Effect of insulin catheter wear-time on subcutaneous adipose tissue blood flow and insulin absorption in humans.
BACKGROUND
Insertion of an insulin catheter for continuous subcutaneous insulin infusion into the subcutaneous adipose tissue (SAT) causes a tissue trauma that may have consequences for insulin absorption. We evaluated the importance of insulin catheter wear-time on subcutaneous adipose tissue blood flow (ATBF) and absorption of the rapid-acting insulin analog insulin aspart over a period of 4 days.


METHODS
Teflon insulin catheters (Medtronic, Minneapolis, MN) were inserted into the abdominal SAT of 10 healthy men without diabetes (mean +/- SEM age, 23.0 +/- 1.1 years; body mass index, 22.1 +/- 0.7 kg/m(2)) and connected to an insulin pump delivering a constant rate of isotonic saline for 4 days. Subjects participated in four study days (days 0, 1, 2, and 4) during which ATBF around the catheter tip was measured by (133)Xe clearance and absorption of an insulin aspart bolus (0.1 U/kg) was measured for 4 h.


RESULTS
ATBF increased from day 0 to day 2 after catheter insertion (2.6 +/- 0.6 to 4.5 +/- 0.8 mL/100 g/min; P = 0.030). By day 4, ATBF had returned to day 0 level. Time to peak plasma insulin aspart concentration after bolus administration decreased with catheter wear-time from 55 +/- 3 min on day 0 to 45 +/- 4 min on day 4 (P = 0.019). Neither peak plasma concentration nor area under the curve of insulin aspart changed significantly.


CONCLUSIONS
Insertion of a Teflon insulin catheter into the SAT results in increased ATBF and faster absorption of insulin aspart in a period of 4 days without any change in the total amount of insulin aspart absorbed.
Clausen
Trine Schnedler
TS
Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
Kaastrup
Peter
P
Stallknecht
Bente
B
D000042:Absorption; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002408:Catheters, Indwelling / Q000009:adverse effects*; D004032:Diet; D006801:Humans; D007004:Hypoglycemic Agents / Q000493:pharmacokinetics*; D015918:Infusion Pumps, Implantable / Q000009:adverse effects*; D007328:Insulin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D061267:Insulin Aspart; D007332:Insulin Infusion Systems / Q000009:adverse effects*; D008297:Male; D012039:Regional Blood Flow; D012885:Skinfold Thickness; D050507:Subcutaneous Fat, Abdominal / Q000098:blood supply* / Q000378:metabolism; D013997:Time Factors; D014980:Xenon Radioisotopes / Q000493:pharmacokinetics; D055815:Young Adult
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D014980:Xenon Radioisotopes; D061267:Insulin Aspart