Effect of breast feeding on the plasma cholesterol and growth of infants.

The effect of breast-feeding on plasma cholesterol, body weight, and body length was studied longitudinally in a large free-living cohort of infants (n = 512) from birth until the age of 1 year. Of the cohort, 21.4% were exclusively breast-fed for at least 3 months, 39.3% received bottle-feeding, and 39.3% received a combination of breast- and bottle-feeding. At birth the plasma cholesterol was similar in the three groups. After 3 months the mean plasma cholesterol and proportion of hypercholesterolemic infants in the breast-fed group were significantly (p less than 0.001) higher than that of the other two groups. These differences had disappeared at the age of 1 year. Breast-fed infants weighed less at 3 and 12 months, but body length was similar to those of the other groups. These results suggest that breast-feeding elevates plasma cholesterol by a direct mechanism and that the effect persists only as long as the breast-feeding is continued.

Changes in smoking during a community-based cardiovascular disease intervention programme. The Coronary Risk Factor Study.

A prospective anti-smoking clinical trial was conducted as part of a coronary risk factor intervention study in three rural South African communities in the south-western Cape over a period of 4 years. The aim of this part of the study was to reduce smoking rates in two of the communities through application of high- and low-intensity intervention. The effect was evaluated by examining the net change in smoking habits, which was defined as the residual change in the intervention areas after allowing for change in the reference area. This paper presents the analyses of the estimated effect of the programme on the cohort aged 15-64 years at baseline who participated in the two surveys (4,087 subjects). The intervention programme among men in the high-intensity intervention area resulted in a reduction of 8.4% in smoking rates and 13.0% in the amount smoked per day. Among women in this area there was a reduction of 30.6% in smoking rates and 20.5% in amount smoked. Smoking and the amount smoked per day also decreased in the low-intensity intervention area, but less so than in the high-intensity intervention area. Smoking quit rates were strongly associated with initial smoking levels, with light smokers being significantly more successful quitters than heavy smokers. This study has proved that a community-based intervention programme can effectively reduce smoking.

Relationship between high density lipoprotein subfractions and coronary risk factors in a rural white population.

The relationship of serum high density lipoprotein cholesterol (HDL-C) levels and of the HDL2-C and HDL3-C subfractions to several factors associated with coronary risk was examined in a cross-sectional study, which included 655 men and 731 women ages 20 to 64 years. Participants with coronary heart disease (CHD) had lower levels of HDL-C, HDL2-C, and HDL3-C; however, only HDL-C in women was significant. Maleness, body mass index, triglyceride levels, tobacco use, and carbohydrate intake (in men) were significantly inversely related to total HDL-C, while alcohol intake was significantly positively related to HDL-C. The associations were stronger for HDL2-C than for HDL3-C, except that alcohol intake in men was more strongly related to HDL3-C. The findings of this study suggest that several factors that influence CHD risk do so in part through modifying HDL2-C levels.

Socio-economic status, risk factors and coronary heart disease. The CORIS baseline study.

The relationship of socio-economic status (SES) indicators and coronary risk factors (RFs) with coronary heart disease (CHD) prevalence was examined in 5 620 subjects aged 20-60 years who participated in the Coronary Risk Factor (CORIS) baseline study. Education and income (with some exceptions in males) were strongly and inversely related to hypercholesterolaemia, low high-density lipoprotein cholesterol, hypertension, smoking, overweight and prevalence of angina pectoris. In contrast, type A behaviour was positively associated with higher income and education. Females showed stronger SES-RF relationships than males. Town-dwelling females were more likely to be smokers, and had a higher prevalence of angina pectoris and myocardial infarction. The lowest overall prevalence of RFs, angina pectoris and myocardial infarction was found in the professional and managerial categories for both males and females. The SES indicators had little or no independent effect on CHD prevalence in multivariate logistic analyses after inclusion of the standard RFs. We conclude that these indicators relate to RFs, and through them to CHD.

Hypercholesterolaemia in a rural white population and its relationship with other coronary risk factors.

The risk factor and dietary associations of hypercholesterolaemia were analysed. Twenty per cent of the 6,332 respondents aged 20-64 years in the Coronary Risk Factor Study (CORIS) were considered hypercholesterolaemic (i.e. above the 80th percentile). In this sample only 13.4% of men and 6.7% of women were on treatment, and only 32.7% and 37.1% respectively had 'desirable' high-density lipoprotein cholesterol levels. Hypercholesterolaemia was significantly associated with a personal or family history of coronary heart disease, hypertension, smoking, obesity and hyperuricaemia. Analysis of the dietary intakes of a 15% subsample of the total population revealed no significant differences between high- and low-risk subjects in intake of dietary fats and cholesterol. However, high-risk subjects consumed significantly more animal protein and significantly less dietary fibre than those with a low cholesterol level. These findings reflect a subpopulation at high risk of coronary heart disease. Their risk can be reduced to some extent by population strategies towards healthier lifestyles; ultimately the high-risk individuals have to be identified and appropriately treated.

Hypertension in a rural South African white population and the effect of antihypertensive treatment on the risk of coronary heart disease.

The association between hypertension and coronary risk factors and the effect of antihypertensive treatment on coronary risk were investigated in rural South African whites aged 15-64 years. Almost 25% of men (range 1.9-46.6%) and almost 27% of women (2.1-56.2%) were hypertensive or being treated for hypertension; the prevalence increased with age, particularly among women. Only 25.8% of male and 43.4% of female hypertensives were being treated, and of these only 38% had controlled blood pressure. Hypertension was associated with a high serum total cholesterol level, a low high-density lipoprotein cholesterol level, a high body mass index, a high uric acid level, a high prevalence of coronary heart disease and, in men, high alcohol consumption. Treated hypertensives had a greater risk of coronary heart disease than untreated hypertensives. Men on beta-blockers had significantly lower high-density lipoprotein cholesterol levels than men not on treatment, while uric acid levels in both men and women on diuretics were higher than those of untreated hypertensives. Hypertension in the study population appears to be inadequately treated, and antihypertensive medication may impact adversely on metabolic risk factors. The goal of antihypertensive therapy should be a net reduction of coronary heart disease risk.

Drop-out and newcomer bias in a community cardiovascular follow-up study.

Bias resulting from a loss of baseline subjects at follow-up (drop-out), and newcomer bias resulting from subjects entering the study at the follow-up stage, were investigated in a three-community coronary risk factor follow-up study. The study consisted of a cross-sectional baseline study on 7188 participants aged 15 to 64 years, a four-year intervention period and a follow-up cross-sectional study in the same communities on 6283 participants aged 19 to 68 years. The overall non-response rate of 45% in men and 42% in women varied from 30 to 79% in the various age and sex groups, with the biggest drop-out rate occurring in the youngest age group of 15 to 24 years. At baseline drop-outs were more likely to have lower educational qualifications than those who participated in both the baseline and follow-up studies (stayers) and included significantly more smokers than non-smokers. Coronary risk factors of newcomers were not different from that of the stayers at follow-up except for slightly, but not significantly, higher smoking rates in newcomers. These findings suggest that drop-out and newcomer bias need to be assessed and its effect studied before final evaluation of data in community follow-up studies.

Chronic atrophic gastritis, gastric pH, nitrites and micronutrient levels in a population at risk for gastric carcinoma.

One hundred and seventy-eight patients at risk for gastric carcinoma had upper gastrointestinal endoscopy. Twenty-seven selected patients with the type B of chronic atrophic gastritis, 32 patients with normal mucosa and 47 non-scoped healthy controls were tested for plasma vitamin C, retinol and tocopherol. The total vitamin C level was also assessed in gastric juice of scoped patients. Micronutrient levels were related to gastric pH, nitrites and gastric mucosal pathology. The study showed a higher level of pH (greater than 4) and high nitrites in gastric juice in patients with chronic atrophic gastritis, gastric malignant and dysplastic lesions. Neither the hypochlorhydria nor gastric nitrites affected the prevalence of C. pylori in gastric mucosa. Low gastric and plasma concentrations of vitamin C observed in patients with chronic atrophic gastritis showed an inverted relationship with pH level, and an inter-relationship of other vitamins with antioxidant properties (vitamins A and E).

Prevalence of overweight and obesity and its relation to coronary heart disease in the CORIS study.

Using body mass index as a measure of overweight and obesity in the Coronary Risk Factor Study (CORIS) on a large white South African study population (N = 7,188) aged 15-64 years, 41.9% of the men and 38.8% of the women were overweight and, in addition, 14.7% of the men and 18.0% of the women were obese. In a subset of the study population (45-64-year-old age group) coronary risk factors were related to the different weight categories. Mean values of serum cholesterol, uric acid and systolic and diastolic blood pressure increased progressively from the underweight, through the normal and overweight to the obese category in both sexes, while the high-density lipoprotein/total cholesterol ratio and the number of cigarettes smoked per day showed an inverse trend. The daily energy expenditure remained unchanged across the weight categories. Coronary heart disease prevalence was progressively higher in the overweight and obese groups compared with the normal weight group.

[The existence of an immunoreactive digitalis-like substance in normal people and hypertensive people]. / Die voorkoms van 'n immuunreaktiewe digitalis-soortige stof in 'n normale bevolking en persone met hipertensie.

A study confirmed the existence of an immune reactive digitalis-like substance in normotensive and hypertensive people between the ages of 15 years and 64 years. In 13.6% of the population examined, values higher than 0.15 ng/ml of digitalis-like substances were obtained. The possible presence of this substance in a large proportion of patients should be borne in mind when interpreting digitalis measurements.