Search PubMed⌕ Search

Biomedical subjects

P L Jooste

Publications and source records attributed to P L Jooste.

At least 19 recordsLinked to original sources
PubMed2005

Knowledge of iodine nutrition in the South African adult population.

OBJECTIVES: To determine the level of knowledge regarding iodine nutrition and its relationship with socio-economic status in the South African population. DESIGN: A cross-sectional population survey collecting questionnaire information on knowledge of iodine nutrition and sociodemographic variables in a multistage, stratified, cluster study sample, representative of the adult South African population. SETTING: Home visits and personal interviews in the language of the respondent. SUBJECTS: Data were collected from one adult in each of the selected 2164 households, and the participation rate was 98%. RESULTS: Only 15.4% of respondents correctly identified iodised salt as the primary dietary source of iodine, 16.2% knew the thyroid gland needs iodine for its functioning, and a mere 3.9% considered brain damage, and 0.8% considered cretinism, as the most important health consequence of iodine deficiency. Compared with respondents from high socio-economic households, respondents from low socio-economic households were considerably less informed about aspects of iodine nutrition covered in this study. CONCLUSIONS: The knowledge level of iodine nutrition is low among South Africans, particularly among the low socio-economic groups. These data suggest that the international emphasis on brain damage resulting from iodine deficiency has not been conveyed successfully to the consumer level in this country.

Adolescent↗
PubMed2003

The use of iodised salt in the manufacturing of processed foods in South Africa: bread and bread premixes, margarine, and flavourants of salty snacks.

Salt is widely used by the food industry, but information on the use of iodised salt as an ingredient in the manufacturing of processed foods in South Africa is not available. The iodine content of salt used in the manufacturing of bread, margarine and salty snack flavourants was investigated in a cross-sectional descriptive study. Questionnaire information and salt sampled on 1 day per week for 5 consecutive weeks were obtained from 12 food manufacturers (eight bread and bread premix manufacturers, two margarine manufacturers and two salty snack flavourant manufacturers). The iodine concentration of salt samples was analysed using the potentiometric titration method. Eleven of the 12 manufacturers surveyed reported that they used non-iodised salt. The reported reasons for using non-iodised salt included properties of the final product, health reasons, and financial considerations. However, substantial amounts of iodine were found in the salt of one-third of these manufacturers (n = 4), ranging from a mean content of 39-69 ppm. Three of these four particular manufacturers distributed their products countrywide. This information serves as a strong indication that iodised salt does not necessarily cause the adverse affects that food manufacturers fear may affect their products. Although the amounts of iodine in the salt were variable, our results showed that an appreciable percentage of the food companies used iodised salt unknowingly in the manufacturing of frequently consumed processed foods, and this may have a considerable impact on the daily iodine intake of consumers.

Bread↗
PubMed2001

A community-based trial for the control of lymphatic filariasis and iodine deficiency using salt fortified with diethylcarbamazine and iodine.

To evaluate the effectiveness of salt fortified with diethylcarbamazine (DEC) and iodine for elimination of Bancroftian filariasis and iodine deficiency, all consenting residents of Miton, Haiti (n = 1,932) were given salt fortified with 0.25% diethylcarbamazine and 25 ppm of iodine for one year. Wuchereria bancrofti microfilaria prevalence and intensity, antigenemia, and urinary iodine were measured before and one year after salt distribution began. To measure the effect of DEC-fortified salt on adult worm motility, 15 microfilaria-positive men were examined by ultrasound of the scrotal area. Entomologic surveys were conducted to determine the proportion of W. bancrofti-infected Culex quinquefasciatus. After one year of treatment, the prevalence and intensity of microfilaremia were both reduced by more than 95%, while antigenemia levels were reduced by 60%. The motility of adult worms, as detected by ultrasound, was decreased, but not significantly, by DEC-fortified salt. The proportion of vector mosquitoes carrying infective stage larvae decreased significantly from 2.3% in the nine months before the intervention to 0.2% in the last three-month follow-up period. Iodine deficiency, which had been moderate to severe, was eliminated after one year of iodized salt consumption. The DEC-fortified salt was well accepted by the community and reduced microfilaremia and transmission to low levels in the absence of reported side effects. Based on these results, salt cofortified with DEC and iodine should be considered as a concurrent intervention for lymphatic filariasis and iodine deficiency elimination programs.

Adolescent↗
PubMed2001

Iodine concentration in household salt in South Africa.

OBJECTIVE: To determine the iodine concentration in household salt, the coverage of adequately iodized salt, the use of non-iodized agricultural and producers' salt, and the usefulness of salt as a carrier of iodine, and to relate these observations to socioeconomic status in South Africa. METHOD: The iodometric titration method was used to analyse 2043 household salt samples collected using a national, multistage, stratified, cluster survey. FINDINGS: The national mean and median iodine concentrations of household salt were 27 mg/kg (95% confidence interval (CI): 25-29 mg/kg) and 30 mg/kg (range = 0-155 mg/kg), respectively. There was considerable variation within and between geographical areas. Coverage of adequately iodized household salt, i.e. iodized at > 15 mg/kg, was 62.4% of households (95% CI: 58.8-66.0%) two years after the introduction of compulsory iodization at a level of 40-60 mg/kg. A total of 7.3% of households used non-iodized agricultural salt and salt obtained directly from producers. People at the lower end of the socioeconomic spectrum were more likely to suffer the consequences of using under-iodized salt because more of them used agricultural or coarse salt than did people in the higher socioeconomic categories. The iodine concentration in salt was lower in rural areas than in urban and periurban areas. CONCLUSIONS: The consequences of using under-iodized or non-iodized salt were most likely to be experienced in the country's three northern provinces, among people in the low socioeconomic categories, and in rural households. Since 95.4% of households in South Africa use salt regularly and 2.9% use it occasionally, the national iodization programme has the potential to meet the iodine requirements of the population. However, this can only be achieved if the primary reasons for the inadequate iodization of salt are eliminated and if special attention is given to vulnerable groups.

Cross-Sectional Studies↗
PubMed2000

Short-term effectiveness of mandatory iodization of table salt, at an elevated iodine concentration, on the iodine and goiter status of schoolchildren with endemic goiter.

BACKGROUND: Goiter rates and iodine deficiency usually show marked improvement in efficacy studies of mandatory iodization of salt, but little is known about the short-term effectiveness of mandatory iodization. OBJECTIVE: The aim of the study was to evaluate, after 1 y, the effectiveness of mandatory iodization of salt at an iodine concentration higher than that occurring under optional iodization on the goiter rates and iodine status of schoolchildren living in an endemically goitrous area. DESIGN: Goiters, measured by palpation, and urinary iodine concentrations of children in grades 4-7 in 4 schools in a known goitrous area in South Africa were assessed before and 1 y after the introduction of mandatory iodization at a higher iodine concentration than occurred with optional iodization. Estimates of the iodine concentration of iodized salt and the proportion of households using iodized salt were also made. RESULTS: Iodine concentration in table salt and household use of iodized salt improved within 1 y. Goiter rates, which varied at baseline from 14. 3% to 30.2% in the 4 schools, remained unchanged, with an overall mean (+/-SE) prevalence of 25.6 +/- 2.5% at baseline and of 27.5 +/- 2.7% 1 y later. The distribution of urinary iodine concentrations in the 4 schools improved substantially from the baseline deficient range. The overall median urinary iodine concentration increased from 0.17 to 1.47 micromol/L. CONCLUSIONS: Mandatory iodization of salt virtually eradicated iodine deficiency within 1 y in South African schoolchildren, but the goiter rate in these children did not decline. Measurement of goiters by palpation may not be appropriate in short-term evaluations of mandatory iodization programs.

Child↗
PubMed1999

Endemic goitre in the absence of iodine deficiency in schoolchildren of the Northern Cape Province of South Africa.

OBJECTIVE: The study was undertaken to investigate whether endemic goitre still exists in the Northern Cape Province of South Africa more than 55 years after it was reported and, if so, whether iodine deficiency, or fluoride in the drinking water, is linked to the goitres. DESIGN: Cross-sectional study of children in three pairs of towns. SUBJECTS: The 6-, 12- and 15-year-old children (n = 671) who had been lifetime residents in two Northern Cape towns with low levels, two towns with near optimal levels and two towns with high levels of fluoride in the drinking water were recruited through the schools as study participants. RESULTS: Endemic goitre was found in all the towns except one, ranging from 5% to 29%. Iodine deficiency did not prevail in the study area because the median urinary iodine concentration, exceeding 1.58 micromol/l in all but one of the towns, indicated a more than adequate iodine consumption. The drinking water and, to a lesser extent, iodised salt were important sources of iodine. No relationship was found between fluoride in the water and the mild goitre prevalence (5% to 18%) in the four towns with either a low or near optimal fluoride content in the water. The causal factor(s) responsible for the goitres in these four towns were not clear from our data. However, the prevalence of goitre was higher (28% and 29%) in the two towns with high levels of fluoride in the water. CONCLUSION: These results indicate that either a high fluoride level in the water or another associated goitrogen, other than iodine deficiency, may have been responsible for these goitres.

Adolescent↗
PubMed1999

Impact after 1 year of compulsory iodisation on the iodine content of table salt at retailer level in South Africa.

The short-term effectiveness of introducing compulsory iodisation through revised health legislation, evaluated in terms of the iodine content of iodised table salt, was investigated in three of the nine provinces in South Africa. Shortly before the introduction of compulsory iodisation of table salt in December 1995, iodised at a higher level than before, 187 iodised salt samples were purchased at retailers in 48 magisterial districts situated in the three provinces of Western and Eastern Cape and Mpumalanga for analysis of the iodine content using the titration method. In a follow-up 1 year later 287 iodised salt samples were obtained from the same retailers for iodine determination. The mean iodine content of iodised salt increased significantly from 14 to 33 ppm. However, large variation in the iodine content of iodised table salt among and within salt brands existed at follow-up, and the mean iodine content was lower than the legal specification of 40 to 60 ppm. Only 24% of the samples were found within the range required by the law at follow-up compared to 42% before revising the salt legislation. Despite the introduction of compulsory salt iodisation, the mean retail price of iodised salt remained the same between 1995 and 1996 for a 500 g package of salt. Further refinement of the iodisation process is necessary to improve the accuracy of iodisation and decrease the variation in iodine content. This study nevertheless showed that the introduction of compulsory iodisation and elevating the legally specified iodine level of table salt resulted in a significantly elevated mean iodine level of iodised salt within 1 year, without any additional cost to the consumer.

Follow-Up Studies↗
PubMed1998

Plasma fibrinogen of black South Africans: the BRISK study.

OBJECTIVE: To describe the distribution of plasma fibrinogen and relationships with other risk factors for coronary heart disease (CHD) and stroke in the black population of the Cape Peninsula. DESIGN: A cross-sectional survey of a stratified proportional sample of randomly selected black men and women. SETTING: Households in Gugulethu, Langa, Nyanga, New Crossroads, KTC, Old Crossroads and Khayelitsha in the Cape Peninsula, South Africa. SUBJECTS: One subject per household (352 men and 447 women), aged 15-64 years, voluntarily participated. Visitors, pregnant, lactating, ill, mentally retarded and intoxicated subjects were excluded. RESULTS: Mean fibrinogen (thrombin time coagulation method) of men and women were higher than published data for Europeans but slightly lower than values of black Americans. Women aged 45-54 years had the highest level (3.13+/-0.89 g l(-1)) and men aged 15-24 years had the lowest (2.13+/-0.88 g l(-1)). Fifteen per cent of the men and 12% of the women had a level greater than 1 standard deviation of the mean for their age group. Univariate and multivariate analyses revealed significant (P<0.05) positive correlations of fibrinogen with smoking habit, age, body mass index (BMI), total and low-density lipoprotein (LDL) cholesterol, triglycerides, blood pressure and white blood cell count, and significant negative correlations with high-density lipoprotein (HDL) cholesterol, gamma glutamyl transferase (GGT), serum iron and ferritin. The correlations with BMI, serum lipoproteins, iron, ferritin, and GGT suggest that nutritional status and therefore diet influences plasma fibrinogen. CONCLUSION: Relatively high fibrinogen levels, tending to cluster with other, including diet-related, risk factors for CHD and stroke, were observed in black South Africans. It is suggested that fibrinogen may contribute to the high stroke incidence of this population group.

Adolescent↗
PubMed1997

The effect of dietary iron deficiency on the fatty acid composition of plasma and erythrocyte membrane phospholipids in the rat.

Severe iron deficiency was introduced in rats by feeding outbred male Wistar rats a purified diet that was either adequate or deficient in iron. The rats were weighed regularly over 4 weeks to monitor body weight differences, after which blood was drawn from a subsample to determine the haemoglobin concentrations and fatty acid composition of plasma total phospholipids and to measure the erythrocyte membrane phosphatidylcholine and phosphatidylethanolamine levels. Comparisons between dietary iron adequate (control) and dietary iron deficient (experimental) rats showed that the experimental rats had lower body weight and plasma total phospholipid linoleic acid levels typical of the symptoms of essential fatty acid deficiency. Erythrocyte membrane phosphatidylethanolamine arachidonic acid levels were increased (P < 0.05) with concomitant decreases in oleic acid (P < 0.01). Correlations between fatty acids and growth suggest that the mechanism whereby iron deficiency affects growth is in some way related to abnormal fatty acid shifts that disturb the delicate balance of essential fatty acids in membranes. Additional omega 3 and omega 6 fatty acids may be necessary to counteract the effect of iron deficiency in rats.

Animals↗
PubMed1997

Twelve-year results of the Coronary Risk Factor Study (CORIS).

BACKGROUND: After 4 years a coronary heart disease risk factor intervention programme produced equally large and significantly reduced risk profiles in two intervention towns compared with a control town. Intervention effects through community participation were assessed after cessation of the active intervention programme. The impact of secular trends was assessed in the control town and in two previously unstudied towns. METHODS: Cross-sectional surveys were done in a random sample of 1620 participants aged 15-64 years in the three original towns 12 years after the initial quasi-experimental study. Two years later 327 subjects, aged 35-44 years, were studied in the original control town and in two non-intervention towns. Risk factor knowledge, smoking and medical histories were determined by questionnaire. Blood pressure, anthropometry and blood lipids were recorded. Data were compared across towns, and with previous surveys. RESULTS: At 12 years the low intensity intervention town maintained a significantly better risk factor profile than the control town, while the high intensity intervention town now matched the control town. No differences in risk factor profiles were found between the control town and the two new towns. Deaths from coronary heart disease and strokes showed a downward trend in the study area. CONCLUSIONS: Outcome suggests large ongoing secular trends during the study could have overtaken the intervention effects in the high intensity town, but not in the low intensity intervention town, which showed an advantage over the control town. These results support the effectiveness of media-based, long term health promotion strategies to reduce cardiovascular disease risk profiles.

Adolescent↗
PubMed1997

Endemic goitre in a rural community of KwaZulu-Natal.

OBJECTIVE: To quantity the prevalence of goitre and iodine deficiency. SETTING: Ndunakazi, a rural community of approximately 8000 people in KwaZulu-Natal. DESIGN: A cross-sectional community-based survey and a school-based survey. PARTICIPANTS: The 127 mothers and 114 children aged 6-11 years, selected during the cross-sectional survey, and 304 children aged 5-14 years, from the school-based survey. METHODS: Urinary iodine levels and thyroid size were determined and categorised according to guidelines proposed jointly by the WHO, UNICEF and the ICCIDD. Z-score anthropometric indicators were calculated, and mid-year exam marks of goitrous and non-goitrous pupils for Zulu and mathematics were compared. RESULTS: In school-aged children, both surveys demonstrated a goitre prevalence in the 20-29.9% range and a median urinary iodine level in the 2-4.9 micrograms/dl range, indicating iodine deficiency of moderate severity. Goitrous subjects scored consistently worse in their Zulu exam papers than those without goitre. Stunting was not more prevalent than in the rest of KwaZulu-Natal. Iodised salt was not available in any of the three community shops. CONCLUSIONS: This level of iodine deficiency in children can adversely affect their neuropsycho-intellectual development. Factors contributing to deficient iodine intake in Ndunakazi are present in many rural areas, and South Africa cannot afforded to be overly confident about the apparent absence of iodine deficiency as a public health problem.

Adolescent↗
PubMed1997

Iodine deficiency and endemic goitre in the Langkloof area of South Africa.

OBJECTIVE: To quantify the prevalence of iodine deficiency and endemic goitre in the Langkloof area. DESIGN: A cross-sectional study. SETTING: Four primary schools in four communities in the Langkloof. SUBJECTS: 565 primary schoolchildren from Standard 2 to Standard 5. OUTCOME MEASURES: Clinical diagnosis of thyroid size by palpation, level of iodine in urine and drinking water samples, level of iodine in iodised salt samples from the area, percentage of households with iodised salt on the premises, and anthropometric measures of body height and weight. RESULTS: The prevalence of endemic goitre varied from 14.3% to 30.2% in the four communities and, based on urinary iodine levels, the iodine deficiency ranged from mild to severe. Both iodised and non-iodised salt were available at the local grocery stores but only small percentages of households had iodised salt in the house. The iodine content of drinking water was low. Anthropometric indices of undernutrition indicated medium to high levels of stunting in three of the four communities, the worst being in the community with the highest goitre prevalence. CONCLUSIONS: Endemic goitre caused by iodine deficiency is a public health problem in the Langkloof, varying in severity from mild to severe in the different communities. The impact of mandatory iodisation of table salt, introduced at the end of 1995, needs to be assessed in these communities.

Adolescent↗
PubMed1997

Nutritional status of rural children in the Lesotho Highlands.

A baseline cross-sectional study was done to evaluate the nutritional status of the population of the Mohale Dam catchment area before construction of the dam commenced. In this article we report on the anthropometric, clinical and dietary assessment of the children less than 15 years of age in the study population. A two stage stratified sampling technique was used to randomly select 29 of the 83 villages in the study area. Children under 15 years of age from 395 households, representing approximately 50% of households in the selected villages, were included in the study. Anthropometric measurements of body height and weight in relation to age and sex indicated undernutrition varying, with few exceptions, from high to very high levels in children under 15 years. Stunting, indicating chronic undernutrition, was of particular concern in children, even from the first year of life. Very few clinical signs of nutritional deficiencies were found except for a goitre prevalence of 17.5% in 10 to 14 year old children. This was supported by the very low urinary iodine excretion (median 1.3 micrograms/dL) which indicated a severe iodine deficiency. Dietary evaluation showed high initiation rates of breastfeeding as well as a long duration of breastfeeding. Complementary foods were introduced at an early age, resulting in low exclusive breastfeeding rates. Regular meals were reported but qualitative analysis of the diet showed that a too small variety of foods were eaten, with an irregular intake of protein-rich foods and milk. Quantitative data on 3- < 5-year-old children showed that micro-nutrient intakes were low and that the energy intake of these children was inadequate. The results showed that these nutritionally vulnerable children should be monitored for the impact of the dam construction on their nutritional status.

Adolescent↗
PubMed1996

The lipid and lipoprotein profile of the urban black South Africa population of the Cape Peninsula - the BRISK study.

OBJECTIVE: To determine the lipid and lipoprotein profile of the urban black South African population of the Cape Peninsula. DESIGN: Cross-sectional design. SETTING: The seven black residential areas of the Cape Peninsula. PARTICIPANTS: A stratified proportional sample was drawn from the study area. The sample consisted of 422 men and 544 women aged between 15 and 64 years. OUTCOME MEASURES: Lipid and lipoprotein levels. Risk levels for coronary heart disease (CHD). RESULTS: The total cholesterol (TC level) was low compared with other South African groups studied. Men had a mean TC of 3.98 mmol/l and women 4.15 mmol/l. Low-density lipoprotein cholesterol (LDLC) values for men (2.03 mmol/l) were lower than those for women (2.30 mmol/l). Men (1.35 mmol/l) and women (1.37 mmol/l) had similar high-density lipoprotein cholesterol (HDLC) levels. Both sexes had a prevalence of protective HDL/TC ratios above 30% for all age groups. High HDL3C levels and low HDL2C levels were found in both men and women. Apolipoprotein A and B followed the trends of HDLC and LDLC and showed no difference between the sexes. The plasma triglyceride (TG) levels increased with age in both sexes. Men displayed higher TG levels than women in all age groups. Seventeen per cent of men and 26% of women had a moderate-to-high risk for CHD, given their TC levels. Other lipid-related risk factors indicated low risk for CHD.

Adolescent↗
PubMed1996

Apolipoprotein B levels and related factors in a rural white South African community--the CORIS study. Coronary Risk Factor Study.

OBJECTIVE: In a survey of the Coronary Risk Factor Study (CORIS), apolipoprotein B (apoB) levels were determined to ascertain their impact on coronary heart disease (CHD) risk. Other CHD risk factors associated with apoB were also identified. DESIGN: Cross-sectional analytical study, which included CHD risk factor and dietary questionnaires, electrocardiography, anthropometric and blood pressure measurements, and a blood sample for a lipid profile. SETTING AND PARTICIPANTS: The three districts of Riversdale, Robertson and Swellendam in the south-western Cape; a 25% random sample of 1,528 white respondents aged 15-68 years. RESULTS: Men tended to have higher mean apoB levels than women. Classification of CHD risk by apoB levels and total cholesterol (TC) levels did not correspond, as only 61% of men and 58.5% of women were classified in the same risk categories. Respondents in the highest apoB risk category reported a medical history of hypercholesterolaemia and hypertension more frequently than those in lower categories. There was a significant increase from the low to the high apoB risk category of TC, low-density lipoprotein (LDL) cholesterol, triglyceride levels, body mass index and percentage body fat. Using stepwise multiple regression, 84.9% of the variation in apoB of men and 85.8% in apoB of women were accounted for by significantly associated variables. CONCLUSION: Although apoB may be a better predictor of CHD than TC or LDL cholesterol concentrations, its easy approximation with the formula (TC-HDLC)/2 + 20, high cost, measurement variability and an approach in management similar to that for raised TC discourage its routine use in the screening of patients for CHD.

Adolescent↗
PubMed1995

Epidemiology and control of schistosomiasis mansoni in communities living on the Cuando River floodplain of East Caprivi, Namibia.

The Cuando River area of eastern Caprivi, Namibia, is highly endemic for Schistosoma mansoni whereas S. haematobium transmission, due to the scarcity of its intermediate host snail, Bulinus africanus, does not occur. Chemotherapy (6-monthly blanket treatments with praziquantel) combined with focal mollusciciding (monthly application of niclosamide) was used in a project in the area to control the disease. Although as many adults and pre-school children as possible were tested and treated, the project concentrated largely on school-age children. It took 3 years for prevalence to decline from > 80% to 20% because of a lack of proper sanitary facilities and piped water supplies and high rates of absenteeism and re-infection. However, intensity of infection decreased more rapidly, from an arithmetic mean of > 200 to < 5 eggs/g faeces. Hepatomegaly was common among school children when the project started but could be seen in only a small percentage of them after 3 years of control. Neither the bovine schistosome, S. mattheei, nor the lechwe schistosomes, S. margrebowiei and S. leiperi, were observed in the excreta of humans living in the area.

Adolescent↗
PubMed1995

The haematological profile of urban black Africans aged 15-64 years in the Cape Peninsula.

A stratified probability sample (n = 986) with quotas was drawn from black residential areas in the Cape Peninsula, South Africa. Subjects (n = 819) aged 15-64 years, participated in a coronary heart disease (CHD) risk factor survey, the BRISK Study. Nutritional status and prevalence of CHD was determined in this population undergoing rapid urbanization. Full blood and differential white blood cell counts provided data to calculate population reference values based on the 95% reference limits of the haematological parameter. Mean haemoglobin concentrations (Hb) in men (14.0 g/dl) and women (12.4 g/dl) were +/- 1.5 g/dl lower than previous South African reports. Mean BRISK Hb values were very similar to the World Health Organization's Hb cutoff criteria (< 13 g/dl men; < 12 g/dl women), indicating a possible high prevalence of anaemia. Significantly higher (P < 0.05) mean values for red cell indices were confirmed in men, which also reflected equally higher red blood cell counts (RBC), haematocrit (HCT) and mean corpuscular haemoglobin (MCH) values. Mean Hb values were significantly lower in the younger (15-24 years) and older (55-64 years) men compared with 25-54 year-olds (P < 0.05). Hypochromic microcytic anaemia was more prevalent in women, possibly due to iron deficiency (ID), while macrocytic anaemia was more prevalent in men. No significant differences were noted in mean total and differential white blood cell counts (WBC) between men and women.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗