A systematic review of the association between obesity and influenza A related morbidity and mortality

Abstract

Background Globally, epidemics of obesity and influenza are always two major public health issues that require immediate actions for human. After the outbreak of pandemic influenza A (H1N1) in 2009, the relationship between obesity and influenza was widely recognized due to severe illness and reported death with obesity among infected cases. We still doubted whether obesity is a risk factor for influenza infection or not. So I conducted this systemic review to explore the association between obesity and influenza A morbidity or mortality. Method PubMed, Google scholar, and HKU library were searched using a prepared strategy for all items in English up to 31 July 2014. Search strategy, exclusion and inclusion criteria, assessment of quality, as well as data analysis were established for screening all relevant publications. Findings Through careful screening, 17 relevant studies were adopted into this review. There were 9 case control studies of all observational studies. Obesity and morbid obesity in influenza A infected adults (below 60 years old) could be regarded as a risk factor for hospitalization and severe sickness. Morbid obesity would be related with higher risk for mortality and ICU admission. Conclusion From my review, there was a strong association between obesity and influenza A infection had been confirmed. However, we need to carry out further research to explore the details of impacts. Obese people, as the high-risk population, should take vaccine during influenza season to protect themselves effectively.