Table 3. The number of cases and the incidence of hyperlactacidemia of three genotyps in groups treated with or without metformin.

	Metformin (n =200)			Non-metformin (n =200)
	GG	GT	TT	GG	GT	TT
	n (%)	n (%)	n (%)	n (%)	n (%)	n (%)
hLA	11 (6.9%)	3 (8.6%)	2 (40%beh)	9 (6.0%)	2 (4.3%)	0 (0%)
nLA	149 (93.1%)	32 (91.4%)	3 (60%)	139 (94.0%)	44 (95.7%)	6 (100%)

hLA: hyperlactacidemia, nLA: nomal lactate concentration. The lactate level higher than 1.96 mmol/L was defined as hyperlactacidemia. Fisher's exact test, ^bP=0.042, ^eP=0.043 compared to GG or GT genotype in non-metformin group; ^hP=0.05, compared with GG genotype in metformin group.