METHODS	Nine healthy male volunteers were studied in random order using three experimental conditions : ( a ) euglycaemic clamp [ glucose 5 mmol L ( -1 ) ] ; ( b ) hyperglycaemic clamp [ glucose 15 mmol L ( -1 ) ] ; and ( c ) euglycaemic hyperinsulinaemic clamp [ glucose 5 mmol L ( - l ) ] .\