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

SummaryObjectiveIn 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.MethodsFull 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.ResultsThe mean TLC, CD4 count, and CD4% as well as CD4/CD8 ratios were 1.932±0.895×109/L, 268±183cells/mm3, 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 <1.0×109/L were unable to predict these values reliably, but showed that at TLC cut-offs of <1.0×109/L there was a high chance of CD4 counts being under 200cells/mm3.ConclusionsThese 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

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.This research was supported by the Wellcome Trust (074786/Z/04/Z) and the Medical Research Council Epidemiology Unit (MC_UU_12015/3).This is the final published version. It first appeared at http://jech.bmj.com/content/early/2015/04/03/jech-2014-205154.long

NEWS for Africa : adaptation and reliability of a built environment questionnaire for physical activity in seven 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). The measure will be useful for surveillance of built environment conditions for planning purposes, and to evaluate physical activity and policy interventions in Africa, two effective strategies for controlling deaths from physical inactivity-related non-communicable diseases. This report includes data collection and analysis, as well as a discussion of findings

Analysis of non-communicable diseases prevention policies in Cameroon : Final report

This research is part of a multi-centre project on the Analysis of NCD Prevention funded by the African Population and Health Research Centre (APHRC) in partnership with the International Development Research Centre (IDRC).Non-communicable diseases (NCDs) currently constitute a serious threat to health worldwide, with the situation expected to worsen if concerted actions are not urgently taken. The World Health Organisation (WHO) identified population-based interventions addressing four NCD risk factors – tobacco use, harmful use of alcohol, unhealthy diet, and physical inactivity; also known as “best buys” – and proposes the use of multi-sectoral approaches (MSA) to engage the public, private, and non-profit sectors to implement these best buys. In November 2014, the African Population and Health Research Centre (APHRC), with funding from the International Development Research Centre (IDRC), led Cameroon and five other African countries in a study to analyse how countries are addressing NCD prevention in order to best facilitate MSA for NCD prevention in Africa

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 0.05). 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.This is the final version of the article. It first appeared from the American Physiological Society via http://dx.doi.org/10.1152/japplphysiol.00421.201

Insulin resistance and associated factors among HIV-infected patients in sub-Saharan Africa: a cross sectional study from Cameroon

BACKGROUND: Little is known on the magnitude and correlates of insulin resistance in HIV-infected people in Africa. We determined the prevalence of insulin resistance and investigated associated factors in HIV-infected adult Cameroonians. METHODS: We conducted a cross-sectional study at the Yaoundé Central Hospital, Cameroon; during which we enrolled HIV-infected people aged 30 to 74 years with no previous history of cardiovascular disease. An homeostatic model assessment of insulin resistance (HOMA-IR) like index served to assess insulin sensitivity with insulin resistance defined by values of 2.1 or higher. RESULTS: We included 452 patients (20% men). Their mean age was 44.4 ± 9.8 years and 88.5% of them were on antiretroviral therapy (93.3% on first line regimen including Zidovudine, lamivudine and Efavirenz/Nevirapine). Of all participants, 28.5% were overweight, 19.5% had obesity and 2.0% had diabetes. The prevalence of insulin resistance was 47.3% without any difference between patients on ART and those ART-naïve (48.5% vs. 38.5%; p = 0.480). Obesity was the only factor independently associated with insulin resistance (adjusted odds ratio: 2.28; 95% confidence interval: 1.10-4.72). CONCLUSION: Insulin resistance is present in nearly half of HIV-infected patients in Cameroon despite a low prevalence rate of diabetes, and is associated with obesity

Analysis of Cameroon's Sectoral Policies on Physical Activity for Noncommunicable Disease Prevention.

Physical inactivity is increasing in low- and middle-income countries (LMICs), where noncommunicable diseases (NCDs), urbanisation and sedentary living are rapidly growing in tandem. Increasing active living requires the participation of multiple sectors, yet it is unclear whether physical activity (PA)-relevant sectors in LMICs are prioritising PA. We investigated to what extent sectors that influence PA explicitly integrate it in their policies in an LMIC such as Cameroon. We systematically identified policy documents relevant to PA and NCD prevention in Cameroon; and using the Walt and Gilson policy triangle we described, analysed, and interpreted the policy contexts, contents, processes, and actors. We found 17 PA and NCD policy documents spanning from 1974 to 2019 across seven ministries. Thirteen (13/17) policies targeted infrastructure improvement, and four (4/17) targeted communication for behaviour change, all aiming to enhance leisure domain PA. Only the health sector explicitly acknowledged the role of PA in NCD prevention. Notably, no policy from the transport sector mentioned PA. Our findings highlight the need for intersectoral action to integrate PA into policies in all relevant sectors. These actions will need to encompass the breadth of PA domains, including transport, while emphasising the multiple health benefits of PA for the population

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

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