'n Ondersoek na faktore wat plasmafibrinogeenvlakke beïvloed

Abstract

Recent epidemiological studies have indicated that plasma fibrinogen and factor VII coagulant activity are major risk factors for the development of coronary heart disease (CHD). Clinical as well as experimental studies on animal models support these observations. Little is available on factors which regulate the synthesis and secretion of fibrinogen, or which influence plasma levels. In this study, the influence of race, diet and obesity on plasma fibrinogen levels is examined. In the literature survey (chapter 2) some of the hypotheses which try to explain the development of atherosclerosis and CHD are briefly outlined. The risk factors for CHD, including raised levels of plasma fibrinogen and factor VII, are then discussed in more detail. Attention is also given to the clinical conditions of diabetes mellitus and obesity. The influence of race on plasma fibrinogen is examined in a study which compares dietary intakes and fibrinogen levels of healthy white and black subjects (chapter 4). In chapter 5 dietary intakes and plasma fibrinogen levels of white and black diabetic subjects are compared. It is known that fibrinogen levels are raised during diabetes mellitus. In chapter 6, the relationship between obesity and plasma fibrinogen is explored, and effects of weight reduction on fibrinogen levels are reported. All methods used in these studies are given in chapter 3.

This study has shown (chapter 7) that race probably does not influence plasma fibrinogen levels, but that diet may play an important role. This was concluded from the results which showed that healthy black and white subjects, who followed a Westernized diet, had comparable fibrinogen levels. Black diabetic subjects however, who followed a more rural (prudent) diet, had lower levels than white diabetics who followed a Westernized diet. The study further demonstrated a significant positive correlation between body mass index and plasma fibrinogen levels. Weight loss was characterized by large fluctuations in fibrinogen levels, probably because of fluctuations in circulating free fatty acid levels. The study gives some support to the hypothesis that plasma fibrinogen may be regulated on an inhibitory level by the hormone insulin.