title: A plausible causal link between antiretroviral therapy and increased blood pressure in a sub-Saharan African setting: A propensity score-matched analysis.
abstract: BACKGROUND
  The transition from association to causation could represent a fundamental step for taking preventive action against hypertension and its complications, especially among HIV-infected persons on antiretroviral therapy in sub-Saharan African countries.
  
  
  METHODS
  406 consecutive HIV-infected adults attending a tertiary HIV clinic in semi-urban Nigeria were prospectively recruited between August and November 2014. These participants were stratified by antiretroviral treatment status. A propensity score matching model was fitted to examine the causal average treatment effects on the treated (ATT) of antiretroviral therapy on blood pressure. Propensity score matching entailed using nearest neighbour matching with a calliper width of 0.2 to achieve similarity in the baseline characteristics between participants naïve and exposed to antiretroviral therapy.
  
  
  RESULTS
  Matching HIV-infected patients naïve and exposed to antiretroviral therapy on the propensity score yielded a total of 303 participants - 229 antiretroviral-exposed and 74 antiretroviral-naïve - matched without any residual differences in the baseline characteristics between both groups of patients. In this propensity score-matched sample, the estimated ATT for the effects of antiretroviral therapy on systolic (7.85mmHg, 95% CI 3.72 to 15.68) and diastolic blood pressure (7.45mmHg, 95% CI 4.99 to 13.61) were statistically significant (P<0.001 for each).
  
  
  CONCLUSIONS
  There is a high probability that the epidemiological association between antiretroviral therapy and increased blood pressure be causal in nature among people living with HIV in sub-Saharan African settings. HIV-infected patients commencing antiretroviral treatment in these settings may require regular hypertension screening and other cardiovascular risk assessments.
authors.affiliation: Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK. Electronic address: C.U.Nduka@warwick.ac.uk.
authors.forename: Chidozie U
authors.initials: CU
authors.lastname: Nduka
authors.affiliation: Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK; Department of Population Health, Luxembourg Institute of Health, Strassen, , Luxembourg.
authors.forename: Saverio
authors.initials: S
authors.lastname: Stranges
authors.affiliation: Department of Medicine, Duke Clinical Research Institute, Duke University, North Carolina, USA; Duke Global Health Institute, Duke University, North Carolina, USA.
authors.forename: Gerald S
authors.initials: GS
authors.lastname: Bloomfield
authors.affiliation: Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry, UK.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Kimani
authors.affiliation: Department of Internal Medicine, Benue State University Teaching Hospital, Makurdi, Nigeria.
authors.forename: Godwin
authors.initials: G
authors.lastname: Achinge
authors.affiliation: Department of Internal Medicine, Benue State University Teaching Hospital, Makurdi, Nigeria.
authors.forename: Abraham O
authors.initials: AO
authors.lastname: Malu
authors.affiliation: Warwick Centre for Applied Health Research and Delivery (WCAHRD), Warwick Medical School, University of Warwick, Coventry, UK; Department of Public Health (IHCAR), Karolinska Institutet, Stockholm, Sweden; Centre for Evidence-Based Health Care, Stellenbosch University, Tygerberg 7505, South Africa.
authors.forename: Olalekan A
authors.initials: OA
authors.lastname: Uthman
mesh_terms: D000293:Adolescent; D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D000368:Aged; D000369:Aged, 80 and over; D023241:Antiretroviral Therapy, Highly Active / Q000009:adverse effects* / Q000639:trends*; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000139:chemically induced* / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009549:Nigeria / Q000453:epidemiology; D057216:Propensity Score; D011446:Prospective Studies; D055815:Young Adult
keywords: Antiretroviral therapy; Blood pressure; Causality; HIV; Propensity score matching