Obesity and risk of respiratory tract infections: results of an infection-diary based cohort study

BMC Public Health. 2018 Feb 20;18(1):271. doi: 10.1186/s12889-018-5172-8.


Background: Respiratory tract infections (RTIs) are a major morbidity factor contributing largely to health care costs and individual quality of life. The aim of the study was to test whether obesity (BMI ≥ 30 kg/m2) is one of the risk factors underlying frequent RTIs in the German adult population.

Methods: We recruited 1455 individuals between 18 to 70 years from a cross-sectional survey on airway infections in Germany and invited them to self-report in diaries incident RTIs experienced during three consecutive winter/spring seasons. RTIs reported in these 18 months and summary measures adding-up individual RTIs were the outcomes of interest.

Results: Compared to individuals with normal weight, obese individuals reported a consistently higher frequency of upper and lower RTIs and predominantly fell in the upper 10% group of a diary sumscore adding-up 10 different RTI symptoms over time. Obesity was associated both with lower RTIs (adjustedOR = 2.02, 95%CI = 1.36-3.00) and upper RTIs (adjustedOR = 1.55, 95%CI = 1.22-1.96). Adjusting for demographic and lifestyle variables did only marginally affect ORs. Stratified analyses suggested a stronger association for women and effect modifications by sports activity and dietary habits.

Conclusions: We confirm the association of obesity with infection burden and present evidence for putative interaction with sports activity and dietary patterns.

Keywords: Adult respiratory tract infections; Diary; Effect modification; Life style factors; Obesity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Cohort Studies
  • Cross-Sectional Studies
  • Female
  • Germany / epidemiology
  • Humans
  • Male
  • Middle Aged
  • Obesity / epidemiology*
  • Respiratory Tract Infections / epidemiology*
  • Risk Factors
  • Seasons
  • Self Report
  • Young Adult