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Browsing by Author "Ogbole G."

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    African Ancestry, APOL1, candidate genes, CDKN2A/CDKN2B, HDAC9, small vessel disease, stroke, West Africa
    (John Wiley & Sons Ltd, 2017) Akinyemi R.; Tiwari H. K.; Arnett D. K.; Ovbiagele B.; Irvin M. R.; Wahab K.; Sarfo F.; Srinivasasainagendra V.; Adeoye A.; Perry R. T.; Akpalu A.; Jenkins C.; Arulogun O.; Gebregziabher M.; Owolabi L.; Obiako R.; Sanya E.; Komolafe M.; Fawale M.; Adebayo P.; Osaigbovo G.; Sunmonu T.; Olowoyo P.; Chukwuonye I.; Obiabo Y.; Onoja A.; Akinyemi J.; Ogbole G.; Melikam S.; Saulson R.; Owolabi M.
    Objective: Worldwide, the highest frequencies of APOL1-associated kidney variants are found in indigenous West Africans among whom small vessel disease (SVD) is chemic stroke is the most common stroke phenotype. The objective of this study was to investigate the association and effect sizes of 23 selected SNPs in 14 genes of relevance, including the APOL1 G1 variants, with the occurrence of SVD ischemic stroke among indigenous West African participants in the Stroke Investigative Research and Education Network (SIREN) Study. Materials and Methods: Cases were consecutively recruited consenting adults (aged 18 years or older) with neuroimaging—confirmed first clinical stroke. Stroke-free controls were ascertained using a locally validated version of the Questionnaire for Verifying Stroke-Free Status (QVSFS). Logistic regression models adjusting for known vascular risk factors were fitted to assess the associations of the 23 SNPs in rigorously phenotyped cases (N = 154) of SVD ischemic stroke and stroke-free (N = 483) controls. Results: Apolipoprotein L1 (APOL1) rs73885319 (OR = 1.52; CI: 1.09-2.13, P value = .013), rs2383207 in CDKN2A/CDKN2B (OR = 3.08; CI: 1.15-8.26, P – value = .026) and rs2107595 (OR = 1.70; CI: 1.12-2.60, P-value = .014) and rs28688791 (OR = 1.52; CI: 1.03-2.26, P-value = .036) in HDAC9 gene were associated with SVD stroke at 0.05 significance level. Polymorphisms in other genes did not show significant associations. Conclusion: This is the first report of a specific association of APOL1 with a stroke subtype. Further research is needed to confirm these initial findings and deepen understanding of the genetics of stroke in people of African ancestry with possible implications for other ancestries as all humans originated from Africa
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    Development and Reliability of a User-Friendly Multicenter Phenotyping Application for Hemorrhagic and Ischemic Stroke
    (Elsevier Inc., 2017) Owolabi M.; Ogbole G.; Akinyemi R.; Salaam K.; Akpa O.; Mongkolwat P.; Omisore A.; Agunloye A.; Efidi R.; Odo J.; Makanjuola A.; Akpalu A.; Sarfo F.; Owolabi L.; Obiako R.; Wahab K.; Sanya E.; Adebayo P.; Komolafe M.; Adeoye A. M.; Fawale M. B.
    "Background: Annotation and Image Markup on ClearCanvas Enriched Stroke– phenotyping Software (ACCESS) is a novel stand-alone computer software application that allows the creation of simple standardized annotations for reporting brain images of all stroke types. We developed the ACCESS application and determined its inter-rater and intra-rater reliability in the Stroke Investigative Research and Educational Network (SIREN) study to assess its suitability for multicenter studies. Methods: One hundred randomly selected stroke imaging reports from 5 SIREN sites were re-evaluated by 4 trained independent raters to determine the inter-rater reliability of the ACCESS (version 12.0) software for stroke phenotyping. To determine intra-rater reliability, 6 raters reviewed the same cases previously reported by them after a month of interval. Ischemic stroke was classified using the Oxfordshire Community Stroke Project (OCSP), Trial of Org 10172 in Acute Stroke Treatment (TOAST), and Atherosclerosis, Small-vessel disease, Cardiac source, Other cause (ASCO) protocols, while hemorrhagic stroke was classified using the Structural lesion, Medication, Amyloid angiopathy, Systemic disease, Hypertensive angiopathy and Undetermined (SMASH-U) protocol in ACCESS. Agreement among raters was measured with Cohen’s kappa statistics. Results: For primary stroke type, inter-rater agreement was .98 (95% confidence interval [CI], .94-1.00), while intra-rater agreement was 1.00 (95% CI, 1.00). For OCSP subtypes, inter-rater agreement was .97 (95% CI, .92-1.00) for the partial anterior circulation infarcts, .92 (95% CI, .76-1.00) for the total anterior circulation infarcts, and excellent for both lacunar infarcts and posterior circulation infarcts. Intra-rater agreement was .97 (.90-1.00), while inter-rater agreement was .93 (95% CI, .84-1.00) for TOAST subtypes. Inter-rater agreement ranged between .78 (cardioembolic) and .91 (large artery atherosclerotic) for ASCO subtypes and was .80 (95% CI, .56-1.00) for SMASH-U subtypes. Conclusion: The ACCESS application facilitates a con cordant and reproducible classification of stroke subtypes by multiple investigators, making it suitable for clinical use and multicenter research.
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    Differential impact of risk factors on stroke occurrence among men versus women in West Africa The SIREN Study
    (American Heart Association, Inc., 2019) Akpalu A.; Gebregziabher M.; Ovbiagele B.; Sarfo F.; Iheonye H.; Akinyemi R.; Akpa O.; Tiwari H. K.; Arnett D.; Wahab K.; Lackland D.; Abiodun A.; Ogbole G.; Jenkins C.; Arulogun O.; Akpalu J.; Obiako R.; Olowoyo P.; Fawale M.; Komolafe M.; Osaigbovo G.; Obiabo Y.; Chukwuonye I.; Owolabi L.; Adebayo P.; Sunmonu T.; Owolabi M.
    Background and Purpose—The interplay between sex and the dominant risk factors for stroke occurrence in sub-Saharan Africa has not been clearly delineated. We compared the effect sizes of risk factors of stroke by sex among West Africans. Methods—SIREN study (Stroke Investigative Research and Educational Networks) is a case-control study conducted at 15 sites in Ghana and Nigeria. Cases were adults aged >18 years with computerized tomography/magnetic resonance imaging confirmed stroke, and controls were age- and sex-matched stroke-free adults. Comprehensive evaluation for vascular, lifestyle, and psychosocial factors was performed using validated tools. We used conditional logistic regression to estimate odds ratios and reported risk factor specific and composite population attributable risks with 95% CIs. Results—Of the 2118 stroke cases, 1193 (56.3%) were males. The mean±SD age of males was 58.1±13.2 versus 60.15±14.53 years among females. Shared modifiable risk factors for stroke with adjusted odds ratios (95% CI) among females versus males, respectively, were hypertension [29.95 (12.49–71.77) versus 16.1 0(9.19–28.19)], dyslipidemia [2.08 (1.42–3.06) versus 1.83 (1.29–2.59)], diabetes mellitus [3.18 (2.11–4.78) versus 2.19 (1.53–3.15)], stress [2.34 (1.48–3.67) versus 1.61 (1.07–2.43)], and low consumption of green leafy vegetables [2.92 (1.89–4.50) versus 2.00 (1.33–3.00)]. However, salt intake and income were significantly different between males and females. Six modifiable factors had a combined population attributable risk of 99.1% (98.3%–99.6%) among females with 9 factors accounting for 97.2% (94.9%–98.7%) among males. Hemorrhagic stroke was more common among males (36.0%) than among females (27.6%), but stroke was less severe among males than females. Conclusions—Overall, risk factors for stroke occurrence are commonly shared by both sexes in West Africa favoring concerted interventions for stroke prevention in the region.
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    Knowledge, attitudes and practices of West Africans on genetic studies of stroke: Evidence from the SIREN Study
    (World Stroke Organization Reprints and permissions, 2018) Akinyemi R. O.; Sarfo F. S.; Akinyemi J.; Singh A.; Akpa M. O.; Akpalu A.; Owolabi L.; Adeoye A. M.; Obiako R.; Wahab K.; Sanya E.; Komolafe M.; Ogbole G.; Fawale M.; Adebayo P.; Osaigbovo G.; Sunmonu T.; Olowoyo P.; Chukwuonye I.; Obiabo Y.; Adeniji O.; Fakunle G.; Melikam E.; Saulson R.; Yaria J.; Uwanruochi K.
    Background: It is crucial to assess genomic literacy related to stroke among Africans in preparation for the ethical, legal and societal implications of the genetic revolution which has begun in Africa. Objective: To assess the knowledge, attitudes and practices (KAP) of West Africans about stroke genetic studies. Methods: A comparative cross-sectional study was conducted among stroke patients and stroke-free controls recruited across 15 sites in Ghana and Nigeria. Participants’ knowledge of heritability of stroke, willingness to undergo genetic testing and perception of the potential benefits of stroke genetic research were assessed using interviewer-administered questionnaire. Descriptive, frequency distribution and multiple regression analyses were performed. Results: Only 49% of 2029 stroke patients and 57% of 2603 stroke-free individuals knew that stroke was a heritable disorder. Among those who knew, 90% were willing to undergo genetic testing. Knowledge of stroke heritability was associated with having at least post-secondary education (OR 1.51, 1.25–1.81) and a family history of stroke (OR 1.20, 1.03–1.39) while Islamic religion (OR¼0.82, CI: 0.72–0.94), being currently unmarried (OR ¼ 0.81, CI: 0.70–0.92), and alcohol use (OR ¼ 0.78, CI: 0.67–0.91) were associated with lower odds of awareness of stroke as a heritable disorder. Willingness to undergo genetic testing for stroke was associated with having a family history of stroke (OR 1.34, 1.03– 1.74) but inversely associated with a medical history of high blood pressure (OR ¼ 0.79, 0.65–0.96). Conclusion: To further improve knowledge of stroke heritability and willingness to embrace genetic testing for stroke, individuals with less formal education, history of high blood pressure and no family history of stroke require targeted interventions
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    Multilingual Validation of the Questionnaire for Verifying Stroke-Free Status in West Africa
    (Lippincott Williams & Wilkins, 2016) Sarfo F.; Gebregziabher M.; Ovbiagele B.; Akinyemi R.; Owolabi L.; Obiako R.; Akpa O.; Armstrong K.; Akpalu A.; Adamu S.; Obese V.; Boa-Antwi N.; Appiah L.; Arulogun O.; Mensah Y.; Adeoye A.; Tosin A.; Adeleye O.; Tabi-Ajayi E.; Phillip I.; Sani A.; Isah S.; Tabari N.; Mande A.; Agunloye A.; Ogbole G.; Akinyemi J.; Laryea R.; Melikam S.; Uvere E.; Adekunle G.; Kehinde S.; Azuh P.; Dambatta A.; Ishaq N.; Saulson R.; Arnett D.; Tiwari H.; Jenkins C.; Lackland D.; Owolabi M.
    Background and Purpose—The Questionnaire for Verifying Stroke-Free Status (QVSFS), a method for verifying stroke-free status in participants of clinical, epidemiological, and genetic studies, has not been validated in low-income settings where populations have limited knowledge of stroke symptoms. We aimed to validate QVSFS in 3 languages, Yoruba, Hausa and Akan, for ascertainment of stroke-free status of control subjects enrolled in an on-going stroke epidemiological study in West Africa. Methods—Data were collected using a cross-sectional study design where 384 participants were consecutively recruited from neurology and general medicine clinics of 5 tertiary referral hospitals in Nigeria and Ghana. Ascertainment of stroke status was by neurologists using structured neurological examination, review of case records, and neuroimaging (gold standard). Relative performance of QVSFS without and with pictures of stroke symptoms (pictograms) was assessed using sensitivity, specificity, positive predictive value, and negative predictive value. Results—The overall median age of the study participants was 54 years and 48.4% were males. Of 165 stroke cases identified by gold standard, 98% were determined to have had stroke, whereas of 219 without stroke 87% were determined to be stroke-free by QVSFS. Negative predictive value of the QVSFS across the 3 languages was 0.97 (range, 0.93–1.00), sensitivity, specificity, and positive predictive value were 0.98, 0.82, and 0.80, respectively. Agreement between the questionnaire with and without the pictogram was excellent/strong with Cohen k=0.92. Conclusions—QVSFS is a valid tool for verifying stroke-free status across culturally diverse populations in West Africa.

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