Does metformin exposure before ICU stay have any impact on patients’ outcome? A retrospective cohort study of diabetic patients

Abstract

BackgroundImpact of metformin exposure before ICU stay remains controversial. Metformin is thought to induce lactic acidosis and haemodynamic instability but may reduce ICU mortality. We evaluated its influence on outcome in diabetic patients admitted in the ICU and then compared two different populations based on the presence of septic shock.MethodsWe conducted a retrospective cohort study in a 24-bed French ICU between October 2010 and December 2013, including all ICU-admitted diabetic patients.ResultsAmong 635 diabetic patients admitted during the study period, 131 (21%) were admitted with septic shock. Multivariate analysis showed no difference in hospital mortality in all metformin users (OR 0.75 [95% CI 0.44–1.28]; p = 0.29), except in the septic shock subgroup (OR 0.61; 95% CI [0.37–0.99]; p = 0.04) despite higher vasopressor dosages in the first hours after shock onset. Blood lactate level was higher in metformin users than in non-metformin users in all patients (p < 0.001), in septic shock patients (p < 0.001) and in patients without kidney injury (p < 0.001). Metformin users did not have more septic shock from unknown aetiology (p = 0.65) or unknown pathogen (p = 0.99).ConclusionsMetformin use before admission to ICU did not affect in-hospital mortality. However, for patients with septic shock, mortality was lower, despite worse clinical presentation on admission. Blood lactate levels were always higher with or without septic shock and indifferent of kidney function.Electronic supplementary materialThe online version of this article (10.1186/s13613-017-0336-8) contains supplementary material, which is available to authorized users.

Prognostic impact of elevated lactate levels on mortality in critically ill patients with and without preadmission metformin treatment: a Danish registry-based cohort study

“…Codes used for each variable are stated in Additional file 1: Appendix S1 b Relative excess risk due to interaction (RERI) quantifies interaction on an additive scale, which approaches zero in the absence of interaction use was not assessed. Consistent with our results, others report that the optimal lactate level on the receiver operating characteristics curve was higher in critically ill metformin users than nonusers [14]. In a single-centre study including 1947 patients with suspected sepsis at the emergency department, metformin use also modified the association of lactate with outcome [16].…”

“…Respiratory, incl. pneumonia 5244 (14) 2223 (15) 1251 (14) 972 (14) 498 (13) 248 (10) also increased in patients admitted with higher lactate levels, whereas this trend was not observed for insulin, sulfonylureas, or other glucose-lowering drugs. Patients admitted with high lactate levels more often had a history of mild-to-severe liver disease.…”

“…Given its mechanism of action, metformin may contribute to plasma lactate elevation without the patient being more severely ill than individuals with similar lactate levels [13]. Compared to critically ill patients not using metformin, some studies reported that metformin users have higher lactate levels at admission without a concomitant increase in mortality [14][15][16][17], although others could not corroborate these findings [18][19][20][21][22]. To determine whether the association between early lactate level and mortality during critical illness is different in metformin users compared with metformin nonusers, we studied a large cohort of patients admitted to intensive care units (ICU) in northern Denmark.…”

Association of Preadmission Metformin Exposure and Outcomes in Acute Kidney Injury Patients with Type 2 Diabetes in Intensive Care Unit: a Cohort Study

“…Second, as the study population contains only AKI patients with type 2 diabetes, it may not be generalizable to AKI patients with type 1 diabetes. Third, we were unable to exclude patients with myocardial infarction during the previous month, who were contraindicated to metformin [18]. We exclude patients admitted to CCU for instead.…”

“…Multivariable logistic regression analyses were performed to assess the independent association after adjusted metformin prescription after hospital admission and adjusted for propensity score. Additionally, A previous study excludes patients with myocardial infarction during the previous month, who were contraindicated to metformin [18]. We exclude patients admitted to CCU for sensitivity analyses.…”