Angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism and circulating ACE levels are not associated with outcome in critically ill septic patients

BACKGROUND: In critically ill patients independent studies have shown contradictory findings regarding the prognostic significance of the D/D genotype of the I/D angiotensin converting enzyme (ACE) polymorphism. The study aim was to evaluate the effect of both ACE I/D polymorphism and ACE serum levels on the clinical outcomes of critically ill septic patients. METHODS: This study recruited 186 Caucasian patients with sepsis, severe sepsis or septic shock. Epidemiological, clinical data, co-morbidities and severity scores were recorded. Measurements of serum ACE activity and genotyping for ACE I/D polymorphism were carried out. Primary outcomes were the 28- and the 90-day mortality; secondary outcomes included the number of days without renal or cardiovascular failure and ventilation-free days over the 28-day period following study enrolment. RESULTS: Neither 28- nor 90-day mortality were associated with ACE I/D polymorphism (p=0.59 and 0.34, respectively) or circulating ACE levels (p=0.17 and 0.25, respectively). Similarly, ACE polymorphism and levels were not related to ventilation-free days (p=0.14 and 0.25, respectively), days without cardiovascular failure (p=0.14 and 0.81, respectively) and days without renal failure (p=0.64 and 0.27, respectively). CONCLUSIONS: Neither ACE I/D polymorphism nor serum ACE levels seem to be significant prognostic factors of clinical outcomes in septic, critically ill patients.