Knowledge generation via publications on hypertension prevalence in population-based studies conducted in sub-Saharan Africa over 30 years: 1990 - 2019

Hypertension prevalence in sub-Saharan Africa (SSA) is high, is rising and has emerged as the most prevalent cardiovascular disease risk factor. Research is required to provide evidence-based findings to prioritise hypertension prevention and control. This systematic review aims to describe the distribution of and trends in scientific outputs on hypertension prevalence in population-based studies in SSA over the last three decades. Relevant English-language articles documenting hypertension prevalence in population-based studies in SSA, published between 1 January 1990 and 25 April 2019, were identified through a comprehensive electronic search of MEDLINE. Of the 3 795 citations retrieved, 414 fulfilled the inclusion criteria. Scientific outputs increased incrementally per 10-year period: 1990 - 1999: n=32; 2000 - 2009: n=65; and 2010 - 2019: n=317. The greatest number of scientific outputs over the 30-year period originated from South Africa (n=81) and Nigeria (n=74). Increasing scientific outputs on hypertension prevalence in SSA have not translated into optimal hypertension management, which remains inadequate

The burden of high blood pressure and related risk factors in urban Sub-Saharan Africa: Evidences from Douala in Cameroon

Objective: To provide the current burden of high blood pressure and related risk factors in urban setting in Cameroon. Methods:We used the WHO STEPS approach for Surveillance of non-communicable diseases and their risk factors to collect data from 2,559 adults aged 15-99 years, residing at Cite des Palmiers in Douala, Cameroon. Results: The level of education was low with up to 60% of participants totalizing less than primary school. Smoking habits were 6 times more frequent in men (

Anemia in patients on chronic hemodialysis in Cameroon: prevalence, characteristics and management in low resources setting

Background: Anemia is a common complication of chronic kidney disease. We investigated the prevalence, characteristics and management of anemia in patients on chronic hemodialysis and assessed the response to blood-transfusion based management in Cameroon.Methods: This was a cohort study of five months’ duration (August-December 2008) conducted at the Yaoundé General Hospital’s hemodialysis center, involving 95 patients (67 men, 70.5%) on chronic hemodialysis by a native arterio-venous fistula. A monthly evaluation included full blood counts, number of pints of red cell concentrates transfused, and vital status.Results: At baseline, 75 (79%) patients had anemia which was microcytic and hypochromic in 32 (43%). Anemia was corrected in 67 (70.5%) patients using blood transfusion only, while 28 (29.5%) patients were receiving erythropoietin (11 regularly, 39%). Only 77.2% of 342 pints (median 3.0, range 0-17 per patients) of red cell concentrates prescribed were effectively received during the follow-up at an unacceptably high cost to patients and families. Mean hemoglobin and mean corpuscular hemoglobin levels remained stable during follow-up, while mean corpuscular volume increased. Erythropoietin treatment was the main determinant of favorable trajectories of hematological markers.Conclusions: Patients on chronic hemodialysis have predominantly microcytic hypochromic anemia, with limited capacity for correction using blood transfusion.Key words: Anemia; Blood transfusion; End stage renal disease; Hemodialysis; Sub-Saharan Afric

Rare Mutations of Peroxisome Proliferator-Activated Receptor Gamma: Frequencies and Relationship with Insulin Resistance and Diabetes Risk in the Mixed Ancestry Population from South Africa

Background. Genetic variants in the nuclear transcription receptor, PPARG, are associated with cardiometabolic traits, but reports remain conflicting. We determined the frequency and the clinical relevance of PPARG SNPs in an African mixed ancestry population. Methods. In a cross-sectional study, 820 participants were genotyped for rs1800571, rs72551362, rs72551363, rs72551364, and rs3856806, using allele-specific TaqMan technology. The homeostatic model assessment of insulin (HOMA-IR), β-cells function (HOMA-B%), fasting insulin resistance index (FIRI), and the quantitative insulin-sensitivity check index (QUICKI) were calculated. Results. No sequence variants were found except for the rs3856806. The frequency of the PPARG-His447His variant was 23.8% in the overall population group, with no difference by diabetes status (). The His447His allele T was associated with none of the markers of insulin resistance overall and by diabetes status. In models adjusted for 2-hour insulin, the T allele was associated with lower prevalent diabetes risk (odds ratio 0.56 (95% CI 0.31–0.95)). Conclusion. Our study confirms the almost zero occurrences of known rare PPARG SNPs and has shown for the first time in an African population that one of the common SNPs, His447His, may be protective against type 2 diabetes

Paraoxonase1 Genetic Polymorphisms in a Mixed Ancestry African Population

Paraoxonase 1 (PON1) activity is markedly influenced by coding polymorphisms, Q/R at position 192 and M/L at position 55 of the PON1 gene. We investigated the frequencies of these polymorphisms and their effects on PON1 and antioxidant activities in 844 South African mixed ancestry individuals. Genotyping was done using allele-specific TaqMan technology, PON1 activities were measured using paraoxon and phenylacetate, oxidative status was determined by measuring the antioxidant activities of ferric reducing antioxidant power and trolox equivalent antioxidant capacity, and lipid peroxidation markers included malondialdehyde and oxidized LDL. The frequencies of Q192R and L55M were 47.6% and 28.8%, respectively, and the most common corresponding alleles were 192R (60.4%) and 55M (82.6%). The Q192 was significantly associated with 5.8 units’ increase in PON1 concentration and 15.4 units’ decrease in PONase activity after adjustment for age, sex, BMI, and diabetes, with suggestion of differential effects by diabetes status. The PON1 L55 variant was associated with none of the measured indices. In conclusion, we have shown that the Q192R polymorphism is a determinant of both PON1 concentration and activity and this association appeared to be enhanced in subjects with diabetes

The epidemiological burden of obesity in childhood: a worldwide epidemic requiring urgent action

Background: In recent decades, the prevalence of obesity in children has increased dramatically. This worldwide epidemic has important consequences, including psychiatric, psychological and psychosocial disorders in childhood and increased risk of developing non-communicable diseases (NCDs) later in life. Treatment of obesity is difficult and children with excess weight are likely to become adults with obesity. These trends have led member states of the World Health Organization (WHO) to endorse a target of no increase in obesity in childhood by 2025. Main body: Estimates of overweight in children aged under 5 years are available jointly from the United Nations Children’s Fund (UNICEF), WHO and the World Bank. The Institute for Health Metrics and Evaluation (IHME) has published country-level estimates of obesity in children aged 2–4 years. For children aged 5–19 years, obesity estimates are available from the NCD Risk Factor Collaboration. The global prevalence of overweight in children aged 5 years or under has increased modestly, but with heterogeneous trends in low and middle-income regions, while the prevalence of obesity in children aged 2–4 years has increased moderately. In 1975, obesity in children aged 5–19 years was relatively rare, but was much more common in 2016. Conclusions: It is recognised that the key drivers of this epidemic form an obesogenic environment, which includes changing food systems and reduced physical activity. Although cost-effective interventions such as WHO ‘best buys’ have been identified, political will and implementation have so far been limited. There is therefore a need to implement effective programmes and policies in multiple sectors to address overnutrition, undernutrition, mobility and physical activity. To be successful, the obesity epidemic must be a political priority, with these issues addressed both locally and globally. Work by governments, civil society, private corporations and other key stakeholders must be coordinated

A new species in the major malaria vector complex sheds light on reticulated species evolution

Complexes of closely related species provide key insights into the rapid and independent evolution of adaptive traits. Here, we described and studied Anopheles fontenillei sp.n., a new species in the Anopheles gambiae complex that we recently discovered in the forested areas of Gabon, Central Africa. Our analysis placed the new taxon in the phylogenetic tree of the An. gambiae complex, revealing important introgression events with other members of the complex. Particularly, we detected recent introgression, with Anopheles gambiae and Anopheles coluzzii, of genes directly involved in vectorial capacity. Moreover, genome analysis of the new species allowed us to clarify the evolutionary history of the 3La inversion. Overall, An. fontenillei sp.n. analysis improved our understanding of the relationship between species within the An. gambiae complex, and provided insight into the evolution of vectorial capacity traits that are relevant for the successful control of malaria in Africa

Tobacco use in pregnant women: analysis of data from Demographic and Health Surveys from 54 low-income and middle-income countries

Background Worldwide, use of tobacco is viewed as an important threat to the health of pregnant women and their children. However, the extent of tobacco use in pregnant women in low-income and middle-income countries (LMICs) remains unclear. We assessed the magnitude of tobacco use in pregnant women in LMICs. Methods We used data from Demographic and Health Surveys (DHS) done in 54 LMICs between Jan 1, 2001, and Dec 1, 2012, comprising 58 922 pregnant women (aged 15–49 years), which were grouped by WHO region. Prevalence of current tobacco use (smoked and smokeless) was estimated for every country. Pooled estimates by regions and overall were obtained from random-eff ects meta-analysis. Findings Pooled prevalence of any tobacco use in pregnant women in LMICs was 2·6% (95% CI 1·8–3·6); the lowest prevalence was in the African region (2·0%, 1·2–2·9) and the highest was in the Southeast Asian region (5·1%, 1·3–10·9). The pooled prevalence of current tobacco smoking in pregnant women ranged from 0·6% (0·3–0·8) in the African region to 3·5% (1·5–12·1) in the Western Pacifi c region. The pooled prevalence of current smokeless tobacco use in pregnant women was lowest in the European region (0·1%, 0·0–0·3) and highest in the Southeast Asian region (2·6%, 0·0–7·6). Interpretation Overall, tobacco use in pregnant women in LMICs was low; however high prevalence estimates were noted in some LMICs. Prevention and management of tobacco use and exposure to second-hand smoke in pregnancy is crucial to protect maternal and child health in LMICs

Efficiency of an intervention package for arterial hypertension comprising telemanagement in a Cameroonian rural setting: The TELEMED-CAM study

Introduction: Sub-Saharan Africa has a disproportionate burden of disease and an extreme shortage of health workforce. Therefore, adequate care for emerging chronic diseases can be very challenging. We implemented and evaluated the effectiveness of an intervention package comprising telecare as a mean for improving the outcomes of care for hypertension in Rural Sub-Saharan Africa. Methods: The study involved a telemedicine center based at the Yaounde General Hospital (5 cardiologists) in the Capital city of Cameroon, and 30 remote rural health centers within the vicinity of Yaoundé (20 centers (103 patients) in the usual care group, and 10 centers (165 patients) in the intervention groups). The total duration of the intervention was 24 weeks. Results: Participants in the intervention group had higher baseline systolic (SBP) and diastolic (DBP) blood pressure, and included fewer individuals with diabetes than those in the usual care group (all p<0.01). Otherwise, the baseline profile was mostly similar between the two groups. During follow-up, more participants in the intervention groups achieved optimal BP control, driven primarily by greater improvement of BP control among High risk participants (hypertension stage III) in the intervention group. Conclusion: An intervention package comprising tele-support to general practitioners and nurses is effective in improving the management and outcome of care for hypertension in rural underserved populations. This can potentially help in addressing the shortage of trained health workforce for chronic disease management in some settings. However context-specific approaches and cost-effectiveness data are needed to improve the application of telemedicine for chronic disease management in resource-limited settings.Key words: Hypertension, control, telemedicine, Cameroon, sub-saharan Afric