Cardiovascular Journal of Africa: Vol 28 No 2 (March/April 2017)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 2, March/April 2017 92 AFRICA
Comparative analysis of anthropometric indices of
obesity as correlates and potential predictors of risk for
hypertension and prehypertension in a population in
Nigeria
Chimaobi James Ononamadu, Chinwe Nonyelum Ezekwesili, Onyemaechi Faith Onyeukwu, Uchenna
Francis Umeoguaju, Obiajulu Christian Ezeigwe, Godwin Okwudiri Ihegboro
Abstract
Background: Obesity is a well-established independent risk
factor for hypertension and other cardiometabolic disorders.
However, the best anthropometric index of obesity that
predicts or associates strongly with hypertension and related
conditions remains controversial and inconclusive.
Objective: This study compared the performance of eight
anthropometric indices of obesity: body mass index (BMI),
ponderal index (PI), waist circumference (WC), hip circum-
ference (HC), waist–hip ratio (WHR), waist–height ratio
(WHtR), body adiposity index (BAI) and conicity index (CI)
as correlates and potential predictors of risk of hyperten-
sion and prehypertension in a Nigerian population, and also
the possible effect of combining two or more indices in that
regard.
Methods: This church-based, cross-sectional study was
conducted in Anambra state, south-eastern Nigeria from
2012 to 2013. A total of 912 persons (436 male and 476
female) drawn randomly from three major cities (Awka,
Onitsha and Nnewi) in the state participated in the study.
Information on demography, medical history and lifestyle
were obtained using a well-structured and validated question-
naire. The systolic/diastolic blood pressure and anthropo-
metric measurements were taken by well-trained personnel.
The resulting data were analysed using descriptive statistics,
logistic regression, Poisson regression and receiver operating
characteristic curve analysis.
Results: The mean values of all the anthropometric indices
studied increased from normotension, through prehyperten-
sion to hypertension in both genders. BMI, WC, HC and CI
were significantly higher (p < 0.05) in females than males.
All the anthropometric indices studied were significantly (p
< 0.001 except for CI) correlated with systolic and diastolic
blood pressure. BMI, WHtR, WC and PI (with higher corre-
lation coefficients for blood pressure) showed the best poten-
tial to predict hypertension and prehypertension in the study:
BMI (cut-off = 24.49, AUC = 0.698; cut-off = 23.62, AUC =
0.659), WHtR (cut-off = 0.55, AUC = 0.682; cut-off = 0.5,
AUC = 0.636), WC (cut-off = 91.44, AUC = 0.692; cut-off
= 82.55, AUC = 0.645), PI (cut-off = 14.45, AUC = 0.670;
cut-off = 13.69, AUC = 0.639), in males; and BMI (cut-off =
24.44, AUC = 0.622; cut-off = 28.01, AUC = 0.609), WHtR
(cut-off = 0.51, AUC = 0.624; cut-off = 0.6, AUC = 0.572),
WC (cut-off = 96.62, AUC = 0.616; cut-off = 96.52, AUC
= 0.584), PI (cut-off = 16.38, AUC = 0.619; cut-off = 17.65,
AUC = 0.599), in females for hypertension and prehyperten-
sion, respectively. In predicting hypertension risk, WC and
WHtR did not significantly improve the performance of BMI
in the models when included using our decision rule. Overall,
CI had a very poor discriminatory power for both conditions
in this study.
Conclusion: BMI, WHtR, WC and PI emerged the best
predictors of hypertension risk, and BMI, WC and PI of
prehypertension risk in this study. The combination of
high-performing anthropometric indices in a model did not
improve their performance. Therefore we recommend the
simultaneous but independent use of BMI and either WC
or WHtR for predicting hypertension, and BMI and WC
for prehypertension risk, bearing in mind that both types of
index (abdominal and general obesity) account for different
forms of obesity.
Keywords: hypertension, prehypertension, obesity, anthropomet-
ric index, ROC curve
Submitted 13/11/15, accepted 12/5/16
Published online 13/7/16
Cardiovasc J Afr 2017; 28: 92–99
DOI: 10.5830/CVJA-2016-061
The burden of the metabolic syndrome, which includes
hypertension, is rising to epidemic proportions in Africa at present.
According to the World Health Organisation (WHO) health report
in 2001, cardiovascular diseases alone accounted for 9.2% of the
total deaths in Africa, killing more people than even malaria.1
Hypertension and prehypertension are considered risk factors
for cardiovascular and coronary heart disease. The prevalence
and diagnosis of hypertension in children and adolescents
appears to have increased in recent times.1 Prehypertension is
considered a new category of hypertension and a major risk
Department of Biochemistry and Forensic Science,
Nigerian Police Academy, Wudil, Kano State, Nigeria
Chimaobi James Ononamadu, PhD,
Godwin Okwudiri Ihegboro, PhD
Department of Applied Biochemistry, Nnamdi Azikiwe
University, Awka Anambra State, Nigeria
Chinwe Nonyelum Ezekwesili, PhD
Onyemaechi Faith Onyeukwu, MSc
Uchenna Francis Umeoguaju, MSc
Obiajulu Christian Ezeigwe, PhD