The global diet and activity research (GDAR) network: a global public health partnership to address upstream NCD risk factors in urban low and middle-income contexts.

BACKGROUND: Non-communicable diseases (NCDs) are the leading cause of death globally. While upstream approaches to tackle NCD risk factors of poor quality diets and physical inactivity have been trialled in high income countries (HICs), there is little evidence from low and middle-income countries (LMICs) that bear a disproportionate NCD burden. Sub-Saharan Africa and the Caribbean are therefore the focus regions for a novel global health partnership to address upstream determinants of NCDs. PARTNERSHIP: The Global Diet and Activity research Network (GDAR Network) was formed in July 2017 with funding from the UK National Institute for Health Research (NIHR) Global Health Research Units and Groups Programme. We describe the GDAR Network as a case example and a potential model for research generation and capacity strengthening for others committed to addressing the upstream determinants of NCDs in LMICs. We highlight the dual equity targets of research generation and capacity strengthening in the description of the four work packages. The work packages focus on learning from the past through identifying evidence and policy gaps and priorities, understanding the present through adolescent lived experiences of healthy eating and physical activity, and co-designing future interventions with non-academic stakeholders. CONCLUSION: We present five lessons learned to date from the GDAR Network activities that can benefit other global health research partnerships. We close with a summary of the GDAR Network contribution to cultivating sustainable capacity strengthening and cutting-edge policy-relevant research as a beacon to exemplify the need for such collaborative groups.

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.

Assessment of the agreement between the Framingham and DAD risk equations for estimating cardiovascular risk in adult Africans living with HIV infection: a cross-sectional study.

BACKGROUND: The Absolute cardiovascular disease (CVD) risk evaluation using multivariable CVD risk models is increasingly advocated in people with HIV, in whom existing models remain largely untested. We assessed the agreement between the general population derived Framingham CVD risk equation and the HIV-specific Data collection on Adverse effects of anti-HIV Drugs (DAD) CVD risk equation in HIV-infected adult Cameroonians. METHODS: This cross-sectional study involved 452 HIV infected adults recruited at the HIV day-care unit of the Yaoundé Central Hospital, Cameroon. The 5-year projected CVD risk was estimated for each participant using the DAD and Framingham CVD risk equations. Agreement between estimates from these equations was assessed using the spearman correlation and Cohen's kappa coefficient. RESULTS: The mean age of participants (80% females) was 44.4 ± 9.8 years. Most participants (88.5%) were on antiretroviral treatment with 93.3% of them receiving first-line regimen. The most frequent cardiovascular risk factors were abdominal obesity (43.1%) and dyslipidemia (33.8%). The median estimated 5-year CVD risk was 0.6% (25th-75th percentiles: 0.3-1.3) using the DAD equation and 0.7% (0.2-2.0) with the Framingham equation. The Spearman correlation between the two estimates was 0.93 (p < 0.001). The kappa statistic was 0.61 (95% confident interval: 0.54-0.67) for the agreement between the two equations in classifying participants across risk categories defined as low, moderate, high and very high. CONCLUSION: Most participants had a low-to-moderate estimated CVD risk, with acceptable level of agreement between the general and HIV-specific equations in ranking CVD risk.

Construct Validity of the Neighborhood Environment Walkability Scale for Africa.

PURPOSE: The development of valid measures of built environments relevant for physical activity is an important step toward controlling the global epidemic of physical inactivity-related noncommunicable diseases and deaths. This study assessed the construct validity of a self-report neighborhood environment walkability scale adapted for Africa (NEWS-Africa), by examining relationships with self-reported walking for transportation and recreation using pooled data from six sub-Saharan African countries. METHODS: NEWS was systematically adapted to assess urban, periurban, and rural environments in sub-Saharan Africa. Adults (n = 469, 18-85 yr, 49.7% women) from Cameroon, Ghana, Mozambique, Nigeria, South Africa, and Uganda were purposively recruited from neighborhoods varying in walkability and socioeconomic status, with some from villages. Participants completed the 76-item (13 subscales) NEWS-Africa by structured interview and reported weekly minutes of walking for transport and recreation using items from the International Physical Activity Questionnaire. RESULTS: The overall "walkability" index had a positive relationship with both walking for transportation (η = 0.020, P = 0.005) and recreation (η = 0.013, P = 0.028) in the pooled analyses. The mixed-use access and stranger danger scales were positively related with transport walking (η = 0.020, P = 0.006 and η = 0.021, P = 0.040, respectively). Proximity of recreational facilities (η = 0.016, P = 0.015), road/path connectivity (η = 0.025, P = 0.002), path infrastructure (η = 0.021, P = 0.005), and overall places for walking and cycling (η = 0.012, P = 0.029) scales were positively related to recreational walking. Country-specific results were mostly nonsignificant except for South Africa and Uganda. CONCLUSIONS: Of 14 NEWS-Africa scales, 7 were significantly related to walking behavior in pooled analyses, providing partial support for the construct validity of NEWS-Africa. However, effect sizes appeared to be lower than those from other continents. Further study with larger and more diverse samples is needed to determine whether the instrument performs well in each country.

Autocalibration of accelerometer data for free-living physical activity assessment using local gravity and temperature: an evaluation on four continents.

Wearable acceleration sensors are increasingly used for the assessment of free-living physical activity. Acceleration sensor calibration is a potential source of error. This study aims to describe and evaluate an autocalibration method to minimize calibration error using segments within the free-living records (no extra experiments needed). The autocalibration method entailed the extraction of nonmovement periods in the data, for which the measured vector magnitude should ideally be the gravitational acceleration (1 g); this property was used to derive calibration correction factors using an iterative closest-point fitting process. The reduction in calibration error was evaluated in data from four cohorts: UK (n = 921), Kuwait (n = 120), Cameroon (n = 311), and Brazil (n = 200). Our method significantly reduced calibration error in all cohorts (P < 0.01), ranging from 16.6 to 3.0 mg in the Kuwaiti cohort to 76.7 to 8.0 mg error in the Brazil cohort. Utilizing temperature sensor data resulted in a small nonsignificant additional improvement (P > 0.05). Temperature correction coefficients were highest for the z-axis, e.g., 19.6-mg offset per 5°C. Further, application of the autocalibration method had a significant impact on typical metrics used for describing human physical activity, e.g., in Brazil average wrist acceleration was 0.2 to 51% lower than uncalibrated values depending on metric selection (P < 0.01). The autocalibration method as presented helps reduce the calibration error in wearable acceleration sensor data and improves comparability of physical activity measures across study locations. Temperature ultization seems essential when temperature deviates substantially from the average temperature in the record but not for multiday summary measures.

Energy expenditure in adults living in developing compared with industrialized countries: a meta-analysis of doubly labeled water studies.

BACKGROUND: There is an assumption that people in developing countries have a higher total energy expenditure (TEE) and physical activity level (PAL) than do people in developed nations, but few objective data for this assertion exist. OBJECTIVE: We conducted a meta-analysis of TEE and PAL by using data from countries that have a low or middle human development index (HDI) compared with those with a high HDI to better understand how energy-expenditure variables are associated with development status and population differences in body size. DESIGN: We performed a literature search for studies in which energy expenditure was measured by using doubly labeled water. Mean data on age, weight, body mass index (BMI; in kg/m(2)), TEE, and PAL were extracted, and HDI status was assessed. Pooled estimates of the mean effect by sex were obtained, and the extent to which age, weight, HDI status, and year of publication explained heterogeneity was assessed. RESULTS: A total of 98 studies (14 studies from low- or middle-HDI countries) that represented 183 cohorts and 4972 individuals were included. Mean (±SE) BMI was lower in countries with a low or middle HDI than in those with a high HDI for both men and women (22.7 ± 1.0 compared with 26.0 ± 0.7, respectively, in men and 24.3 ± 0.7 compared with 26.6 ± 0.4, respectively, in women). In meta-regression models, there was an inverse association of age (P < 0.001) and a positive association of weight (P < 0.001) with TEE for both sexes; there was an association of age only in men with PAL (P < 0.001). There was no association of HDI status with either TEE or PAL. CONCLUSION: TEE adjusted for weight and age or PAL did not differ significantly between developing and industrialized countries, which calls into question the role of energy expenditure in the cause of obesity at the population level.

Accuracy and validity of a combined heart rate and motion sensor for the measurement of free-living physical activity energy expenditure in adults in Cameroon.

BACKGROUND: The increasing burden of non-communicable diseases in sub-Saharan Africa (SSA) warrants rigorous studies of contributing lifestyle factors. Combined heart rate (HR) and movement monitoring make it possible to objectively measure physical activity in free-living individuals. We examined the validity of a combined HR and motion sensor in estimating physical activity energy expenditure (PAEE) in free-living adults in rural and urban Cameroon compared with doubly-labelled water (DLW) as criterion. METHODS: PAEE was measured in 33 free-living rural and urban dwellers by DLW over 7 consecutive days. Simultaneously, the combined sensor recorded HR and uni-axial acceleration. Individual HR vs PAEE calibration was done by a step test. Branched equation modelling was used to estimate PAEE from HR and acceleration. Validity and accuracy of prediction were expressed as mean bias and root mean square error (RMSE). Agreement was analysed using Bland and Altman limits of agreement (LOA). RESULTS: There was no significant mean bias between PAEE estimated from the combined sensor or measured by DLW [mean bias (standard error): -5.4 (5.1) kJ/kg/day; P = 0.3; RMSE = 29.3 kJ/kg/day]. The bias doubled for group compared with individual calibration of HR [-9.1 (5.0) kJ/kg/day, P = 0.08]. PAEE prediction was more accurate in urban compared with rural volunteers. The 95% LOAs between predicted and measured PAEE were ∼50-60 kJ/kg/day above or below perfect agreement. CONCLUSIONS: Combined HR and movement sensing is a valid method for estimating free-living PAEE on group level in adults in SSA.

Predicting physical activity energy expenditure using accelerometry in adults from sub-Sahara Africa.

Lack of physical activity may be an important etiological factor in the current epidemiological transition characterized by increasing prevalence of obesity and chronic diseases in sub-Sahara Africa. However, there is a dearth of data on objectively measured physical activity energy expenditure (PAEE) in this region. We sought to develop regression equations using body composition and accelerometer counts to predict PAEE. We conducted a cross-sectional study of 33 adult volunteers from an urban (n = 16) and a rural (n = 17) residential site in Cameroon. Energy expenditure was measured by doubly labeled water (DLW) over a period of seven consecutive days. Simultaneously, a hip-mounted Actigraph accelerometer recorded body movement. PAEE prediction equations were derived using accelerometer counts, age, sex, and body composition variables, and cross-validated by the jack-knife method. The Bland and Altman limits of agreement (LOAs) approach was used to assess agreement. Our results show that PAEE (kJ/kg/day) was significantly and positively correlated with activity counts from the accelerometer (r = 0.37, P = 0.03). The derived equations explained 14-40% of the variance in PAEE. Age, sex, and accelerometer counts together explained 34% of the variance in PAEE, with accelerometer counts alone explaining 14%. The LOAs between DLW and the derived equations were wide, with predicted PAEE being up to 60 kJ/kg/day below or above the measured value. In summary, the derived equations performed better than existing published equations in predicting PAEE from accelerometer counts in this population. Accelerometry could be used to predict PAEE in this population and, therefore, has important applications for monitoring population levels of total physical activity patterns.

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.

Monitoring antiretroviral therapy in HIV/AIDS patients in resource-limited settings: CD4 counts or total lymphocyte counts?

OBJECTIVE: In order to improve the monitoring of disease progression and therapeutic effectiveness in the management of HIV/AIDS in a resource-limited setting, this study was carried out to establish a correlation between total lymphocyte counts (TLC) and CD4 lymphocyte counts in HIV-1 infected/AIDS adults in Yaoundé, Cameroon. METHODS: Full blood counts, differential white, and CD4 counts were measured in 149 patients using standard methods. The correlation coefficient established correlation between values. Sensitivity, specificity, and positive predictive values were calculated as required. RESULTS: The mean TLC, CD4 count, and CD4% as well as CD4/CD8 ratios were 1.932+/-0.895 x 10(9)/L, 268+/-183 cells/mm(3), 14.51+/-15.9%, and 0.34+/-0.25, respectively. Only a weak correlation was observed between TLC and CD4 counts (r=0.41, p=0.05). As a predictor of CD4 count, TLC cut-offs <2.0 and <1.0 x 10(9)/L were unable to predict these values reliably, but showed that at TLC cut-offs of <1.0 x 10(9)/L there was a high chance of CD4 counts being under 200 cells/mm(3). CONCLUSIONS: These data suggest that TLC are of limited value in predicting CD4 counts and should not be substituted for CD4 counts whenever possible. However, TLC may be reliably used in designing algorithms and programs for initiating patient management and follow-up in this setting.