The Impact of Metformin Exposure on Lactate Level in Tibetan Type 2 Diabetes Living at High-Altitude Area

Abstract

Objective: To investigate the impact of Metformin exposure on lactate level in Tibetan type 2 diabetics living at high-altitude area. Methods: Our hospital sits 3600 meters above sea level. We retrospectively reviewed the in-patients’ documents since Nov. 2016 to Dec. 2017 in our department. We selected those who did not receive Metformin previously and initiated Metformin treatment during their stay in the hospital with their lactate level assayed. Firstly, we compared the lactate level before and after Metformin treatment. We then did the subgroup analysis according to the participants’ age, baseline lactate level and baseline oxygen saturation degree. Finally, we analyzed the associated factors which may influence the lactate level after Metformin exposure by logistic regression test. Results: There were 132 patients recruited into our study, including 98 male patients. The mean age of all the participants were 52±12 years old. There was no significant difference between the lactate level before and after Metformin exposure (3.15±1.82mmol/L vs. 3.29±1.96mmol/L, t=-0.784, P=0.435). For the subgroup analysis, we found that in the normal lactate level (<2.0mmol/L) and hyperlactatemia group (2.0-3.9mmol/L), there was a significant elevation of the lactate level after the exposure of Metformin. Reversely, a significant decrease of the lactate level was seen in the severe hyperlactatemia group (≥4.0mmol/L) after Metformin exposure. There were 73 patients (55.3%) who had an elevated lactate level after the Metformin treatment. We also found that baseline lactate level (P<0.001, OR =0.019, 95% CI 0.002-0.159) and baseline oxygen saturation (P=0.04, OR =1.092, 95% CI 1.004-1.187) were two associated factors leading to the elevation of the lactate level after Metformin treatment. Conclusion: Metformin treatment does not lead to the elevation of lactate level in Tibetan type 2 diabetics living at high-altitude area. Metformin can be safely used in high-altitude residents. Disclosure Y. Luo: None. Y. Geng: None. Q. Ren: None. L. Zhou: None. X. Lv: None. S. Meng: None. L. Yang: None.