Abstract

Objective To search for a better dietary approach to treat postprandial lipid abnormalities and improve glucose control in type 2 diabetic patients.

Research Design and Methods According to a randomized cross-over design, 18 type 2 diabetic patients (age 59±5 years; BMI 27±3 kg/m²)(mean±SD) in satisfactory blood glucose control on diet or diet+metformin, followed a diet relatively rich in CHO (52% total energy), rich in fiber (28g/1000 kcal) and with a low glycemic index (58%)(High CHO-high fiber diet), or a diet relatively low in CHO (45%) and rich in monounsaturated fat (23%) (Low CHO-high MUFA diet) for 4 weeks. Thereafter, they shifted to the other diet for 4 more weeks. At the end of each period, plasma glucose, insulin, lipids and lipoprotein fractions (separated by discontinuous density gradient ultracentrifugation) were determined on blood samples taken at fasting and over 6 hrs after a test meal having a similar composition as the corresponding diet.

Results In addition to a significant decrease in postprandial plasma glucose, insulin responses and glycemic variability, the High CHO-high fiber diet significantly improved also the primary endpoint, as it reduced the postprandial incremental areas (IAUC) of triglyceride-rich lipoproteins, in particular chylomicrons (cholesterol IAUC: 0.05±0.01vs.0.08±0.02 mmol/l·6h; triglycerides IAUC: 0.71±0.35vs.1.03±0.58 mmol/l·6h, p<0.05).

Conclusions A diet rich in CHO and fiber, essentially based on legumes, vegetables, fruit, and whole cereals may be particularly useful for treating diabetic patients, due to its multiple effects on different cardiovascular risk factors, including postprandial lipids abnormalities.