Safety of metformin in diabetic patients at high altitude area

Abstract

Sixty-one newly-diagnosed diabetic patients from high altitude area were treated individually plus metformin 1.5 g/d for 14 days. The difference of oxygen partial pressure was 3.5 mm Hg (1 mm Hg=0. 133kPa) between altitude 2 260 m and 2 780 m districts. In these patients, their serum lactic acid was increased before treatment. At altitude 2 780 m district, serum lactic acid in middle-aged and elder groups were even higher [(3.90±0.85 vs 3.65±0.70), (4. 67±0.80 vs 3.69±0.78) mmol/L, both P＜0. 05＝. After 14-day treatment, serum lactic acid in middle-aged diabetic patients remained statistically unchanged [(4.50±0.50 and 3.79±0.62 ) mmol/L, P＞0.05], while that in elder patients was increased significantly [(5.59±0.55 and 5.27±0.43 ) mmol/L,P＜0. 05]. The results suggested that metformin should not be used or be used carefully in elder diabetic patients at high altitude area. Key words: Hypoxia; Diabetes mellitus; Blood lactic acid; Metformin