Body mass index at age 50 to 64 and risk of subsequent hospitalisation with pneumonia

Abstract number: O248

Nørgaard M., Dethlefsen C., Kornum J.B., Thomsen R.W., Tjønneland A., Sørensen H.T., Overvad K.

Objectives: The incidence of hospitalised pneumonia in Denmark has increased considerably during the last decade. Little information is available on the impact of body mass on the risk of pneumonia. The aim of this study was thus to examine the association between BMI and risk of hospitalised pneumonia.

Methods: We conducted this large prospective cohort study using data from the Danish cohort "Diet, Cancer and Health" including individuals 50–64 years of age recruited during 1993–97 with detailed information concerning diet and other lifestyle factors and anthropometric measurements. We linked data from the cohort study to the Danish National Patients Registry and retrieved information on all incident hospitalisations with pneumonia before 2006. We excluded individuals with a prior hospitalisation for pneumonia and those with incomplete information on anthropometric measurements or potential confounders (n = 1,102), leaving 55,951 for the analysis. We categorised BMI into five groups (<22.5, 22.5–24.9, 25.0–29.9, 30.0–34.9, 35+) and estimated the cumulative risk of hospitalisation for pneumonia within the first 5-years of observation. We used Cox's regression to compute hazard ratios as measure of relative risk (RR) for hospitalisation for pneumonia (reference: BMI = 22.5–24.9). We adjusted for comorbidity, smoking, and alcohol intake. Since changes in body composition differ in men and women we stratified the analysis according to gender.

Results: A total of 2,664 subjects had a first episode of hospitalised pneumonia during a median follow-up of 8.9 years. The 5-year risks of hospitalisation with pneumonia were 7% for BMI < 22.5, 5% for BMI = 22.5–24.9, 5% for BMI = 25.0–29.9, 6% for BMI = 30.0–34.9, and 7% for BMI = 35+. The association between BMI and adjusted relative hazard of pneumonia (Reference is BMI = 23.8)is shown in fig. 1. Compared with participants with a BMI of 22.5–24.9 the adjusted RRs were for men: 1.5 (95% CI:1.2–1.8) for BMI < 22.5, 1.1 (95% CI:1.0–1.3) for BMI = 25.0–29.9, 1.2 (95% CI:1.0–1.4) for BMI = 30.0–34.9, and 1.8 (95% CI:1.4–2.4) for BMI of 35+. For women the adjusted RRs were 1.3 (95% CI:1.1–1.5) for BMI < 22.5, 0.9 (95% CI:0.8–1.0) for BMI = 25.0–29.9, 0.9 (95% CI:0.7–1.0) for BMI = 30.0–34.9, and 0.9 (95% CI:0.6–1.2) for BMI of 35+.

Conclusion: We found a clearly increased risk of pneumonia among individuals with a BMI below 22.5 and for men also among those with a BMI of more than 35.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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