ABSTRACT
Purpose: Surgical stress is a phenomenon not completely understood from the biochemical point of view, although it produces alterations in the oxidative balance and inflammatory status. The present study aimed to investigate the alterations of the circulating levels of paraoxonase-1 (PON1)-related variables and markers of inflammation in hospitalized patients who underwent surgery. Methods: We recruited 285 hospitalized patients. Of those, 115 were hospitalized due to a surgical intervention and 170 for reasons other than surgery. The control group consisted of 128 healthy volunteers. A blood sample was obtained for the measurement of serum PON1-related variables, and C-reactive protein (CRP), chemokine (C-C motif) ligand 2 (CCL2), and procalcitonin concentrations. Results: Hospitalized patients had lower serum PON1 activities [paraoxonase: 215.6 (168.6 - 277.8) vs. 298.7 (229.7 - 382.6) U/L, p < 0.001; lactonase: 3.0 (2.3 - 3.7) vs. 5.7 (4.6 - 6.5) U/L, p < 0.001], and higher CCL2, CRP and procalcitonin concentrations than the healthy individuals. The days elapsed following surgery and the duration of the procedure itself inversely correlated with PON1-related variables, and directly correlated with CRP concentrations. Patients that were operated on by laparotomy had higher PON1 activity than patients operated on by laparoscopy. Local and regional anesthesia was associated with higher PON1 activities and lower CRP concentrations. Conclusion: These results show a decrease in PON1 activities and an increase in acute phase response in hospitalized patients undergoing surgery and support the hypothesis that these phenomena are related to post-surgical metabolic alterations.