Browsing by Author "Njelekela, Marina"

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    The burden of hypertension in sub-Saharan Africa: a four-country cross sectional study
    (BMC public health, 2015) Guwatudde, David; Nankya-Mutyoba, Joan; Kalyesubula, Robert; Laurence, Carien; Adebamowo, Clement; Ajayi, IkeOluwapo; Bajunirwe, Francis; Njelekela, Marina; Chiwanga, Faraja S.; Reid, Todd; Volmink, Jimmy; Adami, Hans-Olov; Holmes, Michelle D.; Dalal, Shona
    Hypertension, the leading single cause of morbidity and mortality worldwide, is a growing public health problem in sub-Saharan Africa (SSA). Few studies have estimated and compared the burden of hypertension across different SSA populations. We conducted a cross-sectional analysis of blood pressure data collected through a cohort study in four SSA countries, to estimate the prevalence of pre-hypertension, the prevalence of hypertension, and to identify the factors associated with hypertension. Methods: Participants were from five different population groups defined by occupation and degree of urbanization, including rural and peri-urban residents in Uganda, school teachers in South Africa and Tanzania, and nurses in Nigeria. We used a standardized questionnaire to collect data on demographic and behavioral characteristics, injuries, and history of diagnoses of chronic diseases and mental health. We also made physical measurements (weight, height and blood pressure), as well as biochemical measurements; which followed standardized protocols across the country sites. Modified Poison regression modelling was used to estimate prevalence ratios (PR) as measures of association between potential risk factors and hypertension. Results: The overall age-standardized prevalence of hypertension among the 1216 participants was 25.9 %. Prevalence was highest among nurses with an age-standardized prevalence (ASP) of 25.8 %, followed by school teachers (ASP = 23.2 %), peri-urban residents (ASP = 20.5 %) and lowest among rural residents (ASP = 8.7 %). Only 50.0 % of participants with hypertension were aware of their raised blood pressure. The overall age-standardized prevalence of pre-hypertension was 21.0 %. Factors found to be associated with hypertension were: population group, older age, higher body mass index, higher fasting plasma glucose level, lower level of education, and tobacco use.
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    Consumption of processed food dietary patterns in four African populations
    (Public Health Nutrition, 2018) Holmes, Michelle D.; Dalal, Shona; Sewram, Vikash; Diamond, Megan B.; Adebamowo, Sally N.; Ajayi, Ikeoluwapo O.; Adebamowo, Clement; Chiwanga, Faraja S.; Njelekela, Marina; Laurence, Carien; Volmink, Jimmy; Bajunirwe, Francis; Nankya-Mutyoba, Joan; Guwatudde, David; Reid, Todd G.; Willett, Walter C.; Adami, Hans-Olov; Fung, Teresa T.
    To identify predominant dietary patterns in four African populations and examine their association with obesity. Design: Cross-sectional study. Setting/Subjects: We used data from the Africa/Harvard School of Public Health Partnership for Cohort Research and Training (PaCT) pilot study established to investigate the feasibility of a multi-country longitudinal study of noncommunicable chronic disease in sub-Saharan Africa. We applied principal component analysis to dietary intake data collected from an FFQ developed for PaCT to ascertain dietary patterns in Tanzania, South Africa, and peri-urban and rural Uganda. The sample consisted of 444 women and 294 men. Results: We identified two dietary patterns: the Mixed Diet pattern characterized by high intakes of unprocessed foods such as vegetables and fresh fish, but also cold cuts and refined grains; and the Processed Diet pattern characterized by high intakes of salad dressing, cold cuts and sweets. Women in the highest tertile of the Processed Diet pattern score were 3·00 times more likely to be overweight (95 % CI 1·66, 5·45; prevalence=74 %) and 4·24 times more likely to be obese (95 % CI 2·23, 8·05; prevalence=44 %) than women in this pattern’s lowest tertile (both P<0·0001; prevalence=47 and 14 %, respectively). We found similarly strong associations in men. There was no association between the Mixed Diet pattern and overweight or obesity. Conclusions: We identified two major dietary patterns in several African populations, a Mixed Diet pattern and a Processed Diet pattern. The Processed Diet pattern was associated with obesity.
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    Feasibility of a large cohort study in sub-Saharan Africa assessed through a four-country study
    (Global Health Action, 2015) Dalal, Shona; Holmes, Michelle D.; Laurence, Carien; Bajunirwe, Francis; Guwatudde, David; Njelekela, Marina; Adebamowo, Clement; Nankya-Mutyoba, Joan; Chiwanga, Faraja S.; Volmink, Jimmy; Ajayi, Ikeoluwapo; Kalyesubula, Robert; Reid, Todd G.; Dockery, Douglas; Hemenway, David; Adami, Hans-Olov
    Large prospective epidemiologic studies are vital in determining disease etiology and forming national health policy. Yet, such studies do not exist in sub-Saharan Africa (SSA) notwithstanding the growing burden of chronic diseases. Objective: We explored the feasibility of establishing a large-scale multicountry prospective study at five sites in four sub-Saharan countries. Design: Based on country-specific considerations of feasibility, Nigeria enrolled health care professionals, South Africa and Tanzania enrolled teachers, and Uganda enrolled village residents at one rural and one periurban site each. All sites used a 6-month follow-up period but different approaches for data collection, namely standardized questionnaires filled out by participants or face-to-face interviews. Results: We enrolled 1415 participants from five sites (range 200489) with a median age of 41 years. Approximately half had access to clean-burning cooking fuel and 70% to piped drinking water, yet 92% had access to a mobile phone. The prevalence of chronic diseases was 49% among 45- to 54-year-olds and was dominated by hypertension (21.7% overall) ranging from 4.5 to 31.2% across sites and a serious injury in the past 12 months (12.4% overall). About 80% of participants indicated willingness to provide blood samples. At 6-month follow-up, 68% completed a questionnaire (45 to 96% across sites) with evidence that mobile phones were particularly useful. Conclusions: Our pilot study indicates that a large-scale prospective study in SSA is feasible, and the burden of chronic disease in SSA may already be substantial necessitating urgent etiologic research and primary prevention.
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    Neighborhood greenness and burden of non-communicable diseases in Sub-Saharan Africa: A multi-country cross-sectional study
    (Environmental Research, 2021) Iyer, Hari S.; James, Peter; Valeri, Linda; Bajunirwe, Francis; Nankya-Mutyoba, Joan; Njelekela, Marina; Chiwanga, Faraja; Sewram, Vikash; Ajayi, IkeOluwapo; Adebamowo, Clement; Dalal, Shona; Reid, Todd G.; Rebbeck, Timothy R.; Adami, Hans-Olov; Holmes, Michelle D.
    Population growth, demographic transitions and urbanization in sub-Saharan Africa (SSA) will increase non-communicable disease (NCD) burden. We studied the association between neighborhood greenness and NCDs in a multi-country cross-sectional study. Among 1178 participants, in adjusted models, a 0.11 unit NDVI increase was associated with lower BMI (β: −1.01, 95% CI: −1.35, −0.67), and lower odds of overweight/obesity (aOR: 0.73, 95% CI: 0.62, 0.85), diabetes (aOR: 0.77, 95% CI: 0.62, 0.96), and having ≥3 allostatic load components compared to none (aOR: 0.66, 95% CI: 0.52, 0.85). Except for diabetes, these remained statistically significant after Bonferroni correction. We observed no association between NDVI and hypertension or cholesterol. Our findings are consistent with health benefits of neighborhood greenness reported in other countries, suggesting greening strategies could be considered as part of broader public health interventions for NCDs.
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    Non-communicable diseases in sub-Saharan Africa: what we know now
    (International Journal of Epidemiology, 2011) Dalal, Shona; Beunza, Juan Jose; Volmink, Jimmy; Adebamowo, Clement; Bajunirwe, Francis; Njelekela, Marina; Mozaffarian, Dariush; Fawzi, Wafaie; Willett, Walter; Adami, Hans-Olov; Holmes, Michelle D.
    Sub-Saharan Africa (SSA) has a disproportionate burden of both infectious and chronic diseases compared with other world regions. Current disease estimates for SSA are based on sparse data, but projections indicate increases in non-communicable diseases (NCDs) caused by demographic and epidemiologic transitions. We review the literature on NCDs in SSA and summarize data from the World Health Organization and International Agency for Research on Cancer on the prevalence and incidence of cardiovascular diseases, diabetes mellitus Type 2, cancer and their risk factors. We searched the PubMed database for studies on each condition, and included those that were community based, conducted in any SSA country and reported on disease or risk factor prevalence, incidence or mortality.We found few community-based studies and some countries (such as South Africa) were over-represented. The prevalence of NCDs and risk factors varied considerably between countries, urban/rural location and other sub-populations. The prevalence of stroke ranged from 0.07 to 0.3%, diabetes mellitus from 0 to 16%, hypertension from 6 to 48%, obesity from 0.4 to 43% and current smoking from 0.4 to 71%. Hypertension prevalence was consistently similar among men and women, whereas women were more frequently obese and men were more frequently current smokers.The prevalence of NCDs and their risk factors is high in some SSA settings. With the lack of vital statistics systems, epidemiologic studies with a variety of designs (cross-sectional, longitudinal and interventional) capable of in-depth analyses of risk factors could provide a better understanding of NCDs in SSA, and inform health-care policy to mitigate the oncoming NCD epidemic.
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    Urban–Rural And Geographic Differences In Overweight And Obesity In Four Sub-Saharan African Adult Populations: A Multi-Country Cross-Sectional Study
    (BMC public health, 2016) Ajayi, IkeOluwapo O.; Adebamowo, Clement; Adami, Hans-Olov; Dalal, Shona; Diamond, Megan B.; Bajunirwe, Francis; Guwatudde, David; Njelekela, Marina; Mutyoba, Joan Nankya; Chiwanga, Faraja S.; Volmink, Jimmy; Kalyesubula, Robert; Laurence, Carien; Reid, Todd G.; Dockery, Douglas; Hemenway, David; Spiegelman, Donna; Holmes, Michelle D.
    Overweight and obesity are on the rise in developing countries including sub-Saharan Africa. We undertook a four-country survey to show the collective burden of these health conditions as they occur currently in sub-Saharan Africa and to determine the differences between urban and rural populations and other socio-economic factors.Participants were nurses in two hospitals in Nigeria (200), school teachers in South Africa (489) and Tanzania (229), and village residents in one peri-urban (297) and one rural location in Uganda (200) who completed a standardised questionnaire. Their height and weight were measured and body mass index calculated. Factor analysis procedure (Principal component) was used to generate a wealth index. Univariate and multivariate analyses with binary logistic regression models were conducted to examine the associations between potential correlates and the prevalence of overweight and obesity with 95 % confidence intervals.The prevalence of overweight and obese (combined) was 46 %, 48 %, 68 %, 75 % and 85 % in rural Uganda, peri-urban Uganda, Nigeria, Tanzania and South Africa (SA), respectively. Rural Uganda, Peri- urban Uganda, Nigeria, Tanzania and SA had obesity prevalence of 10 %, 14 %, 31 %, 40 % and 54 %, respectively (p < 0.001). Overall, prevalence of overweight was 374 (31 %) and obesity, 414 (34 %). Female sex was a predictor of overweight and obesity (combined) in peri-urban Uganda [AOR = 8.01; 95 % CI: 4.02, 15.96) and obesity in rural Uganda [AOR = 11.22; 95%CI: 2.27, 55.40), peri-urban Uganda [AOR = 27.80; 95 % CI: 7.13,108.41) and SA [AOR = 2.17; 95 % CI: 1.19, 4.00). Increasing age was a predictor of BMI > =25 kg/m2 in Nigeria [Age > =45 - AOR = 9.11; 95 % CI: 1.72, 48.16] and SA [AOR = 6.22; 95 % CI: 2.75, 14.07], while marital status was predictor of BMI > =25 kg/m2 only in peri-urban Uganda. [Married - AOR = 4.49; 95 % CI: 1.74, 11.57]. Those in Nigeria [AOR = 2.56; 95 % CI: 1.45, 4.53], SA [AOR = 4.97; 95 % CI: 3.18, 7.78], and Tanzania [AOR = 2.68; 95 % CI: 1.60, 4.49] were more likely to have BMI > =25 kg/m2 compared with the rural and peri-urban sites.The high prevalence of overweight and obesity in these sub-Saharan African countries and the differentials in prevalence and risk factors further highlights the need for urgent focused intervention to stem this trend, especially among women, professionals and urban dwellers.