The postprandial state and risk of cardiovascular disease

Metabolism in man is regulated by complex hormonal signals and substrate in teractions, and for many years the clinical focus has centred on the metabo lic and hormonal picture after an overnight fast. Move recently, the postpr andial state, i.e. 'the period that comprises and follows a meal', has rece ived more attention. The oral glucose tolerance test (OGTT), although highl y non-physiological, has been used largely as a model of the postprandial s tate. Epidemiological studies have, shown that, when 'impaired', oral gluco se tolerance is associated with an increased risk of cardiovascular disease . Postprandial hyperlipidaemia has been investigated more recently in epide miological, mechanistical and intervention studies, most of which indicate that high postprandial triglyceride levels, and particularly postprandial r ich triglyceride remnants, constitute an increased risk for cardiovascular disease. Recent studies have shown that excessive postprandial glucose excu rsions are accompanied by oxidative stress and, less well known, activation of blood coagulation (increase in circulating D-dimers and prothrombin fra gments). The mechanisms through which increased postprandial glucose levels and lipid concentrations may damage endothelial cells on blood vessel wall s appear to be complex. These mechanisms include the activation of protein kinase C, increased expression of adhesion molecules, increased adhesion an d uptake of leucocytes, increased production of proliferative substances su ch as endothelin, increased proliferation of endothelial cells, increased s ynthesis of collagen IV and fibronectin, and decreased production of nitric oxide (NO). In conclusion, the 'postprandial state' cumulatively covers al most half of the nycthemeral period, and its physiology involves numerous f inely regulated motor, secretory, hormonal and metabolic events. Epidemiolo gical and mechanistical studies have suggested that perturbations of the po stprandial state are involved in cardiovascular disease. Correcting the abn ormalities of the postprandial state must form part of the strategy for the prevention and management of cardiovascular diseases, particularly those t hat are associated with diabetes mellitus. (C) 1998 John Wiley & Sons, Ltd.