Predictors, incidence of hypertension and trajectories of blood pressure during a five year period among HIV-infected and uninfected Rwandan women
Introduction: The Human Immunodeficiency Virus (HIV) and Acquired Immune-deficiency Syndrome (AIDS) epidemic is one of the most devastating health crises of the modern time, affecting mostly the African continent. Non-communicable diseases such as hypertension (HTN) are also becoming increasingly important health threats in Sub-Saharan Africa (SSA) linked to a rapid epidemiological transition. In this study, the incidence of HTN and risk factors associated with blood pressure (BP) changes in HIV+ and uninfected (HIV-) Rwandan women were determined. Method: Participants were recruited in 2005 as an observational cohort, and measurements taken every six months to assess the effectiveness and toxicity of HAART in HIV+ women in Kigali, Rwanda. Clinical examination was conducted and socio-demographic information, blood pressure readings, anthropometric and laboratory risk factors were collected in 710 HIV+ and 224 HIV- women aged 22 – 78 years. Of these, 662 HIV+ and 202 HIV- women met the inclusion criteria for this study. HTN incidence rates were estimated from 2005 to 2011. Generalized estimating equations were used to determine risk factors associated with systolic and diastolic blood pressure (SBP/DBP) changes over time. Results: In this analysis of 864 women, 202 (23%) were HIV- and 662 (77%) were HIV+ HAART-naïve at recruitment. Of the HIV+ participants, 497 (75%) were initiated on treatment by the end of the study in February, 2011. HIV- participants were significantly older than the HIV+ participants (median age 43 (33.8-49.4) vs. 35 (30.6-39.5) years; p < 0.001) and had on average higher SBP (119 SD (15) versus 116 SD (10) mmHg, p = 0.012) and higher DBP (73.3 SD (10.4) versus 71.2 SD (7.5) mmHg, p = 0.0013) measurements at recruitment. 607676 Page iv The incidence rate (IR) of HTN from 2005 to 2010 in HIV + participants on antiretroviral treatment was 7 cases per 1000 per person-years at risk (95% CI 4.2 – 10.9); for HIV- women the IR was 23 cases per 1000 person-years (95% CI 15.3 – 36) and for HIV + patients HAART naive the IR was 3 cases per 1000 person-years (95% CI 0.47 – 23.72). Being underweight was associated with a 3.1 mmHg decrease in mean SBP compared to being normal weight (95% -5.48 – (-0.68); p = 0.012) for HIV + participants on HAART. For every unit increase in monthly income, SBP increased by 2.34 mmHg (95 % CI 0.077- 4.75; p = 0.058) for the HIV + HAART naïve and by age (p < 0.0001) and income (p < 0.0001) for the HIV-. Being underweight decreases DBP by 1.59 mmHg compared to being normal weight (95% CI -3.17 – (-0.013); p = 0.048) for the HIV+ on HAART. Being employed was associated with 5.1 mmHg decrease in DBP (95% CI -9.06 – (-1.14); p = 0.012) compared to not being employed for the HIV+ HAART naïve and for every year increase in age the HIV-, DBP increased by 0.2 mmHg (95 % CI 0.018 – 0.327; p = 0.028) and with every unit increase in depression score, DBP decreased by 0.02 mmHg (95 % CI -0.35 – (-0.02); p = 0.025). Conclusion: Incidence rates of HTN were higher in HIV- compared with HIV+ participants, most likely due to the older age of the HIV- study participants. The findings also show that socio-economic factors such as income and employment status and lifestyle factors such as BMI and depression were also associated with blood pressure changes. Therefore, efforts should be made in raising the awareness of potential modifiable risks, such as lifestyle factors, for prevention of HTN and blood pressure control.
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand in partial fulfilment of the requirements for the degree of Masters of Science In Epidemiology and Biostatistics Johannesburg, January 2015