On oscillations of blood-sugar values within brief periods, and the blood-sugar curve on uniform ingestion of glucose

IN late years a number of investigations on the blood-sugar have demon- strated not only that the daily fasting blood-sugar has no constant value, but also that, if instead of one single determination being made, the fasting blood-sugar is determined repeatedly through a certain period-with blood withdrawn at intervals of i to i hour-the blood-sugar curve obtained will show wide and long, more or less regular waves, which are supposed to be due to "sugar waves" issuing from the liver.Undoubtedly these waves are one of the reasons why the fasting blood-sugar value is found to change from day to day.In addition to these rather regular curve waves Hansen [1923] has reported other oscillations in the blood-sugar, which were found on determining the blood-sugar at very frequent intervals for some time.Hansen found these oscillations, as distinct from the regular curve waves, (1) in normal individuals during fasting;(2) in diabetics during fasting, apart from the well-known steady fall in blood-sugar which is usually associated with fasting in hyperglycaemia;(3) aftet ingestion of carbohydrate, as 'the rise in blood-sugar does not proceed in a smooth curve but in connection with oscillations of the main grade.These oscillations are particularly brisk and relatively large when the blood-sugar level is fairly settled, that is, at the top of a rise which forms a plateau before the fall sets in, or at an unchanged high level.Later similar results after ingestion of glucose have been reported by Klein [1925].Gilbert, Schneider and Bock [1926] found similar results, but the blood was withdrawn only at intervals of 10-20 minutes.Hansen thinks that these oscillations "represent the manner in which the blood-sugar regulation takes place."Various observations in other work of mine have necessitated a further investigation into the occurrence of these oscillations.In particular, it was important to ascertain whether they really occur as a fairly constant phenomenon, which would seem most likely if they were a part of the intermediate sugar metabolism, or whether their appearance to some extent might be due to external factors resulting more or less from the experimental conditions under which the patients were examined.To get