Burden of infection and fat mass in healthy middle-aged men

Objective: Our aim was to study the effect of exposure to four infections on fat mass. Research Methods and Procedures: This was a cross‐sectional study of healthy middle‐aged men from the general population (n = 74). Each study subject's serum was tested for specific IgG class antibodies against herpes simplex virus (HSV)‐1, HSV‐2, enteroviruses, and Chlamydia pneumoniae through the use of quantitative in vitro enzyme‐linked immunosorbent assays (ELISAs). A total pathogen burden score based on these seropositivities [Quantitative Seropositivity Index (QSI)] was constructed. Fat mass was measured by bioelectrical impedance. Results: We observed significant relationships between the HSV‐1 titer and fat mass and percentage fat mass. The associations were stronger when considering the infection burden. The QSI was significantly associated with fat mass (r = 0.30, p = 0.009) and percentage fat mass (r = 0.27, p = 0.01). Those subjects in the highest tertile of fat mass showed significantly higher QSI (259.5 ± 74.1 vs. 206.9 ± 78.2, p = 0.007). In subjects that were seropositive for Enteroviruses, the relationship between the QSI and fat mass was strengthened (r = 0.51, p = 0.02). In a multivariate regression analysis, the QSI, independently of age and C‐reactive protein, contributed to 9% of fat mass variance. Discussion: Pathogen burden showed an association with fat mass. Subjects with increased fat mass could be more susceptible to developing multiple infections resulting in a chronic low‐grade inflammation. We can not exclude the possibility that exposure to multiple infections leads to increased fat mass.