Intraperitoneal insulin delivery decreases the levels of chylomicron remnants in patients with IDDM.
OBJECTIVE
To investigate whether intraperitoneal insulin (IPII) decreases the levels of circulating chylomicron remnants in patients with insulin-dependent diabetes mellitus (IDDM).


METHODS
Eight nonobese, normolipidemic IDDM patients were studied twice: before (while on subcutaneous insulin) and 6 months after initiation of IPII by a programmable implanted medication system. Fasting and mean blood glucose, HbA1, and lipid values were determined. Blood samples were also drawn before and every 2 h for 10 h after ingestion of a fat meal (corn oil + Vitamin A). Triglycerides (TGs), apolipoprotein B (apoB), and retinyl esters were determined over time in two TG-rich lipoprotein subfractions (Sf > 100 and Sf20-100) isolated from plasma by density-gradient ultracentrifugation.


RESULTS
IPII slightly decreased the mean blood glucose from 7.8 +/- 1.1 to 7.4 +/- 1.1 mmol/l (mean +/- SD, P = 0.027, paired Student's t test) and the HbA1 from 9.4 +/- 1.5 to 8.7 +/- 1.2 (NS). TG and apoB levels in postprandial Sf > 100 and Sf20-100 were not changed by IPII. On IPII, however, retinyl ester levels in Sf > 100 decreased (P = 0.05, analysis of variance [ANOVA]) and tended to be lower in Sf20-100 (P = 0.075). In addition, following IPII, the retinyl ester:apoB ratio was lower in Sf > 100 (P = 0.0002) and marginally lower (P = 0.06) in Sf 20-100.


CONCLUSIONS
IPII decreased chylomicron remnant levels, which might decrease the atherosclerotic risk in IDDM. Since glycemic control was only slightly improved, the effect was most likely due to the intraperitoneal route of delivery.
Georgopoulos
A
A
Department of Medicine, University of Minnesota, Minneapolis.
Saudek
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CD
D000328:Adult; D001055:Apolipoproteins B / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D002784:Cholesterol / Q000097:blood; D002914:Chylomicrons / Q000097:blood*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy*; D004041:Dietary Fats / Q000008:administration & dosage; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D015918:Infusion Pumps, Implantable; D007263:Infusions, Parenteral; D007328:Insulin / Q000008:administration & dosage*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D014280:Triglycerides / Q000097:blood; D014801:Vitamin A / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood
D001055:Apolipoproteins B; D001786:Blood Glucose; D002784:Cholesterol; D002914:Chylomicrons; D004041:Dietary Fats; D006442:Glycated Hemoglobin; D007328:Insulin; D008074:Lipoproteins; D014280:Triglycerides; D014801:Vitamin A