 Clinical pharmacology trials investigating insulin detemir in subjects with type 1 diabetes have shown a prolonged and reproducible action profile of insulin detemir compared with NPH insulin and insulin glargine. Duration of action of insulin detemir has been reported to be up to 24 hours.9,10,11 It has, however, been proposed that the mean duration of action is underestimated in glucose clamps lasting only 24 hours. This is so because a duration of action longer than 24 hours in individual clamps will be set to 24 hours in the mean calculation, whereas a shorter duration of action in individual clamps will be set to the true value. 