LAUSR

Introduction Recently, Stenotrophomonas maltophilia (SM) has been shown to have an increased prevalence in the sputum of people with CF-related diabetes (CFRD), raising the question as to whether CFRD is a risk factor for its acquisition. We investigated this at a population level by looking at UK CF Registry data. Methods We analysed national UK CF Registry data for 2011–2015, looking at demographics, lung function and sputum microbiology, using descriptive and multivariable strategies to establish independent predictors for SM culture and associated outcomes. 6234 people with CF older than age 12 (mean 26 years, CFRD 26%, SM 15%, 54% male) with more than 3 years complete sputum microbiology and lung function data were included. Results Although on univariate analysis those with SM were more likely to have CFRD (odds ratio [95% CI] 1.18 [1.01–1.39] p<0.0001), lower lung function (mean FEV1 [% predicted] 66.6 vs. 74.15, p<0.001) and more IV days (24 vs. 10, p<0.0001), multivariate logistic regression analysis showed no independent association for CFRD or Hba1c but IV antibiotic use and Aspergillus culture independently demonstrated an increased likelihood of SM growth (see Table 1). Furthermore, longevity of SM growth showed weak but statistically significant correlations with poorer FEV1 (rho −0.2, p<0.0001) and more IV days (rho=0.1, p<0.0001) but no association with CFRD (OR 1.09 [0.98–1.21]) or Hba1c (rho=-0.001, p=0.94). Abstract P248 Table 1 Multivariate analysis of potential predictors of SM growth Variable Odds Ratio (95% CI) Age (years) >18 0.99 (0.98–1.00) NS FEV1 (% predicted) <50<30 1.22 (0.92–1.64)1.28 (0.82–2.01) NSNS IV antibiotics (days/year) 0>0>14 0.41 (0.31–0.52)1.46 (1.05–2.02)1.64 (1.06–2.23) ******** DysglycaemiaCFRDHba1c>48 1.08 (0.80–1.46)0.98 (0.62–1.58) NSNS Microbiology Pseudomonas aeruginosa Aspergillus Burkholderdia Cepacia Complex Staphylococcus aureus 0.69 (0.55–0.87)3.76 (2.93–4.82)0.59 (0.34–1.03) 1.46 (1.18–1.83) *****NS ** NS=not statistically significant *=<0.05 **=<0.01 ***=<0.001 Conclusion Our data suggests CFRD is not an independent risk factor for SM growth in CF. The increased prevalence of SM in CFRD may be explained by increased intravenous antibiotic pressure in this group. Acknowledgement We would like to thank the CF Registry Research Committee for releasing the data used in this analysis.