Metabolic syndrome increases the risk of severe disease from a viral infection, according to a review of the literature performed by a team of researchers from St. Jude Graduate School of Biomedical Sciences and the University of Tennessee Health Science Center, both in Memphis.
The research has been published in the Journal of Virology, a publication of the American Society for Microbiology.
Metabolic syndrome is a cluster of at least 3 co-occurring conditions that raise the risk of heart disease, stroke and type 2 diabetes mellitus (T2DM). These conditions include excess abdominal fat, high blood pressure, excess blood sugar, abnormalities of lipids (including excess triglycerides and cholesterol), insulin resistance and a proinflammatory state.
Multiple studies have shown that obesity is associated with increased severity of influenza A, higher viral titers in exhaled breath and prolonged transmission of the virus, according to the report.
Changes in the viral population may abet the emergence of more pathogenic influenza variants, according to the report. Despite the fact that influenza vaccines generate robust antibody titers in obese subjects, obesity doubles the likelihood of developing influenza.
As with influenza virus, the Centers for Disease Control and Prevention recently recognized obesity as a risk factor for severe illness caused by SARS-CoV-2.
“This is not surprising because excess body weight and fat deposition apply pressure to the diaphragm, which further increases the difficulty of breathing during a viral infection,” the researchers write.