Blood pressure trajectories and visit-to-visit variability among aging adults with HIV retained in long-term care in Zambia

Background As people with HIV (PWH) age on antiretroviral therapy (ART), hypertension and cardiovascular complications increasingly influence long-term outcomes. However, blood pressure (BP) trajectories and visit-to-visit variability (VVV) remain poorly characterized in African HIV care settings. Methods We conducted a retrospective longitudinal analysis of a long-term survivor cohort of adults with HIV retained in ART care at a peri-urban hospital in Zambia between 2011 and 2024. Routinely collected clinic BP measurements were used to estimate long-term systolic BP (SBP), diastolic BP (DBP), and VVV. Participants who initiated ART before age 50 and subsequently reached age ≥ 50 years during follow-up were compared with those who initiated ART at age ≥ 50 years. Linear mixed-effects models with participant-level random intercepts and random slopes for time were fitted for SBP and DBP, using years since the first recorded BP as the primary time scale. VVV was summarized using within-person standard deviation (SD) and coefficient of variation. Results A total of 107 adults contributed longitudinal data, with approximately two BP measurements per year over a median follow-up of 10–11 years. The median age at ART initiation was 45 years (IQR 40–47) among those initiating ART before age 50 and 57 years (IQR 53–68) among those initiating ART at ≥ 50 years. Participants initiating ART at ≥ 50 years had higher SBP at the end of observation (148 vs. 130 mmHg; p = 0.008) and greater SBP variability (16.05 vs. 12.75 mmHg; p = 0.010). In adjusted VVV models, mean SBP and DBP were associated with SD-based variability (SBP: β = 0.17, p < 0.001; DBP: β = 0.08, p = 0.024). Model-predicted SBP differences by age at ART initiation widened from 6.4 mmHg at baseline to 14.2 mmHg at 10 years, while differences by first BP hypertension status widened from 21.2 mmHg to 26.1 mmHg. Conclusion Older age at ART initiation and hypertension at the first recorded BP measurement were associated with higher long-term SBP levels and greater systolic BP variability among adults with HIV retained in long-term care in Zambia. These findings support systematic BP assessment at ART entry and continued longitudinal BP monitoring in aging adults with HIV.