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

Introduction

Several studies of critically ill patients have suggested an association of the D/D genotype of the insertion/deletion (I/D) angiotensin-converting enzyme (ACE) polymorphism with poor outcome probably by enhancing the inflammatory response and leading to a procoagulant state. Our aim was to evaluate the effect of both the ACE I/D polymorphism and its gene product, on the clinical outcome of critically ill septic patients.

Methods

The study cohort included 186 consecutive Caucasian patients with sepsis, severe sepsis or septic shock. Epidemiological, clinical data and co-morbidities along with severity scores were recorded. Measurements of serum ACE activity and genotyping for ACE I/D polymorphism were carried out in all patients. The primary outcomes were the 28-day and 90-day mortalities; secondary outcomes included the number of days without renal or cardiovascular failure, and ventilation-free days over the 28-day period following the study enrollment. One hundred and eighty healthy blood donors were genotyped and used as controls.

Results

The genotype distribution in the patients' group was comparable with that observed in controls (P = 0.45). ACE I/D polymorphism and circulating ACE levels were not associated with mortality (P > 0.05) or with secondary outcomes including ventilation-free days and days without cardiovascular or renal failure among septic critically ill patients (P > 0.05). See Figure 1.

Figure 1

Kaplan-Meier curves of survival up to 28 days for the three ACE gene polymorphisms.

Conclusions

Neither the ACE I/D polymorphism nor the serum ACE levels seem to be significant prognostic factors of the outcome of sepsis in critically ill patients.