A MUFA-rich diet improves posprandial glucose, lipid and GLP-1 responses in insulin-resistant subjects.
OBJECTIVE
To study the effects of three weight-maintenance diets with different macronutrient composition on carbohydrate, lipid metabolism, insulin and incretin levels in insulin-resistant subjects.


METHODS
A prospective study was performed in eleven (7 W, 4 M) offspring of obese and type 2 diabetes patients. Subjects had a BMI > 25 Kg/m2, waist circumference (men/women) > 102/88, HBA1c < 6.5% and were regarded as insulin-resistant after an OGTT (Matsuda ISIm <4). They were randomly divided into three groups and underwent three dietary periods each of 28 days in a crossover design: a) diet high in saturated fat (SAT), b) diet rich in monounsaturated fat (MUFA; Mediterranean diet) and c) diet rich in carbohydrate (CHO).


RESULTS
Body weight and resting energy expenditure did not changed during the three dietary periods. Fasting serum glucose concentrations fell during MUFA-rich and CHO-rich diets compared with high-SAT diets (5.02 +/- 0.1, 5.03 +/- 0.1, 5.50 +/- 0.2 mmol/L, respectively. Anova < 0.05). The MUFA-rich diet improved insulin sensitivity, as indicated by lower homeostasis model analysis-insulin resistance (HOMA-ir), compared with CHO-rich and high-SAT diets (2.32 +/- 0.3, 2.52 +/- 0.4, 2.72 +/- 0.4, respectively, Anova < 0.01). After a MUFA-rich and high-SAT breakfasts (443 kcal) the postprandial integrated area under curve (AUC) of glucose and insulin were lowered compared with isocaloric CHO-rich breakfast (7.8 +/- 1.3, 5.84 +/- 1.2, 11.9 +/- 2.7 mmol . 180 min/L, Anova < 0.05; and 1004 +/- 147, 1253 +/- 140, 2667 +/- 329 pmol . 180 min/L, Anova <0.01, respectively); while the integrated glucagon-like peptide-1 response increased with MUFA and SAT breakfasts compared with isocaloric CHO-rich meals (4.22 +/- 0.7, 4.34 +/- 1.1, 1.85 +/- 1.1, respectively, Anova < 0.05). Fasting and postprandial HDL cholesterol concentrations rose with MUFA-rich diets, and the AUCs of triacylglycerol fell with the CHO-rich diet. Similarly fasting proinsulin (PI) concentration fell, while stimulated ratio PI/I was not changed by MUFA-rich diet.


CONCLUSIONS
Weight maintenance with a MUFA-rich diet improves HOMA-ir and fasting proinsulin levels in insulin-resistant subjects. Ingestion of a virgin olive oil-based breakfast decreased postprandial glucose and insulin concentrations, and increased HDL-C and GLP-1 concentrations as compared with CHO-rich diet.
Paniagua
Juan A
JA
Lipids and Atherosclerosis Research Unit, University Hospital Reina Sofía, Córdoba, Spain. japaniaguag@yahoo.es
de la Sacristana
Angel Gallego
AG
Sánchez
Esther
E
Romero
Inmaculada
I
Vidal-Puig
Antonio
A
Berral
Francisco J
FJ
Escribano
Antonio
A
Moyano
Maria José
MJ
Peréz-Martinez
Pablo
P
López-Miranda
José
J
Pérez-Jiménez
Francisco
F
D000704:Analysis of Variance; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism*; D002153:Calorimetry, Indirect; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005227:Fatty Acids / Q000032:analysis / Q000097:blood; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D005951:Glucose Tolerance Test; D006801:Humans; D054795:Incretins / Q000097:blood; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism; D019518:Postprandial Period; D011446:Prospective Studies
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D054795:Incretins; D007328:Insulin; D008055:Lipids; D052216:Glucagon-Like Peptide 1