ISSN:
1432-0428
Keywords:
Type 1 (insulin-dependent) diabetes mellitus
;
HDL cholesterol
;
apolipoprotein A-I
;
apolipoprotein A-II
;
kinetic analyses
;
VLDL triglyceride
;
lipolytic enzymes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Concentrations of HDL cholesterol and apolipoprotein A-I are commonly increased in Type 1 (insul-independent) diabetes mellitus but the mechanisms whereby diabetes influences HDL metabolism have not been studied. We investigated the metabolism of HDL apoproteins A-I and II in normolipidaemic Type 1 diabetic men (n=17, HbA1 6.4–11.9%) without microalbuminuria but with a wide range of HDL cholesterol (0.85–2.10 mmol/l) and in nondiabetic men (n=18) matched for body mass index and the range of HDL cholesterol. Input rates and fractional catabolic rates for apolipoproteins A-I and II were determined following injection of 125I-apolipoprotein A-I and 131I-apolipoprotein A-II tracers. Additional multicompartmental analysis was performed using a model to describe the kinetics of HDL particles containing only apolipoprotein A-I (Lp A-I) and apolipoprotein A-I and apolipoprotein A-II (Lp A-I/ A-II). No gross differences from normal subjects were observed in the mean levels of lipids, lipoproteins, apoproteins and the lipolytic enzymes in the diabetic men as a result of the selection process. Furthermore, the relationship between apolipoprotein A kinetics and plasma HDL cholesterol levels appeared to be preserved in the diabetic group. However, some normal interrelationships were disrupted in the diabetic men. Firstly, the rate of apolipoprotein A-II synthesis was 22% lower than in control subjects (p〈0.05). Modelling indicated that this was due to decreased input of Lp A-I/A-II particles whereas the input of Lp A-I particles was similar in the two groups. Secondly, there was no correlation between VLDL triglyceride and HDL cholesterol or VLDL triglyceride and the fractional catabolic rate of apolipoproteins A-I and A-II in diabetic men in contrast to that seen in control subjects. We conclude that there is a disruption in the normal association between VLDL and HDL metabolism in Type 1 diabetic men and postulate that the observed differences may be due to the therapeutic use of exogenous insulin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00401202
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