Marianne Alberts

Prevalence of cardiovascular diseases and associated risk factors in a rural black population of South Africa

Background To determine the prevalence and associated risk factors of cardiovascular diseases in a rural adult black population from Limpopo Province in South Africa. Design A cross-sectional study. Methods A sample of 1608 women and 498 men aged 30 years and above participated in the study. Sociodemographic data, anthropometric measures (body mass index, waist/hip ratio), blood pressure and biochemical risk factors were measured. A global cardiovascular disease (CVD) risk profile was developed. Results There was a high prevalence of tobacco use for men (57%) and women (35.4%), with women (28.1%) predominantly using smokeless tobacco. Alcohol use was very common in men (57.2%). Women weighed a great deal more than men, and 51.7% were either overweight or obese. Diabetes was diagnosed in 8.8 and 8.5% of women and men, respectively. High-density lipoprotein-cholesterol was relatively high, whereas 42.3% of women and 28.5% of men had low-density lipoprotein-cholesterol levels of 3 mmol/l or more. Hypertension (blood pressure ≥ 140/90 mmHg) was found in 25.5% of women and 21.6% of men. According to the Framingham formulae, 18.9% of women and 32.1% of men had a 20% or higher chance of having a CVD event in the next 10 years. Conclusions There was a high prevalence of chronic disease risk factors in the rural, poor black community in Limpopo, South Africa. Consequently, the population had a higher than expected risk of developing a CVD event in the following 10 years when compared with similar studies in black Africans.

Prevalence and determinants of stunting and overweight in 3-year-old black South African children residing in the Central Region of Limpopo Province, South Africa

OBJECTIVES To determine the prevalence of stunting, wasting and overweight and their determinants in 3-year-old children in the Central Region of Limpopo Province, South Africa. DESIGN Prospective cohort study. SETTING Rural villages in the Central Region of the Limpopo Province, South Africa. SUBJECTS One hundred and sixty-two children who were followed from birth were included in the study. Anthropometric measurements and sociodemographic characteristics of the children were recorded. RESULTS Height-for-age Z-scores were low, with a high prevalence of stunting (48%). The children also exhibited a high prevalence of overweight (22%) and obesity (24%). Thirty-one (19%) children were both stunted and overweight. Gaining more weight within the first year of life increased the risk of being overweight at 3 years by 2.39 times (95% confidence interval (CI) 1.96-4.18) while having a greater length at 1 year was protective against stunting (odds ratio (OR) 0.41; 95% CI 0.17-0.97). Having a mother as a student increased the risk for stunting at 3 years by 18.21 times (95% CI 9.46-34.74) while having a working mother increased the risk for overweight by 17.87 times (95% CI 8.24-38.78). All these factors also appeared as risks or as being protective in children who were both overweight and stunted, as did living in a household having nine or more persons (OR 5.72; 95% CI 2.7-12.10). CONCLUSION The results of this study highlight the importance of evaluating anthropometric status in terms of both stunting and overweight. Furthermore, it is important to realise the importance of normal length and weight being attained at 1 year of age, since these in turn predict nutritional status at 3 years of age.

Dietary intake and barriers to dietary compliance in black type 2 diabetic patients attending primary health-care services.

OBJECTIVE To determine the dietary intake, practices, knowledge and barriers to dietary compliance of black South African type 2 diabetic patients attending primary health-care services in urban and rural areas. DESIGN A cross-sectional survey. Dietary intake was assessed by three 24-hour recalls, and knowledge and practices by means of a structured questionnaire (n = 133 men, 155 women). In-depth interviews were then conducted with 25 of the patients to explore their underlying beliefs and feelings with respect to their disease. Trained interviewers measured weight, height and blood pressure. A fasting venous blood sample was collected from each participant in order to evaluate glycaemic control. SETTING An urban area (Sheshego) and rural areas near Pietersburg in the Northern Province of South Africa. SUBJECTS The sample comprised 59 men and 75 women from urban areas and 74 men and 80 women from rural areas. All were over 40 years of age, diagnosed with type 2 diabetes for at least one year, and attended primary health-care services in the study area over a 3-month period in 1998. RESULTS Reported dietary results indicate that mean energy intakes were low (< 70% of Recommended Dietary Allowance), 8086-8450 kJ day(-1) and 6967-7382 kJ day(-1) in men and women, respectively. Urban subjects had higher (P < 0.05) intakes of animal protein and lower ratios of polyunsaturated fat to saturated fat than rural subjects. The energy distribution of macronutrients was in line with the recommendations for a prudent diet, with fat intake less than 30%, saturated fat less than 10% and carbohydrate intake greater than 55% of total energy intake. In most respects, nutrient intakes resembled a traditional African diet, although fibre intake was low in terms of the recommended 3-6 g/1000 kJ. More than 90% of patients ate three meals a day, yet only 32-47% had a morning snack and 19-27% had a late evening snack. The majority of patients indicated that they followed a special diet, which had been given to them by a doctor or a nurse. Only 3.4-6.1% were treated by diet alone. Poor glycaemic control was found in both urban and rural participants, with more than half of subjects having fasting plasma glucose above 8 mmol l(-1) and more than 35% having plasma glycosylated haemoglobin level above 8.6%. High triglyceride levels were found in 24 to 25% of men and in 17 to 18% of women. Obesity (body mass index > or = 30 kg m(-2)) was prevalent in 15 to 16% of men compared with 35 to 47% of women; elevated blood pressure (> or = 160/95 mmHg) was least prevalent in rural women (25.9%) and most prevalent in urban men (42.4%). CONCLUSIONS The majority of black, type 2 diabetic patients studied showed poor glycaemic control. Additionally, many had dyslipidaemia, were obese and/or had an elevated blood pressure. Quantitative and qualitative findings indicated that these patients frequently received incorrect and inappropriate dietary advice from health educators.

Relationship between adiposity and pedometer-assessed ambulatory activity in adult, rural African women

Purpose:To investigate the association between adiposity and pedometry-assessed ambulation in a convenience sample of adult, rural black South African women.Methods:Pedometry data were collected over 7 days in 121 subjects. Adiposity measures included body mass index (BMI), waist circumference (WC) and percentage body fat (PBF).Results:Sedentarism (<5000 steps day−1) was found in 13.7%, while 39.7% were classified as accruing sufficient physical activity (⩾10 000 steps day−1). Significant associations (P<0.02) existed between steps day−1 and adiposity measures (r=−0.22 to −0.23). After adjusting for age, only BMI remained significantly associated with steps day−1 (r=−0.20, P=0.032). Significant age-adjusted linear trends were found across combined BMI–WC risk categories for steps day−1 (P=0.036). Adjusting for age, motor vehicle access, education, use of tobacco products and comorbidities, BMI decreased 1.4 kg m−2 per 5000 steps day−1 (P=0.035), access to a motor vehicle within the household increased PBF by 4% (P=0.018), and compared with sedentarism, the risk of obesity (BMI ⩾30 kg m−2) was 52% lower at 10 000 steps day−1 (P=0.028).Conclusion:Modest associations were found between adiposity and ambulation. Ambulation decreased the risk for obesity, while motor vehicle access was associated with increased adiposity levels.

Prevalence of gestational diabetes mellitus and the effect of weight on measures of insulin secretion and insulin resistance in third-trimester pregnant rural women residing in the Central Region of Limpopo Province, South Africa.

Aims  To examine the prevalence of gestational diabetes in third‐trimester pregnant women as well as to assess their insulin secretion and insulin resistance (IR).

Spatial and temporal clustering of mortality in Digkale HDSS in rural northern South Africa.

Background: Mortality1 data are frequently presented at the overall population level, possibly obscuring small-scale variations over time and space and between different population sub-groups. Objective: Analysis of mortality data from the Dikgale Health and Demographic Surveillance System, in rural South Africa, over the period 1996–2007, to identify local clustering of mortality among the eight villages in the observed population. Design: Mortality data and person-time of observation were collected annually in an open-cohort population of approximately 8,000 people over 12 years. Poisson regression modelling and space–time clustering analyses were used to identify possible clustering of mortality. Results: Similar patterns of mortality clustering emerged from Poisson regression and space–time clustering analyses after allowing for age and sex. There was no appreciable clustering of mortality among children under 15 years of age nor in adults 50 years and over. For adults aged 15–49 years, there were substantial clustering effects both in time and in space, with mortality increasing during the period observed and particularly so in some locations, which were nearer to local conurbations. Mortality was relatively lower in the vicinity of the local health centre. Conclusions: Although cause-specific mortality data were not available, the rise in mortality in the 15–49-year age group over time and in areas closer to conurbations strongly suggests that the clustering observed was due to the development of HIV/AIDS-related mortality, as seen similarly elsewhere in South Africa. The HIV/AIDS services offered by the local health centre may have contributed to lower relative mortality around that location.

Descriptive Epidemiology of Ambulatory Activity in Rural, Black South Africans

PURPOSE We investigated the distribution of objectively measured ambulation levels and the association of ambulation levels to adiposity levels in a convenience sample of adolescent and adult, rural black South Africans. METHODS We analyzed 7-d pedometry data, collected over a period of nine consecutive days, in 789 subjects (women, n = 516; men, n = 273). Adiposity measures included body mass index (BMI) and waist circumference (WC). Obesity was defined as BMI > or = 30 kg x m(-2) or WC > or = 102 cm for men and WC > or = 88 cm for women. RESULTS The average age- and BMI-adjusted 7-d ambulation level was 12,471 steps per day (95% confidence interval (CI) = 12,107-12,834). Ambulation levels differed between sexes (P = 0.0012), and weekday ambulation differed from weekend ambulation (P = 0.0277). Prevalences, age adjusted to the world population, for sedentarism (SED; <5000 steps per day), low active-somewhat active (5000-9999 steps per day), and active-very active (ACT; > or =10,000 steps per day) were 8.0%, 25.5%, and 66.6%, respectively. In contrast, published self-reported national prevalences for physical inactivity, insufficient physical activity, and physically active have been estimated to be 43%-49%, 20%-27%, and 25%-37%, respectively. After adjusting for sex and age, adiposity measures remained significantly associated with steps per day (BMI, r = -0.08; WC, r = -0.12; P < 0.03). Adjusting for sex, age, village, and season, SED increased the risk of obesity by more than twofold compared with ACT (P < 0.05). Achieving <10,000 steps per day compared with ACT was associated with an increased multivariate-adjusted obesity risk of 86%-89% (P < 0.001). CONCLUSIONS Ambulation levels were high for this rural African sample, and prevalences for SED and ACT differed from published self-reported estimates.

Folate and iron status of South African non-pregnant rural women of childbearing age, before and after fortification of foods

after fortification, none of the women had low serum folate. Low red cell folate (<164 ng/ml) was observed in 26.4% of subjects before fortification, and in 1.9% of subjects after fortification. The prevalence of vitamin B12 deficiency (<145 pg/ml) was 6.3% during phase 1 of the study and increased to 11.3% during phase 2. Low haemoglobin levels were present in 7.5% of women before fortification, and in 5% of women after fortification. The percentage of women with low ferritin levels was similar before and after fortification (25%). Conclusion. The study shows a significant improvement in folate status in women of childbearing age approximately 9 months after fortification of maize and wheat foodstuffs in South Africa, whereas no improvement in iron status as measured by serum ferritin was observed.

All-cause mortality trends in Dikgale, rural South Africa, 1996—2003:

Aims: The Dikgale Demographic Surveillance System (DDSS) site, established in 1995, is one of three rural surveillance sites in South Africa. This paper describes detailed mortality patterns of a rural African population in the central region of Limpopo Province. Methods: These data were based on yearly household visits to collect data on vital events, covering 63, 873 person-years of observation over eight years. Results: Crude mortality was 7.5 per 1,000 person-years (females: 6.9, males: 8.1). Under-1 year and under-5 years mortality was 15.1 and 5.8 per 1,000 person-years, respectively. Life expectancy at birth was 64.3 years (females: 68.1, males: 60.0). For the two four-year periods (1996—9 and 2000—3) under-20 years mortality risk decreased (rate ratio=0.45, 95% CI: 0.25 to 0.80) while 20—49 years mortality risk increased (rate ratio=1.55, 95% CI: 1.10 to 2.20). Multivariate mortality risk for migrants remained relatively constant (0.71, 95% CI: 0.54 to 0.94) across the two four-year periods, but has increased 2.5-fold in all DDSS +50 year-old adults across the two four-year periods. Conclusions: The DDSS mortality estimates appear to have remained relatively constant while recent mortality estimates for the Agincourt Demographic and Health Surveillance System (ADHSS) site suggest that mortality risk is higher and life expectancy is lower in ADHSS residents. Moreover, DDSS mortality estimates are substantially more favourable compared with provincial and national mortality estimates.

Can the high prevalence of micronutrient deficiencies, stunting and overweight in children at ages 1 and 3 years in the Central Region of Limpopo province be explained by diet?

Abstract Objective. To assess whether the high prevalence of stunting and overweight accompanied by serum deficiencies of iron, folate and vitamin B12 in children at ages 1 and 3 years, can be explained by their diet. Design. A prospective cohort study. Setting. Villages in the central region of Limpopo province, which are serviced by Mankweng Hospital. Subjects. A cohort of children (N = 219) followed from birth were included in the study. Of the original cohort, 156 and 162 could be traced and assessed at ages 1 and 3 years, respectively. Dietary intake of the children was assessed using a quantitative food frequency questionnaire and at 3 years a 24-hour recall questionnaire was also administered. Results. The children in this cohort consumed an energy-dense diet of poor quality as evidenced by insufficient intakes of iron, zinc, calcium and phosphates as well as folate, riboflavin, vitamin B6, niacin and vitamin A. Overall, nearly 70% of the energy intake of the diet came from carbohydrates while the contribution from fat was less than 20%. Average protein intake was adequate but comprised mainly protein from vegetable sources which are poor sources of iron and certain essential amino acids. Furthermore, the diet was judged to be high in phytates because of the high intake of cereals and this would have contributed to making iron and zinc less available for absorption. Low fruit and vegetable intake was the cause of the low intake of folate, vitamin A and vitamin C. The prevalence of micronutrient deficiencies was confirmed by the high prevalence of children with iron and folate biochemical deficiencies. Conclusion. The children’s diet was poor in several micronutrients which included iron, calcium, folate and vitamin A. Chronic energy deficiency, especially from animal sources, seems to be the factor contributing to the high levels of stunting observed.