Aim and objectives: This study set out to investigate the diet and blood lipid profiles of subjects in
transition in the North West Province in South Africa. It looked specifically at how the diet differed
between rural and urban areas, how the blood lipid profiles differed between rural and urban subjects,
establishing an association between dietary fat, fatty acid and cholesterol intakes respectively and blood
lipid profiles, as well as investigating the differences in blood lipid profiles at different ages, body mass
index (BMI) and genders respectively in rural and urban areas.
Design: The present study was a cross–sectional data analysis nested within the Prospective Urban and
Rural Epidemiology (PURE) study that is currently undertaken in the North West Province of South
Africa amongst other countries.
Methods: Baseline data was obtained in 2005. A randomised paper selection was done of people
between 35 - 70 years of age with no reported chronic diseases of lifestyle, TB or HIV of those enrolled
into the PURE study if they had provided written consent. Eventually a paper selection was made of 2000
subjects, 500 people in each of the four communities (rural, urban–rural, urban, established urban). For
the interpretation purposes of this study, data was stratified for rural (1000 subjects) and urban (1000
subjects) only, with no further sub–division into communities. Physical activity levels and habitual diets
were obtained from these subjects. Demographic and dietary intake data in the PURE study was collected
using validated, culture sensitive questionnaires. Anthropometric measures and lipid analysis were
determined using standardised methodology. Descriptive statistics (means, standard deviations and
proportions) were calculated. One–way analysis of variance (ANOVA) was used to determine
differences between the different levels of urbanisation on blood lipid profiles and dietary intake. When a
dietary intake variable proved to be significant for different levels of a factor (urbanisation, blood lipid
profile), post–hoc tests were calculated to determine which levels for specific variables differed
significantly. Bonferroni–type adjustments were made for the multiple comparisons. Spearman
correlations were calculated to determine associations.
Results: Mean fat intake was significantly higher in urban areas than in rural areas (67.16 ± 33.78 g vs.
32.56 ± 17.66 g, p<0.001); and the same was true for the individual fatty acid intakes. Fat and fatty acid
intakes were still within recommendations even for urban areas, and low for rural areas. N–3 intake was
very low in both rural and urban areas. Serum lipids did not differ significantly between rural and urban
areas. Almost half of rural (43%) and urban (47%) subjects presented with elevated total cholesterol
(5.0 mmol/L). In rural areas 52% and in urban areas 55% of subjects had elevated LDL–C (3.0
mmol/L). Amongst 23% of males in rural areas and 18% of males in urban areas HDL–C levels were
decreased. Of the females living in rural areas 34.3% had decreased HDL–C levels and 39% of those who lived in urban areas presented with lowered HDL–C levels. In rural areas 16.3% of subjects and in urban
areas 23% of subjects presented with high triglyceride levels. TC, LDL–C and triglyceride levels were
higher in higher body mass index (BMI) classes, however, obese subjects did not differ significantly from
overweight subjects in terms of blood lipids, suggesting that values stabilise after reaching overweight
status. These blood lipids were also higher in higher age groups and higher in women than men, probably
due to the high incidence of obesity in women.
Conclusions: Associations between the diet and blood lipid profiles were weak, and diet is not likely to
be the only factor responsible for high TC and LDL–C levels. Blood lipid profiles did not differ
significantly between rural and urban areas due to the fact that the diet was prudent in terms of fat intake
in both rural and urban areas. Higher prevalence of underweight was noted in males (32% in rural areas
and 28% in urban areas), while overwieght was a bigger problem amongst women (48% in rural areas and
54% in urban areas). TC, LDL–C and TAG were higher with higher BMI’s, while HDL–C levels were
lower. TC, LDL–C, and TAG were higher in higher age goups while HDL–C levels were lower. Female
subjects presented with higher mean triglycerides than males, probably due to higher prevalence of
overweight and obesity. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2011.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:nwu/oai:dspace.nwu.ac.za:10394/4654 |
| Date | January 2010 |
| Creators | Richter, Marilize |
| Publisher | North-West University |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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