The association between plasma zinc concentrations and markers of glucose metabolism in adults in Cameroon.

An abnormal Zn status has been suggested to play a role in the pathogenesis of type 2 diabetes. However, epidemiological studies of the relationship between plasma Zn concentrations and diabetes are sparse and inconclusive. We aimed to investigate the association between plasma Zn concentrations and glycaemic markers (fasting glucose, 2-h glucose and homeostatic model assessment of insulin resistance) in rural and urban Cameroon. We studied 596 healthy adults (63·3 % women) aged 25-55 years in a population-based cross-sectional study. The mean plasma Zn concentration was 13·7 ± 2·7 µmol/L overall, with higher levels in men (14·4 ± 2·9 µmol/l) than in women (13·2 ± 2·6 µmol/l), P-value < 0·0001. There was an inverse relationship between tertiles of plasma Zn and 2-h glucose concentrations (P-value for linear trend = 0·002). The difference in 2-h glucose between those in the highest tertile of plasma Zn compared to the lowest was -0·63 (95 % CI - 1·02, -0·23) mmol/l. This remained significant after adjusting for age, sex, smoking status, alcohol intake, education level, area of residence, adiposity and objectively measured physical activity -0·43(-0·82, -0·04). Similar inverse associations were observed between plasma Zn concentrations and fasting glucose and homeostatic model assessment of insulin resistance when adjusted for socio-demographic and health-related behavioural characteristics. The current findings of an inverse association between plasma Zn concentrations and several markers of glucose homeostasis, together with growing evidence from intervention studies, suggest a role for Zn in glucose metabolism. If supported by further evidence, strategies to improve Zn status in populations may provide a cheap public health prevention approach for diabetes.

Association between circulating 25-hydroxyvitamin D and cardiometabolic risk factors in adults in rural and urban settings.

BACKGROUND: An inverse association between vitamin D status and cardiometabolic risk has been reported but this relationship may have been affected by residual confounding from adiposity and physical activity due to imprecise measures of these variables. We aimed to investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) and cardiometabolic risk factors, with adjustment for objectively-measured physical activity and adiposity. METHODS: This was a population-based cross-sectional study in 586 adults in Cameroon (63.5% women). We assessed markers of glucose homoeostasis (fasting blood glucose (BG), 2 h post glucose load BG, HOMA-IR)) and computed a metabolic syndrome score by summing the sex-specific z-scores of five risk components measuring central adiposity, blood pressure, glucose, HDL cholesterol and triglycerides. RESULTS: Mean±SD age was 38.3 ± 8.6 years, and serum 25(OH)D was 51.7 ± 12.5 nmol/L. Mean 25(OH)D was higher in rural (53.4 ± 12.8 nmol/L) than urban residents (50.2 ± 12.1 nmol/L), p = 0.002. The prevalence of vitamin D insufficiency (<50 nmol/L) was 45.7%. There was an inverse association between 25(OH)D and the metabolic syndrome score in unadjusted analyses (ß = -0.30, 95% CI -0.55 to -0.05), which became non-significant after adjusting for age, sex, smoking status, alcohol intake and education level. Serum 25(OH)D was inversely associated with fasting BG (-0.21, -0.34 to -0.08)), which remained significant after adjustment for age, sex, education, smoking, alcohol intake, the season of data collection, BMI and physical activity (-0.17, -0.29 to -0.06). There was an inverse association of 25(OH)D with 2-h BG (-0.20, -0.34 to -0.05) and HOMA-IR (-0.12, -0.19 to -0.04) in unadjusted analysis, but these associations became non-significant after adjustment for potential confounders. CONCLUSION: Vitamin D insufficiency was common in this population. This study showed an inverse association between vitamin D status and fasting glucose that was independent of potential confounders, including objectively measured physical activity and adiposity, suggesting a possible mechanism through insulin secretion.

Adolescent Levers for a Diet and Physical Activity Intervention Across Socioecological Levels in Kenya, South Africa, Cameroon, and Jamaica: Mixed Methods Study Protocol.

BACKGROUND: The increasing burden of noncommunicable diseases that are prevalent in low- and middle-income countries (LMICs) is largely attributed to modifiable behavioral risk factors such as unhealthy diets and insufficient physical activity (PA). The adolescent stage, defined as 10 to 24 years of age, is an important formative phase of life and offers an opportunity to reduce the risk of noncommunicable diseases across the life course and for future generations. OBJECTIVE: The aim of this paper is to describe a protocol for a study using a convergent mixed methods design to explore exposures in the household, neighborhood, school, and the journey from home to school that may influence diet and PA behaviors in adolescents from LMICs. METHODS: Male and female adolescents (n≥150) aged between 13 and 24 years will be recruited from selected high schools or households in project site countries to ensure the socioeconomic diversity of perspectives and experiences at the individual, home, and neighborhood levels. The project will be conducted at 5 sites in 4 countries: Kenya, Cameroon, Jamaica, and South Africa (Cape Town and Johannesburg). Data on anthropometric measures, food intake, and PA knowledge and behavior will be collected using self-report questionnaires. In addition, a small number of learners (n=30-45) from each site will be selected as citizen scientists to capture data (photographs, audio notes, text, and geolocations) on their lived experiences in relation to food and PA in their homes, the journey to and from school, and the school and neighborhood environments using a mobile app, and for objective PA measurements. In-depth interviews will be conducted with the citizen scientists and their caregivers to explore household experiences and determinants of food intake and foodways, as well as the PA of household members. RESULTS: The study described in this protocol paper was primarily funded through a UK National Institute for Health Research grant in 2017 and approved by the relevant institutional ethics review boards in the country sites (South Africa, Cameroun, and Jamaica in 2019, and Kenya in 2020). As of December 23, 2020, we had completed data collection from adolescents (n≥150) in all the country sites, except Kenya, and data collection for the subgroup (n=30-45) is ongoing. Data analysis is ongoing and the output of findings from the study described in this protocol is expected to be published by 2022. CONCLUSIONS: This project protocol contributes to research that focuses on adolescents and the socioecological determinants of food intake and PA in LMIC settings. It includes innovative methodologies to interrogate and map the contexts of these determinants and will generate much-needed data to understand the multilevel system of factors that can be leveraged through upstream and downstream strategies and interventions to improve health outcomes. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/26739.

Associations of Serum Folate and Holotranscobalamin with Cardiometabolic Risk Factors in Rural and Urban Cameroon.

A low intake of fruit and vegetables and a high intake of meat are associated with higher cardiometabolic disease risk; however much prior research has relied on subjective methods for dietary assessment and focused on Western populations. We aimed to investigate the association of blood folate as an objective marker of fruit and vegetable intake and holotranscobalamin (holoTC) as a marker of animal-sourced food intake with cardiometabolic risk factors. We conducted a population-based cross-sectional study on 578 adults (mean ± SD age = 38.2 ± 8.6 years; 64% women). The primary outcome was a continuous metabolic syndrome score. The median serum folate was 12.9 (IQR: 8.6-20.5) nmol/L and the mean holoTC was 75 (SD: 34.3) pmol/L. Rural residents demonstrated higher serum folate concentrations (15.9 (9.8-25.9) nmol/L) than urban residents (11.3 (7.9-15.8) nmol/L), but lower holoTC concentrations (rural: 69.8 (32.9) pmol/L; urban: 79.8 (34.9)) pmol/L, p < 0.001 for both comparisons. There was an inverse association between serum folate and metabolic syndrome score by -0.20 in the z-score (95% CI, -0.38 to -0.02) per 10.8 (1 SD) of folate) in a model adjusted for socio-demographic factors, smoking status, alcohol intake, BMI, and physical activity. HoloTC was positively associated with the metabolic syndrome score in unadjusted analysis (0.33 (95% CI, 0.10 to 0.56)) but became non-significant (0.17 (-0.05 to 0.39)) after adjusting for socio-demographic and behavioural characteristics. In conclusion, serum folate and holoTC were associated with the metabolic syndrome score in opposite directions. The positive association between serum holoTC and the metabolic syndrome score was partly dependent on sociodemographic characteristics. These findings suggest that, based on these biomarkers reflecting dietary intakes, public health approaches promoting a higher intake of fruit and vegetables may lower cardiometabolic risk factors in this population.

Implications of COVID-19 control measures for diet and physical activity, and lessons for addressing other pandemics facing rapidly urbanising countries.

At the time of writing, it is unclear how the COVID-19 pandemic will play out in rapidly urbanising regions of the world. In these regions, the realities of large overcrowded informal settlements, a high burden of infectious and non-communicable diseases, as well as malnutrition and precarity of livelihoods, have raised added concerns about the potential impact of the COVID-19 pandemic in these contexts. COVID-19 infection control measures have been shown to have some effects in slowing down the progress of the pandemic, effectively buying time to prepare the healthcare system. However, there has been less of a focus on the indirect impacts of these measures on health behaviours and the consequent health risks, particularly in the most vulnerable. In this current debate piece, focusing on two of the four risk factors that contribute to >80% of the NCD burden, we consider the possible ways that the restrictions put in place to control the pandemic, have the potential to impact on dietary and physical activity behaviours and their determinants. By considering mitigation responses implemented by governments in several LMIC cities, we identify key lessons that highlight the potential of economic, political, food and built environment sectors, mobilised during the pandemic, to retain health as a priority beyond the context of pandemic response. Such whole-of society approaches are feasible and necessary to support equitable healthy eating and active living required to address other epidemics and to lower the baseline need for healthcare in the long term.

Prevalence of major cardiovascular disease risk factors among a group of sub-Saharan African young adults: a population-based cross-sectional study in Yaoundé, Cameroon.

OBJECTIVE: To determine the prevalence estimates of some major risk factors for cardiovascular disease (CVD) in a young adult-aged population living in Yaoundé, Cameroon. DESIGN: A cross-sectional study held from May to July 2017. SETTING: PARTICIPANTS: Students aged 18-35 years, with no known history of CVD, found at the campus during recruitment and who voluntarily agreed to be included in the study. PRIMARY AND SECONDARY OUTCOME MEASURES: Data were collected on personal and family history as well as lifestyle and nutritional habits; anthropometric parameters and blood pressure were also measured. Prevalence rates were calculated with their respective 95% CI. RESULTS: Overall, 931 participants (53.8% males) were included, with a median age of 23 years (IQR 21-25). The prevalence estimates for some major CVD risk factors were: 3.1% (95% CI 2.0 to 4.2) for family history of heart attack, 6.3% (95% CI 4.7 to 7.9) for family history of stroke, 26.7% (95% CI 23.9 to 29.5) for hazardous alcohol consumption, 0.9% (95% 0.3 to 1.5) for current tobacco smoking, 27.6% (95% CI 24.7 to 30.5) for secondhand smoking, 88.9% (95% CI 86.9 to 90.9) for physical inactivity, 99.0% (95% CI 98.4 to 99.6) for inadequate fruits and/or vegetables consumption, 39.8% (95% CI 36.7 to 42.9) for self-reported anxiety, 49.2% (95% CI 46.0 to 52.4) for self-reported depression, 22.1% (95% CI 19.4 to 24.8) for overweight, 3.9% (95% CI 2.7 to 5.1) for obesity, 14.4% (95% CI 12.1 to 16.7) for abdominal obesity, 14.5% (95% CI 12.2 to 16.8) for excess body fat mass, 30.0% (95% CI 27.1 to 32.9) for suspected prehypertension and 2.8% (95% CI 1.7 to 3.9) for suspected hypertension. CONCLUSION: The prevalence of some major CVD risk factors is high among young adults living in Yaoundé, Cameroon. Therefore, specific actions should be undertaken in this population to mitigate the upcoming burden of CVD. Accordingly, younger-aged adult populations should be encouraged and accompanied to practice physical activity, eat healthily, and stop or avoid smoking and/or hazardous alcohol consumption.

Two decades of tobacco use prevention and control policies in Cameroon: results from the analysis of non-communicable disease prevention policies in Africa.

BACKGROUND: Tobacco use is the leading cause of preventable death in the world today. In 2010, the World Health Organization (WHO) proposed efficient and inexpensive "best buy" interventions for prevention of tobacco use including: tax increases, smoke-free indoor workplaces and public places, bans on tobacco advertising, promotion and sponsorship, and health information and warnings. This paper analyzes the extent to which tobacco use prevention policies in Cameroon align with the WHO tobacco "best buy" interventions. It further explores the context, content, formulation and implementation level of these policies. METHODS: This was a case study combining a structured review of 19 government policy documents related to tobacco use and prevention, in-depth interviews with 38 key stakeholders and field observations. The Walt and Gilson's policy analysis triangle was used to describe and interpret the context, content, processes and actors during the formulation and implementation of tobacco prevention and control policies. Direct observations ascertained the level of implementation of some selected policies. RESULTS: Twelve out of 19 policies for tobacco use and prevention address the WHO "best buy" interventions. Cameroon policy formulation was driven locally by the social context of non-communicable diseases, and globally by the adoption of the WHO Framework Convention on Tobacco Control. These policies incorporated at a certain level all four domains of tobacco use "best buy" interventions. Formulating policy on smoke-free areas was single-sector oriented, while determining tobacco taxes and health warnings was more complex utilizing multisectoral approaches. The main actors involved were ministerial departments of Health, Education, Finances, Communication and Social Affairs. The level of implementation varied widely from one policy to another and from one region to another. Political will, personal motivation and the existence of formal exchange platforms facilitated policy formulation and implementation, while poor resource allocation and lack of synergy constituted barriers. CONCLUSIONS: Despite actions made by the Government, there is no real political will to control tobacco use in Cameroon. Significant shortcomings still exist in developing and/or implementing comprehensive tobacco use and prevention policies. These findings highlight major gaps as well as opportunities that can be harnessed to improve tobacco control in Cameroon.

Influence of the WHO framework convention on tobacco control on tobacco legislation and policies in sub-Saharan Africa.

BACKGROUND: The World Health Organization's Framework Convention on Tobacco Control, enforced in 2005, was a watershed international treaty that stipulated requirements for signatories to govern the production, sale, distribution, advertisement, and taxation of tobacco to reduce its impact on health. This paper describes the timelines, context, key actors, and strategies in the development and implementation of the treaty and describes how six sub-Saharan countries responded to its call for action on tobacco control. METHODS: A multi-country policy review using case study design was conducted in Cameroon, Kenya, Nigeria, Malawi, South Africa, and Togo. All documents related to the WHO Framework Convention on Tobacco Control and individual country implementation of tobacco policies were reviewed, and key informant interviews related to the countries' development and implementation of tobacco policies were conducted. RESULTS: Multiple stakeholders, including academics and activists, led a concerted effort for more than 10 years to push the WHO treaty forward despite counter-marketing from the tobacco industry. Once the treaty was enacted, Cameroon, Kenya, Nigeria, Malawi, South Africa, and Togo responded in unique ways to implement tobacco policies, with differences associated with the country's socio-economic context, priorities of country leaders, industry presence, and choice of strategies. All the study countries except Malawi have acceded to and ratified the WHO tobacco treaty and implemented tobacco control policy. CONCLUSIONS: The WHO Framework Convention on Tobacco Control provided an unprecedented opportunity for global action against the public health effects of tobacco including non-communicable diseases. Reviewing how six sub-Saharan countries responded to the treaty to mobilize resources and implement tobacco control policies has provided insight for how to utilise international regulations and commitments to accelerate policy impact on the prevention of non-communicable diseases.

Chronic kidney disease in sugarcane workers in Cameroon: a cross-sectional study.

BACKGROUND: Agricultural workers especially in sugarcane plantations have a high risk of chronic kidney disease (CKD). Little is known about CKD among sugarcane plantation workers in Cameroon. This study sought to evaluate the prevalence and identify factors associated with CKD in sugarcane plantation workers in Cameroon. METHODS: We conducted an analytic cross-sectional study including 204 adult workers at the sugarcane plantation complex in Mbandjock, Cameroon; over 500 m above sea level. Chronic kidney disease (proteinuria as estimated by urine dipstick analysis and/or estimated glomerular filtration rate < 60 ml/min/1.73 m2 persistent after 3 months) was the outcome of interest. Those with abnormal results were seen again after 3 months to confirm the diagnosis. We evaluated the association between CKD and participant age, sex, contract-type, duration of employment, socio-economic status, workspace, exposure to agrochemicals, heavy metals and heat, selected risk factors and co-morbid conditions. RESULTS: The overall prevalence of CKD was 3.4%. The factory workers were the most affected (7%), compared to the field (2.4%) and office workers (0%). 2.9% of the participants had persistent proteinuria, mild in every case, and 0.5% of them had an estimated glomerular filtration rate < 60 ml/min/1.73 m2. Age ≥ 40 years was an independent predictor of CKD. CONCLUSION: The prevalence of CKD among employees of the Mbandjock sugarcane plantation is low, probably reflecting the preventive measures against heat stress and dehydration in place.

NEWS for Africa: adaptation and reliability of a built environment questionnaire for physical activity in seven African countries.

BACKGROUND: Built environment and policy interventions are effective strategies for controlling the growing worldwide deaths from physical inactivity-related non-communicable diseases. To improve built environment research and develop African specific evidence, it is important to first tailor built environment measures to African contexts and assess their psychometric properties across African countries. This study reports on the adaptation and test-retest reliability of the Neighborhood Environment Walkability Scale in seven sub-Saharan African countries (NEWS-Africa). METHODS: The original NEWS comprising 8 subscales measuring reported physical and social attributes of neighborhood environments was systematically adapted for Africa through extensive input from physical activity and public health researchers, built environment professionals, and residents in seven African countries: Cameroon, Ghana, Kenya, Mozambique, Nigeria, South Africa and Uganda. Cognitive testing of NEWS-Africa was conducted among diverse residents (N = 109, 50 youth [12 - 17 years] and 59 adults [22 - 67 years], 69 % from low socioeconomic status [SES] neighborhoods). NEWS-Africa was translated into local languages and evaluated for 2-week test-retest reliability in adult participants (N = 301; female = 50.2 %; age = 32.3 ± 12.9 years) purposively recruited from neighborhoods varying in walkability (high and low walkable) and SES (high and low income) and from villages in six of seven participating countries. RESULTS: The original 67 NEWS items was expanded to 89 scores (76 individual NEWS items and 13 computed scales). Several modifications were made to individual items, and some new items were added to capture important attributes in the African environment. A new scale on personal safety was created, and the aesthetics scale was enlarged to reflect African specific characteristics. Over 95 % of all NEWS-Africa scores (items plus computed scales) demonstrated evidence of "excellent" (ICCs > .75 %) or "good" (ICCs = 0.60 to 0.74) reliability. Seven (53.8 %) of the 13 computed NEWS scales demonstrated "excellent" agreement and the other six had "good" agreement. No items or scales demonstrated "poor" reliability (ICCs < .40). CONCLUSIONS: The systematic adaptation and initial psychometric evaluation of NEWS-Africa indicates the instrument is feasible and reliable for use with adults of diverse demographic characteristics in Africa. The measure is likely to be useful for research, surveillance of built environment conditions for planning purposes, and to evaluate physical activity and policy interventions in Africa.

Patterns and correlates of objectively measured free-living physical activity in adults in rural and urban Cameroon.

BACKGROUND: Urbanisation in sub-Saharan Africa is changing lifestyles and raising non-communicable disease burden. Understanding the underlying pattern of physical activity and its correlates may inform preventive interventions. We examined correlates of objectively-measured physical activity in rural and urban Cameroon. METHODS: Participants were 544 adults resident in rural (W-156, M-89) or urban (W-189, M-110) regions. Physical activity was measured using individually-calibrated combined heart rate and movement sensing over seven continuous days. Sociodemographic data were collected by self-report. Independent associations of sociodemographic correlates with physical activity energy expenditure (PAEE) or moderate-to-vigorous physical activity (MVPA) were analysed in multivariate regression models. RESULTS: Rural dwellers were significantly more active than their urban counterparts (PAEE: 58.0 vs 42.9 kJ/kg/day; MVPA: 107 vs 62 min/day; MVPA of 150 min/week in >10 min bouts: 62 vs 39%) and less sedentary (923 vs 1026 min/day); p<0.001. There was no significant seasonal difference (dry vs rainy) in activity in urban dwellers whereas in rural dwellers activity was higher during dry seasons compared to rainy seasons (p<0.001). Age, obesity and education showed significant inverse associations with activity. Urban dwellers who considered themselves adequately active were only as active as rural dwellers who thought they were not adequately active. CONCLUSIONS: This is the first study providing data on sociodemographic patterning of objectively-measured physical activity in rural and urban sub-Saharan Africa. Age, urban residence, obesity and higher educational level are important correlates of lower levels of physical activity. These suggest targets for public health interventions to improve physical activity in Cameroon.

Free-living physical activity energy expenditure is strongly related to glucose intolerance in Cameroonian adults independently of obesity.

OBJECTIVE: We examined the cross-sectional association between objectively measured free-living physical activity energy expenditure (PAEE) and glucose tolerance in adult Cameroonians without known diabetes. RESEARCH DESIGN AND METHODS: PAEE was measured in 34 volunteers using the doubly labeled water method and indirect calorimetry (resting). Fasting blood glucose and 2-h postload blood glucose were measured during a standard 75-g oral glucose tolerance test. RESULTS: There was a significant negative correlation between PAEE and 2-h glucose (r = -0.43; P = 0.01) but not fasting glucose (r = 0.1; P = 0.57). The inverse association between PAEE and 2-h glucose remained after adjustment for age, sex, smoking, alcohol consumption, and BMI (beta = -0.017 [95% CI -0.033 to -0.002]) and was unchanged after further adjustment for waist circumference, body fat percentage, or aerobic fitness. CONCLUSIONS: PAEE is inversely associated with 2-h glucose independently of adiposity or fitness. Interventions aimed at increasing PAEE could play an important role in diabetes prevention in developing countries.

Ten-year changes in central obesity and BMI in rural and urban Cameroon.

OBJECTIVE: To compare the 10-year changes in the distribution of adiposity in rural and urban Cameroonian populations. METHODS AND PROCEDURES: Two cross-sectional surveys of populations in the same rural and urban areas of Cameroon, aged>or=24 years, were carried out in 1994 (1,762 subjects) and 2003 (1,398 subjects) using similar methodology. All eligible subjects answered a structured questionnaire on their educational level, alcohol consumption, and tobacco smoking and weight, height, and waist circumference (WC) were measured. RESULTS: Between 1994 and 2003, the age-standardized prevalence of BMI>or=25 kg/m2 increased significantly only in the rural area (+54% for women and +82% for men), while the age-standardized prevalence of central obesity (WC>or=80 cm (women), >or=94 cm (men)) increased significantly only in the urban population (+32% for women and +190% for men). These differences persisted after adjustments for age group, alcohol consumption, tobacco smoking, and level of education, and within almost all the strata of the studied risk factors. DISCUSSION: Changes in adiposity over time in Cameroon were characterized by an increase of BMI in the rural area and of WC in the urban area.