The lipoprotein profile differs during insulin treatment alone and combination therapy with insulin and sulphonylureas in patients with Type 2 diabetes mellitus.
OBJECTIVE
To study whether changes in endogenous insulin secretion at the same glycaemic control affect the plasma concentrations of lipoproteins in patients with Type 2 diabetes mellitus.


METHODS
Fifteen patients, age 59+/-2 years (mean +/- SEM), body weight 86.3+/-3.0kg, body mass index 29.6+/-0.9 kg/m2 were treated with sulphonylurea and insulin in combination or with insulin alone in a randomized, double-blind, crossover study. All patients were treated with a multiple daily injection regimen with the addition of glibenclamide 10.5 mg daily or placebo tablets.


RESULTS
During combination therapy, the dose of insulin was 25% less (P < 0.002) and there was a 29% increase in plasma C-peptide concentration (P = 0.01). Plasma levels of free insulin were not changed. Plasma levels of sex hormone-binding globulin (SHBG) and insulin-like growth factor-binding protein (IGFBP)-1 were lowered. There were no differences in the 24-h blood glucose profiles or HbA1c (6.0+/-0.2 vs. 6.3+/-0.2%; P = 0.16). Body weight was similar. There was a significant decrease in plasma LDL cholesterol (3.04+/-0.24 vs. 3.41+/-0.21 mmol/l; P = 0.04), apolipoprotein A1 and of lipoprotein(a) but an increase in VLDL-triglycerides (1.36+/-0.31 vs. 0.96+/-0.16 mmol/l; P = 0.02) during combination therapy. The ratio between LDL cholesterol and apolipoprotein B concentrations was significantly lower during combination therapy (P < 0.01).


CONCLUSIONS
Combination therapy with insulin and sulphonylureas increases portal insulin supply and thereby alters liver lipoprotein metabolism when compared with insulin therapy alone.
Lindström
T
T
Faculty of Health Sciences, Linköping University, Sweden. Torbjorn.Lindstrom@end.us.lio.se
Nyström
F H
FH
Olsson
A G
AG
Ottosson
A M
AM
Arnqvist
H J
HJ
D000368:Aged; D002096:C-Peptide / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007328:Insulin / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008074:Lipoproteins / Q000097:blood*; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D013453:Sulfonylurea Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D014280:Triglycerides / Q000097:blood
D002096:C-Peptide; D008078:Cholesterol, LDL; D007328:Insulin; D018970:Insulin-Like Growth Factor Binding Protein 1; D008074:Lipoproteins; D008079:Lipoproteins, VLDL; D012738:Sex Hormone-Binding Globulin; D013453:Sulfonylurea Compounds; D014280:Triglycerides; D007334:Insulin-Like Growth Factor I