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Biomedical subjects

K Steyn

Publications and source records attributed to K Steyn.

At least 73 records · Page 4Linked to original sources
PubMed1992

Beliefs about smoking and health and attitudes toward tobacco control measures.

The opinions of a representative sample of adult South Africans about the effects of smoking on health and their attitudes toward tobacco control measures were surveyed by means of an interviewer-administered questionnaire. Seventy-five per cent of the respondents were black and 55.3% were female. More than 50% of blacks and Asians (61.7% and 53.2%) were non-smokers, whereas 52.1% of 'coloureds' were current smokers and 23.8% of whites ex-smokers. The majority of smokers (68.5%) acknowledged the harmful effects of direct smoking and a larger percentage of non- and ex-smokers (79.7% and 77% respectively) shared this view. A similar trend was observed in beliefs about passive smoking. Seventy-five per cent of participants felt that tobacco sales to minors should be banned and 55.8% thought that taxes on tobacco products should be increased. There was substantial white opposition to measures that prohibit tobacco companies from sponsoring sporting events. Most respondents felt that tobacco advertising should be banned on television (59.7%), radio (60.1%), in newspapers (58.4%), on billboards (58.7%) and in cinemas (59.3%). The results indicate that in the main the public supports the introduction of the measures proposed in the draft Tobacco Products Control Act and even more extensive legislation to control tobacco consumption. This augurs well for future strategies aimed at tobacco control in South Africa.

Adolescent↗
PubMed1992

Hypertension in family practice. A study of knowledge, attitudes and practices.

A study was conducted in Cape Town during 1990 to investigate the knowledge, attitudes and practices of 90 family practitioners with regard to hypertension and its management. Hypertension was regarded as an important health problem by 59% while 5% thought that it was not important. Sixty-eight per cent of family practitioners estimated that less than 15% of their patients suffered from hypertension and 78% of family practitioners estimated that more than 70% of their hypertensive patients' blood pressures were controlled. Fifty-five per cent of family practitioners thought it acceptable for a lay person to measure blood pressure and 68% felt that the use of a hypertension register in the practice would assist in the management of hypertension. The information gathered will be of great value in planning intervention strategies and developing hypertension management aids that could assist the family practitioner.

Clinical Competence↗
PubMed1992

Simvastatin in non-insulin-dependent diabetic patients with hypercholesterolaemia.

The objective of this study was to evaluate the lipid-lowering effect of simvastatin in non-insulin-dependent diabetes mellitus (NIDDM) patients with hypercholesterolaemia while possible clinical and biochemical adverse effects were monitored for. Forty-three NIDDM patients with hypercholesterolaemia (total cholesterol > 6.5 mmol/l) used simvastatin after a detailed clinical laboratory evaluation as well as a 4-week wash-out period and a 4-week placebo baseline period. Simvastatin treatment was initiated with a 10 mg dose for 6 weeks; this was increased to 20 mg and 40 mg at 12 and 18 weeks of follow-up respectively if the total cholesterol level had not decreased to below 5.17 mmol/l. Patients were placed on a lipid-lowering diet and continued to take any regular non-lipid-lowering medication throughout the trial; side-effects were monitored at 6-week intervals until patients had taken simvastatin for 24 weeks. The mean total cholesterol level was reduced by 22.2% at the first follow-up visit, and by 24.2%, 23.3%, and 28.5% at the second, third and fourth follow-up visits respectively compared with base-line levels. A dose of 10 mg simvastatin brought about a reduction in total cholesterol similar to those found with higher doses. The mean triglyceride level was reduced by 20.9% with 20 mg simvastatin. The high-density lipoprotein cholesterol level was not altered significantly and neither was the control of diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

A 6-month trial of simvastatin (HMG-CoA reductase inhibitor) in the treatment of hypercholesterolaemia.

The aim of this study was to evaluate the long-term efficacy and tolerability of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor simvastatin, over a 24-week period. Patients (108) with primary hypercholesterolaemia were clinically, haematologically and biochemically evaluated and established on a cholesterol-lowering diet. After a wash-out period free from other lipid-lowering drugs and a baseline period on placebo of 1 month each, 10 mg simvastatin was introduced at night. The dose was increased to 20 mg and 40 mg at 6 and 12 weeks' follow-up respectively if the total cholesterol (TC) level was still above 5.17 mmol/l. Follow-up took place every 6 weeks and included lipid, haematological, biochemical and clinical evaluation. A full ophthalmological evaluation was conducted at baseline and at 24 weeks' follow-up. Overall the TC level was reduced below the baseline level by 34.3% at week 18 of follow-up and 32.5% at week 24. Patients with higher initial TC levels showed greater TC lowering in response to simvastatin than did those with lower initial TC levels. A group of 45 patients was followed up for an additional 12 weeks after the end of the trial and maintained TC reductions similar to those at the end of the trial. Fourteen patients experienced adverse effects which were thought to be drug-related. One patient was withdrawn from the trial after developing conjunctivitis that proved to be related to the use of simvastatin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Risk factors for coronary heart disease in the black population of the Cape Peninsula. The BRISK study.

A cross-sectional study of risk factors for ischaemic heart disease (IHD) in a random sample of 986 black people aged 15-64 years living in the Cape Peninsula revealed a population at lower risk for IHD than other South Africans. Blood pressures of 140/95 mmHg or above were found in 14.4% of males and 13.7% of females. Fifty-two per cent of males and 8.4% of females smoked, while 16.5% of males and 25.8% of females had a total cholesterol (TC) level imparting risk for developing IHD. In this population the TC level is not a good surrogate measure for low-density lipoprotein cholesterol because of the high level of high-density lipoprotein cholesterol (HDLC) found in this population. A protective HDLC/TC ratio of 20% was found in 96% of males and 96.1% of females. When considering the three major reversible IHD risk factors at a high level of risk, 30.8% of males and 12.5% of females had at least one such a risk factor. The population was frequently exposed to the media, with 80% listening to the radio every day and 55% watching television at least once a week. This suggests that a healthy lifestyle could be promoted successfully by means of these media. In addition, schools should promote a healthy lifestyle and the prevention of chronic degenerative diseases should be incorporated into the evolving primary health care services in South Africa.

Adolescent↗
PubMed1990

The relationship between dietary factors and serum cholesterol values in the coloured population of the Cape Peninsula.

A cross-sectional study of 976 coloured subjects aged 15-64 years identified a population consuming a typical Western diet. Nutrient intake, determined by the 24-hour dietary recall method, reflected a diet high in fat (37% of total energy intake) and animal protein and a polyunsaturated/saturated fatty acid ratio of 0.85. Only 32.2% of men and 27.5% of women consumed a prudent diet (Keys score less than or equal to 28). The influence of this Western diet on serum total cholesterol (TC) levels was seen to be marked when participants with a high risk of developing coronary heart disease (CHD) were compared with those with a TC level putting them at low risk; the former consumed significantly more saturated fat and had a higher mean Keys score. Multiple linear regression analysis on TC levels of men identified six variables that explained 26.9% of the variation of TC. These were body mass index, age, the inverse of the polyunsaturated fat intake, saturated fat intake, polyunsaturated/saturated fat ratio and cholesterol intake. For women only three variables (age, the inverse of the polyunsaturated/saturated fat ratio, and body mass index) explained 30.2% of the variation of TC. Promotion of the prudent diet to lower TC levels of the coloured population of the Cape Peninsula is an increasingly urgent priority.

Adolescent↗
PubMed1990

The coexistence of major coronary heart disease risk factors in the coloured population of the Cape Peninsula (CRISIC study).

A cross-sectional study of risk factors for coronary heart disease in a random sample of 976 people from a South African coloured population revealed this group to be at great risk. The prevalences of individual and of coexisting reversible risk factors--hypercholesterolaemia, hypertension and smoking--were highest in the older subjects, who use medical services more often. One or more of the three risk factors was present in 80% of men aged 45 years or over. Smoking was the most common single risk factor for both sexes, and almost 30% of women aged 45 years or over were hypertensive. Hypertension and smoking was the most common combination for males and hypertension and hypercholesterolaemia the most common for females. Medical personnel could identify and treat these very-high-risk patients if they were to screen for all the risk factors after identifying any one risk factor. Younger people at risk and particularly younger men, who rarely utilise health services, should be reached at their workplace for early identification of risk factors.

Adolescent↗
PubMed1990

Anthropometric profile of the coloured population of the Cape Peninsula.

Study of a sample of 976 randomly selected coloured persons 15-64 years of age living in the Cape Peninsula included measurement of height, weight and mid-arm circumference and calculation of the body mass index (BMI). The mean height of the men was 167.6 cm and that of the women 156 cm. Mean weight, BMI and mid-arm circumference for men were 65.9 kg, 23.4 and 27.5 cm respectively and those for women 65.8 kg, 27.1 and 28.9 cm respectively. The prevalence of underweight for men (BMI less than 20) was 23.6% and for women (BMI less than 19) 9.8%; 17.7% of men were overweight (BMI greater than or equal to 25) and 3.7% obese (BMI greater than or equal to 30), while 35.2% of women were overweight (BMI greater than or equal to 24) and 18.8% obese. Overweight and obesity were more common among the older coloured women than among a group of South African white women of the same age. Obese women in the age group 35-44 years were 4.8 times more likely to be hypertensive than women of normal weight in the same age group (odds ratio; 95% confidence interval 2.2-4). Older women did not show this association. There were too few obese men to analyse in this manner. Many of the obese participants did not see themselves as obese. Only 19.7% of men and 45.2% of women had attempted to lose weight during the year preceding the study, in many cases using methods known to be ineffective. The coloureds of the Cape Peninsula were found to be a population with shorter stature than South African white and American populations. Some young participants of both sexes and some older men were underweight, while among older women there was a high prevalence of overweight and obesity. The findings may suggest previous undernutrition in both sexes, with a marked tendency to current overnutrition in adult females.

Adolescent↗
PubMed1990

Health actions and disease patterns related to coronary heart disease in the coloured population of the Cape Peninsula.

The health-related behaviour of the Cape Peninsula coloured population, which has been shown to have an adverse coronary heart disease (CHD) risk factor profile, is reported. Private medical services were used most often by participants: 54.1% and 51.6% of males and females respectively had made use of these services during the preceding year. Only 17.9% and 21.8% of males and females respectively had attended day hospitals during the year. Blood pressures were measured in 43.8% and 57.1% of male and female participants respectively during the year preceding the study. The results indicated the need for the measurement of blood pressure to determine the true prevalence of hypertension, since patient reporting of the condition was inaccurate. Attempts to give up smoking had been made by 44.4% of male and 47.1% of female smokers. About 75% of the participants were found to have hypercholesterolaemia, yet their knowledge of the prudent diet was poor and few reported appropriate dietary modifications to protect against CHD. Frequent reporting of hypercholesterolaemia, hypertension and constipation by the study population highlights the need for dietary education. Mortality rates (MRs) for CHD and cerebrovascular disease (CVD) for the coloured and the white populations were compared. In all age groups white males had higher MRs for CHD than coloured males, while coloured females older than 34 years had higher rates than their white counterparts. The coloured population had MRs for CVD that were higher than those of whites.

Adolescent↗
PubMed1990

Requirements of a coronary heart disease risk factor intervention programme for the coloured population of the Cape Peninsula.

The coloured population of the Cape Peninsula has been identified as having a high prevalence of risk factors for coronary heart disease (CHD), notably hypertension, cigarette smoking and hypercholesterolaemia. The need for an appropriate and effective CHD intervention programme, directed at the population as a whole, has become urgent. Three central problem areas relating to hypertension control--diagnosis, management and compliance--will have to be addressed. Hypertension was underdiagnosed among men, particularly those aged 25-44 years. Apart from educating this group regarding the need to have their blood pressure measured, detection programmes are therefore needed at the workplace to improve hypertension diagnosis. Inadequate management of hypertension was commonest in women aged over 45 years. Compliance with hypertension treatment regimens was poor in all men as well as in both sexes belonging to the lower socio-economic strata. Establishing easily accessible blood pressure stations for monitoring blood pressure and educating hypertensives regarding their condition could lead to improved management and compliance. Coloureds were found to smoke heavily, and the women had the highest smoking prevalence of all South African women. Furthermore, the age of onset of smoking is decreasing among coloured children. A general anti-smoking campaign directed at all South Africans is necessary to control smoking. Anti-smoking education programmes at primary school level are of particular importance to prevent the onset of the habit. More than 70% of coloureds had a serum cholesterol level imparting CHD risk, few followed a prudent diet and their knowledge of the prudent diet was poor. Health education programmes to promote the prudent diet are required.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The use of low density lipoprotein receptor activity of lymphocytes to determine the prevalence of familial hypercholesterolaemia in a rural South African community.

The diagnosis of heterozygous familial hypercholesterolaemia in three rural South African communities in which hypercholesterolaemia is very prevalent could be confirmed by the measurement of low density lipoprotein (LDL) receptor activity in circulating lymphocytes. A nominal cut off point could be proposed which separated the LDL receptor activity of 24 clinically diagnosed heterozygous FH patients and 31 healthy people. LDL receptor activity was measured as total degradation of 125I-LDL and expressed as ng LDL/mg cell protein/6 hours. The cut off point was set at 970 ng/mg protein/6 hours. This proposed cut off point was tested by assaying the LDL receptor of three homozygous FH patients and seven of their obligate heterozygous FH first degree relatives. The three homozygous FH patients showed no receptor activity and the activity of the seven obligate heterozygous first degree relatives fell below the proposed cut off point. To determine the prevalence of FH in the study population, all persons aged 15 to 24 years whose total cholesterol levels fell above the 80th centile for their age and sex, as well as their families, were approached (n = 114). The LDL receptor activity in lymphocytes of 77 of these persons aged 15 to 24 years was determined after applying the exclusion criteria. Ten of the 77 participants had LDL receptor activity below 970 ng LDL/mg protein/6 hours and were therefore diagnosed as being heterozygous FH patients. The calculation of the prevalence (corrected for exclusions) revealed that one in 71 of the 15 to 24 year old permanent residents in the predominantly Afrikaans speaking community suffered from heterozygous FH. This is higher than any FH prevalence previously reported for any group.

Adolescent↗
PubMed1989

Media use and preference related to coronary heart disease of the coloured population of the Cape Peninsula. The CRISIC study.

As a part of a comprehensive coronary risk factor study among the coloured population of the Cape Peninsula (the CRISIC study), the media use and preference of the population were examined with a view to suggesting appropriate media for conveying health messages. A stratified sample (N = 976) was randomly drawn from the coloured population in the age group 15 to 64 years in the Cape Peninsula. Data were collected by means of a pre-tested questionnaire. Analysis of the data showed that information on the prevention of heart disease was obtained in greater measure from the mass media than from interpersonal communication. As far as media preference is concerned, television was considered the most effective medium factor conveying information to the community, followed by instruction given to school children. Greater use of health educators to convey health messages, as well as a multi-media approach, is suggested for a successful intervention programme.

Adolescent↗
PubMed1988

Towards standardisation of pre- and post-analytical variables in the assessment of lipid risk factors for ischaemic heart disease.

A wide disparity exists between statistical and optimal reference ranges for total cholesterol (TC) levels in South Africa. The haphazard downward adjustments by some laboratories over the years have resulted in highly variable and confusing 'normal cholesterol' values. Using essentially the same enzymatic method and equipment the TC upper limits varied by almost 50% (5.7-8.5 mmol/l) in 24 private laboratories, while it ranged from 5.7 mmol/l to 6.7 mmol/l in 6 academic hospital laboratories. The greatest disparity occurred in the lower limits of 'normal' for high-density lipoprotein cholesterol (HDLC), which ranged from 0.45 mmol/l to 1.43 mmol/l. Although triglycerides may not be an independent risk factor for ischaemic heart disease, the upper limit ranged from 1.69 mmol/l to 2.5 mmol/l despite comparable methods and equipment used. Lipid data obtained on approximately 5,000 healthy adults from the Transvaal, Natal and the Orange Free State revealed remarkable similarities to those obtained in the CORIS study. It therefore confirms the applicability of the CORIS epidemiological findings to other westernized groups in different regions of South Africa. This congruency in blood lipid values and methodologies used in different laboratories should also enable all state and private laboratories to use the same age-specific limits for desirable TC and HDLC levels.

Adult↗
PubMed1988

Action limits for serum total cholesterol. A statement for the medical profession by an ad hoc committee of the Heart Foundation of Southern Africa.

Hypercholesterolaemia is common in many segments of the South African population, both by virtue of high mean population serum total cholesterol (TC) values and of a high prevalence of familial hypercholesterolaemia (FH). Age-specific action limits for TC are proposed in order to remove the variation in 'normal values' used by different laboratories. The action limits are derived from epidemiological studies rather than purely statistical norms. They are used to designate individuals as falling into high, moderate and ideal TC ranges. The high-risk action limit has also proved to be useful for screening for FH. After an initial screening TC estimation, the further management of a patient will depend on the TC risk category and the presence or absence of other risk factors. Risk factors such as hypertension, a smoking habit, a low high-density lipoprotein cholesterol value, diabetes, evidence of existing coronary heart disease (CHD) or a family history of premature CHD multiply the risk conferred by elevated TC, and change the moderate-risk status of an individual with moderately elevated TC to a high-risk status. Intensity of investigation, treatment and follow-up depend on the overall risk status of an individual patient. Drug therapy is reserved for high-risk patients who have not responded to a reasonable trial of non-drug measures. Other reversible risk factors are treated in their own right. The guidelines embodied in this report are intended to facilitate and justify the clinical approach to individual patients with hypercholesterolaemia. They do not replace the need for a population strategy to reduce risk factors in the general population.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Hypercholesterolaemia in a group of senior South African Transport Services employees.

The lipid profiles of 104 volunteer senior South African Transport Service (SATS) personnel showed that all volunteers had some lipid abnormality, which increased their risk for coronary heart disease. All participants received a single counselling interview with a nursing sister on a lipid-lowering lifestyle. Retesting after 3-4 months of 91 participants revealed that this group had lowered their mean total serum cholesterol value significantly. Twenty-one per cent of the participants had normalised their lipid profiles and the prevalence of hypercholesterolaemia, defined in a number of ways, was reduced, as was the number of possible familial hypercholesterolaemic patients, by 60%. Participants who complied with the dietary recommendations strictly reduced their cholesterol levels significantly, while those who did not were less successful in lowering their serum cholesterol levels. Screening and a single intervention counselling interview improved the coronary risk factor profile of this group of senior SATS personnel.

Adult↗
PubMed1987

Hypercholesterolaemia in the coloured population of the Cape Peninsula (CRISIC study).

A cross-sectional study of hypercholesterolaemia in a random sample of 976 subjects showed that hypercholesterolaemia was common in a coloured population. Of the males 17.4% and of the females 16.2% had total serum cholesterol values above 6.5 mmol/l. Using a cut-off point of 5.7 mmol/l the age-standardised prevalence of hypercholesterolaemia was 34.5% for males and 32.9% for females. Age- and sex-specific cut-off points showed that 69.2% of males and 65.9% of females were at risk for coronary heart disease (CHD) by virtue of the total cholesterol level. Of the males 19.1% and of the females 13.4% warranted investigation for possible familial hypercholesterolaemia. A protective high-density lipoprotein cholesterol/total cholesterol ratio was found in 61.2% of males and 51.9% of females. Hypercholesterolaemia was statistically significantly associated with a reported history and a familial history of CHD as well as with hypertension and diabetes in some groups studied. Unlike most cross-sectional studies this study showed that hypercholesterolaemic participants consumed more saturated fat and their diets had a higher Keys score than did normocholesterolaemic participants. Only 16.5% of males and 21.7% of females had modified their diets to prevent heart disease. High levels of total cholesterol were found to be associated with high levels of serum triglycerides and uric acid, high body mass index, high diastolic and systolic blood pressure and higher socio-economic standing. An education programme to initiate the dietary modifications that lead to the lowering of serum cholesterol levels is necessary to reduce CHD in the coloured population.

Adolescent↗
PubMed1987

Smoking patterns in the coloured population of the Cape Peninsula (CRISIC study).

A cross-sectional study of tobacco-smoking habits in a random sample of 976 coloured subjects aged 15-64 years revealed that smoking was common, 57% of men and 41% of women being current smokers and 10.4% of men and 9.6% of women having stopped smoking. Heavy smoking prevailed, indicating by mean daily consumption of 14.2 and 13.1 cigarettes among male and female smokers respectively; only 33.5% of male and 39.6% of female smokers used less than 10 cigarettes per day. Coloured smokers smoked more heavily during the weekend. Both men and women smoked mostly filter cigarettes. Forty-four per cent of male and 49.5% of female smokers stated that they had attempted to stop smoking, mainly for health reasons. More than one-third of the participants had a positive attitude to combating smoking, particularly those with an educational level higher than Standard 7. Former smokers and heavy smokers had a significantly higher prevalence of ischaemic heart disease than the other participants. Smoking was associated with a low body mass index, low high-density lipoprotein cholesterol levels, low socio-economic standing, high alcohol consumption and type A coronary-prone behaviour in men. In 1982 the economically active coloured population of the Cape Peninsula spent an estimated R36.2 million on cigarettes.

Adolescent↗