title: The highly neglected burden of resistant hypertension in Africa: a systematic review and meta-analysis.
abstract: The hypertension epidemic in Africa collectively with very low rates of blood pressure control may predict an incremented prevalence of resistant hypertension (RH) across the continent. The aim of this study was to determine the prevalence of RH and associated risk factors in Africa.
  
  
  
  We conducted a comprehensive search of electronic databases (PubMed, EMBASE, Africa Wide Information and Africa Index Medicus) completed by manual search of articles, regardless of language or publication date.
  
  
  
  We included studies which have reported the prevalence and/or risk factors for RH in Africa from inception to 19 May 2016. Forest plots were drawn to visualise the combined prevalence of RH and extent of statistical heterogeneity between studies.
  
  
  
  Out of 259 retrieved studies, only 5 from Cameroon, Nigeria, Burkina Faso, Lesotho and Algeria with a total population of 4 068 patients were finally included in this review. There was no study from the Eastern part of Africa. Though the definition of RH was not similar across studies, its prevalence was respectively 11.7%, 4.9%, 14.6%, 14.3% and 19.0%, with an overall pooled prevalence of 12.1% (95% CI 8.0% to 17.7%). Potential risk factors were: non-compliance to treatment, ageing, male sex, dyslipidaemia, metabolic syndrome, previous cardiovascular events, physical inactivity and stress, but not excessive salt intake, alcohol and coffee ingestions. Moreover, diabetes, smoking, obesity and renal insufficiency yielded discrepant results.
  
  
  
  There is a huge dearth of research on the epidemiology of RH in Africa. Thereby, an extensive study of RH prevalence and risk factors is still largely warranted to curtail the high and continuously increasing burden of hypertension across Africa.
authors.affiliation: Department of Public Health, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon Sickle Cell Disease Unit, Mother and Child Center, Chantal Biya Foundation, Yaoundé, Cameroon.
authors.forename: Jobert Richie N
authors.initials: JR
authors.lastname: Nansseu
authors.affiliation: Department of Medicine, Groote Schuur Hospital and University of Cape Town, Cape Town, South Africa Medical Diagnostic Center, Yaoundé, Cameroon.
authors.forename: Jean Jacques N
authors.initials: JJ
authors.lastname: Noubiap
authors.affiliation: Department of Internal Medicine and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon.
authors.forename: Michel K
authors.initials: MK
authors.lastname: Mengnjo
authors.affiliation: Faculty of Medicine & Biomedical Sciences, School of Public Health, The University of Queensland, Brisbane, Queensland, Australia Non-communicable Diseases Unit, Clinical Research Education, Networking and Consultancy, Douala, Cameroon.
authors.forename: Leopold Ndemnge
authors.initials: LN
authors.lastname: Aminde
authors.affiliation: Division of Medicine, Sangmelima Reference Hospital, Sangmelima, Cameroon.
authors.forename: Mickael
authors.initials: M
authors.lastname: Essouma
authors.affiliation: Department of Internal Medicine and Specialties, Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon.
authors.forename: Ahmadou M
authors.initials: AM
authors.lastname: Jingi
authors.affiliation: Department of Epidemiology and Public Health, Centre Pasteur of Cameroon, Yaoundé, Cameroon.
authors.forename: Jean Joel R
authors.initials: JJ
authors.lastname: Bigna
mesh_terms: D000462:Algeria / Q000453:epidemiology; D002050:Burkina Faso / Q000453:epidemiology; D002163:Cameroon / Q000453:epidemiology; D017281:Cost of Illness; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D007927:Lesotho / Q000453:epidemiology; D009549:Nigeria / Q000453:epidemiology; D015995:Prevalence
keywords: Africa; prevalence; resistant hypertension; risk factors; systematic review