There were differences ( p < @ ) between the group fasted for @ compared with @ hours in mean concentrations of free fatty acids ( @ ( SD @ ) vs. @ ( SD @ ) mmol/L ) , - hydroxybutyrate ( @ ( SD @ ) vs. @ ( SD @ ) mmol/L ) , triglycerides ( @ ( min @ , max @ ) vs. @ ( min @ , max @ ) mmol/L ) and urea ( @ ( SD @ ) vs. @ ( SD @ ) mmol/L ) .