About

Alana Brennan, PhD, MPH, is an Associate Professor in the Department of Global Health at the Boston University School of Public Health. She received both her MPH and PhD in Epidemiology from the Boston University School of Public Health. Her areas of expertise include HIV, tuberculosis, non-communicable chronic disease, and health systems research. Brennan's research focuses on these health issues, contributing to the understanding and improvement of health outcomes related to infectious diseases and health system performance.

Research topics

• Internal medicine
• Pediatrics
• Medicine
• Environmental health
• Virology
• Physical therapy

Selected publications

• Type 1 Diabetes and Incident Dementia

  Neurology · 2026-03-18 · 2 citations

  articleOpen access

  BACKGROUND AND OBJECTIVES: Although diabetes mellitus (DM) is a well-established determinant of dementia risk, most studies have evaluated type 2 DM (T2DM) or any DM. The influence of type 1 DM (T1DM) on dementia risk remains unclear. We evaluated associations of T1DM and T2DM, separately, with incident dementia using linked electronic health records (EHRs). METHODS: This prospective cohort study used previously collected survey and EHR data from the All of Us (AoU) cohort, a convenience sample of US adults. Eligible participants were 50 years or older and completed baseline surveys. Enrollment began in 2017, with data available through October 2023, along with records before enrollment. Mean follow-up from baseline was 2.4 years. We developed an algorithm to distinguish DM type based on count of T1DM encounters. This algorithm was validated against 2 reference measures: self-reported diabetes type and C-peptide values. Using AoU data, we classified participants as having no DM, T1DM, or T2DM. We ascertained incident dementia using ICD-9, ICD-10, and Systematized Nomenclature of Medicine codes in participants' EHRs. We estimated hazard ratios (HRs) and 95% CIs for the association of diabetes type with incident dementia using Cox proportional hazards models. RESULTS: Among 283,772 participants (mean [SD] age 64.62 [8.96] years; 56.7% women), 60.3% identified as non-Hispanic White and 13.3% as Hispanic/Latino. Optimal DM classification algorithm cutoffs varied by reference standard: self-reported diabetes: ≥1 T1DM EHR encounter (sensitivity: 0.59; specificity: 0.90) and C-peptide: ≥3 T1DM EHR encounters (sensitivity: 0.76; specificity: 0.79). Defining T1DM as having ≥1 T1DM encounter, 5,442 participants had T1DM. Compared with those without DM, participants with T1DM had higher dementia incidence (sociodemographic-adjusted HR 2.82; 95% CI 2.28-3.48) and those with T2DM also had elevated risk (sociodemographic-adjusted HR 2.08; 95% CI 2.87-2.31). Results were similar across sex, race, and ethnicity strata. DISCUSSION: In AoU, DM was associated with elevated dementia risk, with the highest risk among those with T1DM. These findings highlight the need to better understand mechanisms tying T1DM to dementia.

  PublisherOA PDFDOI

• The longitudinal care cascade for hypertension: a clinic-based study of people with and without HIV in South Africa

  medRxiv · 2026-02-17

  articleOpen access

  Background: Hypertension (HTN) constitutes a major and growing public health challenge in South Africa, a setting where HIV prevalence also remains high. Despite this dual burden, longitudinal evidence describing how individuals move through the HTN care cascade particularly comparing people living with HIV (PLHIV) and people not living with HIV (PNLHIV) remains limited. Understanding patterns of progression and regression across the cascade is essential to inform health system strategies for integrated chronic disease management. Methods and Findings: We conducted a longitudinal secondary analysis using data collected from the iHEART-SA trial, which was implemented across nine public primary healthcare clinics in Johannesburg between August 2022 and May 2024. with follow-up through May 2025. Adults (≥18 years) with a known HIV status and a completed medical file review were included. Progression and regression were assessed across the HTN care cascade.Of 23 855 participants, 78.5% were PLHIV (median age 42 years, IQR 36-49; 69% female). Overall, 34.4% had high blood pressure (BP), with prevalence higher among PNLHIV than PLHIV (53.5% vs 29.3%; p<0.001). Along the HTN care cascade, PLHIV were substantially more likely to remain undiagnosed compared with PNLHIV (aRR 3.40; 95% CI 3.12-3.71). Among those treated, PLHIV were less likely to achieve BP control (aRR 0.83; 95% CI 0.75-0.91). During follow-up, PLHIV experienced higher rates of cascade regression, including regression to untreated HTN (29% vs 19%; aRR 1.51; 95% CI 1.35-1.70) and from controlled to uncontrolled BP (aRR 1.12; 95% CI 1.05-1.18). Conclusions: Despite frequent health-system contact, PLHIV had lower HTN diagnosis and higher regression, including treatment discontinuation and loss of BP control, underscoring persistent gaps in longitudinal HTN management within HIV programmes and the need for integrated and targeted chronic care models that ensure treatment continuity and sustained control.

  PublisherOA PDFDOI

• Initiation of dolutegravir vs efavirenz on 12- and 24-month weight, body mass index, blood pressure, and incident hypertension: A target trial emulation

  Annals of Epidemiology · 2026-03-10

  articleOpen access

  Using the Target Trial Emulation Framework, we evaluated the impact of initiating dolutegravir versus efavirenz on 12- and 24-month weight, body mass index (BMI), blood pressure (BP), and incident hypertension among treatment-naïve individuals in Johannesburg, South Africa from 2019-2022. We used linear models to estimate the mean difference in weight, BMI, BP and a log-binomial model to estimate the causal risk difference of incident hypertension, adjusting for patient characteristics via inverse probability weighting. Among 2,930 people initiating treatment from 2019-2022, 1,847 initiated dolutegravir and 1,083 initiated efavirenz. At 12-months, mean difference comparing dolutegravir to efavirenz in weight was 2.9 kilograms (95% Confidence Interval (CI): -0.3, 5.5), BMI was 0.8 kg/m 2 (95% CI: -0.3, 1.9), diastolic BP was 1.6 mmHg (95% CI: -0.7, 3.9) and systolic BP was 3.9 mmHg (95% CI: 1.2, 6.6). Risk of incident hypertension rose by 35% (95% CI: 0.04, 0.5). At 24-months, mean weight difference was 1.9 kilograms (95% CI: -1.3, 5.1), BMI was 0.6 kg/m 2 (95% CI: -0.6, 1.9), diastolic BP was -0.4 mmHg (95% CI: -1.8, 5.1) and systolic BP was 1.7 mmHg (95% CI: -1.8, 5.1). Risk of incident hypertension rose by 22% (95% CI: -0.1, 0.4). Dolutegravir was associated with greater increases in weight, systolic BP, and incident hypertension over 24-months, particularly in the first 12-months. Future research is needed to determine whether this reflects a direct effect of dolutegravir or the weight-suppressing effects of efavirenz.

  PublisherDOI

• One- and Two-Year Outcomes of Switching to a Dolutegravir-Based ART Regimen: An Observational Emulation of Sequential Target Trials

  Open Forum Infectious Diseases · 2026-04-24

  articleOpen access

  Background: Clinical trials evaluating the impact of switching to dolutegravir have excluded individuals with poorly controlled viremia. However, in practice, clinicians may switch individuals to dolutegravir who have such challenges. Utilizing the Target Trial Framework, we estimated the effect of switching to a dolutegravir-based regimen, vs not switching and remaining on an efavirenz-based regimen, on 12- and 24-month retention and viral suppression in Johannesburg, South Africa, from 2019 to 2022. Methods: Using data from the Themba Lethu HIV Clinical Cohort, individuals were eligible if they were currently on an efavirenz-based regimen, aged 16+, and not pregnant at the start of each trial. We conducted a pooled linear regression model with bootstrapping to estimate the causal risk difference and 95% CI adjusting for patient characteristics via inverse probability treatment weighting. Results: Of 1493 individuals, 967 (64.7%) switched to a dolutegravir-based regimen over 9 sequential trials, and 526 (35.2%) did not. At 12 months, switch to a dolutegravir-based regimen was associated with a 14 percentage point (95% CI, 0.10 to 0.19) increase in retention and a 2 percentage point (95% CI, -0.04 to 0.08) increase in viral suppression. By 24 months, we observed a 1 percentage point (95% CI, -0.05 to 0.07) increase in retention and an 8 percentage point (95% CI, 0.02 to 0.14) increase in viral suppression. Conclusions: Switching to dolutegravir was associated with a 14 percentage point increase in retention at 12 months and an 8 percentage point increase in viral suppression at 24 months. Our findings suggest that switching to dolutegravir does not harm and might improve retention and viral suppression over a 24-month period.

  PublisherDOI

• Risk of obesity, diabetes, hypertension, and major adverse cardiovascular events after a switch to an integrase inhibitor: a target trial emulation in REPRIEVE

  The Lancet HIV · 2026-03-28

  articleOpen access
  PublisherOA PDFDOI

• Clinical modifiers of the association between type 1 diabetes and dementia incidence

  medRxiv · 2025-09-18

  preprintOpen accessSenior author

  Background: Type 1 diabetes mellitus (T1DM) is associated with elevated dementia risk, but the mechanisms are not well understood. Prior studies suggest that co-occurring diabetes-related complications and other comorbidities may further increase dementia risk, but these studies are few and typically have small samples. Whether diabetes-related complications and other comorbidities modify the effect of T1DM on dementia risk remains unclear. Methods: Data are from participants of the All of Us (AoU) cohort ages ≥ 50 years, with complete baseline surveys, linked electronic health records (EHRs), and either T1DM or no DM. Enrollment began in 2017, with data available through October 2023, including information prior to enrollment in AoU. Incident dementia was identified based on ICD-9, ICD-10, and SNOMED codes in participants' EHRs. Baseline clinical comorbidities (diabetes complications and eye diseases, other vascular and metabolic comorbidities, and mental health conditions) were also identified using participants' EHRs, classifying each as present if at least one diagnostic code occurred on or before the baseline survey. Results: Among 232,429 participants (mean [SD] age 64.5 [9.0] years; 57.3% women), 2.3% had a T1DM diagnosis. Participants averaged 1.67 total comorbidities (SD = 2.08). T1DM and each comorbidity was associated with higher dementia incidence. T1DM was associated with higher dementia incidence among individuals with no comorbidities (HR = 1.77; 95% CI: 0.95-3.30), though the CI included 1. Each additional comorbidity increased risk (HR = 1.22; 95% CI: 1.19-1.26), with some evidence that the effect of T1DM differed by the number of comorbidities (HR = 0.94; 95% CI:0.86-1.01). The combined estimated effect of T1DM and most comorbidities was less than multiplicative. Depression was an exception; the dementia HR for individuals with both T1DM and depression (HR = 5.47; 95% CI: 4.23, 7.08) roughly reflected what would have been expected based on the HR for T1DM (HR = 2.01; 95% CI: 1.38, 2.92) times the HR for depression among those without T1DM (HR = 2.55; 95% CI: 2.22, 2.95). Conclusion: Our findings suggest that T1DM and common comorbidities independently increase dementia risk, though their combined effects are generally less than multiplicative. However, depression in the context of T1DM is associated with major elevations in dementia risk.

  PublisherOA PDFDOI

• Type I diabetes and incident dementia: a prospective study in the All of Us cohort

  medRxiv · 2025-07-14 · 1 citations

  preprintOpen access

  Importance Although diabetes mellitus (DM) is a well-established determinant of dementia risk, most studies have evaluated type 2 DM (T2DM) or any DM without considering type 1 DM (T1DM) separately. Questions remain about the influence of T1DM on risk of dementia. Objective To evaluate associations of T1DM and T2DM with incident dementia using linked electronic health records (EHRs). Design, Setting, Participants This cohort study used data from the All of Us (AoU) cohort, a convenience sample of US adults. Eligible participants were ≥ 50 years, completed baseline surveys, and had EHR information. Enrollment began in 2017, with data available through October 2023, including records prior to enrollment in AoU. Mean follow-up was 2.4 years. Exposures We developed and validated an algorithm to distinguish DM type using three reference measures: (1) self-report diabetes type; (2) C-peptide values; and (3) islet-specific autoantibodies (ISAs). Participants were classified as no DM, T1DM, or T2DM based on number of T1DM encounters. Main Outcomes and Measures Incident dementia was identified based on ICD-9, ICD-10, and SNOMED codes in participants’ EHRs. Results Among 283,965 participants (mean [SD] age 64.62 [8.96] years; 56.7% women); 60.3% identified as Non-Hispanic White; 13.3% as Hispanic/Latino; and 26.4% as Non-Hispanic Other. Optimal DM classification algorithm cutoas varied by reference standard: (1) self-reported diabetes: ≥ 1 T1DM EHR encounter (sensitivity: 0.59; specificity: 0.90); (2) C-peptide: ≥ 3 T1DM EHR encounters (sensitivity: 0.76; specificity: 0.79); and (3) ISAs: ≥ 4 T1DM EHR encounters (sensitivity: 0.48; specificity: 0.74). Using at least one T1DM encounter cutoa, 5,444 participants were classified with T1DM. Compared with those without DM, participants with T1DM had higher incidence of dementia (sociodemographic-adjusted HR = 2.79; 95% CI: 2.26-3.45); those with T2DM also had elevated risk (sociodemographic-adjusted HR = 2.09; 95% CI: 1.88-2.33). Results were similar across gender and race and ethnicity stratified groups. Conclusion and Relevance In this cohort, participants with diabetes had a higher dementia risk than did those without DM, with the highest risk among those with T1DM. These findings highlight the need to better understand mechanisms linking T1DM and dementia in aging populations.

  PublisherOA PDFDOI

• Systematic review and meta‐analysis of retention and disengagement after initiation on antiretroviral therapy in low‐ and middle‐income countries after the introduction of Universal Test and Treat policies

  Journal of the International AIDS Society · 2025-09-01 · 3 citations

  reviewOpen access

  INTRODUCTION: We previously published a systematic review evaluating retention in care after antiretroviral therapy initiation among adults in low- and middle-income countries from 2008 to 2013. This review evaluates retention after the implementation of Universal Test and Treat (UTT) in 2015. METHODS: We searched PubMed, ISI Web of Science, Cochrane Database of Systematic Reviews and EMBASE for studies published 1 January 2017, through 31 December 2024 and searched conference abstract repositories from AIDS, IAS and CROI from 2015 to 2024. Retention for each study was estimated using (1) simple averages and (2) interpolated for missing time points through the last reported time point. Our outcomes were all-cause attrition and retention. We estimated retention rates using a generalized linear mixed model (GLMM) with a logit distribution using interpolated data. RESULTS: Seventy studies met our inclusion criteria. Most studies came from Africa, with very few from Europe and Asia. Few studies reported retention past the first 12 months following treatment initiation. Across all studies, we estimated simple average retention without interpolation of missing time points to be 72.6% at 12 months, 75.2% at 24 months, 67.7% at 36 months and 64.8% at 48 months. Utilizing a GLMM model, we estimated retention to be 79.6% at 12 months, 81.2% at 24 months, 75.6% at 36 months and 72.8% at 48 months. Whereas in our prior 2015 review, we estimated retention rates to be 86.0% at 12 months, 79.0% at 24 months, 75.0% at 36 months, and 69.0% at 48 months. These results generally reflect retention at the initiating facility and omit the effect of unreported transfers. DISCUSSION: Retention in care at 36 months was estimated to be between 67% and 75%. Compared to results from our prior review, retention is largely similar in the post-UTT era. Further research evaluating retention in other geographic areas (i.e. Latin America and the Caribbean, Europe, and Asia) is needed. CONCLUSIONS: Attrition after the first 2 years in treatment remains a concern, and concerted efforts should be made to ensure patients remain engaged in care over their lifetime. The impact of PEPFAR's recent cuts needs to be evaluated further to understand the effect it may have on long-term retention.

  PublisherOA PDFDOI

• Urine kidney injury molecule-1 predicts subclinical kidney disease among persons living with HIV initiating tenofovir disoproxil fumarate-based ART in Zambia

  Frontiers in Nephrology · 2025-01-06 · 1 citations

  articleOpen access

  Introduction Antiretroviral therapy (ART) increases the life expectancy of persons living with HIV (PLWH), but not without potentially serious adverse effects. Tenofovir disoproxil fumarate (TDF) can cause nephrotoxicity, manifesting as acute kidney injury (AKI) that may persist after treatment discontinuation. Kidney injury biomarkers such as kidney injury molecule-1 (KIM-1), retinol-binding protein-4 (RBP-4), interleukin-18 (IL-18), and neutrophil gelatinase-associated lipocalin (NGAL) can aid early diagnosis and predict TDF-associated nephrotoxicity. This study aimed to determine whether the change from baseline in urine KIM-1 (δKIM-1) and NGAL (δNGAL) following 2 weeks of TDF use could predict subclinical TDF-associated nephrotoxicity before the overt manifestation as acute kidney disease after 3 months. Methods A prospective cohort study of 205 PLWH was conducted at the Adult Center for Infectious Disease Research (AIDC) in Lusaka, Zambia. ART-naïve PLWH who were starting treatment with TDF with intact kidney function [estimated glomerular filtration rate (eGFR)&amp;gt; 60 mL/min/1.73m 2 ] were followed at initiation, 2 weeks, and approximately 3 months to determine the incidence of TDF-associated nephrotoxicity. We measured urine KIM-1 and NGAL at baseline and after 2 weeks of treatment to determine if it predicted subclinical nephrotoxicity. The presence of TDF-associated nephrotoxicity was defined according to the established acute kidney disease and disorders criteria (AKD) as having either 1) one or more episodes of eGFR&amp;lt; 60ml/min/1.73m 2 within 3 months, 2) a reduction in eGFR of greater than 35% (from baseline) within 3 months, and/or 3) an increase in serum creatinine of more than 50% (from baseline) within 3 months. Results The incidence of TDF-associated nephrotoxicity was 22%. Baseline eGFR, creatinine, age, female sex, and BMI predicted the risk of overt TDF-associated nephrotoxicity. The median baseline KIM-1-to-creatinine and NGAL-1-to-creatinine ratios of the participants who developed overt TDF-associated nephrotoxicity and those who did not were not significantly different. However, every 1 pg/mg increase in δKIM-1 was associated with a 41% higher risk of TDF-associated nephrotoxicity. No association was observed with δNGAL. Conclusions The incidence of TDF-associated nephrotoxicity was high. Change in KIM-1 level within 2 weeks of the initiation of TDF treatment predicted subclinical TDF-associated nephrotoxicity before overt manifestation as acute kidney disease while δNGAL within the same period did not predict subclinical TDF-associated nephrotoxicity.

  PublisherOA PDFDOI

• No cause for complacency regarding health of children who are HIV-exposed but uninfected

  AIDS · 2025-12-24

  articleSenior author
  PublisherDOI

Frequent coauthors

• Matthew P. Fox

  University of the Witwatersrand

  307 shared

• Sydney Rosen

  Boston University

  192 shared

• Ian Sanne

  Advanced Biological Laboratories (Luxembourg)

  165 shared

• Lawrence Long

  Boston University

  95 shared

• Mhairi Maskew

  University of the Witwatersrand

  82 shared

• George Davey Smith

  63 shared

• Jacob Bor

  University of the Witwatersrand

  49 shared

• Gesine Meyer‐Rath

  Boston University

  39 shared

Labs

• Admissions TeamPI

Education

• PhD, Department of Epidemiology

  Boston University School of Public Health

  2016

• MPH, Department of Epidemiology

  Boston University School of Public Health

  2008