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RESEARCH ARTICLE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
30
VOLUME 16 NUMBER 1 • JULY 2019
Ellisras Longitudinal Study 2017: The relationship
between waist circumference, waist-to-hip ratio,
skinfolds and blood pressure among young adults in
Ellisras, South Africa (ELS 14)
RB Sebati, Kotsedi D Monyeki, MS Monyeki, B Motloutsi, AL Toriola, MJL Monyeki
Correspondence to: Kotsedi D Monyeki
Department of Physiology and Environmental Health, University of Limpopo,
Sovenga, South Africa
e-mail:
kotsedi.monyeki@ul.ac.zaRB Sebati, MS Monyeki, B Motloutsi, MJL Monyeki
Department of Physiology and Environmental Health, University of Limpopo,
Sovenga, South Africa
AL Toriola
Department of Sport, Rehabilitation and Dental Sciences, Tshwane University
of Technology, Pretoria, South Africa
Previously published in
Cardiovasc J Afr
2019;
30
: 24–28
S Afr J Diabetes Vasc Dis
2018;
16
: 30–34
Abstract
Background:
Obesity and hypertension are major risk factors
for non-communicable diseases in the world today. The
relationshipbetween indicators of obesity andbloodpressure
needs attention in the rural South African population.
Aim:
This study examined the relationship between anthro-
pometric parameters and blood pressure (BP) among young
adults in the Ellisras rural area of South Africa.
Methods:
A total of 742 (365 females and 377 males) young
adults aged 22 to 30 years, who were part of the Ellisras
Longitudinal Study (ELS), participated in the research.
Anthropometric and BP measurements were taken using the
protocol of the International Society for the Advancement
of Kinanthropometry (ISAK). Linear regression was used
to determine the relationship between anthropometric
parameters and BP. The risk of developing hypertension
among young Elisras adults was evaluated using logistic
regression.
Results:
The results indicted a higher but non-significant
prevalence of hypertension in men (2.7%) than women
(2.4%). Linear regression showed a significant positive (
p
<
0.05) association between waist circumference and systolic
BP (beta = 0.273, 95% CI: 0.160–0.386), even after being
adjusted for age and gender (beta = 253, 95% CI: 0.127–
0.343). The risk for developing hypertension was significant
(
p
< 0.05) for waist circumference (OR = 2.091, 95% CI: 1.129–
3.871) after adjustment for age and gender.
Conclusion:
Of all anthropometric parameters, waist
circumference was most significantly associated with BP
(
p
< 0.05). Anthropometric indicators of obesity were strong
predictors of hypertension among young adults in the Ellisras
rural area.
Keywords:
hypertension, skinfolds, waist circumference, waist-to-
hip ratio, central obesity, adults
Hypertension is a significant global challenge that contributes to
high risk of cardiovascular and kidney disease.
1
The prevalence
of hypertension continues to increase in low- and middle-income
countries,
2
and is mainly due to population growth, aging and
behavioural risk factors such as unhealthy diet, which lead to
obesity.
3
Obesity usually refers to excessive storage of energy in the
form of adipose tissue,
4
and remains a strong predictor for the
risk of developing hypertension.
5
Moreover, a high prevalence
of hypertension is found in individuals who are more obese or
overweight than normal individuals, thus further increasing the risk
for cardiovascular disease.
6
Studies have also shown that obesity
increases fatty tissue, which heightens vascular resistance and
overworks the heart to pump blood throughout the body, thereby
elevating blood pressure.
7
Studies have established that anthropometry is an easy and
reliable method to use for predicting cardiovascular diseases
(CVDs), including hypertension.
8,9
However, such studies were
mostly conducted in children and fewer in adults, especially in rural
areas.
10,11
In the same rural population, Monyeki
et al
.
12
reported
skinfold thickness, waist circumference (WC) and body mass index
(BMI) to have a significant positive association with blood pressure
at a younger age (seven to 13 years). However, little is known
about the association between WC, waist-to-hip ratio (WHR) and
skinfold thickness with BP in young adults. Therefore, the aim of
this study was to assess the relationship between anthropometric
(WC, skinfold thickness, WHR) parameters and BP among young
Ellisras adults aged between 22 and 30 years.
Methods
Ellisras, now known as Lephalale, is a rural area based in Limpopo
province, South Africa. Ellisras has approximately 42 settlements,
with a population of about 5 000 people.
13
Ellisras village (23°
40’S, 27° 44’W) is about 70 km from the nearest settlement on the
Botswana border.
In Ellisras, the Iscor coal mine and Matimba electricity station
are the main sources of employment for the people, while other
sources of livelihood include crop farming and cattle rearing, as few
individuals are educated. Unemployment and poverty appear to be
a major concern in South African rural areas, including Ellisras.
14
Details of the Ellisras Longitudinal Study (ELS) research design
and sampling procedure have been reported elsewhere.
15,16
For the
purpose of this analysis, a total of 742 young adults aged 22 to