Metformin increases skeletal muscle lactate production in pigs: a microdialysis study

Introduction Lactic acidosis during metformin intoxication is mainly attributed to impaired hepatic lactate clearance [1]. The aim of this present work was to clarify whether metformin at high dose also increases skeletal muscle lactate production. Methods Reverse microdialysis was used in six healthy, sedated and mechanically ventilated pigs, equipped with two skeletal muscle catheters (CMA Microdialysis AB, Sweden). Following a baseline recording, a continuous infusion of saline (control) or metformin diluted in saline (1 mol/l) began. Outfl ow lactate concentration was measured every 3 hours, up to 12 hours. Results Data are presented as the mean and standard deviation in Figure 1. The interaction between infusion (saline vs. metformin) and time was statistically signifi cant (P = 0.02; two-way repeated-measures ANOVA). Conclusions In skeletal muscle, a high dose of metformin increases interstitial lactate levels, a fi nding consistent with local lactate overproduction. Reference 1. Lalau JD: Drug Saf 2010, 33:727-740.