Stroke Investigative Research And Educational Network Research Articles

O13 ASSOCIATION OF SECONDHAND SMOKE EXPOSURE IN RELATION TO HYPERTENSION TREATMENT STATUS WITH STROKE OCCURRENCE IN GHANA AND NIGERIA

Background and objective: It is unclear whether secondhand smoke exposure (SHSE) in hypertensive states with a disproportionate gap in hypertension treatment status is fuelling the epidemic of stroke in sub-Saharan Africa. This study, therefore, assessed the association of SHSE in relation to hypertension treatment status with stroke occurrence among West Africans. Methods: The Stroke Investigative Research and Educational Network (SIREN) is a case-control study across 16 study sites in Ghana and Nigeria. Cases were acute stroke (n =3684) with age- and sex-matched stroke-free controls (n =3684). Hypertension definition was based on standard guidelines, and SHSE was based on self-reported exposure to smoke from a burning cigarette or exhaled from a smoker in any indoor area. We evaluated the associations of untreated hypertension, treated but uncontrolled hypertension, and controlled hypertension at BP of <140/90 mmHg with odds of stroke occurrence. Multivariable-adjusted logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of the risk of stroke by hypertension treatment and SHSE status. Results: Overall, mean age was 59.0±14.9 years, and 54.2% were male. Among stroke cases, the prevalence of SHSE was 352 (20.7%), and the frequencies of no hypertension, untreated hypertension, treated but uncontrolled hypertension, and controlled hypertension were 4.0%, 47.7%, 37.1%, and 9.2%. The aOR and PAR (95% CI) for untreated hypertension were 6.58 (5.15-8.41) and 35.4% (33.4-37.4); treated but uncontrolled hypertension was 9.95 (7.60-13.02) and 35.9% (34.2-37.5); and controlled hypertension was 5.37 (3.90-7.41) and 8.5% (7.6-9.5) respectively. The aOR (95% CI) of stroke, given exposure to secondhand smoke, was 1.15 (0.94-1.41), while among untreated hypertensives and treated but uncontrolled hypertensives was 1.54 (0.99-2.37) and 1.15 (0.48-1.46) respectively. Conclusion: SHSE with hypertension significantly aggravated the odds of stroke occurrence, particularly when hypertension is untreated. Implementing targeted multi-sectoral interventions that advocate for clean air and aggressive hypertension treatment can potentially reduce the escalating burden of stroke in Africa.

Stroke occurrence by hypertension treatment status in Ghana and Nigeria: A case-control study

BackgroundHypertension is preeminent among the vascular risk factors for stroke occurrence. The wide gaps in awareness, detection, treatment, and control rates of hypertension are fueling an epidemic of stroke in sub-Saharan Africa. PurposeTo quantify the contribution of untreated, treated but uncontrolled, and controlled hypertension to stroke occurrence in Ghana and Nigeria. MethodsThe Stroke Investigative Research and Educational Network (SIREN) is a case-control study across 16 study sites in Ghana and Nigeria. Cases were acute stroke (n = 3684) with age- and sex-matched stroke-free controls (n = 3684). We evaluated the associations of untreated hypertension, treated but uncontrolled hypertension, and controlled hypertension at BP of <140/90 mmHg with risk of stroke occurrence. We assessed the adjusted odds ratio and population-attributable risk of hypertension treatment control status associated with stroke occurrence. ResultsThe frequencies of no hypertension, untreated hypertension, treated but uncontrolled hypertension and controlled hypertension among stroke cases were 4.0%, 47.7%, 37.1%, and 9.2% vs 40.7%, 34.9%, 15.9%, and 7.7% respectively among stroke-free controls, p < 0.0001. The aOR and PAR (95% CI) for untreated hypertension were 6.58 (5.15–8.41) and 35.4% (33.4–37.4); treated but uncontrolled hypertension was 9.95 (7.60–13.02) and 35.9% (34.2–37.5); and controlled hypertension 5.37 (3.90–7.41) and 8.5% (7.6–9.5) respectively. Untreated hypertension contributed a PAR of 47.5% to the occurrence of intracerebral hemorrhage vs 29.5% for ischemic stroke. The aOR of untreated hypertension for stroke occurrence was 13.31 (7.64–23.19) for <50 years; 7.14 (4.51–11.31) for 50–64 years; and 3.48 (2.28–5.30) for 65 years or more. ConclusionThe contribution of untreated hypertension and treated but uncontrolled hypertension to stroke occurrence among indigenous Africans is substantial. Implementing targeted interventions that address gaps in hypertension prevention and treatment, involving the local population, healthcare providers, and policymakers, can potentially substantially reduce the escalating burden of strokes in Africa.

Comparison of performances of SIREN or MFSRS in stroke risk prediction in an African environment

BackgroundThe Modified Framingham Stroke Risk Score (MFSRS) is a widely utilized stroke risk assessment algorithm usually applied in international comparison. The Stroke Investigative Research and Educational Network (SIREN) is the only known African-specific stroke risk assessment algorithm.Aims and objectivesTo compare stroke risk estimates from the SIREN and the MFSRS in an African community.MethodsThis was a population-based cross-sectional survey involving consecutively recruited 310 consenting adult residents (mean age = 37.21 ± 15.84 years) of a Nigerian community. Risk factors of stroke were assessed among the participants and were utilized in calculating stroke risk estimates on the MFSRS and the SIREN. The obtained data were analyzed using descriptive statistics and the Spearman-rank order correlation test at an alpha level of 0.05.ResultsThe percentage stroke risk scores estimated by the SIREN and the MFSRS were 34.5% and 6.79% respectively. The most prevalent risk factors among the participants were hypertriglyceridemia (100.0%), raised waist-hip ratio (50.6%), hypercholesterolemia (45.5), physical inactivity (43.2%), psychological stress (41.3%), and hypertension (37.7%). Only two (hypertriglyceridemia and high blood pressure) out of the six factors considered in the MFSRS were rated among the first 10 most impactful risks by the SIREN. There was a weak correlation between the total scores on the MFSRS and the SIREN (rho = 0.39; p < 0.01) suggesting that the two ratings were discordant.ConclusionThere were disagreements between the risk estimates on the SIREN and MFSRS with SIREN having a higher estimate that corresponded with the literature; this may be suggesting a poorer estimation of stroke risks by the MFSRS in an African environment. There is a need for large African-based quality control studies to determine and address these lapses.

Novel functional insights into ischemic stroke biology provided by the first genome-wide association study of stroke in indigenous Africans

BackgroundAfrican ancestry populations have the highest burden of stroke worldwide, yet the genetic basis of stroke in these populations is obscure. The Stroke Investigative Research and Educational Network (SIREN) is a multicenter study involving 16 sites in West Africa. We conducted the first-ever genome-wide association study (GWAS) of stroke in indigenous Africans.MethodsCases were consecutively recruited consenting adults (aged > 18 years) with neuroimaging-confirmed ischemic stroke. Stroke-free controls were ascertained using a locally validated Questionnaire for Verifying Stroke-Free Status. DNA genotyping with the H3Africa array was performed, and following initial quality control, GWAS datasets were imputed into the NIH Trans-Omics for Precision Medicine (TOPMed) release2 from BioData Catalyst. Furthermore, we performed fine-mapping, trans-ethnic meta-analysis, and in silico functional characterization to identify likely causal variants with a functional interpretation.ResultsWe observed genome-wide significant (P-value < 5.0E−8) SNPs associations near AADACL2 and miRNA (MIR5186) genes in chromosome 3 after adjusting for hypertension, diabetes, dyslipidemia, and cardiac status in the base model as covariates. SNPs near the miRNA (MIR4458) gene in chromosome 5 were also associated with stroke (P-value < 1.0E−6). The putative genes near AADACL2, MIR5186, and MIR4458 genes were protective and novel. SNPs associations with stroke in chromosome 2 were more than 77 kb from the closest gene LINC01854 and SNPs in chromosome 7 were more than 116 kb to the closest gene LINC01446 (P-value < 1.0E−6). In addition, we observed SNPs in genes STXBP5-AS1 (chromosome 6), GALTN9 (chromosome 12), FANCA (chromosome 16), and DLGAP1 (chromosome 18) (P-value < 1.0E−6). Both genomic regions near genes AADACL2 and MIR4458 remained significant following fine mapping.ConclusionsOur findings identify potential roles of regulatory miRNA, intergenic non-coding DNA, and intronic non-coding RNA in the biology of ischemic stroke. These findings reveal new molecular targets that promise to help close the current gaps in accurate African ancestry-based genetic stroke’s risk prediction and development of new targeted interventions to prevent or treat stroke.

Factors associated with frequency of fruit and vegetable consumption among selected sub-Saharan African populations: evidence from the Cardiovascular H3Africa Innovation Resource Project.

Frequent fruit and vegetable consumption is considered a promising dietary behaviour that protects health. However, most existing studies about the factors associated with this phenomenon among Africans are based on single-country reports, apart from one meta-regression combining smaller studies. This study harmonized large datasets and assessed factors associated with the frequency of fruit and vegetable consumption in this population. Individual-level data on sociodemographics, lifestyle and diet from 20 443 participants across five African countries (Burkina Faso, Ghana, Kenya, South Africa and Nigeria), from the Stroke Investigative Research and Educational Network (SIREN) and Africa Wits-INDEPTH partnership for Genomic Research (AWI-Gen) studies, were harmonized. Total frequency of fruit and vegetable consumption (in portions/week) was classified as 'low' (≤6), 'moderate' (7-14) and 'high' (≥15). Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of factors associated with the total frequency of fruit and vegetable consumption (using 'low' consumption as the reference) were estimated using multinomial regression models. Mean age of participants was 54.3 ± 11.8 years, 10 641 (52.1%) were female, and the median (interquartile range) frequency of total fruit and vegetable consumption was 10.0 (4.0, 21.0) portions/week. Participants with a family history of cardiovascular disease [moderate (aOR, 0.92; 95% CI, 0.85, 1.00) and high (aOR, 0.85; 95% CI, 0.78, 0.92)], current smokers [moderate (aOR, 0.83; 95% CI, 0.74, 0.94) and high (aOR, 0.78; 95% CI, 0.69, 0.88)], current alcohol users [moderate (aOR, 0.92; 95% CI, 0.85, 1.00) and high (aOR, 0.82; 95% CI, 0.76, 0.89)] and physically inactive participants [moderate (aOR, 0.85; 95% CI, 0.75, 0.96) and high (aOR, 0.80; 95% CI, 0.70, 0.90)] were less likely to consume fruits and vegetables frequently. Africans with lifestyle risk factors for cardiovascular disease were less likely to consume fruit and vegetables frequently.

Clinical and neuroimaging factors associated with 30-day fatality among indigenous West Africans with spontaneous intracerebral hemorrhage

BackgroundSpontaneous intracerebral hemorrhage (ICH) is associated with a high case fatality rate in resource-limited settings. The independent predictors of poor outcome after ICH in sub-Saharan Africa remains to be characterized in large epidemiological studies. We aimed to determine factors associated with 30-day fatality among West African patients with ICH. MethodsThe Stroke Investigative Research and Educational Network (SIREN) study is a multicentre, case-control study conducted at 15 sites in Nigeria and Ghana. Adults aged ≥18 years with spontaneous ICH confirmed with neuroimaging. Demographic, cardiovascular risk factors, clinical features and neuroimaging markers of severity were assessed. The independent risk factors for 30-day mortality were determined using a multivariate logistic regression analysis with an adjusted odds ratio (OR) and 95% confidence interval (CI). ResultsAmong 964 patients with ICH, 590 (61.2%) were males with a mean age (SD) of 54.3(13.6) years and a case fatality of 34.3%. Factors associated with 30-day mortality among ICH patients include: Elevated mean National Institute of Health Stroke Scale(mNIHSS);(OR 1.06; 95% CI 1.02–1.11), aspiration pneumonitis; (OR 7.17; 95% CI 2.82–18.24), ICH volume > 30mls; OR 2.68; 95% CI 1.02–7.00)) low consumption of leafy vegetables (OR 0.36; 95% CI 0.15–0.85). ConclusionThis study identified risk and protective factors associated with 30-day mortality among West Africans with spontaneous ICH. These factors should be further investigated in other populations in Africa to enable the development of ICH mortality predictions models among indigenous Africans.

Non-cigarette Tobacco Use and Stroke Among West Africans: Evidence From the SIREN Study.

Non-cigarette tobacco (NCT) represents a form of tobacco use with a misperceived significance in chronic disease events. Whether NCT use is sufficient to promote stroke events, especially among Africans, is yet to be understood. This study assessed the relationship between NCT use and stroke among indigenous Africans. A total of 7617 respondents (NCT users: 41 vs. non-NCT: 7576) from the Stroke Investigative Research and Educational Network (SIREN) study were included in the current analysis. NCT use was defined as self-reported use of smoked (cigars or piper) or smokeless (snuff or chewed) tobacco in the past year preceding stroke events. Stroke was defined based on clinical presentation and confirmed with a cranial computed tomography/magnetic resonance imaging. Multivariable-adjusted logistic regression was applied to estimate the odds ratio (OR) and 95% confidence interval (CI) for the relationship of NCT with stroke at a two-sided p < .05. Out of the 41 (0.54%) who reported NCT use, 27 (65.9%) reported using smokeless NCT. NCT users were older than non-NCT users (62.8 ± 15.7 vs. 57.7 ± 14.8 years). Overall, NCT use was associated with first-ever stroke (OR: 2.08; 95% CI: 1.02, 4.23) in the entire sample. Notably, smokeless NCT use was independently associated with higher odds of stroke (OR: 2.74; 95% CI: 1.15, 6.54), but smoked NCT use (OR: 0.16; 95% CI: 0.02, 1.63) presented a statistically insignificant association after adjusting for hypertension and other covariates. NCT use was associated with higher odds of stroke, and public health interventions targeting NCT use might be promising in reducing the burden of stroke among indigenous Africans. A detailed understanding of the relationship between NCT use and stroke will likely inform well-articulated policy guidance and evidence-based recommendations for public health prevention and management of stroke on the African continent.

Patient-level and system-level determinants of stroke fatality across 16 large hospitals in Ghana and Nigeria: a prospective cohort study

Every minute, six indigenous Africans develop new strokes. Patient-level and system-level contributors to early stroke fatality in this region are yet to be delineated. We aimed to identify and quantify the contributions of patient-level and system-level determinants of inpatient stroke fatality across 16 hospitals in Ghana and Nigeria. The Stroke Investigative Research and Educational Network (SIREN) is a multicentre study involving 16 sites in Ghana and Nigeria. Cases include adults (aged ≥18 years) with clinical and radiological evidence of an acute stroke. Data on stroke services and resources available at each study site were collected and analysed as system-level factors. A host of demographic and clinical variables of cases were analysed as patient-level factors. A mixed effect log-binomial model including both patient-level and system-level covariates was fitted. Results are presented as adjusted risk ratios (aRRs) with respective 95% CIs. Overall, 814 (21·8%) of the 3739 patients admitted with stroke died as inpatients: 476 (18·1%) of 2635 with ischaemic stroke and 338 (30·6%) of 1104 with intracerebral haemorrhage. The variability in the odds of stroke fatality that could be attributed to the system-level factors across study sites assessed using model intracluster correlation coefficient was substantial at 7·3% (above a 5% threshold). Stroke units were available at only five of 16 centres. The aRRs of six patient-level factors associated with stroke fatality were: low vegetable consumption, 1·19 (95% CI 1·07-1·33); systolic blood pressure, 1·02 (1·01-1·04) for each 10 mm Hg rise; stroke lesion volume more than 30 cm3, 1·48 (1·22-1·79); National Institutes of Health Stroke Scale (NIHSS) score, 1·20 (1·13-1·26) for each 5-unit rise; elevated intracranial pressure, 1·75 (1·31-2·33); and aspiration pneumonia, 1·79 (1·16-2·77). Studies are needed to assess the efficacy of interventions targeting patient-level factors such as aspiration pneumonia in reducing acute stroke fatality in this region. Policy directives to improve stroke unit access are warranted. US National Institutes of Health. For the Twi, Yoruba and Hausa translations of the abstract see Supplementary Materials section.

Differential associations between pre-diabetes, diabetes and stroke occurrence among West Africans

BackgroundThere are limited data from Africa on the burden and associations between pre-diabetes (pre-DM), diabetes mellitus (DM) and stroke occurrence in a region experiencing a profound rise in stroke burden. PurposeTo characterize the associations between stroke and dysglycemic status among West Africans. MethodsThe Stroke Investigative Research and Educational Network (SIREN) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with clinical and radiological evidence of an acute stroke. Controls were age-and-gender matched stroke-free adults. Detailed evaluations for vascular factors were performed. Pre-diabetes was defined as HBA1c of 5.7%-6.4% or Fasting blood glucose (FBG) 5.6-7.0 mmol/L and DM as HBA1c >6.5% or FBG>7.0 mmol/L. We used conditional logistic regression to estimate adjusted odds ratios (aOR) with 95% Confidence Interval. ResultsAmong 2,935 stroke cases the mean age was 60.0 ± 14.2 years with 55.2% being males. By glycemic status, 931 (31.7%) were euglycemic, 633 (21.6%) had Pre-diabetes and 1371 (46.7%) had DM. Of the age- and sex-matched stroke-free controls 69.2% were euglycemic, 13.3% had pre-DM and 17.5% had DM. Pre-DM [aOR (95% CI): 3.68(2.61-5.21)] and DM [4.29 (3.19-5.74)] were independently associated with stroke. The aOR of Pre-DM for ischemic stroke 3.06 (2.01–4.64)] was lower than 4.82 (3.37-6.89) for DM. However, the aOR of Pre-DM for hemorrhagic stroke 6.81 (95% CI: 3.29 – 14.08)] was higher than 3.36 (1.94–5.86) for DM. Furthermore, the aOR of pre-DM for ischemic stroke subtypes were 9.64 (1.30-71.57) for cardio-embolic stroke, 3.64 (1.80–7.34) for small-vessel occlusive disease and 4.63 (0.80-26.65) for large-vessel disease. ConclusionPre-DM is strongly and independently associated with stroke in Africans. Improving glycemic control through screening, healthy lifestyle and pharmacotherapy at a population level may be strategic in reducing the rising burden of stroke in Africa.

Determinants of metabolic syndrome and its prognostic implications among stroke patients in Africa: Findings from the Stroke Investigative Research and Educational Network (SIREN) study

BackgroundThe prognostic implications of metabolic syndrome (METS) among African stroke patients are poorly understood. This study aimed to investigate the determinants of METS and its prognostic implications among Africans with newly diagnosed stroke in the SIREN study. MethodsWe included stroke cases (adults aged >18 years with CT/MRI confirmed stroke). The validated tools comprehensively evaluated vascular, lifestyle, and psychosocial factors. We used logistic regression to estimate adjusted odds ratios (OR) with 95% CIs for the association between METS and risk factors. We also computed the prediction power of the domain of covariates in a sequential manner using the area under the receiver operating curve (ROC) curve. ResultsAmong 3998 stroke subjects enrolled in the study, 76.8% had METS by at least one of the clinical definitions. Factors associated with METS were age > 50 years (OR- 1.46, CI-1.19-1.80), male gender (OR 4.06, CI- 3.28-5.03), income >100USD (OR1.42, CI-1.17-1.71), stress (OR1.46, CI-1.14-1.87), family history of diabetes mellitus (OR1.38, CI-1.06-1.78), and cardiac disease (OR1.42, CI-1.18-1.65). Stroke severity was higher among those with METS (SLS = 5.8 ± 4.3) compared with those without METS (6.2 ± 4.5) at p = 0.037. METS was associated with higher odds (aOR 1.31, CI-1.08-1.58) of one-month fatality after adjusting for stroke severity, age > 50 years, and average monthly income >100USD. ConclusionMETS is very common among African stroke patients and is associated with stroke severity and worse one-month fatality. Lifestyle interventions may prevent METS and attenuate its impact on stroke occurrence and outcomes.

COMMUNITY INSIGHT ON THE ETHICAL, LEGAL, AND SOCIAL IMPLICATIONS OF STROKE GENOMIC AND BIOBANKING RESEARCH IN SUB-SAHARAN AFRICA

Background Sub-Saharan Africa (SSA) continues to have a high prevalence of stroke. While rapid advancements in genomic science, biobanking, and precision medicine provide insight and opportunities for targeted treatment advances, the ethical, legal, and social implications (ELSI) of stroke genomics and biobanking require further exploration. Methods We conducted a descriptive qualitative focused ethnography using Key Informant Interviews (KIIs) and Focus Group Discussions (FGDs) across our team's existing Stroke Investigative Research and Education Network (SIREN) sites (n = 7) in Nigeria and Ghana. Interview guides were developed with expert input and beta tested prior to use and questions elicited perspectives on brain and blood donation, genomic research, biobanking, sample re- use, bio-rights, data ownership, informed consent, and return of findings. Audio-recorded interviews were transcribed and translated to English. Data analysis, using a framework analytical approach, was conducted. Site Community Advisory Board (CAB) members confirmed interpretation. Results We conducted KIIs (n =70) and FGDs (n =28) across the seven sites with stroke survivors, stroke free controls, lay persons, caregivers, and CAB members. Themes included limited awareness of genomics, biobanking, and precision medicine, informed consent preferences, the influence of cultural and religious beliefs on willingness to donate biospecimens, and the ELSI of sample sharing/data re-use. Belief systems and knowledge strongly influenced willingness to engage in genomic and biobanking research and participants conveyed desire for increased governance, autonomy over sample use, and benefit sharing. Conclusions Stakeholder input, obtained through qualitative inquiry, is critical in the design, conduct, and oversight of genomic and biobanking science. Sub-Saharan Africa (SSA) continues to have a high prevalence of stroke. While rapid advancements in genomic science, biobanking, and precision medicine provide insight and opportunities for targeted treatment advances, the ethical, legal, and social implications (ELSI) of stroke genomics and biobanking require further exploration. We conducted a descriptive qualitative focused ethnography using Key Informant Interviews (KIIs) and Focus Group Discussions (FGDs) across our team's existing Stroke Investigative Research and Education Network (SIREN) sites (n = 7) in Nigeria and Ghana. Interview guides were developed with expert input and beta tested prior to use and questions elicited perspectives on brain and blood donation, genomic research, biobanking, sample re- use, bio-rights, data ownership, informed consent, and return of findings. Audio-recorded interviews were transcribed and translated to English. Data analysis, using a framework analytical approach, was conducted. Site Community Advisory Board (CAB) members confirmed interpretation. We conducted KIIs (n =70) and FGDs (n =28) across the seven sites with stroke survivors, stroke free controls, lay persons, caregivers, and CAB members. Themes included limited awareness of genomics, biobanking, and precision medicine, informed consent preferences, the influence of cultural and religious beliefs on willingness to donate biospecimens, and the ELSI of sample sharing/data re-use. Belief systems and knowledge strongly influenced willingness to engage in genomic and biobanking research and participants conveyed desire for increased governance, autonomy over sample use, and benefit sharing. Stakeholder input, obtained through qualitative inquiry, is critical in the design, conduct, and oversight of genomic and biobanking science.

Abstract WP226: Secondhand Smoking And Odds Of Stroke Among Non-smoking Indigenous Africans From Ghana And Nigeria: A Matched Case-control Study

Introduction: Second-hand smoking (SHS) is an emerging phenomenon in cardiovascular disease (CVD) epidemiology, but whether SHS is associated with stroke is not clearly understood. We assessed the association between SHS and stroke risk in a cohort of West Africans in the Stroke Investigative Research and Educational Network (SIREN) study. Hypothesis: SHS is not associated with stroke among indigenous West Africans from Ghana and Nigeria. Methods: 3131 stroke cases who had never smoked matched (for age and sex) with 3131 healthy smoke-free controls were identified in the multi-centre SIREN study in Ghana and Nigeria. Information on SHS was obtained through the collection of data on regular exposure to exhaled smoke or burning tobacco in an indoor environment. We assessed the relationship between SHS and stroke by estimating the odds ratio (OR) and 95% confidence interval (CI) using conditional logistic regression, adjusting for relevant covariates at P &lt;0.05 in a two-sided test. Results: The mean age of the participants was 58.8±14.1years (males, 48.0%). History of exposure to SHS was present in 20.2% of the overall sample. The multivariable-adjusted OR for the association between SHS and all stroke events was 1.12 (0.93, 1.34), P = 0.210. When the association was stratified by stroke type, the multivariable-adjusted OR were 1.42 (1.03, 1.98) P = 0.033 for haemorrhagic stroke and 1.01 (0.80, 1.26) P = 0.935 for ischaemic stroke. Conclusion(s): SHS was independently associated with higher odds of haemorrhagic stroke, but not ischaemic stroke in this cohort of indigenous West Africans. Intervention(s) to reduce SHS might help lower the burden of stroke in this population, pending longitudinal studies to evaluate the causal effect of SHS on stroke.

Risk Factor Characterization of Ischemic Stroke Subtypes Among West Africans.

To identify the qualitative and quantitative contributions of conventional risk factors for occurrence of ischemic stroke and its key pathophysiologic subtypes among West Africans. The SIREN (Stroke Investigative Research and Educational Network) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with ischemic stroke who were etiologically subtyped using the A-S-C-O-D classification into atherosclerosis, small-vessel occlusion, cardiac pathology, other causes, and dissection. Controls were age- and gender-matched stroke-free adults. Detailed evaluations for vascular, lifestyle, and psychosocial factors were performed. We used conditional logistic regression to estimate adjusted odds ratios with 95% CI. There were 2431 ischemic stroke case and stroke-free control pairs with respective mean ages of 62.2±14.0 versus 60.9±13.7 years. There were 1024 (42.1%) small vessel occlusions, 427 (17.6%) large-artery atherosclerosis, 258 (10.6%) cardio-embolic, 3 (0.1%) carotid dissections, and 719 (29.6%) undetermined/other causes. The adjusted odds ratio (95% CI) for the 8 dominant risk factors for ischemic stroke were hypertension, 10.34 (6.91-15.45); dyslipidemia, 5.16 (3.78-7.03); diabetes, 3.44 (2.60-4.56); low green vegetable consumption, 1.89 (1.45-2.46); red meat consumption, 1.89 (1.45-2.46); cardiac disease, 1.88 (1.22-2.90); monthly income $100 or more, 1.72 (1.24-2.39); and psychosocial stress, 1.62 (1.18-2.21). Hypertension, dyslipidemia, diabetes were confluent factors shared by small-vessel, large-vessel and cardio-embolic subtypes. Stroke cases and stroke-free controls had a mean of 5.3±1.5 versus 3.2±1.0 adverse cardio-metabolic risk factors respectively (P<0.0001). Traditional vascular risk factors demonstrate important differential effect sizes with pathophysiologic, clinical and preventative implications on the occurrence of ischemic stroke among indigenous West Africans.

Frequency and factors associated with post-stroke seizures in a large multicenter study in West Africa

BackgroundPost-stroke seizures (PSS) are associated with significant morbidity and mortality across the globe. There is a paucity of data on PSS in Africa. PurposeTo assess the frequency and factors associated with PSS by stroke types across 15 hospitals in Nigeria and Ghana. MethodsWe analyzed data on all stroke cases recruited into the Stroke Investigative Research and Educational Network (SIREN). We included adults aged ≥18 years with radiologically confirmed ischemic stroke (IS) or intracerebral hemorrhage (ICH). PSS were defined as acute symptomatic seizures occurring at stroke onset and/or during acute hospitalization up until discharge. We used logistic regression to estimate adjusted odds ratios (aOR) with 95% Confidence Interval. ResultsAmong 3344 stroke patients, 499 (14.9%) had PSS (95% CI: 13.7–16.2%). The mean duration of admission in days for those with PSS vs no PSS was 17.4 ± 28.6 vs 15.9 ± 24.7, p = 0.72. There were 294(14.1%) PSS among 2091 ischemic strokes and 159(17.7%) among 897 with ICH, p = 0.01. The factors associated with PSS occurrence were age < 50 years, aOR of 1.59 (1.08–2.33), National Institute of Health Stroke Score (NIHSS), 1.29 (1.16–1.42) for each 5 units rise and white cell count 1.07 (1.01–1.13) for each 10^3 mm3 rise. Factors associated with PSS in ischemic were NIHSS score, aOR of 1.17 (1.04–1.31) and infarct volume of 10–30 cm3 aOR of 2.17(1.37–3.45). Among ICH, associated factors were alcohol use 5.91 (2.11–16.55) and lobar bleeds 2.22 (1.03–4.82). ConclusionThe burden of PSS among this sample of west Africans is substantial and may contribute to poor outcomes of stroke in this region. Further longitudinal studies are required to understand the impact on morbidity and mortality arising from PSS in Africa.

Abstract P616: Characterization of the Associations Between Pre-Diabetes and Diabetes With Occurrence of Stroke by Its Types, Subtypes and Outcomes Among West Africans

Background: Pre-diabetes and diabetes mellitus (DM) are dysglycemic states associated with stroke occurrence. However, there is limited data from sub-Saharan Africa on the burden and associations between pre-DM and DM and stroke occurrence in a region experiencing an astronomic rise in stroke burden Purpose: To characterize the associations between stroke occurrence, types, subtypes, severity and outcome indicators according to glycemic status among West Africans. Methods: The Stroke Investigative Research and Educational Network (SIREN) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with evidence of an acute stroke. Controls were age-and-gender matched stroke-free adults. Detailed evaluations for vascular, lifestyle, psychosocial factors, stroke severity and outcomes were performed. We used conditional logistic regression to estimate adjusted odds ratios (aOR) with 95% Confidence Interval. Results: Among 2,935 stroke cases the mean age was 60.0 ± 14.2 years with 55.2% being males. By glycemic status, 931 (31.7%) were euglycemic, 633 (21.6%) had Pre-diabetes and 1371 (46.7%) had DM. The frequencies of euglycemia, pre-DM and DM among age- and sex-matched stroke-free controls were 69.2%, 13.3% and 17.5% respectively. Pre-diabetes was independently associated with stroke, adjusted odds ratio (95% CI) of 3.68 (2.61 - 5.21) as was having DM, aOR of 4.29 (3.19 - 5.74). The effect size of Pre-DM for ischemic stroke of 3.06 (95% CI: 2.01 - 4.64) was lower than that for DM of 4.82 (3.37-6.89). However, the effect size of Pre-DM for hemorrhagic stroke of 6.81 (95% CI: 3.29 - 14.08) is higher than 3.36 (1.94 - 5.86) for DM. Furthermore, the effect sizes of pre-DM for ischemic stroke subtypes were 9.64 (95% CI: 1.30-71.57) for cardio-embolic stroke, 3.64 (95% CI: 1.80-7.34) for small-vessel occlusive disease and 4.63 (95% CI: 0.80-26.65) for large-vessel disease. Conclusion: Every 2 out of 3 stroke cases admitted had a blood glucose abnormality. In addition to confirming the known associations between DM and stroke occurrence, we demonstrate that pre-DM is independently and more potently associated with hemorrhagic than ischemic strokes among West Africans.

Abstract P614: Effect Sizes of Vascular Risk Factors for Stroke Occurrence by Age Among West Africans

Background: Age is a non-modifiable risk factor for stroke occurrence due its influence on vascular risk factor acquisition. In sub-Saharan Africa, the effect sizes of vascular risk factors for stroke occurrence by age is unknown. Objective: To quantify the magnitude and direction of the effect sizes of key modifiable risk factors of stroke according to three age groups: &lt;50years(young), 50-65 years(middle age) and &gt;65 years(elderly) in West Africa. Methods: The Stroke Investigative Research and Educational Network (SIREN) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with evidence of an acute stroke. Controls were age-and-gender matched stroke-free adults. Detailed evaluations for vascular, lifestyle, stroke severity and outcomes were performed. We used conditional logistic regression to estimate adjusted odds ratios (aOR) of vascular risk factors of stroke. Results: Among 3,553 stroke cases, 813(22.9%) were young, 1441(40.6%) were middle-aged and 1299(36.6%) were elderly. Five modifiable risk factors were consistently associated with stroke occurrence regardless of age namely hypertension, dyslipidemia, diabetes mellitus, regular meat consumption and non-consumption of green vegetables. Among the 5 co-shared risk factors, the effect size, aOR(95%CI) of dyslipidemia, 4.13(2.64-6.46), was highest among the young age group, hypertension, 28.93(15.10-55.44) and non-consumption of vegetables 2.34(1.70-3.23) was highest among the middle-age group while diabetes, aOR of 3.50(2.48-4.95) and meat consumption, 2.40(1.76-3.26) were highest among the elderly age group. Additionally, among the young age group cigarette smoking and cardiac disease were associated with stroke. Furthermore, physical inactivity and salt intake were associated with stroke in the middle-age group while cardiac disease was associated with stroke in the elderly age group. Conclusions: Age has a profound influence on the profile, magnitude and direction of effect sizes of vascular risk factors for stroke occurrence among West Africans. Population-level prevention of stroke must target both co-shared dominant risk factors as well as factors that are unique to specific age bands in Africa.

Factors associated with hypertension among stroke-free indigenous Africans: Findings from the SIREN study.

Hypertension is one of the most important risk factors for stroke and cardiovascular diseases (CVD) globally. Understanding risk factors for hypertension among individuals with matching characteristics with stroke patients may inform primordial/primary prevention of hypertension and stroke among them. This study identified the risk factors for hypertension among community‐dwelling stroke‐free population in Ghana and Nigeria. Data for 4267 community‐dwelling stroke‐free controls subjects in the Stroke Investigative Research and Education Network (SIREN) study in Nigeria and Ghana were used. Participants were comprehensively assessed for sociodemographic, lifestyle and metabolic factors using standard methods. Hypertension was defined as a previous diagnosis by a health professional or use of an anti‐hypertensive drug or mean systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg. Logistic regression analysis was used to estimate adjusted odds ratios (aOR) of hypertension and their 95% confidence intervals (CI) at p < .05. Overall, 56.7% of the participants were hypertensive with a higher proportion among respondents aged ≥60 years (53.0%). Factors including physical inactivity (aOR: 9.09; 95% CI: 4.03 to 20.53, p < .0001), diabetes (aOR: 2.70; CI: 1.91 to 3.82, p < .0001), being ≥60 years (aOR: 2.22; 95% CI: 1.78 to 2.77, p < .0001), and family history of CVD (aOR 2.02; CI: 1.59 to 2.56, p < .0001) were associated with increased aOR of hypertension. Lifestyle factors were associated with hypertension in the current population of community‐dwelling stroke‐free controls in west Africa. Community‐oriented interventions to address sedentary lifestyles may benefit this population and reduce/prevent hypertension and stroke among them.

Pre-Stroke Depression in Ghana and Nigeria: Prevalence, Predictors and Association With Poststroke Depression.

Depression is a risk factor for stroke. There is a knowledge gap on the predictors of prestroke depression in stroke survivors living in low- and middle-income countries (LMICs). We estimated prevalence and predictors of prestroke depression, as well as its association with poststroke depression (PSD) in the largest study of stroke in Africa. We evaluated information collected as part of the Stroke Investigative Research and Education Network (SIREN) study, a multicentre, case-control study conducted at 15 sites in Ghana and Nigeria. Prestroke depression status was ascertained in stroke survivors using a validated self-report tool, while PSD was assessed using a stroke specific screening tool for depression ("HRQOLISP-E"). Independent associations were investigated using complementary log-log regression and binary logit models. Among 1,977 participants, prestroke depression was found in 141 (7.1%). In multivariate analyses, prestroke depression was significantly associated with tachycardia (OR = 2.22, 95% CI = 1.37-3.56) and low consumption of green leafy vegetables (OR = 1.91, 95% CI = 1.12-3.24). Forty-one (29.1%) of the prestroke depression sub-sample developed PSD. However, prestroke depression was not significantly associated with PSD. The findings should energize before-the-stroke identification and prioritization of limited treatment resources in LMICs to persons with depression who have multiple, additional, risks of stroke.

Antecedent febrile illness and occurrence of stroke in West Africa: The SIREN study

BackgroundAcute infections have been posited as potential precipitants or triggers of the occurrence of stroke among adults with traditional vascular risk factors. We evaluated associations between stroke occurrence and reported febrile illness within 4 weeks (potential antecedent infections) among West Africans. MethodsThe Stroke Investigative Research and Educational Network (SIREN) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with radiologically confirmed strokes. Controls were stroke-free adults matched with cased by age, gender and ethnicity. Detailed evaluations for vascular, lifestyle and psychosocial factors were performed. Participants were asked for evidence of any febrile illness within the past 4 weeks. We used conditional logistic regression to estimate adjusted odds ratios (aOR) with 95% Confidence Interval. ResultsAmong 3588 stroke cases recruited in Ghana and Nigeria between August 2014 and July 2018, 363 cases (10.1%) reported having a febrile illness within the 4 weeks prior to stroke occurrence. Having an antecedent infection was associated with stroke occurrence with an unadjusted OR of 1.19 (1.00–1.51) but aOR of 0.83 (0.59–1.17) upon adjusting for traditional vascular risk factors. Stress, aOR of 4.69 (2.59–8.50) and consumption of green vegetables 2.27 (1.35–2.85) were associated with antecedent febrile illness. Conclusion1 in 10 stroke cases reported antecedent history of febrile illness prior to occurrence of stroke but no independent association was observed in this study. Infectious exposures may be important triggers of cardiovascular events requiring further exploratory studies to better understand the role of this emerging risk factor.

Association between white matter hyperintensities and stroke in a West African patient population: Evidence from the Stroke Investigative Research and Educational Network study

BackgroundThis study is part of the Stroke Investigative Research and Educational Network (SIREN), the largest study of stroke patients in Africa to date, with computed tomography (CT) or magnetic resonance (MR) imaging data for each patient to confirm stroke. Prior imaging studies performed using high-field MR (≥1.5T) have shown that white matter hyperintensities (WMH), signs of microangiopathy in the subcortical brain, are correlated with many stroke risk factors as well as poor stroke outcomes. The aim of this study was the evaluation of MR images (0.3T–1.5T) from the SIREN study to determine associations between WMH volumes in West African patients and both stroke outcomes and stroke risk factors identified in the SIREN study. Materials and methodsBrain MR images of 130 Western African stroke patients (age ​= ​57.87 ​± ​14.22) were processed through Lesion Segmentation Toolbox of the Statistical Parametric Mapping software to extract all areas of hyperintensity in the brain. WMH was separated from stroke lesion hyperintensity and WMH volume was computed and summed. A stepwise linear regression and multivariate analysis was performed between patients’ WMH volume and sociodemographic and clinical indices. ResultsMultivariate analysis showed that high WMH volume was statistically significantly positively correlated with age (β ​= ​0.44, p ​= ​0.001), waist/hip ratio (β ​= ​0.22, p ​= ​0.03), and platelet count (β ​= ​0.19, p ​= ​0.04) after controlling for head size in a Western African stroke population. ConclusionAssociations between WMH and age and waist/hip ratio previously identified in Western countries were demonstrated for the first time in a resource-limited, homogeneous black African community using low-field MR scanners.