Background: Diets rich in whole-grain cereals and foods with a low
glycemic index may protect against type 2 diabetes, but the underlying
molecular mechanisms are unknown. Objective: The main objective was to test
whether 2 different carbohydrate modifications—a rye-pasta diet characterized
by a low postprandial insulin response and an oat-wheat-potato diet
characterized by a high postprandial insulin response—affect gene expression
in subcutaneous adipose tissue (SAT) in persons with the metabolic syndrome.
Design: We assessed the effect of carbohydrate modification on SAT gene
expression in 47 subjects [24 men and 23 women with a mean (±SD) age of 55 ± 6
y] with the features of the metabolic syndrome in a parallel study design.
The subjects had a mean (±SD) body mass index (kg/m2) of 32.1 ± 3.8 and a 2-h
plasma glucose concentration of 8.0 ± 2.3 mmol/L. Adipose tissue biopsies were
performed, and oral-glucose-tolerance tests and other biochemical
measurements were conducted before and after the intervention. Results: We
detected 71 down-regulated genes in the rye-pasta group, including genes
linked to insulin signaling and apoptosis. In contrast, the 12-wk
oat-wheat-potato diet up-regulated 62 genes related to stress,
cytokine-chemokine–mediated immunity, and the interleukin pathway. The
insulinogenic index improved after the rye-pasta diet (P = 0.004) but not
after the oat-wheat-potato diet. Body weight was unchanged in both groups.
Conclusions: Dietary carbohydrate modification with rye and pasta or oat,
wheat, and potato differentially modulates the gene expression profile in
abdominal subcutaneous adipose tissue, even in the absence of weight loss.
- Gene-nutrient interactions
- metabolic syndrome
- insulin resistance
- adipose tissue
- diet intervention
- insulinemic response