connections between obesity and outcomes other than VTE such as heart attack, stroke, heart failure, and cardiomyopathy where they found similar patterns in both men and women.