Hypertension In Sub-Saharan Africa

Geographic variation of hypertension in sub-saharan Africa: a case study of South Africa

BACKGROUND

Hypertension is of public health importance in sub-Saharan Africa, with considerable underdiagnosis, poor management, and lack of community-wide preventive strategies. We examined the geographic variation of hypertension at the province level in South Africa, while accounting for individual-level risk factors such as sociodemographics, lifestyle, and cardiovascular comorbidities.

METHODS

Our analysis was based on the South African Demographic and Health Survey, including 13,596 men and women aged 15 years and over. Individual data were collected on lifestyle habits and cardiovascular comorbidities, but were aggregated to the nine country's provinces. We used a Bayesian geo-additive mixed model to map the geographic distribution of hypertension at the province level, accounting for individual risk factors.

RESULTS

The overall prevalence of hypertension (blood pressure ≥140/90 mmHg or self-reported diagnosis or on medication) was 30.4%. In multivariate Bayesian geo-additive models, current smokers (odds ratio [OR] and 95% credible region [CR]: 1.14 [1.03, 1.26]), current drinkers (1.17 [1.05, 1.29]), people reporting sleep problems (1.16 [1.02, 1.31]), and participants with prevalent cardiovascular comorbidities, such as type 2 diabetes (2.49 [1.92, 3.13]), were significantly associated with a higher prevalence of hypertension. There was a striking variation in hypertension prevalence across provinces, the highest being in North West (1.33 [1.14, 1.61]), Free State (1.32 [1.08, 1.68]) and Northern Cape (1.30 [1.02, 1.55]), the lowest in Limpopo (0.68 [0.56, 0.84]).

CONCLUSIONS

This study showed distinct geographic patterns in hypertension prevalence in South Africa, suggesting the potential role of socioeconomic, nutritional, and environmental factors at the province level, beyond individual-level risk factors in this setting.

Epidemiology of ischaemic heart disease in sub-Saharan Africa

BACKGROUND

The epidemiology of ischaemic heart disease (IHD) in sub-Saharan Africa (SSA) remains largely enigmatic. Major obstacles to our understanding of the condition include lack of reliable health statistics, particularly cause-specific mortality data, inadequate diagnostic capabilities, shortage of physicians and cardiologists, and misguided opinions.

METHODS

This review of the epidemiology of ischaemic heart disease in sub-Saharan Africa involved a systematic bibliographic MEDLINE search of published data on IHD in SSA over the past century. Search words included epidemiology, ischaemic (coronary) heart disease, myocardial infarction, cardiovascular risk factors and sub-Saharan Africa. Selected data are presented on the prevalence of cardiovascular risk factors and mortality from ischaemic heart disease from different countries representing the main regions of the continent.

RESULTS

Although IHD in SSA remains relatively uncommon, its prevalence is predicted to rise in the next two decades due to the rising prevalence of risk factors, especially hypertension, diabetes, overweight and obesity, physical inactivity, increased tobacco use and dyslipidaemia. It is estimated that age-standardised mortality rates for IHD will rise by 27% in African men and 25% in women by 2015, and by 70 and 74%, respectively by 2030.

CONCLUSION

Ischaemic heart disease remains relatively uncommon in SSA, despite an increasing prevalence of risk factors, but its incidence is rising. The pace and direction of economic development, rates of urbanisation, and changes in life expectancy resulting from the impact of pre-transitional diseases and violence will be major determinants of the IHD epidemic in SSA. The best window of opportunity for prevention of the emerging epidemic of ischaemic heart disease in sub-Saharan Africa is now.

Prevalence of active convulsive epilepsy in sub-Saharan Africa and associated risk factors: cross-sectional and case-control studies

BACKGROUND

The prevalence of epilepsy in sub-Saharan Africa seems to be higher than in other parts of the world, but estimates vary substantially for unknown reasons. We assessed the prevalence and risk factors of active convulsive epilepsy across five centres in this region.

METHODS

We did large population-based cross-sectional and case-control studies in five Health and Demographic Surveillance System centres: Kilifi, Kenya (Dec 3, 2007-July 31, 2008); Agincourt, South Africa (Aug 4, 2008-Feb 27, 2009); Iganga-Mayuge, Uganda (Feb 2, 2009-Oct 30, 2009); Ifakara, Tanzania (May 4, 2009-Dec 31, 2009); and Kintampo, Ghana (Aug 2, 2010-April 29, 2011). We used a three-stage screening process to identify people with active convulsive epilepsy. Prevalence was estimated as the ratio of confirmed cases to the population screened and was adjusted for sensitivity and attrition between stages. For each case, an age-matched control individual was randomly selected from the relevant centre's census database. Fieldworkers masked to the status of the person they were interviewing administered questionnaires to individuals with active convulsive epilepsy and control individuals to assess sociodemographic variables and historical risk factors (perinatal events, head injuries, and diet). Blood samples were taken from a randomly selected subgroup of 300 participants with epilepsy and 300 control individuals from each centre and were screened for antibodies to Toxocara canis, Toxoplasma gondii, Onchocerca volvulus, Plasmodium falciparum, Taenia solium, and HIV. We estimated odds ratios (ORs) with logistic regression, adjusted for age, sex, education, employment, and marital status.

RESULTS

586,607 residents in the study areas were screened in stage one, of whom 1711 were diagnosed as having active convulsive epilepsy. Prevalence adjusted for attrition and sensitivity varied between sites: 7·8 per 1000 people (95% CI 7·5-8·2) in Kilifi, 7·0 (6·2-7·4) in Agincourt, 10·3 (9·5-11·1) in Iganga-Mayuge, 14·8 (13·8-15·4) in Ifakara, and 10·1 (9·5-10·7) in Kintampo. The 1711 individuals with the disorder and 2032 control individuals were given questionnaires. In children (aged <18 years), the greatest relative increases in prevalence were associated with difficulties feeding, crying, or breathing after birth (OR 10·23, 95% CI 5·85-17·88; p<0·0001); abnormal antenatal periods (2·15, 1·53-3·02; p<0·0001); and head injury (1·97, 1·28-3·03; p=0·002). In adults (aged ≥18 years), the disorder was significantly associated with admission to hospital with malaria or fever (2·28, 1·06-4·92; p=0·036), exposure to T canis (1·74, 1·27-2·40; p=0·0006), exposure to T gondii (1·39, 1·05-1·84; p=0·021), and exposure to O volvulus (2·23, 1·56-3·19; p<0·0001). Hypertension (2·13, 1·08-4·20; p=0·029) and exposure to T solium (7·03, 2·06-24·00; p=0·002) were risk factors for adult-onset disease.

INTERPRETATION

The prevalence of active convulsive epilepsy varies in sub-Saharan Africa and that the variation is probably a result of differences in risk factors. Programmes to control parasitic diseases and interventions to improve antenatal and perinatal care could substantially reduce the prevalence of epilepsy in this region.

[A comparison of stroke patients' characteristics between a sub-Saharan Africa population (Abidjan) and a French stroke unit (Amiens): An observational study]

INTRODUCTION

Stroke characteristics in Sub-Saharan Africa (SSA) differ from developed countries. However, SSA subjects undergo epidemiological and demographic transition and it appears that the prevalence of vascular risk factors (RF) increases in this population. Here we aimed to compare stroke patients' characteristics between a SSA hospital (Cocody University Hospital, Abidjan, Côte d'Ivoire) and a French stroke unit (Amiens University Hospital, Amiens, France).

METHODS

This retrospective study included all consecutive stroke patients admitted between January and May 2008 (Cocody University Hospital, Abidjan, Côte d'Ivoire) and between October and December 2008 (Amiens University Hospital, Amiens, France). We assessed each patient's demographic details, RF, and CT confirmed pathological stroke type. The glomerular filtration rate (GFR) was estimated using the four-component Modification of Diet in Renal Disease (MDRD) equation and CKD was defined as a GFR less than 60ml/min/1.73 m(2).

RESULTS

One hundred and ninety five patients were included (Amiens: 92; Abidjan: 103) with a mean age of 63±14 years. Patients in Amiens had more known vascular RF than African patients, whereas African patients had more RF discovered during hospitalisation. Furthermore, CKD was significantly more common in SSA patients (43% vs 24%, P=0.001). More African than European patients had cerebral hemorrhage (34% vs 8%, P<0.001) but acute stroke mortality and treatments at hospital discharge were similar between the two hospitals. Finally, a high proportion of patients in Abidjan suffered from cervical atherosclerosis, although it was significantly lower than patients in Amiens (37% vs 67%, P<0.001).

CONCLUSION

Although this was a hospital-based study, CKD appears to be very common in SSA acute stroke patients. These findings could partly explain the high prevalence of cervical atherosclerosis found in this population. These results warrant confirmation in prospective studies.

Hypertension in Northern Angola: prevalence, associated factors, awareness, treatment and control

Background

Seventy-five million people are estimated to be hypertensive in sub-Saharan Africa. This translates in high morbidity and mortality, as hypertension is now considered to be the number one single risk factor for death worldwide. Accurate data from countries lacking national disease surveillance is needed to guide future evidence-driven health policies. The authors aimed to estimate the prevalence, awareness, management and control of hypertension and associated factors in an adult population of Angola.

Methods

A community-based survey of 1,464 adults, following the World Health Organization's Stepwise Approach to Chronic Disease Risk Factor Surveillance, was conducted to estimate the prevalence of hypertension, awareness, treatment and control in Dande, Northern Angola. Using a demographic surveillance system database, a representative sample of subjects, stratified by sex and age (18–40 and 41–64 years old), was selected.

Results

Prevalence of hypertension (systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg and/or hypertensive therapy) was of 23% (95% CI: 21% to 25.2%). A follow-up consultation confirmed the hypertensive status in 82% of the subjects who had a second measurement on average 23 days after the first. Amongst hypertensive individuals, 21.6% (95% CI: 17.0% to 26.9%) were aware of their status. Only 13.9% (95% CI: 5.9% to 29.1%) of the subjects aware of their condition were under pharmacological treatment, of which approximately one-third were controlled. Older age, lower level of education, higher body mass index and abdominal obesity were found to be significantly (p<0.01) associated with hypertension.

Conclusions

Our survey is the first to provide insightful data on hypertension prevalence in Angola. There is an urgent need for strategies to improve prevention, diagnosis and access to adequate treatment in this country, where a massive economic growth and consequent potential impact on lifestyle risk factors could lead to an increase in the prevalence of hypertension and cardiovascular disease.

Self-reported health and health care use in an ageing population in the Agincourt sub-district of rural South Africa

Background

South Africa is experiencing a demographic and epidemiological transition with an increase in population aged 50 years and older and rising prevalence of non-communicable diseases. This, coupled with high HIV and tuberculosis prevalence, puts an already weak health service under greater strain.

Objective

To measure self-reported chronic health conditions and chronic disease risk factors, including smoking and alcohol use, and to establish their association with health care use in a rural South African population aged 50 years or older.

Methods

The Study on Global Ageing and Adult Health (SAGE), in collaboration with the INDEPTH Network and the World Health Organization, was implemented in the Agincourt sub-district in rural northeast South Africa where there is a long-standing health and socio-demographic surveillance system. Household-based interviews were conducted in a random sample of people aged 50 years and older. The interview included questions on self-reported health and health care use, and some physical measurements, including blood pressure and anthropometry.

Results

Four hundred and twenty-five individuals aged 50 years or older participated in the study. Musculoskeletal pain was the most prevalent self-reported condition (41.7%; 95% Confidence Interval [CI] 37.0–46.6) followed by hypertension (31.2%; 95% CI 26.8–35.9) and diabetes (6.1%; 95% CI 4.1–8.9). All self-reported conditions were significantly associated with low self-reported functionality and quality of life, 57% of participants had hypertension, including 44% of those who reported normal blood pressure. A large waist circumference and current alcohol consumption were associated with high risk of hypertension in men, whereas in women, old age, high waist–hip ratio, and less than 6 years of formal education were associated with high risk of hypertension. Only 45% of all participants reported accessing health care in the last 12 months. Those who reported higher use of the health facilities also reported lower levels of functioning and quality of life.

Conclusion

Self-reported chronic health conditions, especially hypertension, had a high prevalence in this population and were strongly associated with higher levels of health care use. The primary health care system in South Africa will need to provide care for people with non-communicable diseases.

Different lipid profiles according to ethnicity in the Heart of Soweto study cohort of de novo presentations of heart disease

Background

Historically, sub-Saharan Africa has reported low levels of atherosclerotic cardiovascular disease (CVD). However as these populations undergo epidemiological transition, this may change.

Methods

This was an observational cohort study performed at Chris Hani Baragwanath Hospital in Soweto, South Africa. As part of the Heart of Soweto study, a clinical registry captured detailed clinical data on all de novo cases of structural and functional heart disease presenting to the Cardiology unit during the period 2006 to 2008. We examined fasting lipid profiles in 2 182 patients (of 5 328 total cases) according to self-reported ethnicity. The study cohort comprised 1 823 patients of African descent (61% female, aged 56 ± 16 years), 142 white Europeans (36% female, aged 57 ± 13 years), 133 Indians (51% female, aged 59 ± 12 years) and 87 of mixed ancestry (40% female, aged 56 ± 12 years).

Results

Consistent with different patterns in heart disease aetiology, there were clear differences in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides across ethnicities (p < 0.001): patients of African descent had the lowest TC and LDL-C levels and Indians the highest. However, there were no significant differences in high-density lipoprotein cholesterol (HDL-C) levels between ethnicities (p = 0.20). Adjusting for age, gender and body mass index, patients of African descent were significantly less likely to record a TC of > 4.5 mmol/l (OR 0.33, 95% CI: 0.25–0.41) compared to all ethnic groups (all p < 0.001).

Conclusions

These data confirm important blood lipid differentials according to ethnicity in patients diagnosed with heart disease in Soweto, South Africa. Such disparities in CVD risk factors may justify the use of specialised prevention and management protocols.

Review of community-based interventions for prevention of cardiovascular diseases in low- and middle-income countries

BACKGROUND

An increasing burden of cardiovascular disease (CVD) is occurring in low- and middle-income countries (LMICs) as a result of urbanisation and globalisation. Low rates of awareness and treatment of risk factors worsen the prognosis in these settings. Prevention of CVD is proven to be cost effective and should be the main intervention. Insight into prevention programmes in LMIC is important in addressing the rising levels of these diseases.

OBJECTIVE

To evaluate the effectiveness of the community-based interventions for CVD prevention programmes in LMIC.

DESIGN

A literature review with searches in the databases of PubMed, EMBASE, CINAHL, LILACS, African Index Medicus and Google Scholar between 1990 and May 2012.

RESULTS

Twenty-six studies involving population-based and high-risk interventions have been included in this review. The content of the population intervention was mainly health promotion through media and health education, and the high-risk approach focused often on education of patients, training of health care providers and implementing treatment guidelines. A few studies had a single intervention on exercising or salt reduction. Most studies showed a significant reduction of cardiovascular risk ranging from lifestyle changes on diet, smoking and alcohol to biomedical outcomes like blood pressure, glucose levels or weight. Some studies showed improved management of risk factors like increased control of hypertension or adherence to medication.

CONCLUSION

There have been effective community-based programmes aimed at reducing cardiovascular risk factors in LMIC but these have generally been limited to the urban poor. Health education with a focus on diet and salt, training of health care providers and implementing treatment guidelines form key elements in successful programmes.

Assessing the global burden of ischemic heart disease, part 2: analytic methods and estimates of the global epidemiology of ischemic heart disease in 2010

BACKGROUND

Ischemic Heart Disease (IHD) is the leading cause of death worldwide. The Global Burden of Diseases, Injuries and Risk Factors (GBD) 2010 Study estimated IHD mortality and disability burden for 21 world regions for the years 1990 to 2010.

METHODS

Data sources for GBD IHD epidemiology estimates were mortality surveillance, verbal autopsy, and vital registration data (for IHD mortality) and systematic review of IHD epidemiology literature published 1980-2008 (for non-fatal IHD outcomes). An estimation and validation process led to an ensemble model of IHD mortality by country for all 21 world regions, adjusted for country-level covariates. Disease models were developed for the nonfatal sequelae of IHD: myocardial infarction, stable angina pectoris, and ischemic heart failure.

RESULTS

Country level covariates including metabolic and nutritional risk factors, education, war, and annual income per capita contributed to the ensemble model for the analysis of IHD death. In the acute myocardial infarction model, inclusion of troponin in the diagnostic criteria of studies published after the year 2000 was associated with a 50% higher incidence. Self-reported diagnosis of angina significantly overestimated stable angina prevalence compared with "definite" angina elicited by the Rose angina questionnaire. For 2010, Eastern Europe and Central Asia had the highest rates of IHD death and the Asia Pacific High-Income, East Asia, Latin American Andean, and sub-Saharan Africa regions had the lowest.

CONCLUSIONS

Global and regional IHD epidemiology estimates are needed for estimating the worldwide burden of IHD. Using descriptive meta-analysis tools, the GBD 2010 standardized and pooled international data by adjusting for region-level mortality and risk factor data, and study level diagnostic method. Analyses maximized internal consistency, generalizability, and adjustment for known sources of bias. The GBD IHD analysis nonetheless highlights the need for improved IHD epidemiology surveillance in many regions and the need for uniform diagnostic standards.

Modifiable socio-behavioural factors associated with overweight and hypertension among persons aged 35 to 60 years in eastern Uganda

BACKGROUND

Few studies have examined the behavioural correlates of non-communicable, chronic disease risk in low-income countries. The objective of this study was to identify socio-behavioural characteristics associated with being overweight or being hypertensive in a low-income setting, so as to highlight possible interventions and target groups.

METHODS

A population based survey was conducted in a Health and Demographic Surveillance Site (HDSS) in eastern Uganda. 1656 individuals aged 35 to 60 years had their Body Mass Index (BMI) and blood pressure (BP) assessed. Seven lifestyle factors were also assessed, using a validated questionnaire. Logistic regression was used to identify socio-behavioural factors associated with being overweight or being hypertensive.

RESULTS

Prevalence of overweight was found to be 18% (25.2% of women; 9.7% of men; p<0.001) while prevalence of obesity was 5.3% (8.3% of women; 2.2% of men). The prevalence of hypertension was 20.5%. Factors associated with being overweight included being female (OR 3.7; 95% CI 2.69-5.08), peri-urban residence (OR 2.5; 95% CI 1.46-3.01), higher socio-economic status (OR 4.1; 95% CI 2.40-6.98), and increasing age (OR 1.8; 95% CI 1.12-2.79). Those who met the recommended minimum physical activity level, and those with moderate dietary diversity were less likely to be overweight (OR 0.5; 95% CI 0.35-0.65 and OR 0.7; 95% CI 0.49-3.01). Factors associated with being hypertensive included peri-urban residence (OR 2.4; 95%CI 1.60-3.66), increasing age (OR 4.5; 95% CI 2.94-6.96) and being over-weight (OR 2.8; 95% CI 1.98-3.98). Overweight persons in rural areas were significantly more likely to be hypertensive than those in peri-urban areas (p = 0.013).

CONCLUSIONS

Being overweight in low-income settings is associated with sex, physical activity and dietary diversity and being hypertensive is associated with being overweight; these factors are modifiable. There is need for context-specific health education addressing disparities in lifestyles at community levels in rural Africa.

A pilot study to clinically evaluate the role of herbomineral compound "Rakatchap Har" in the management of essential hypertension

The aim of the present study was to investigate the clinical efficacy of a herbomineral medicine Rakatchaphar (Each 500 mg cap contains Sarpgandha 150 mg, Shankhpushpi 75 mg, Jatamansi 75 mg, Jahar Mohra Khatai Pishti 75 mg, Moti Pishti 75 mg, Ras Sindoor 50 mg) in essential hypertension, an observational prospective study was done at Shri Ashutosh Maharaj (SAM) Ayurvedic Treatment and Research Centre, Noormahal. Ninety-eight patients in the age group 28-76 years with essential hypertension without any co-morbid illness were included in the study. Patients were treated with cap Rakatchaphar 500 mg twice a day. Blood pressure (BP) was monitored on subsequent follow-up visits at 2, 4, 6, and 8 weeks. Change in Diastolic BP (DBP), Systolic BP (SBP), and Mean BP (MBP) were analyzed statistically by Student's t test, ANOVA, and Post hoc Bonferroni test. On first visit the mean SBP, DBP, and MBP was 164.16±17.27, 101.88±9.20, and 122.27±10.57 mm Hg, respectively. After 8 weeks of therapy there was a statistically significant fall in SBP (122.98±11.36), DBP (80.90±8.57), and MBP (94.86±9.24) in mmHg (P value <0.0001). Rakatchap Har offers an efficacious and safe combination of natural products available for the treatment of hypertension.

The quality of care provided to patients with chronic non-communicable diseases: a retrospective multi-setup study in jimma zone, southwest ethiopia

Background

Chronic Non-Communicable Diseases are among the major causes of morbidity and mortality worldwide. However, access to and quality of health care for patients is very low in developing countries including Ethiopia. Hospitals and Health Centers are the main sources of health care for such patients in Ethiopia. In this study we assessed the quality of care patients with Chronic Non-Communicable Diseases received in hospital and health center setups.

Methods

A retrospective multi-setup study was conducted in Jimma University Specialized Hospital and four Health Centers in Jimma Zone from February to March 2010. A total of 52 process indicators of quality covering three disease conditions: Diabetes, Hypertension and Epilepsy were measured by reviewing randomly selected medical records. Quality of care was measured as a proportion of recommended components of care actually provided to patients. And also outcome and structural measures were assessed to supplement process measures of quality.

Results

Six hundred seventy four medical records were reviewed. Recommended care components were actually provided to patients in 35.1% (95% CI:34.1%, 36.0%), 38.5% (95% CI:37.5%, 39.5%) and 60.1% (95% CI:59.3%, 61.0%) of times on which patients were eligible, among patients with Diabetes, Hypertension and Epilepsy, respectively. After case mix adjustment, it was found that 45.9% (95% CI:45.4%, 46.5%) of recommended components of care was actually provided to patients. This was 45.1% (95% CI:44.4%, 45.8%) in the hospital and 30.5% (95% CI:29.7%, 31.3%) in the health centers. Among patients for whom outcome data was available, optimal level of disease control was achieved only for 47 (30.5%), 40 (38.5%) and 193 (52.9%) of patients with Diabetes, Hypertension and Epilepsy, respectively.

Conclusion

The quality of care provided to patients with Chronic Non-Communicable Diseases is very low in both settings though it is relatively better in Jimma University Specialized Hospital. Therefore, a continuous process of quality improvement is recommended in both settings.

Leveraging rapid community-based HIV testing campaigns for non-communicable diseases in rural Uganda

BACKGROUND

The high burden of undiagnosed HIV in sub-Saharan Africa limits treatment and prevention efforts. Community-based HIV testing campaigns can address this challenge and provide an untapped opportunity to identify non-communicable diseases (NCDs). We tested the feasibility and diagnostic yield of integrating NCD and communicable diseases into a rapid HIV testing and referral campaign for all residents of a rural Ugandan parish.

METHODS

A five-day, multi-disease campaign, offering diagnostic, preventive, treatment and referral services, was performed in May 2011. Services included point-of-care screening for HIV, malaria, TB, hypertension and diabetes. Finger-prick diagnostics eliminated the need for phlebotomy. HIV-infected adults met clinic staff and peer counselors on-site; those with CD4 ≤ 100/µL underwent intensive counseling and rapid referral for antiretroviral therapy (ART). Community participation, case-finding yield, and linkage to care three months post-campaign were analyzed.

RESULTS

Of 6,300 residents, 2,323/3,150 (74%) adults and 2,020/3,150 (69%) children participated. An estimated 95% and 52% of adult female and male residents participated respectively. Adult HIV prevalence was 7.8%, with 46% of HIV-infected adults newly diagnosed. Thirty-nine percent of new HIV diagnoses linked to care. In a pilot subgroup with CD4 ≤ 100, 83% linked and started ART within 10 days. Malaria was identified in 10% of children, and hypertension and diabetes in 28% and 3.5% of adults screened, respectively. Sixty-five percent of hypertensives and 23% of diabetics were new diagnoses, of which 43% and 61% linked to care, respectively. Screening identified suspected TB in 87% of HIV-infected and 19% of HIV-uninfected adults; 52% percent of HIV-uninfected TB suspects linked to care.

CONCLUSIONS

In an integrated campaign engaging 74% of adult residents, we identified a high burden of undiagnosed HIV, hypertension and diabetes. Improving male attendance and optimizing linkage to care require new approaches. The campaign demonstrates the feasibility of integrating hypertension, diabetes and communicable diseases into HIV initiatives.

Hypertension in developing countries

Data from different national and regional surveys show that hypertension is common in developing countries, particularly in urban areas, and that rates of awareness, treatment, and control are low. Several hypertension risk factors seem to be more common in developing countries than in developed regions. Findings from serial surveys show an increasing prevalence of hypertension in developing countries, possibly caused by urbanisation, ageing of population, changes to dietary habits, and social stress. High illiteracy rates, poor access to health facilities, bad dietary habits, poverty, and high costs of drugs contribute to poor blood pressure control. The health system in many developing countries is inadequate because of low funds, poor infrastructure, and inexperience. Priority is given to acute disorders, child and maternal health care, and control of communicable diseases. Governments, together with medical societies and non-governmental organisations, should support and promote preventive programmes aiming to increase public awareness, educate physicians, and reduce salt intake. Regulations for the food industry and the production and availability of generic drugs should be reinforced.

Migration and hypertension in Dakar, Senegal

This article examines social and environmental influences on the development of hypertension in a sample of 568 adults (290 men; 278 women) aged 20 years and older from Dakar, Senegal. We test the hypothesis that more recent immigrants to the city of Dakar will have lower blood pressure and lower rates of hypertension than those who have lived there longer. Cross-sectional sociodemographic, anthropometric and blood pressure data were collected during 2009. The overall prevalence of hypertension was 27.1% (95% CI: 25.2-29.0). Hypertension rates were not significantly associated with place of birth; however, length of residence in Dakar was a significant predictor, with those living in the city for less than 10 years having reduced risks of developing hypertension (OR = 0.25; P = 0.003). Other important correlates of blood pressure and hypertension risk in this sample were age and body mass index. These findings suggest that length of exposure to the urban environment-and associated changes in lifestyle-are linked to hypertension. Public health officials should thus pay particular attention to this phenomenon, and future anthropological research should include measures of both environmental and biological characteristics to study hypertension in Senegal.

Are behavioural risk factors to be blamed for the conversion from optimal blood pressure to hypertensive status in Black South Africans? A 5-year prospective study

BACKGROUND

Longitudinal cohort studies in sub-Saharan Africa are urgently needed to understand cardiovascular disease development. We, therefore, explored health behaviours and conventional risk factors of African individuals with optimal blood pressure (BP) (≤ 120/80 mm Hg), and their 5-year prediction for the development of hypertension.

METHODS

The Prospective Urban Rural Epidemiology study in the North West Province, South Africa, started in 2005 and included African volunteers (n = 1994; aged > 30 years) from a sample of 6000 randomly selected households in rural and urban areas.

RESULTS

At baseline, 48% of the participants were hypertensive (≥ 140/90 mmHg). Those with optimal BP (n = 478) were followed at a success rate of 70% for 5 years (213 normotensive, 68 hypertensive, 57 deceased). Africans that became hypertensive smoked more than the normotensive individuals (68.2% vs 49.8%), and they also had a greater waist circumference [ratio of geometric means of 0.94 cm (95% CI: 0.86-0.99)] and greater amount of γ-glutamyltransferase [0.74 U/l (95% CI: 0.62-0.88)] at baseline. The 5-year change in BP was independently explained by baseline γ-glutamyltransferase [R(2) = 0.23, β = 0.13 U/l (95% CI: 0.01-0.19)]. Alcohol intake also predicted central systolic BP and carotid cross-sectional wall area (CSWA) at follow-up. Waist circumference was another predictor of BP changes [β = 0.18 cm (95% CI: 0.05-0.24)] and CSWA. HIV infection was inversely associated with increased BP.

CONCLUSIONS

During the 5 years, 24% of Africans with optimal BP developed hypertension. The surge in hypertension in Africa is largely explained by modifiable risk factors. Public health strategies should focus aggressively on lifestyle to prevent a catastrophic burden on the national health system.

A prospective review of acute coronary syndromes in an urban hospital in sub-Saharan Africa

OBJECTIVES

To determine the epidemiology of acute coronary syndromes (ACS) in sub-Saharan Africa.

METHODS

A prospective survey was carried out of all patients with a diagnosis of ACS who were admitted to the critical care unit of a tertiary teaching hospital over a 25-month period. Demographics, presentation, management and outcomes were subsequently recorded.

RESULTS

A total of 111 (5.1% of all hospitalisations) patients were recruited, with 56% presenting with ST-elevation myocardial infarction (STEMI) and the rest non-ST-elevation myocardial infarction (NSTEMI) or unstable angina (UA). Chest pain was the most common presenting symptom, and up to one-third of all STEMI patients did not receive any form of reperfusion therapy, primarily due to late presentation. As in the developed world, diabetes, hypertension and cigarette smoking still account for the most common predisposing risk-factor profile, and the mortality associated with ACS is about six to 10% in our unit.

CONCLUSIONS

ACS, contrary to common belief, is increasingly more prevalent in sub-Saharan Africa, with similar risk profiles to that in the developed world. Late presentation to hospital is common and accounts for the increased mortality associated with this condition.

Prevalence, awareness, treatment, and control of hypertension among Ghanaian population in Amsterdam, The Netherlands: the GHAIA study

BACKGROUND

Migration from sub-Saharan Africa to industrialized countries has increased tremendously over the last few decades, yet very little is known about the health status of sub-Saharan African populations living in industrialized communities. The aim of this study was to assess prevalence, levels of awareness, treatment, and control of hypertension among the largest sub-Saharan African group (Ghanaians) living in the Netherlands.

METHODS

Cross-sectional study of Ghanaian adults aged 18-60 years in Amsterdam, the Netherlands.

RESULTS

The overall prevalence of hypertension was 55%. Of these, about half were aware of their condition, 45% were receiving antihypertensive medication, and 15% were controlled (blood pressure <140/90 mmHg). The prevalence rates of hypertension, awareness, and treatment were similar among males and females. However, males had a lower blood pressure control rate than females. Among all hypertensives, 22% of females had their blood pressure controlled compared with 5.8% in males: adjusted prevalence ratio (APR) 3.94 (95% CI 1.05-14.79). Among those receiving treatment for their hypertension, 48% of females were controlled compared with only 13% of males: APR 4.08 (95% CI 1.20-13.87).

CONCLUSION

Hypertension is a major problem among this recently migrated sub-Saharan African population. Furthermore, hypertension control rate is very low particularly in males. Urgent measures are needed to halt the increasing prevalence of hypertension and to improve hypertension control among these populations.

Hypertension in sub-Saharan Africa: cross-sectional surveys in four rural and urban communities

Background

Cardiovascular disease (CVD) is the leading cause of adult mortality in low-income countries but data on the prevalence of cardiovascular risk factors such as hypertension are scarce, especially in sub-Saharan Africa (SSA). This study aims to assess the prevalence of hypertension and determinants of blood pressure in four SSA populations in rural Nigeria and Kenya, and urban Namibia and Tanzania.

Methods and Findings

We performed four cross-sectional household surveys in Kwara State, Nigeria; Nandi district, Kenya; Dar es Salaam, Tanzania and Greater Windhoek, Namibia, between 2009–2011. Representative population-based samples were drawn in Nigeria and Namibia. The Kenya and Tanzania study populations consisted of specific target groups. Within a final sample size of 5,500 households, 9,857 non-pregnant adults were eligible for analysis on hypertension. Of those, 7,568 respondents ≥18 years were included. The primary outcome measure was the prevalence of hypertension in each of the populations under study.

The age-standardized prevalence of hypertension was 19.3% (95%CI:17.3–21.3) in rural Nigeria, 21.4% (19.8–23.0) in rural Kenya, 23.7% (21.3–26.2) in urban Tanzania, and 38.0% (35.9–40.1) in urban Namibia. In individuals with hypertension, the proportion of grade 2 (≥160/100 mmHg) or grade 3 hypertension (≥180/110 mmHg) ranged from 29.2% (Namibia) to 43.3% (Nigeria). Control of hypertension ranged from 2.6% in Kenya to 17.8% in Namibia. Obesity prevalence (BMI ≥30) ranged from 6.1% (Nigeria) to 17.4% (Tanzania) and together with age and gender, BMI independently predicted blood pressure level in all study populations. Diabetes prevalence ranged from 2.1% (Namibia) to 3.7% (Tanzania).

Conclusion

Hypertension was the most frequently observed risk factor for CVD in both urban and rural communities in SSA and will contribute to the growing burden of CVD in SSA. Low levels of control of hypertension are alarming. Strengthening of health care systems in SSA to contain the emerging epidemic of CVD is urgently needed.

Prevalence of cardiovascular disease in Gabon: a population study

BACKGROUND

Data supporting epidemiological transition from a predominant burden of infectious diseases to one of chronic diseases in Africa result mostly from hospital surveys.

AIM

To estimate the cardiovascular disease (CVD) burden in Gabon.

METHODS

The study was conducted in Ntoum (8765 inhabitants). All subjects aged greater or equal to 40 years were invited to participate. Participants were interviewed about CVD history and risk factors; they responded to questionnaires on claudication and angina and had a clinical examination, including lower limb pulse palpation and bilateral brachial pressure measurement. Subjects were considered to have CVD in case of history of CVD (coronary artery, cerebrovascular and peripheral arterial diseases), a positive questionnaire or an abnormal finding during clinical examination.

RESULTS

The study included 736 subjects (313 men; 423 women). Systolic hypertension was highly prevalent (up to 47.7% and 53.7% in men and women aged 50 to 60 years, respectively). Of the 382 patients with hypertension, 74 (19.4%) were treated and only 22 (5.8%) were considered to have controlled hypertension. Overall, CVD was identified in 98 (13.3%) cases. Overall and newly diagnosed CVD prevalence rates were 14.7% and 11.5% for men and 14.9% and 8.9% for women, respectively. The presence of CVD was associated with hypertension (hazard ratio [HR] 3.69, 95% confidence interval [CI] 2.21-6.16; P<0.0001). Hypertension was predictive of stroke (HR 4.57, 95% CI 1.26-16.50; P<0.05), peripheral artery disease (HR 2.03, 95% CI 1.03-4.00; P<0.05) and subclavian artery stenosis (HR 5.79, 95% CI 2.21-15.2; P<0.05).

CONCLUSIONS

Our findings provide strong evidence of ongoing epidemiological transition in Gabon, where CVD prevalence rates increase mainly with hypertension, affecting about one in six individuals aged over 40 years.

Prevalence, awareness, treatment and control of hypertension in a self-selected sub-Saharan African urban population: a cross-sectional study

OBJECTIVES

Hypertension has been established as a major public health problem in Africa, but its specific contributions to disease burden are still incompletely understood. We report the prevalence and determinants of hypertension, detection, treatment and control rates among adults in major cities in Cameroon.

DESIGN

Cross-sectional study.

SETTINGS

Community-based multicentre study in major cities in Cameroon.

PARTICIPANTS

Participants were self-selected urban dwellers from the Center, Littoral, North-West and West Regions, who attended on 17 May 2011 a screening campaign advertised through mass media. PRIMARY AND SECONDARY OUTCOMES MEASURES: Hypertension defined as systolic (and/or diastolic) blood pressure (BP)≥ 140 (90) mm Hg, or ongoing BP-lowering medications.

RESULTS

In all, 2120 participants (1003 women) were included. Among them, 1007 (prevalence rate 47.5%) had hypertension, including 319 (awareness rate 31.7%) who were aware of their status. The prevalence of hypertension increased with age overall and by sex and region. Among aware hypertensive participants, 191 (treatment rate 59.9%) were on regular BP-lowering medication, and among those treated, 47 (controlled rate 24.6%) were at target BP levels (ie, systolic (and diastolic) BP<140 (90) mm Hg). In multivariable logistic regression analysis, male gender, advanced age, parental history of hypertension, diabetes mellitus, elevated waist and elevated body mass index (BMI) were the significant predictors of hypertension. Likewise, male gender, high BMI and physical inactivity were associated with poor control.

CONCLUSIONS

High prevalence of hypertension with low awareness, treatment and control were found in this urban population; these findings are significant and alarming with consideration to the various improvements in the access to healthcare and the continuing efforts to educate communities over the last few decades.

Ethnicity and cardiovascular health research: pushing the boundaries by including comparison populations in the countries of origin

Chronic diseases such as cardiovascular diseases (CVD) are major health problems in most ethnic minority and migrant populations living in high income countries. By the same token, CVD is a looming threat that is creating a double burden in most of the countries where these populations originate from. The causes of the rising burden are unclear, but they are likely to be multifaceted. Traditionally, ethnicity and health research have mostly concentrated on comparing the health of ethnic minority groups with the majority populations of the countries in which they live. This is an important area of research which illuminates ethnic inequalities in health. However, a few studies on international comparisons show that a lot can be learned from comparing similar ethnic groups living in different industrialised countries. Equally, comparing ethnic minority and migrant populations to similar populations in their countries of origin will generate new knowledge about factors that predispose them to poor health outcomes. Thus, to make progress in the field of ethnicity and health research, we need a new conceptual framework that simultaneously studies migrant/ethnic groups in the country of settlement, in similar countries of settlement, and in the countries of ancestral origin. Such studies need to go beyond the commonest design of cross-sectional studies to include more cohort studies, interventions and linkage studies. This article discusses (1) the burden of CVD in ethnic minority and migrant populations; (2) approaches to understanding predisposing factors; and (3) application of the results to give insight into the potential threats that their countries of origin are likely to face.

Adverse trends of cardiovascular risk factors among low risk populations (1983-1994)--a cohort study of workers and farmers in Guangzhou, China

BACKGROUND

The levels and trends of cardiovascular risk factors vary greatly throughout China. We examine 10-year trends of cardiovascular risk factors (1983-1994) and the factors related to these trends among low-risk cohorts of workers and farmers in Guangzhou, China.

METHODS

This is a cohort study of 3,131 workers and 3,493 farmers aged 25-64 years at baseline with 10 years of follow-up. We performed a longitudinal analysis to account for the aging of the cohorts and the repeated measures of the same individual.

RESULTS

At baseline the prevalence of overweight (including obese) ranged from 1.0% to 11.8%, hypertension ranged from 3.8% to 10.5%, and mean serum total cholesterol (TC) ranged from 155.4 mg/dl to 187.2 mg/dl. Although prevalence of smoking declined, blood pressure levels and body mass index (BMI) increased significantly, and lipid profiles changed unfavorably during the 10-year follow-ups. The prevalence of hypertension increased from 5.0 percentage points (female farmers) to 12.3 percentage points (male farmers). Mean TC increased significantly (e.g., +22.8 mg/dl and +17.0 mg/dl in male and female farmers, respectively). In the longitudinal data analyses, increase in BMI was associated with increase in blood pressure levels and TC. Significant adverse trends of risk factors persisted after adjustment for aging, education, BMI, smoking, and alcohol intake.

CONCLUSION

Urgent action is needed to prevent and reverse the unhealthy trends occurring among these low risk Chinese workers and farmers.

Health state utilities of a population of Nigerian hypertensive patients

BACKGROUND

Establishment of the health impact of hypertension on quality of life of Nigerians is a step towards controlling the disease. The study aimed to provide a Nigerian specific reference list of utility scores of hypertensive patients with various interacting conditions.

FINDINGS

An interviewer-based, cross-sectional study was conducted using hypertensive patients in two purposively selected tertiary hospitals located in South-Eastern Nigeria. Health Utility Index Mark 3 (HUI3) was used.A total of 384 participants with either hypertension alone or with hypertension-associated complications were interviewed in the two tertiary hospitals.The overall mean utility score was 0.35 +/- 0.42. Patients with hypertension alone had the highest overall mean utility score (0.57 +/- 0.29) while hypertensive patients with stroke had the lowest overall mean score (0.04 +/- 0.36). Being a male, increase in age and mean arterial blood pressure, emergency visit and loss of work due to illness were associated with significant decrease in overall utility scores.

CONCLUSIONS

This study presented a reference for health state utilities of a population of Nigerian hypertensive patients.

Hypertension and incident dementia in community-dwelling elderly Yoruba Nigerians

OBJECTIVES

To investigate the relationship between hypertension and dementia incidence in community-dwelling elderly Yoruba (aged 70 years and above) because of sparse information on dementia and its risk factors in developing countries.

MATERIALS AND METHODS

Community-based, prospective study of consenting elderly Yoruba using two-stage design. Blood pressure was measured during the baseline evaluation at 2001 and hypertension was defined as BP ≥ 140/90 mmHg. Diagnosis of dementia and normal cognition was by consensus using standard criteria. Non-demented subjects from the 2001 evaluation wave were re-evaluated during the 2004 and 2007 waves for dementia. Logistic regression was used to examine the association of baseline hypertension and incident dementia, after adjusting for age, gender, education, and histories of stroke and smoking. P-values <0.05 were considered significant.

RESULTS

During the 6-year follow-up, 120 individuals developed dementia, while 1633 remained non-demented. The frequency of hypertension in the demented group was significantly higher than in the non-demented (70.0% vs 60.2%, P = 0.034). Baseline hypertension was a significant risk factor for dementia (OR = 1.52; 95% CI 1.01-2.30). Higher systolic, diastolic or pulse pressure was associated with increased risk (P < 0.05). Participants with diastolic BP ≥ 90 mmHg were at a significantly greater risk than those with readings below 70 mmHg (OR = 1.65; 95% CI 1.01-2.69).

CONCLUSIONS

Hypertension was associated with increased risk of dementia in elderly Yoruba and its appropriate treatment may lower the risk.

Incidence of hypertension and its risk factors in rural Kerala, India: a community-based cohort study

OBJECTIVES

To investigate the incidence of hypertension and its risk factors in Kerala, India where the epidemiological transition is more advanced than elsewhere in India.

STUDY DESIGN

Prospective cohort study.

METHODS

A sample of 297 individuals (aged 15-64 years) in rural Kerala, India, who were free of hypertension at study enrolment, were followed-up from 2003 to 2010. At enrolment, demographic characteristics and behavioural risk factors were determined by interview, and the participants underwent physical (blood pressure, height, weight and waist circumference) and biochemical examinations (fasting plasma glucose and serum lipids). At follow-up, blood pressure readings were repeated using the original tool following the same protocol.

RESULTS

Nearly one-quarter (23.6%) of the sample developed hypertension over a mean follow-up period of 7.1 (standard deviation 0.2) years. Age ≥35 years [relative risk (RR) 4.00, 95% confidence interval (CI) 2.37-6.03], current smoking [RR 1.99, 95% CI 1.14-2.97, population-attributable risk percent (PAR%) 13.3%], high-normal blood pressure (RR 3.53 vs optimal blood pressure, 95% CI 2.17-5.28, PAR% 44.0%) and central obesity (RR 2.45, 95% CI 1.45-3.70, PAR% 40.4%) were significantly associated with incident hypertension. Collectively, current smoking, high-normal blood pressure and central obesity accounted for 70.1% of all new cases of hypertension. Awareness, treatment and control rates of incident hypertension were 42.9%, 22.9% and 11.4%, respectively.

CONCLUSIONS

This rural sample showed a high incidence of hypertension. This underscores the need for primary prevention of hypertension through lifestyle modification strategies targeting individuals with high-normal blood pressure, central obesity and current smoking. The healthcare system needs to improve the level of awareness, treatment and control of hypertension in this population.

Prevalence of asymptomatic left ventricular systolic dysfunction in hypertensive Nigerians: echocardiographic study of 832 subjects

BACKGROUND

We sought to determine the prevalence of echocardiographically determined left ventricular systolic dysfunction in asymptomatic hypertensive subjects seen in Abeokuta, Nigeria.

METHODS

Echocardiography was performed in 832 consecutive hypertensive subjects referred for cardiac evaluation over a three-year period.

RESULTS

Data were obtained in 832 subjects (50.1% women) aged 56.0 ± 12.7 years (men 56.9 ± 13.3 years, women 55.0 ± 12.0 years, range 15-88). The prevalence of left ventricular systolic dysfunction (LVSD) was 18.1% in the study population (mild LVSD = 9.6%, moderate LVSD = 3.7% and severe LVSD = 4.8%). In a multivariate analysis, male gender, body mass index and LV mass were the predictors of LVSD.

CONCLUSION

Significant numbers of hypertensive subjects in this study had varying degrees of left ventricular systolic dysfunction. Early introduction of disease-modifying drugs in these patients, such as angiotensin converting enzyme inhibitors or angiotensin receptor blockers may retard or prevent the progression to overt heart failure.

Management of hypertension in the elderly patient at abidjan cardiology institute (ivory coast)

Background. Since the treatment of hypertension is beneficial for the elderly, we have undertaken this study that aims to evaluate the management of hypertension in elderly patient in Côte d'Ivoire. Methods. A retrospective study was conducted among 854 hypertensive elderly patients of Abidjan Cardiology Institute who were followed for a minimum of one year, between January 2000 and December 2009. Results. The patients mean age was 73.1 ± 5.3 years, and 59% were women. At the first presentation, it was mostly systolic-diastolic hypertension (51.8%) and isolated systolic hypertension (38.5%). Mean blood pressure was 169.4 ± 28.4 mmHg for systolic, 95.3 ± 15.7 mmHg for diastolic, and 74.1 ± 22.8 mmHg for pulse pressure. Pulse pressure was ≥60 mmHg in 80.4%. According to the European Guidelines stratification of the cardiovascular risk-excess attributable to high blood pressure, 82.1% of the sample had a very high added risk. The pharmacological therapy was prescribed in 93.5%. More than 66% of patients were receiving ≥2 antihypertensive drugs including fixed-dose combination drugs. The most common agents used were diuretics (63.5%) followed by angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in 61.3%. The most common agents used for monotherapy were calcium antagonists. When ≥2 drugs were used, diuretics and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers were the most common. Blood pressure control was achieved in 42.6%. Conclusion. The control of elderly hypertension can be effective in Sub-Saharan Africa. He required at least two antihypertensive drugs to meet the recommended blood pressure target.

Prevalence, awareness, treatment and control of hypertension among adults 50 years and older in Dakar, Senegal

Background

Older adults are disproportionately affected by hypertension, which is an established risk factor for cardiovascular disease. Despite these facts, no study on the prevalence, awareness, treatment and control on arterial hypertension in Senegal has been conducted, specifically among elderly people.

Methods

Five hundred people aged 50 years and older, living in the city of Dakar were interviewed. This sample was constructed using the combined quota method in order to strive for representativeness of the target population.

Results

Prevalence of hypertension was 65.4% in our sample. Half of those suffering from high blood pressure were aware of their problem and among the latter, 70% said they were on treatment. However, of these, only 17% had controlled arterial blood pressure. The only factor associated with awareness, treatment and control of hypertension was the frequency of doctor visits.

Conclusion

Improving follow-up health checks of older adults are necessary to limit the consequences of hypertension in Dakar.

Current and projected prevalence of arterial hypertension in sub-Saharan Africa by sex, age and habitat: an estimate from population studies

INTRODUCTION

In sub-Saharan Africa (SSA), data on hypertension prevalence in terms of urban or rural and sex difference are lacking, heterogeneous or contradictory. In addition, there are no accurate estimates of hypertension burden.

OBJECTIVE

To estimate the age-specific and sex-specific prevalence of arterial hypertension in SSA in urban and rural adult populations.

METHODS

We searched for population studies, conducted from 1998 through 2008 in SSA. We extracted data from selected studies on available prevalences and used a logistic regression model to estimate all age/sex/habitat (urban/rural)/country-specific prevalences for SSA up to 2008 and 2025. On the basis of the United Nations Population Fund data for 2008 and predictions for 2025, we estimated the number of hypertensives in both years.

RESULTS

Seventeen studies pertaining to 11 countries were analysed. The overall prevalence rate of hypertension in SSA for 2008 was estimated at 16.2% [95% confidence interval (CI) 14.1-20.3], ranging from 10.6% in Ethiopia to 26.9% in Ghana. The estimated prevalence was 13.7% in rural areas, 20.7% in urban areas, 16.8% in males, and 15.7% in women. The total number of hypertensives in SSA was estimated at 75 million (95% CI 65-93 million) in 2008 and at 125.5 million (95% CI 111.0-162.9 million) by 2025.

CONCLUSION

The estimated number of hypertensives in 2008 is nearly four times higher than the last (2005) estimate of the World Health Organization Regional Office for Africa. Prevalences were significantly higher in urban than in rural populations. Population data are lacking in many countries underlining the need for national surveys.

Addressing the social and environmental determinants of urban health equity: evidence for action and a research agenda

Urban living is the new reality for the majority of the world's population. Urban change is taking place in a context of other global challenges--economic globalization, climate change, financial crises, energy and food insecurity, old and emerging armed conflicts, as well as the changing patterns of communicable and noncommunicable diseases. These health and social problems, in countries with different levels of infrastructure and health system preparedness, pose significant development challenges in the 21st century. In all countries, rich and poor, the move to urban living has been both good and bad for population health, and has contributed to the unequal distribution of health both within countries (the urban-rural divide) and within cities (the rich-poor divide). In this series of papers, we demonstrate that urban planning and design and urban social conditions can be good or bad for human health and health equity depending on how they are set up. We argue that climate change mitigation and adaptation need to go hand-in-hand with efforts to achieve health equity through action in the social determinants. And we highlight how different forms of governance can shape agendas, policies, and programs in ways that are inclusive and health-promoting or perpetuate social exclusion, inequitable distribution of resources, and the inequities in health associated with that. While today we can describe many of the features of a healthy and sustainable city, and the governance and planning processes needed to achieve these ends, there is still much to learn, especially with respect to tailoring these concepts and applying them in the cities of lower- and middle-income countries. By outlining an integrated research agenda, we aim to assist researchers, policy makers, service providers, and funding bodies/donors to better support, coordinate, and undertake research that is organized around a conceptual framework that positions health, equity, and sustainability as central policy goals for urban management.

Effect of rural-to-urban within-country migration on cardiovascular risk factors in low- and middle-income countries: a systematic review

CONTEXT

Limited information is available of effects of rural-to-urban within-country migration on cardiovascular (CV) risk factors in low- and middle- income countries (LMIC).

OBJECTIVE

A systematic review of studies evaluating these effects was performed with rural and/or urban control groups.

STUDY SELECTION

Two teams of investigators searched observational studies in Medline, Web of Science and Scopus until May 2011. Studies evaluating international migration were excluded.

DATA EXTRACTION

Three investigators extracted the information stratified by gender. Information on 17 known CV risk factors was obtained.

RESULTS

Eighteen studies (n=58,536) were included. Studies were highly heterogeneous with respect to study design, migrant sampling frame, migrant urban exposure and reported CV risk factors. In migrants, commonly reported CV risk factors-systolic and diastolic blood pressure, body mass index, obesity, total cholesterol and low-density lipoprotein-were usually higher or more common than in the rural group and usually lower or less common than in the urban group. This gradient was usually present in both genders. Anthropometric (waist-to-hip ratio, hip/waist circumference, triceps skinfolds) and metabolic (fasting glucose/insulin, insulin resistance) risk factors usually followed the same gradient, but conclusions were weak as information was insufficient. Hypertension, high-density lipoprotein, fibrinogen and C-reactive protein did not follow any pattern.

CONCLUSIONS

In LMIC, most but not all, CV risk factors are higher or more common in migrants than in rural groups but lower or less common than in urban groups. Such gradients may or may not be associated with differential CV events and long-term evaluations are necessary.

Relationship between Tei index of myocardial performance and left ventricular geometry in Nigerians with systemic hypertension

INTRODUCTION

Left ventricular geometry is associated with cardiovascular events and prognosis. The Tei index of myocardial performance is a combined index of systolic and diastolic dysfunction and has been shown to be a predictor of cardiovascular outcome in heart diseases. The relationship between the Tei index and left ventricular geometry has not been well studied. This study examined the association between the Tei index and left ventricular geometry among hypertensive Nigerian subjects.

METHODS

We performed echocardiography on 164 hypertensives and 64 control subjects. They were grouped into four geometric patterns based on left ventricular mass and relative wall thickness. The Tei index was obtained from the summation of the isovolumic relaxation time and the isovolumic contraction time, divided by the ejection time. Statistical analysis was done using SPSS 16.0.

RESULTS

Among the hypertensive subjects, 68 (41.4%) had concentric hypertrophy, 43 (26.2%) had concentric remodelling, 24 (14.6%) had eccentric hypertrophy, and 29 (17.7%) had normal geometry. The Tei index was significantly higher among the hypertensives with concentric hypertrophy (CH), concentric remodelling (CR) and eccentric hypertrophy (EH) compared to the hypertensives with normal geometry (0.83 ± 1.0, 0.71 ± 0.2, 0.80 ± 0.2 vs 0.61 ± 0.2, respectively). The Tei index was higher among hypertensives with CH and EH than those with CR. Stepwise regression analysis showed that the Tei index was related to ejection fraction, fractional shortening and mitral E/A ratio.

CONCLUSION

Among Nigerian hypertensives, LV systolic and diastolic functions (using the Tei index) were impaired in all subgroups of hypertensive patients according to their left ventricle geometry compared to the control group. This impairment was more advanced in patients with concentric and eccentric hypertrophy.

A systematic overview of prospective cohort studies of cardiovascular disease in sub-Saharan Africa

Background

Cardiovascular diseases (CVDs) are becoming increasingly significant in sub-Saharan Africa (SSA). Reliable measures of the contribution of major determinants are essential for informing health services and policy solutions.

Objective

To perform a systematic review of all longitudinal studies of CVDs and related risk factors that have been conducted in SSA.

Data source

We searched electronic databases from 1966 to October 2009. Published studies were retrieved from PubMed and Africa EBSCO. Reference lists of identified articles were scanned for additional publications.

Study selection

Any longitudinal study with data collection at baseline on major cardiovascular risk factors or CVD, including 30 or more participants, and with at least six months of follow up were included.

Data extraction

Data were extracted on the country of study, year of inception, baseline evaluation, primary focus of the study, outcomes, and number of participants at baseline and final evaluation.

Results

Eighty-one publications relating to 41 studies from 11 SSA countries with a wide range of participants were included. Twenty-two were historical/prospective hospital-based studies. These studies focused on risk factors, particularly diabetes mellitus and hypertension, or CVD including stroke, heart failure and rheumatic heart disease. The rate of participants followed through the whole duration of studies was 72% (64–80%), with a significant heterogeneity between studies (for heterogeneity, p < 0.001). Outcomes monitored during follow up included trajectories of risk markers and mortality.

Conclusions

Well-designed prospective cohort studies are needed to inform and update our knowledge regarding the epidemiology CVDs and their interactions with known risk factors in the context of common infectious diseases in this region.