Francesca Ghilotti1,2, Rino Bellocco2,3, Weimin Ye3, Hans-Olov Adami3,4, Ylva Trolle Lagerros1,5. 1. Department of Medicine, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden. 2. Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Milan, Italy. 3. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. 4. Clinical Effectiveness Research Group, Institute of Health and Society, University of Oslo, Oslo, Norway. 5. Obesity Center, Academic Specialist Center, Stockholm Health Services, Stockholm, Sweden.
Abstract
BACKGROUND: Previous studies have shown an association between body mass index (BMI) and infections, but the literature on type-specific community acquired infections is still limited. METHODS: We included 39 163 Swedish adults who completed a questionnaire in September 1997 and were followed through record-linkages until December 2016. Information on BMI was self-reported and infections were identified from the Swedish National Patient Register using International Classification of Diseases (ICD), Tenth Revision (ICD-10) codes. We fitted multivariable Cox proportional hazards models for time-to-first-event analysis, and we used extensions of the standard Cox model when repeated events were included. RESULTS: During a 19-year follow-up 32% of the subjects had at least one infection requiring health care contact, leading to a total of 27 675 events. We found an increased incidence of any infection in obese women [hazard ratio (HR) = 1.22; 95% confidence interval (CI) = 1.12; 1.33] and obese men (HR = 1.25; 95% CI = 1.09; 1.43) compared with normal weight subjects. For specific infections, higher incidences were observed for skin infections in both genders (HR = 1.76; 95% CI = 1.47; 2.12 for obese females and HR = 1.74; 95% CI = 1.33; 2.28 for obese males) and gastrointestinal tract infections (HR = 1.44; 95% CI = 1.19; 1.75), urinary tract infections (HR = 1.30; 95% CI = 1.08; 1.55) and sepsis (HR = 2.09; 95% CI = 1.46; 2.99) in obese females. When accounting for repeated events, estimates similar to the aforementioned ones were found. CONCLUSIONS: Obesity was associated with an increased risk of infections in both genders. Results from multiple-failure survival analysis were consistent with those from classic Cox models.
BACKGROUND: Previous studies have shown an association between body mass index (BMI) and infections, but the literature on type-specific community acquired infections is still limited. METHODS: We included 39 163 Swedish adults who completed a questionnaire in September 1997 and were followed through record-linkages until December 2016. Information on BMI was self-reported and infections were identified from the Swedish National Patient Register using International Classification of Diseases (ICD), Tenth Revision (ICD-10) codes. We fitted multivariable Cox proportional hazards models for time-to-first-event analysis, and we used extensions of the standard Cox model when repeated events were included. RESULTS: During a 19-year follow-up 32% of the subjects had at least one infection requiring health care contact, leading to a total of 27 675 events. We found an increased incidence of any infection in obesewomen [hazard ratio (HR) = 1.22; 95% confidence interval (CI) = 1.12; 1.33] and obesemen (HR = 1.25; 95% CI = 1.09; 1.43) compared with normal weight subjects. For specific infections, higher incidences were observed for skin infections in both genders (HR = 1.76; 95% CI = 1.47; 2.12 for obese females and HR = 1.74; 95% CI = 1.33; 2.28 for obese males) and gastrointestinal tract infections (HR = 1.44; 95% CI = 1.19; 1.75), urinary tract infections (HR = 1.30; 95% CI = 1.08; 1.55) and sepsis (HR = 2.09; 95% CI = 1.46; 2.99) in obese females. When accounting for repeated events, estimates similar to the aforementioned ones were found. CONCLUSIONS: Obesity was associated with an increased risk of infections in both genders. Results from multiple-failure survival analysis were consistent with those from classic Cox models.
Authors: April Rees; Oliver Richards; Megan Chambers; Benjamin J Jenkins; James G Cronin; Catherine A Thornton Journal: Clin Exp Immunol Date: 2022-06-11 Impact factor: 5.732