Rotation of the anatomic regions used for insulin injections and day-to-day variability of plasma glucose in type I diabetic subjects
J. P. Bantle, M. S. Weber, S. M. Rao, M. K. Chattopadhyay and R. P. Robertson
Department of Medicine, University of Minnesota School of Medicine, Minneapolis.
Treatment of type I diabetes mellitus is hindered by the often large
fluctuations in blood glucose concentration experienced by affected
individuals. To determine to what extent day-to-day variation in blood
glucose levels can be reduced if insulin is injected in the same anatomic
region rather than in different regions using a rotational scheme, as is
commonly recommended, 12 type I diabetic subjects were studied. Insulin
injections were given in the abdomen for 3 days and rotated among arms,
abdomen, and thighs for 3 days using a crossover design with random
assignment of treatment order. Blood samples for measurement of plasma
glucose levels were obtained at nine scheduled times on each day. Insulin
dose, diet, and physical activity were held constant for each subject.
During the abdominal injection period, the mean SD of plasma glucose levels
and the mean variance of plasma glucose levels were both less at all nine
time points than during the rotating injection period. Overall values for
the SD of plasma glucose levels were 2.7 +/- 0.2 mmol/L for the abdominal
injection period and 3.7 +/- 0.3 mmol/L for the rotating injection period.
Overall values for the variance of plasma glucose levels were 9.2 +/- 1.4
mmol2/L2 for the abdominal injection period and 17.4 +/- 2.2 mmol2/L2 for
the rotating injection period. We conclude that the common clinical
practice of rotating the anatomic regions used for insulin injections
increases day-to-day variation in blood glucose concentration. Use of a
single anatomic region, eg, the abdomen, for all insulin injections may
reduce this variation and allow greater precision in the adjustment of
insulin doses.
