There were also differences in the pharmacokinetic parameters ( @ % confidence interval ) of metformin between these two groups -LSB- area under the concentration-time curve ( AUC ) @ - @ ( @-@ @ ) vs. @ ( @-@ @ ) g h/L ; renal clearance ( CLr ) @ ( @-@ @ ) vs. @ ( @-@ @ ) L/h ; tubular secretion clearance ( CLt ) @ ( @-@ @ ) vs. @ ( @-@ @ ) L/h ; all P < @ -RSB- .