Browsing by Author "Michele Ramsay"

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    Adiposity phenotypes and subclinical atherosclerosis in adults from subSaharan Africa a H3AfricaAWIGen study
    E Nonterah; M Bots; A Oduro; G Agongo; Cassandra Soo; Lisa Micklesfield; Alisha Wade; Shane Norris; Stephen Tollman; Michele Ramsay; Kerstin Klipstein-Grobusch; Nigel Crowther
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    Advancing noncommunicable diseases research in Ghana Key stakeholders recommendations from a symposium
    P Tindana; Michele Ramsay; Kerstin Klipstein-Grobusch; M Amoakoh-Coleman
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    The African Liver Tissue Biorepository Consortium Capacitating PopulationAppropriate Drug Metabolism Pharmacokinetics and Pharmacogenetics Research in Drug Discovery and Development
    (AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS) Collen Masimirembwa; Michele Ramsay; J Botha; E Ellis; Harriet Etheredge; Tracey Hurrell; C Kanji; Heather Maher; Busisiwe Mthembu; Sharan Rambarran; F van der Schyff; Natalie Smyth; Bernd Strobele; E et al; Jerome Loveland; June Fabian
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    Apolipoprotein E Genetic Variation and Its Association With Cognitive Function in RuralDwelling Older South Africans
    Cassandra Soo; MT Farrell; Stephen Tollman; Lisa Berkman; Almut Nebel; Michele Ramsay
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    The association of menopause with cardiometabolic disease risk factors in women living with and without HIV in subSaharan Africa Results from the AWIGen 1 study
    (ELSEVIER IRELAND LTD) Raylton Chikwati; Nicole Jaff; Nasrin Goolam Mahyoodeen; Lisa Micklesfield; Michele Ramsay; Francesc Gomez-Olive Casas; S F Mohamed; S S R Choma; Jaya George; Nigel Crowther
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    Building knowledge, optimising physical and mental health and setting up healthier life trajectories in South African women (Bukhali): a preconception randomised control trial part of the Healthy Life Trajectories Initiative (HeLTI)
    (2022-03-25) Shane A Norris; Catherine E Draper; Alessandra Prioreschi; CM Smuts; Lisa Jayne Ware; CindyLee Dennis; Philip Awadalla; D Bassani; Zulfiqar Bhutta; Laurent Briollais; D William Cameron; Tobias Chirwa; B Fallon; CM Gray; Jill Hamilton; J Jamison; Heather Jaspan; Jennifer Jenkins; Kathleen Kahn; AP Kengne; Estelle V Lambert; Naomi Levitt; Marie-Claude Martin; Michele Ramsay; Daniel Roth; Stephen Scherer; Daniel Sellen; Wiedaad Slemming; Deborah Sloboda; M Szyf; Stephen Tollman; Mark Tomlinson; Suzanne Tough; Stephen G Matthews; Linda Richter; Stephen Lye
    is challenging due to a persistent infectious disease, burgeoning obesity, most notably among women and rising rates of non-communicable diseases (NCDs). With two thirds of women presenting at their first antenatal visit either overweight or obese in urban South Africa (SA), the preconception period is an opportunity to optimise health and offset transgenerational risk of both obesity and NCDs. Methods and analysis Bukhali is the first individual randomised controlled trial in Africa to test the efficacy of a complex continuum of care intervention and forms part of the Healthy Life Trajectories Initiative (HeLTI) consortium implementing harmonised trials in Canada, China, India and SA. Starting preconception and continuing through pregnancy, infancy and childhood, the intervention is designed to improve nutrition, physical and mental health and health behaviours of South African women to offset obesity-risk (adiposity) in their offspring. Women aged 18–28 years (n=6800) will be recruited from Soweto, an urban-poor area of Johannesburg. The primary outcome is dual-energy X-ray absorptiometry derived fat mass index (fat mass divided by height2 ) in the offspring at age 5 years. Community health workers will deliver the intervention randomly to half the cohort by providing health literacy material, dispensing a multimicronutrient supplement, providing health services and feedback, and facilitating behaviour change support sessions to optimise: (1) nutrition, (2) physical and mental health and (3) lay the foundations for healthier pregnancies and early child development. Ethics and dissemination Ethical approval has been obtained from the Human Ethics Research Committee University of the Witwatersrand, Johannesburg, South Africa (M1811111), the University of Toronto, Canada (19-0066-E) and the WHO Ethics Committee (ERC.0003328). Data and biological sample sharing policies are consistent with the governance policy of the HeLTI Consortium (https://helti.org) and South African government legislation (POPIA). The recruitment and research team will obtain informed consent.
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    Cardiometabolic disease risk factors in pre- and postmenopausal women from four sub-Saharan African countries: A cross-sectional study
    (2023-06) Raylton P. Chikwati; Nasrin Goolam Mahyoodeen; Nicole G. Jaff; Michele Ramsay; Lisa K. Micklesfield; Alisha N. Wade; Godfred Agongo; Gershim Asik; Solomon S.R. Choma; Palwende R. Boua; Jaya A. George; Nigel J. Crowther
    Objective: To compare the risk factors for cardiometabolic disease between pre- and postmenopausal women from four sub-Saharan African countries. Study design: This cross-sectional study included 3609 women (1740 premenopausal and 1869 postmenopausal) from sites in Ghana (Navrongo), Burkina Faso (Nanoro), Kenya (Nairobi), and South Africa (Soweto and Dikgale). Demographic, anthropometric and cardiometabolic variables were compared between pre- and postmenopausal women, within and across sites using multivariable regression analyses. The sites represent populations at different stages of the health transition, with those in Ghana and Burkina Faso being rural, whilst those in Kenya and South Africa are more urbanised. Main outcome measures: Anthropometric and cardiometabolic variables. Results: The prevalence rates of risk factors for cardiometabolic disease were higher in South (Soweto and Dikgale) and East (Nairobi) Africa than in West Africa (Nanoro and Navrongo), irrespective of menopausal status. Regression models in combined West African populations demonstrated that postmenopausal women had a larger waist circumference (β = 1.28 (95 % CI: 0.58; 1.98) cm), log subcutaneous fat (β =0.15 (0.10; 0.19)) diastolic (β = 3.04 (1.47; 4.62) mm Hg) and log systolic (β = 0.04 (0.02; 0.06)) blood pressure, log carotid intima media thickness (β = 0.03 (0.01; 0.06)), low-density lipoprotein cholesterol (β = 0.14 (0.04; 0.23) mmol/L) and log triglyceride (β= 0.10 (0.04; 0.16)) levels than premenopausal women. No such differences were observed in the South and East African women. Conclusions: Menopause-related differences in risk factors for cardiometabolic disease were prominent in West but not East or South African study sites. These novel findings should inform cardiometabolic disease prevention strategies in midlife women specific to rural and urban and peri-urban locations in sub-Saharan Africa.
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    Estimating the burden of cardiovascular risk in community dwellers over 40 years old in South Africa Kenya Burkina Faso and Ghana
    Ryan Wagner; Nigel Crowther; Lisa Micklesfield; R Boua; E Nonterah; F Mashinya; S Mohamed; E et al; Stephen Tollman; Michele Ramsay; Justine Davies
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    Genetic Susceptibility to Breast Cancer in SubSaharan African Populations
    Mahtaab Hayat; Wenlong Chen; Jean-Tristan Brandenburg; Chantal Babb; Michele Ramsay; Christopher Mathew
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    Identifying the prevalence and correlates of multimorbidity in middle-aged men and women: a cross-sectional populationbased study in four African countries
    (2023-02-15) Lisa K Micklesfield; Richard Munthali; Godfred Agongo; Gershim Asiki; Palwende Boua; Solomon SR Choma; Nigel J Crowther; June Fabian; Francesc Xavier Gómez-Olivé; Chodziwadziwa Kabudula; Eric Maimela; Shukri F Mohamed; Engelbert A Nonterah; Frederick J Raal; Hermann Sorgho; Furahini D Tluway; Alisha N Wade; Shane A Norris; Michele Ramsay
    Objectives To determine the prevalence of multimorbidity, to identify which chronic conditions cluster together and to identify factors associated with a greater risk for multimorbidity in sub-Saharan Africa (SSA). Design Cross-sectional, multicentre, population-based study. Setting Six urban and rural communities in four subSaharan African countries. Participants Men (n=4808) and women (n=5892) between the ages of 40 and 60 years from the AWI-Gen study. Measures Sociodemographic and anthropometric data, and multimorbidity as defined by the presence of two or more of the following conditions: HIV infection, cardiovascular disease, chronic kidney disease, asthma, diabetes, dyslipidaemia, hypertension. Results Multimorbidity prevalence was higher in women compared with men (47.2% vs 35%), and higher in South African men and women compared with their East and West African counterparts. The most common disease combination at all sites was dyslipidaemia and hypertension, with this combination being more prevalent in South African women than any single disease (25% vs 21.6%). Age and body mass index were associated with a higher risk of multimorbidity in men and women; however, lifestyle correlates such as smoking and physical activity were different between the sexes. Conclusions The high prevalence of multimorbidity in middle-aged adults in SSA is of concern, with women currently at higher risk. This prevalence is expected to increase in men, as well as in the East and West African region with the ongoing epidemiological transition. Identifying common disease clusters and correlates of multimorbidity is critical to providing effective interventions.
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    Measurement of kidney function in Malawi, South Africa, and Uganda: a multicentre cohort study
    (2022) June Fabian; Robert Kalyesubula; Joseph Mkandawire; Christian Holm Hansen; Dorothea Nitsch; Eustasius Musenge; Wisdom P Nakanga; Josephine E Prynn; Gavin Dreyer; Tracy Snyman; Billy Ssebunnya; Michele Ramsay; Liam Smeeth; Stephen Tollman; Saraladevi Naicker; Amelia Crampin; Robert Newton; Jaya A George; Laurie Tomlinson
    Background The burden of kidney disease in many African countries is unknown. Equations used to estimate kidney function from serum creatinine have limited regional validation. We sought to determine the most accurate way to measure kidney function and thus estimate the prevalence of impaired kidney function in African populations. Methods We measured serum creatinine, cystatin C, and glomerular filtration rate (GFR) using the slope-intercept method for iohexol plasma clearance (mGFR) in population cohorts from Malawi, Uganda, and South Africa. We compared performance of creatinine and cystatin C-based estimating equations to mGFR, modelled and validated a new creatinine-based equation, and developed a multiple imputation model trained on the mGFR sample using age, sex, and creatinine as the variables to predict the population prevalence of impaired kidney function in west, east, and southern Africa. Findings Of 3025 people who underwent measured GFR testing (Malawi n=1020, South Africa n=986, and Uganda n=1019), we analysed data for 2578 participants who had complete data and adequate quality measurements. Among 2578 included participants, creatinine-based equations overestimated kidney function compared with mGFR, worsened by use of ethnicity coefficients. The greatest bias occurred at low kidney function, such that the proportion with GFR of less than 60 mL/min per 1·73 m² either directly measured or estimated by cystatin C was more than double that estimated from creatinine. A new creatinine-based equation did not outperform existing equations, and no equation, including the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 race-neutral equation, estimated GFR within plus or minus 30% of mGFR for 75% or more of the participants. Using a model to impute kidney function based on mGFR, the estimated prevalence of impaired kidney function was more than two-times higher than creatinine-based estimates in populations across six countries in Africa. Interpretation Estimating GFR using serum creatinine substantially underestimates the individual and populationlevel burden of impaired kidney function in Africa with implications for understanding disease progression and complications, clinical care, and service provision. Scalable and affordable ways to accurately identify impaired kidney function in Africa are urgently needed.
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    Physical Activity and Its Association With Body Mass Index: A Cross-Sectional Analysis in Middle-Aged Adults From 4 Sub-Saharan African Countries
    (2023-08-17) Monica Mut; Lisa J. Ware; Lisa K. Micklesfield; Michele Ramsay; Godfred Agongo; Palwende R. Boua; Isaac Kisiangani; Ian Cook; Francesc Xavier Go´mez-Olivé; Nigel J. Crowther; Chodziwadziwa Kabudula; Shane A. Norris; Tinashe Chikowore
    Background: This study aimed to explore association of self-reported physical activity domains of work, leisure, and transport-related physical activity and body mass index (BMI) in 9388 adult men and women from the Africa-Wits-INDEPTH partnership for Genomic (AWI-Gen) study in Africa. Africa-Wits-INDEPTH partnership for Genomic is a large, population-based cross-sectional cohort with participants from 6 sites from rural and urban areas in 4 sub-Saharan African countries. Methods: A sex-stratified meta-analysis of cross-sectional data from men and women aged 29–82 years was used to assess the association of physical activity with BMI. Results: Overall, meeting physical activity guidelines of at least 150 minutes per week was associated with 0.82 kg/m2 lower BMI in men (β = −0.80 kg/m2 ; 95% confidence interval [CI], −1.14 to −0.47) and 0.68 kg/m2 lower BMI in women (β = −0.68 kg/m2 ; 95% CI, −1.03 to −0.33). Sex and site-specific differences were observed in the associations between physical activity domains and BMI. Among those who met physical activity guidelines, there was an inverse association between transport-related physical activity and BMI in men from Nanoro (Burkina Faso) (β = −0.79 kg/m2 ; 95% CI, −1.25 to −0.33) as well as work-related physical activity and BMI in Navrongo men (Ghana) (β = −0.76 kg/m2 ; 95% CI, −1.25 to −0.27) and Nanoro women (β = −0.90 kg/m2 ; 95% CI, −1.44 to −0.36). Conclusions: Physical activity may be an effective strategy to curb rising obesity in Africa. More studies are needed to assess the impact of sex and geographic location-specific physical activity interventions on obesity.
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    Postprandial glucose variability and clusters of sex hormones liver enzymes and cardiometabolic factors in a South African cohort of African ancestry
    Bontle Masango; Julia Goedecke; Michele Ramsay; Karl-Heinz Storbeck; Lisa Micklesfield; Tinashe Chikowore
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    Systematic Review of Genomic Associations with Blood Pressure and Hypertension in Populations with AfricanAncestry
    Surina Singh; Jean-Tristan Brandenburg; Ananyo Choudhury; Francesc Gomez-Olive Casas; Michele Ramsay
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    Telomere length, health, and mortality in a cohort of older black South African adults
    S Gao; J Rohr; I de Vivo; Michele Ramsay; N Kriegler; Chodziwadziwa Kabudula; E et al; Lisa Berkman
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    Trans-ethnic genomic informed risk assessment for Alzeheimer's disease: an International Hundred K+ Cohorts Consortium study.
    (2023-07-14) Patrick M Sleiman; Hui-Qi Qu; John J Connolly; Frank Mentch; Alexandre Pereira; Paulo A Lotufo; Stephen Tollman; Ananyo Choudhury; Michele Ramsay; Norihiro Kato; Kouichi Ozaki; Risa Mitsumori; Jae-Pil Jeon; Chang Hyung Hong; Sang Joon Son; Hyun Woong Roh; Dong-Gi Lee; Naaheed Mukadam; Isabelle F Foote; Charles R Marshall; Adam Butterworth; Bram P Prins; Joseph T Glessner; Hakon Hakonarson
    Background: As a collaboration model between the International HundredK+ Cohorts Consortium (IHCC) and the Davos Alzheimer's Collaborative (DAC), our aim was to develop a trans-ethnic genomic informed risk assessment (GIRA) algorithm for Alzheimer's disease (AD). Methods: The GIRA model was created to include polygenic risk score calculated from the AD genome-wide association study loci, the apolipoprotein E haplotypes, and non-genetic covariates including age, sex, and the first three principal components of population substructure. Results: We validated the performance of the GIRA model in different populations. The proteomic study in the participant sites identified proteins related to female infertility and autoimmune thyroiditis and associated with the risk scores of AD. Conclusions: As the initial effort by the IHCC to leverage existing large-scale datasets in a collaborative setting with DAC, we developed a trans-ethnic GIRA for AD with the potential of identifying individuals at high risk of developing AD for future clinical applications.
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    Transethnic genomic informed risk assessment for Alzeheimers disease an international Hundred K and Cohorts Consortium
    PM Sleiman; H-Q Qu; JJ Connolly; F Mentch; Stephen Tollman; Ananyo Choudhury; Michele Ramsay; E et al
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    Transethnic genomic informed risk assessment for Alzheimers disease An International Hundred K Cohorts Consortium study
    P M Sleiman; H Q Qu; J J Connolly; F Mentch; Stephen Tollman; Ananyo Choudhury; Michele Ramsay; E et al
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    UGT1A1 regulatory variant with potential effect on efficacy of HIV and cancer drugs commonly prescribed in South Africa
    Jenny Mathew; Phelelani Mpangase; Dhriti Sengupta; S Kwenda; Demetra Mavri-Damelin; Michele Ramsay