Effect of insulin resistance on postprandial elevations of remnant lipoprotein concentrations in postmenopausal women.
BACKGROUND
Questions remain as to why postmenopausal women are at a higher risk of coronary artery disease (CAD) than are premenopausal women. Studies have shown that plasma concentrations of remnant lipoproteins (RLPs) are elevated in patients with CAD and that increases in plasma RLP concentrations may be related to variations in insulin-mediated glucose disposal.


OBJECTIVE
We sought to evaluate the possibility that postprandial accumulation of plasma RLPs will be accentuated in insulin-resistant, postmenopausal women.


METHODS
Postmenopausal women were divided into insulin-sensitive (n = 15) and insulin-resistant (n = 15) groups according to their steady state plasma glucose concentrations in response to a 180-min infusion of octreotide, insulin, and glucose. Plasma insulin, triacylglycerol, and RLP-cholesterol concentrations were measured either hourly (insulin) or every 2 h (triacylglycerol and RLP cholesterol) for 8 h, before and after breakfast (0800) and lunch (1200).


RESULTS
By selection, insulin-resistant women had higher steady state plasma glucose concentrations than did insulin-sensitive women (10.8 +/- 0.5 compared with 4.1 +/- 5 mmol/L, respectively; P < 0.001), associated with higher fasting triacylglycerol (1.58 +/- 0.04 compared with 1.00 +/- 0.03 mmol/L; P = 0.01) and lower HDL-cholesterol (1.06 +/- 0.08 compared with 1.34 +/- 0.05; P = 0.01) concentrations. In addition, measurements of daylong concentrations of insulin, triacylglycerol, and RLP cholesterol were also significantly greater in insulin-resistant than in insulin-sensitive women (P < 0.001).


CONCLUSIONS
Postprandial accumulation of RLPs is accentuated in insulin-resistant, postmenopausal women. This may contribute to the increased risk of CAD in these individuals.
Kim
H S
HS
Department of Medicine, Stanford University School of Medicine, California 94305, USA.
Abbasi
F
F
Lamendola
C
C
McLaughlin
T
T
Reaven
G M
GM
D001786:Blood Glucose / Q000032:analysis; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D002914:Chylomicrons / Q000097:blood; D003324:Coronary Artery Disease / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008074:Lipoproteins / Q000097:blood*; D008079:Lipoproteins, VLDL / Q000097:blood; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D019518:Postprandial Period; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D008076:Cholesterol, HDL; D002914:Chylomicrons; D007328:Insulin; D008074:Lipoproteins; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D002784:Cholesterol