Unchanged insulin absorption after 4 days' use of subcutaneous indwelling catheters for insulin injections.
OBJECTIVE
Since 1985, we have used indwelling catheters (Insuflon, Maersk Medical, Lynge, Denmark; Chronimed, Minnetonka, MN) to lessen pain when injecting insulin. However, some patients experience a rise in blood glucose after using indwelling catheters for a few days. We therefore studied the absorption of 125I-labeled insulin when using indwelling catheters.


METHODS
Five men and five women participated (age 18-25 years, C-peptide negative, HbA1c 9.0 +/- 1.0% [mean +/- SD, DCA-2000 method], diabetes duration 5-21 [median 9.5] years). After thyroid blockage with potassium iodide, we injected 5IU of 125I-labeled short-acting insulin subcutaneously in the abdomen ("ordinary injection") and 5 IU on the contralateral side through an indwelling catheter ("catheter injection"). The injection/insertion area was free of lipohyper- and lipohypotrophies. Disappearance rate was measured for 180 min with a gamma camera. The patients injected all premeal injections of short-acting insulin through the same indwelling catheter in the following 4 days. The investigation procedure was repeated day 3 and 5.


RESULTS
We found no statistically or clinically (95% CI) significant difference in residual activity of 125I-insulin after 60 min or in time for 50% of the injected depot to disappear (T-50%) among catheter injections on day 1, 3, and 5; ordinary injections on days 1, 3, and 5; or catheter and ordinary injections on days 1, 3, and 5, respectively. HbA1c correlated both to T-50% (r = 0.73, P = 0.016) and residual activity of 125I-insulin after 60 min (r = 0.69, P = 0.028), indicating that patients with a slower absorption will have a less ideal metabolic control when using premeal bolus injections.


CONCLUSIONS
We conclude that using indwelling subcutaneous catheters for insulin injections for up to 4 days does not affect the absorption of short-acting insulin.
Hanas
S R
SR
Department of Pediatrics, Uddevalla Hospital, Sweden. ragnar.hanas@bll.se
Carlsson
S
S
Frid
A
A
Ludvigsson
J
J
D000042:Absorption; D000293:Adolescent; D000328:Adult; D002096:C-Peptide / Q000097:blood; D002408:Catheters, Indwelling; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007279:Injections, Subcutaneous / Q000295:instrumentation / Q000379:methods*; D007328:Insulin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D061389:Insulin, Regular, Pork; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male
D002096:C-Peptide; D006442:Glycated Hemoglobin; D007328:Insulin; D061389:Insulin, Regular, Pork; D007457:Iodine Radioisotopes; C000006:insulin, neutral