Background and aims: The prevalence of diabetes is increasing worldwide indicating that life-style habits are important determinants for this disease. The aim of this study was to examine the effects of dietary fats on insulin sensitivity in diabetic patients.
Methods: In a randomly selected sample of population aged 65 and older, plasma phospholipid fatty acid composition was determined by gaschromatography. The plasma phospholipid fatty acid composition is a reliable marker of the type of fats present in the diet. Insulin resistance was estimated with the Homeostasis Model Assessment (HOMA).
Results: Body weight, height, body mass index (BMI), waist circumference, serum cholesterol as well as fasting insulin, and the HOMA index were lower in the older groups. With increasing age, there was an increase in the monounsaturated fatty acid content and a decrease in the polyunsaturated and n-6 polyunsaturated fatty acids. In the linear regression analysis, saturated fatty acids were significantly related to waist circumference, fasting glucose, fasting insulin, and HOMA. Significant relations were also obserued between HOMA and BMI, triglycerides, waist circumference, and age. Triglycerides and HDL cholesterol were strongly interrelated as well as BMI and waist circumference. In the multiple regression analysis including age, BMI, waist circumference, triglycerides, HDL cholesterol, and saturated fatty acids, the HOMA index was predicted significantly only by age, BMI, and triglycerides. This model explained 28% of the HOMA variance.
Conclusions: In elderly diabetic patients insulin sensitivity is modulated by age, BMI, and triglycerides, but the type of dietary fats is not independently associated with insulin sensitivity.