Serum cholesterol, lipoproteins, and plasma coagulation factors in South Africa blacks on a high-egg but low-fat intake

Dietary cholesterol and coronary artery disease: a systematic review

Coronary heart disease (CHD) remains one of the leading causes of death in the United States and other industrialized nations. A better understanding of modifiable risk factors for CHD is critical in order to effectively prevent this disease. Dietary factors known to influence the risk of CHD include saturated fats, trans-fats, and polyunsaturated fatty acids. Although higher plasma levels of low-density lipoprotein cholesterol are associated with an increased risk of coronary disease and lipid-lowering therapy has been shown to reduce the risk of cardiovascular disease, the relation between dietary cholesterol and the risk of CHD is not clearly understood. This article reviews the current evidence on the association between dietary cholesterol and the risk of CHD.

Diet and haemostatic processes

Diet plays an important role in the primary and secondary prevention of cardiovascular disease. The growing perception that abnormal haemostatic processes of coagulation, platelet aggregation and fibrinolysis contribute to cardiovascular disease aetiology motivated this review on the relationships of diet, specific foods and nutrients with haemostatic function. Functional endpoints that reflect the function and status of some of these processes and which can be measured in dietary trials are identified. The effects of energy intake and expenditure, alcohol, total fat and specific fatty acids, non-starch polysaccharides (dietary fibre), antioxidant nutrients and some foods on a variety of haemostatic markers are reviewed. The results indicate that the prudent low-fat, high-fibre diet and maintenance of ideal body weight recommended to protect against and treat hyperlipidaemia and coronary heart disease will also benefit haemostatic profiles. It is concluded that more research on specific effects is needed for improved recommendations on a population level for prevention of cardiovascular disease.

Diet and haemostasis: time for nutrition science to get more involved

Abnormal haemostasis, and specifically a pre-thrombotic state characterized by hypercoagulability, increased platelet aggregation and impaired fibrinolysis, is associated with increased atheroma and thrombosis. The recent literature clearly indicates that diet may prevent or be used to treat some abnormal haemostatic states. There are reports on effects of energy intake and expenditure, alcohol consumption, intakes of total fat, different fatty acids, fish oil, NSP and vitamins on markers of coagulation, platelet function and fibrinolysis. Some of the confusion and controversy in this field has arisen because the wrong markers of haemostasis have been measured in dietary trials. Moreover, many of the studies have lacked good dietary control. It is suggested that more sensitive, functional markers of the balance between the different facets of the haemostatic system should be measured. It is also important to test hypotheses developed from known observations and to propose mechanisms of action of the various dietary factors, based on our improved understanding of the haemostatic system.

Serum lipids and lipoprotein in adult Ghanaians

OBJECTIVES

To date, no measurement of serum lipid levels in healthy adult Ghanaians have been carried out. This study was undertaken with the objective of providing reference values for serum lipid levels in the Ghanaian population.

DESIGN/SETTING

Fasting serum lipid levels were measured in 79 adult Ghanaians living in an urban setting. Volunteers were randomly selected from the work force of the University of Ghana in Accra. There were 54 males and 25 females in the study population.

RESULTS

The mean serum cholesterol (SC) for Ghanaian males was 4.27 +/- 1.00 mmol L-1. A value of 4.34 +/- 1.12 mmol L-1 was obtained for the females in this study. High-density lipoprotein cholesterol (HDL-C) in Ghanaian males averaged 1.37 +/- 0.44 mmol L-1 and 1.47 +/- 0.50 mmol L-1 in females. There was no statistically significant difference in low-density-lipoprotein cholesterol (LDL-C) and very-low-density-lipoprotein cholesterol (VLDL-C) levels between the females and males in this study.

CONCLUSIONS

Compared to other studies, our results show that populations in Europe and North America have higher levels of total cholesterol and LDL cholesterol than Ghanaians. The levels of HDL cholesterol as well as VLDL cholesterol are higher in Ghanaians than in Europeans and Americans. Further work needs to be done to compare lipid levels in urban and rural Ghanaians as well as in those with cardiovascular disorders.

Fibrinogen as a cardiovascular risk factor in Spanish children and adolescents. The Niño Jesus Group

Studies done on adults reveal a significant role of fibrinogen (FG) in cardiovascular disease. The main purpose of our study was to determine the level of plasma FG in children, its distribution according to age and sex, and its relationship to other cardiovascular risk factors such as cigarette smoking, plasma lipid disturbances, and a positive family history for other cardiovascular risk factors. We studied a population of 2224 children, aged 2 to 18 years, from five different schools located in Madrid. We found a significantly higher level of FG in the groups of females aged 6 to 8 and 16 to 18 years than in males of the same ages (p < 0.001). The study population was distributed into two groups according to the plasma fibrinogen level: > 394 mg/dl and < 394 mg/dl. In both groups we determined plasma levels of total cholesterol, triglycerides, and very low-density lipoprotein (VLDL) cholesterol and found these parameters significantly higher in the group with an FG level > 394 mg/dl (p < 0.05).

Associations of fish intake and dietary n-3 polyunsaturated fatty acids with a hypocoagulable profile. The Atherosclerosis Risk in Communities (ARIC) Study

Recent epidemiological evidence indicates that the hemostatic profile is an important predictor of cardiovascular disease, yet its dietary determinants are not well established. An important question is whether dietary fatty acid intake influences blood levels of coagulation proteins. We examined potential dietary determinants of six hemostatic factors--fibrinogen, factor VII, factor (vWF), protein C, and antithrombin III--in four population-based samples totaling over 15,000 participants, blacks and whites, in the Atherosclerosis Risk in Communities (ARIC) Study. Usual dietary intake was assessed by a food frequency questionnaire. Cross-sectional associations were explored using multiple linear regression analysis, adjusting for gender, race, age, body mass index, smoking status, alcohol use, diabetes, and field center. Dietary intake of n-3 polyunsaturated fatty acids (PUFAs) showed negative associations with fibrinogen, factor VIII, and vWF (blacks and whites) and a positive association with protein C (whites only). Fish intake, the major source of dietary n-3 PUFAs, was similarly related to the hemostatic profile: a 1 serving per day greater fish intake was associated with the following predicted differences (95% confidence interval): fibrinogen, -2.9 mg/dL (-6.3, 0.5); factor VIII, -3.3% (-5.4, -1.3); vWF, -2.7% (-5.2, -0.1) (blacks and whites); and protein C, +0.07 microgram/mL (0.03, 0.11) (whites only). Other nutrients or foods were variably associated with the hemostatic factors. These population-based associations, although cross-sectional, suggest that increases in n-3 PUFA intake from fish may modify the blood levels of several coagulation factors.

Factors associated with high density lipoprotein cholesterol in a population with high high density lipoprotein cholesterol levels

A cross-sectional study of a random sample of 976 coloureds (mixed race) of the Cape Peninsula, ages 15 to 64 years old, revealed a population with unexpectedly high levels of high density lipoprotein (HDL) cholesterol. The mean level for men was 55.4 +/- 16.1 mg/dl (SD) and for women, 60.8 +/- 16.0 mg/dl. The ratio of HDL cholesterol to total cholesterol expressed as a percentage was 26.3% +/- 9.5% for men and 28.1% +/- 9.3% for women. The HDL cholesterol levels were apparently lower than those of black and Negro populations, yet higher than those of Caucasian populations. Men with levels of HDL cholesterol above the median reported a personal history and a family history of coronary heart disease less frequently than did men with lower levels, while women with high levels of HDL cholesterol were less likely to have a history of hypertension or diabetes. Stepwise multiple regression analysis of variables significantly associated with HDL cholesterol levels showed that they explained 29.7% and 24.7%, respectively, of the variation in HDL cholesterol in men and women. Those variables independently associated with HDL cholesterol in both men and women were: serum triglyceride (-), cigarette consumption (-), alcohol, body mass index (-), age, and serum low density lipoprotein cholesterol levels (-). The reasons for the relatively high HDL cholesterol levels in this population are unknown. However, it would seem possible that these levels offer some protection against the high risk factors of smoking, hypertension, and hypercholesterolemia.

Stone agers in the fast lane: chronic degenerative diseases in evolutionary perspective

From a genetic standpoint, humans living today are Stone Age hunter-gatherers displaced through time to a world that differs from that for which our genetic constitution was selected. Unlike evolutionary maladaptation, our current discordance has little effect on reproductive success; rather it acts as a potent promoter of chronic illnesses: atherosclerosis, essential hypertension, many cancers, diabetes mellitus, and obesity among others. These diseases are the results of interaction between genetically controlled biochemical processes and a myriad of biocultural influences--lifestyle factors--that include nutrition, exercise, and exposure to noxious substances. Although our genes have hardly changed, our culture has been transformed almost beyond recognition during the past 10,000 years, especially since the Industrial Revolution. There is increasing evidence that the resulting mismatch fosters "diseases of civilization" that together cause 75 percent of all deaths in Western nations, but that are rare among persons whose lifeways reflect those of our preagricultural ancestors.