Postprandial metabolic responses to dietary glycemic index in hypercholesterolemic postmenopausal women

Abstract

Cardiovascular disease is the leading cause of death in postmenopausal women. While diet and lifestyle remain the cornerstones of prevention, a low-fat/high-carbohydrate diet is associated with hyperglycemia and hyperlipemia-atherosclerotic risk factors affected by postprandial conditions. The objective of this study was to examine the acute response of lipids and insulin to a low-fat/high-carbohydrate meal with either a high-glycemic or a low-glycemic index in healthy postmenopausal women. Fifteen healthy postmenopausal women were enrolled in a randomized crossover dietary intervention study. Levels of glucose, triglyceride, free fatty acids (FFAs), and insulin were measured preprandially and for 240 minutes after consumption of the test meals. In response to the high-glycemic compared with the low-glycemic index meal, postprandial insulin levels had a higher peak (65.4 vs 48.1 microU/mL, respectively), the homeostasis model assessment-insulin resistance (HOMA-IR) was significantly higher (P=.014), serum triglyceride levels declined significantly (P<.001), and there was a small reduction in FFA levels, although the difference did not reach statistical significance. The results suggest a postprandial impact of glycemic index on cardiovascular metabolic biomarkers in postmenopausal women and may have implications for dietary glycemic modification of cardiovascular risk in women.

Figure 1

Serum glucose levels (mg/dL) during fasting (t=0) and after consumption of the test meal according to high-glycemic index (◇) (n=15) and low-glycemic index (●) (n=15). Values are expressed as mean ± SEM.

Figure 2

Insulin levels (μU/dL) during fasting (t=0) and after consumption of the test meal according to high-glycemic index (◇) (n=15) and low-glycemic index (●) (n=15). Values are expressed as mean ± SEM.

Figure 3

Homeostasis model assessment-insulin resistance during fasting (t=0) and after consumption of the test meal according to high-glycemic index (◇) (n=15) and low-glycemic index (●) (n=15). Values are expressed as mean ± SEM.

Figure 4

Triglyceride levels (mg/dL) during fasting (t=0) and after consumption of the test meal according to high-glycemic index (◇) (n=15) and low-glycemic index (●) (n=15). Values are expressed as mean ± SEM.