There were no major differences in demographics and clinical characteristics of the patients by ACE genotype (Table 1
). Based on microbiological data, the patients were categorized as pneumococcal pneumonia, atypical pneumonia, pneumonia with Gram negative strain, viral pneumonia, or etiology unknown. In total, etiology was available for 127 patients (64%). Etiology was not different for the three ACE genotype groups (Table 1). The overall median duration of hospital stay was 9.5 days, and 21 patients were admitted to the intensive care ward (Table 2
). During hospital stay, 10 patients died, all due to pneumonia. The overall 28-day mortality rate was 5.0% and was not statistically different between the three ACE genotypes (7.1%, 3.8%, and 5.8% for II, ID, and DD, respectively; p = 0.668). The mean highest APS score during hospital stay was 23.9 and was not statistically different between the genotype groups. There was no trend toward an association between ACE genotype and risk of ARDS. Figure 1
shows the mean APS scores during the episode of pneumonia by ACE genotype. Using one-way analysis of variance, the scores were not statistically different on any of the days (p = 0.350). None of the patients in the low PSI risk classes (risk class I–II) died during hospital stay. For the patients with a moderate (risk class IV) or high risk (risk class V), the in-hospital mortality rates were 5.4% and 22.2%, respectively. In univariate analysis, the risk class at admission was significantly associated with in-hospital mortality (p < 0.01). In the multivariate analyses, no associations between ACE I/D polymorphism and need for ICU admittance, in-hospital mortality, nor 28-day mortality could be detected as ACE genotype did not reach significance in any of the models. When ACE genotype (DD vs II+ID) was added to the final model afterwards, this yielded odds ratios of 0.81 (95% confidence interval [CI], 0.15 to 4.29), 1.53 (95% CI, 0.34 to 6.86), and 0.47 (95% CI, 0.12 to 1.77) for in-hospital mortality, 28-day mortality, and ICU admittance, respectively. Exclusion of patients using ACE inhibitors or angiotensin-II receptor blockers from the analyses did not cause a change in the findings (data not shown).