Association between visceral fat and influenza infection in Japanese adults: A population-based cross-sectional study

Background Several studies have reported that obesity is associated with influenza infection; however, the role of visceral fat remains unclear. The aim of this study was to investigate the association between visceral fat and influenza infection in community-dwelling Japanese adults. Methods A cross-sectional study was performed using data from an annual community-based health check-up conducted from May to June in 2019. In total, 1,040 Japanese adults aged 20-89 years were enrolled in this study. Influenza infection status was determined by participants' responses to a self-administered questionnaire. The visceral fat area (VFA) was measured using a bioimpedance-type visceral fat meter. Participants were classified into four groups using the following cut-off points: VFA < 100 cm(2) was set as the reference category according to the Japanese criteria, 100 <= VFA < 150 cm(2), 150 <= VFA < 200 cm(2), and 200 cm(2) <= VFA. Logistic regression models were used to assess the association between VFA and influenza infection. Results In total, 119 participants had influenza infections in the past year. In the multivariate adjusted model, a higher VFA was significantly associated with increased influenza infection; the adjusted odds ratio for 200 cm(2) <= VFA was 5.03 [95% confidence interval (CI): 1.07-23.6], that for 150 <= VFA < 200 cm(2) was 1.97 (95% CI: 0.71-5.45), and that for 100 <= VFA < 150 cm(2) was 1.62 (95% CI: 0.84-3.12), compared with that for VFA < 100 cm(2) (p for trend = 0.049). These findings were confirmed in the same cohort the following year. Conclusions Our results suggest that visceral fat accumulation is associated with influenza infection. Large-scale prospective studies using diagnostic information for influenza infection are required to confirm this association.

Automated summary

This study investigates the association between visceral fat and influenza infection in Japanese adults. The results suggest that higher visceral fat accumulation is associated with increased influenza infection risk.