Effects of Triacylglycerol Structure on Gut Hormones and Haemostatic Markers

Type 2 diabetes mellitus (T2DM) is a chronic disorder determined by lifestyle and genes. It is associated with chronic hyperglycaemia along with other metabolic abnormalities. It is also one of the risk factors for cardiovascular disease (CVD). This disease is due to insulin resistance and/or deficiency as well as increased hepatic glucose output. According to the Third National Health and Morbidity Survey (3rd NHMS), the prevalence of T2DM for adults aged 30 years and above is 14.9%, increased by almost 80% from 1996 to 2006. Dietary composition may affect insulin sensitivity, postprandial triacylglycerol concentration and the risk of T2DM. The role of dietary fats in T2DM is of particular interest and has been clinically studied for many decades. The type of fat we ingest every day consists of different types of fatty acids and different degree of saturation, which in turn influence glucose metabolism by altering cell membrane function, enzyme activity, insulin signalling and gene expression. Previous studies demonstrated that interesterification of dietary fat alter postprandial lipaemia. Saturated fat such as palm olein has been reported to display lower postprandial lipaemia after interesterification. Changing the structure of triacylglycerol (TAG) alters the physical properties of dietary fat which affects digestibility, metabolism and atherogenicity. A recent study conducted by Sanders and co-workers demonstrated reduced levels of plasma glucose-dependent insulinotropic polypeptide (GIP) following both the lard and interesterified palm olein (IPO) compared with the palm olein (PO) and high oleic sunflower oil (HOS) diets in healthy subjects. The GIP and glucagon-like peptide-1 (GLP-1) are major players in the modulation of postprandial insulin secretion by the pancreas. Although GIP secretion in response to meals is normal in patients with Type 2 diabetes mellitus (T2DM), GIP induced secretion of insulin is defective in diabetes. This is observed to be predominantly a defective stimulation of the late phase of insulin response (20-120 minutes). The effect of IPO on GIP may be exaggerated in T2DM patients with impaired insulin sensitivity. Hence, IPO may change the concentrations of gut hormones, postprandial lipaemia, insulinaemic response and CVD related haemostatic markers.