Original article
Prevalence of hypertension and associated risk factors in BeninPrévalence de l’hypertension artérielle et facteurs de risque associés en population générale au Bénin

https://doi.org/10.1016/j.respe.2011.09.010Get rights and content

Abstract

Background

Hypertension is one of the main risk factors of cardiovascular diseases. There has been a lack of data on this risk factor in the general population in Benin. The aim of this study was to determine the prevalence of hypertension and identify the associated risk factors in Benin.

Methods

A cross-sectional study was conducted from July to August 2008 in Benin's 12 departments. The questionnaire and anthropometric measurements of the World Health Organization STEPWISE survey were used. The sample included 6853 subjects 25–64 years of age, randomly selected by five-stage random sampling. Blood pressure was measured using standard procedures. Data was processed and analyzed using EPI DATA and STATA 9.2 software. Prevalence levels were compared using Pearson's chi2 and means with the Student t-test. Univariate and multivariate regression analysis, taking the sampling method into account, was used to identify risk factors.

Results

The sample comprised 49.5% females, the 25- to 34-year-old age group was the largest, and the mean age was 42.7 ± 12.4 years. The prevalence of hypertension was 27.9% [95% CI: 26.3–29.5%], 77.5% of the subjects were unaware of their high blood pressure, and 81.6% had not taken their drugs two weeks before the survey. Prevalence of known hypertension was 6.9%, prevalence of treated hypertension 4.8%, and prevalence of controlled hypertension 1.9%. Age and obesity were significantly associated with hypertension. Department and profession were not associated with hypertension.

Conclusion

This study showed a high prevalence of hypertension in the general population in Benin. Better management of this risk factor will contribute to reducing morbidity and mortality due to cardiovascular diseases.

Résumé

Position du problème

L’hypertension artérielle (HTA) est l’un des principaux facteurs de risque de maladies cardiovasculaires. L’objectif de ce travail est de déterminer la prévalence de l’HTA en population générale au Bénin en 2008 et d’identifier ses facteurs de risque.

Patients et méthodes

Il s’agit d’une étude transversale qui s’est déroulée de juillet à août 2008 dans les 12 départements du Bénin. La méthode d’enquête STEPWISE de l’Organisation mondiale de la santé a été utilisée. L’étude a porté sur 6853 personnes, âgées de 25 à 64 ans sélectionnées par sondage aléatoire à cinq degrés. La pression artérielle a été mesurée selon les procédures standards. Les données ont été saisies à l’aide de EPI DATA et analysées par STATA 9.2. Les prévalences ont été comparées par le Khi2 de Pearson et les moyennes par le test t de Student. Une régression logistique prenant en compte le schéma d’échantillonnage a été utilisée pour identifier les facteurs de risque.

Résultats

La tranche d’âge de 25–34 ans était la plus représentée et l’âge moyen (écart-type) était de 42,7 ± 12,4 ans et il y avait 49,5 % de femmes. La prévalence de l’HTA était de 27,9 % [IC 95 % : 26,3–29,5 %], 77,5 % des hypertendus ignoraient qu’ils avaient une pression artérielle élevée et 81,6 % des patients sous traitement n’avaient pas pris leurs médicaments dans les deux semaines précédant l’enquête. La prévalence de l’HTA connue était de 6,9 %, celle de l’HTA traitée de 4,8 % et celle de l’HTA contrôlée de 1,9 %. L’âge et l’obésité étaient significativement associés à l’HTA. Le département de résidence et la profession n’étaient pas associés avec la survenue de l’HTA.

Conclusion

Cette étude indique l’importance de la prévalence de l’HTA en population générale au Bénin. Une meilleure prise en charge de ce facteur de risque contribuera à réduire la morbidité et la mortalité dues aux maladies cardiovasculaires.

Introduction

More than one-quarter of the world adult population has hypertension (HTN), expected to reach 29% by 2025, i.e., nearly 1.6 billion hypertensive subjects in the world [1]. HTN is one of the main cardiovascular risk factors in terms of cardiovascular mortality and morbidity [2]. Of 17 million patients who die every year of cardiovascular diseases, seven to eight million are estimated to be hypertensive [3]. The prevalence of HTN is gradually increasing in the world because of the aging of the population as well as the increase in the proportion of obese or overweight subjects [4], [5]. It is estimated that in 2025 nearly three-quarters of the hypertensive population will be living in developing countries because of massive urbanization [6], [7]. HTN involves approximately 20 million people in Africa and its prevalence varies widely, between 20 and 30% [8], [9], [10], [11], [12], [13]. Continuing to carry the burdensome weight of infectious diseases, over the past few decades, Africa has been confronted with an explosion of noncommunicable diseases as well.

Benin has not been spared, in view of the partial data available [14]. In terms of risk factors, the expression “high blood pressure” (HBP) is recommended and the 2002 report on health in the world identified it as one of the eight main risk factors of noncommunicable diseases [3]. The lack of national studies on this risk factor and the absence of a monitoring system designed for noncommunicable diseases in this country have motivated this study.

The objective of this study was to determine the prevalence of hypertension in Benin in 2008 and to identify the associated risk factors.

Section snippets

Study description

Located in Western Africa on the Gulf of Guinea between 6 and 12 degrees north, Benin covers a surface area of 114,763 km2. Its population was estimated at 8,364,942 inhabitants in 2008 based on projections of the 2002 census [15]. Children under 15 years of age comprise 49% of the population. Life expectancy at birth is 59.2 years. Benin is composed of 12 administrative departments, 77 towns, and 546 arrondissements subdivided into neighborhoods/villages. Its main economic activities are

Description of the sample

A total of 6853 individuals, 25–64 years of age, were included in the sample, taking into account that in order to complete each cluster, all the eligible subjects in the last household were interviewed. Within this sample, 6786 answered all the questions, for a 99% response rate. Females accounted for 49.5% of this population. Subjects who were 25–34 years old comprised the largest group: 31.5% (Table 1). The mean age (± standard deviation) was 42.7 ± 12.4 years. The proportions of subjects by

Discussion

This study was conducted following the STEPS method recommended by the WHO for screening and monitoring risk factors of noncommunicable diseases [21]. This approach ensures that the results of STEPS studies conducted at different sites can be compared. The behavioral factors were studied based on subject declarations and therefore information and data biases may have been introduced. However, they were minimized in a context in which the factors studied were not stigmatizing and the times

Conclusion

This study has measured the significance of HTN in the general population in Benin. More than one adult out of four has hypertension and nearly four subjects out of five are not aware that they have high blood pressure. These results are very worrying. It is therefore clear that effective preventive measures must be implemented to contribute to reducing the incidence, morbidity, and mortality caused by HTN. Moreover, they indicate the need to conduct more detailed research to explain the high

Disclosure of interest

The authors declare that they have no conflicts of interest concerning this article.

References (32)

  • K. Steyn et al.

    Hypertension in South African adults: results from the demographic and health survey, 1998

    J Hypertens

    (2001)
  • J. Addo et al.

    Prevalence, detection, management, and control of hypertension in Ghanaian civil servants

    Ethn Dis Autumn

    (2008)
  • R. Adedoyin et al.

    Prevalence and pattern of hypertension in a semiurban community in Nigeria

    Eur J Cardiovasc Prev Rehabil

    (2008)
  • Ministère de la Santé de Côte d’Ivoire. Rapport d’enquête STEPS sur la surveillanc des facteurs de risque des maladies...
  • A. N’Gouin-Claih et al.

    Prevalence of hypertension in Guinean rural areas

    Arch Mal Coeur Vaiss

    (2003)
  • R. Sodjinou et al.

    Obesity and cardio-metabolic risk factors in urban adults of Benin: relationship with socio-economic status, urbanisation, and lifestyle patterns

    BMC Public Health

    (2008)
  • Cited by (17)

    • Carissa edulis Vahl (Apocynaceae) extract, a medicinal plant of Benin pharmacopoeia, induces potent endothelium-dependent relaxation of coronary artery rings involving nitric oxide

      2022, Phytomedicine
      Citation Excerpt :

      Although hypertension is a major cardiovascular risk factor identified initially in Western industrialized countries (Maione et al., 2013), its prevalence is increasing continuously in developing countries and, in particular, in sub-Saharan Africa (Tokoudagba et al., 2010). Studies conducted in 2008 in 12 departments of Benin on 6853 people aged 25–64 years old showed that the prevalence of hypertension is 27.9% (Houinato et al., 2012). Additional studies have been carried out in 2015 on 1777 people aged over 25 years in the population of Tanvè, a rural area 150 km north of Cotonou, and on 717 people aged 18–64 years in the Atlantic region of Benin.

    View all citing articles on Scopus

    Study conducted within the National Noncommunicable Disease Control Program (Programme national de lutte contre les maladies non transmissibles [PNLMNT]) of the Benin Health Ministry in partnership with the World Health Organization (WHO).

    View full text