The prevalence of hypertension and its relationship with obesity: results from a national blood pressure survey in Eritrea

Abstract

The prevalence of cardiovascular diseases has been shown to be on the increase in Africa based on hospital-based information and limited national surveys. A recent report on analysis of data from Health Information Management Systems (HIMS) highlighted an increasing burden of noncommunicable diseases (NCDs) in Eritrea, with the incidence of hypertension doubling in a space of 6 years. HMIS data are only a proxy of national prevalence rates, necessitating the conduct of national surveys. The WHO STEPwise approach to surveillance of NCDs was used for the national NCD risk factor survey in 2004. This report focuses on blood pressure (BP) and obesity (body mass index (BMI)>30 kg/m2) as NCD risk factors in Eritrea. A total of 2352 people in age groups 15 to 64 years participated in the survey. The prevalence of hypertension defined as BP>140/90 mmHg was 15.9% in the general population, with 16.4% in urban and 14.5% in rural areas, 17% of whom were males while 15% were females. BMI was positively associated with systolic (SBP), diastolic and mean arterial pressure. Although the prevalence of obesity (3.3%) was higher in females, the effect of BMI on BP was higher in males than in females (regression coefficient 0.64 and 0.38, respectively, P0.05), especially in those >45 years. BMI did not have a significant effect on BP in lean people (BMI<19) and in those with high BMI, but was positively correlated to SBP in those with normal BMI (P0.02). BMI and age appear to play a synergistic role in creating a strong association with BP.

Introduction

There is limited literature on the epidemiology of noncommunicable diseases (NCDs) in Africa.1, 2, 3 Most countries including Eritrea have not conducted national surveys of these diseases.4, 5 NCDs have been neglected in developing countries particularly given the background of their coexistence with infectious diseases in endemic proportions. These countries are therefore confronted with a double burden of disease, posing as two challenges to resources reserved for health-care delivery.

The first challenge is the ongoing burden from the endemic infectious diseases including resurgence of old diseases such as tuberculosis and the relatively new diseases like HIV/AIDS pandemic.

The second and new challenge is that of the previously and still mostly neglected emerging burden of NCDs, especially that of hypertension and its manifestations on target organs presenting as strokes, heart failure and myocardial infarction.6, 7 The limited material and human resources available in the developing countries are directed towards combating infectious diseases.

Hypertension has been linked with a number of risk factors, for example, urbanization, dietary factors and metabolic disorders.8, 9, 10, 11, 12, 13 Even though the same NCD risk factors may be prevailing globally, the causal relationship between them and the development of hypertension has never been resolved. Initially, the pathophysiology of essential hypertension was thought to occur through the insulin resistance common pathway, but the existence of hypertension in lean subjects has somewhat clouded this hypothesis and called for alternative mechanisms, including increased psychosocial stress.14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 Further, the concept of risk factors associated with NCDs was derived from prospective epidemiological studies conducted mainly in Western populations.4, 5 It has been demonstrated that what pertains to Caucasians does not necessarily occur to the same magnitude in other races especially the black population. Even among black subjects, differences have been observed in the expression of risk factors depending on the environment.4, 5 Whether it is prudent to extrapolate verbatim the conclusions derived from Western studies to people in developing countries with different ethnic divides is unsettled and should be subject to further investigation.

A recent report based on analysis of data from Health Information Management Systems (HIMS) noted the emergency of a silent hypertension epidemic in Eritrea.25 In that study, the incidence of hypertension was reported to have doubled in just 6 years. However, the data did not provide the correlates of the hypertension. Although this information was a proxy for NCD health profile, it was not good enough to be used as a surveillance tool and risk factor reduction measure.

The main objective of this study was to conduct a baseline survey of the main risk factors for the major NCDs in all the urban and rural areas of the six Zobas (regions) of Eritrea in the anticipation of setting up a national programme for prevention, early detection, control and surveillance of risk factors for NCDs.

Methods

Background

The study was carried out among all the nine ethnic groups in Eritrea. It was a cross-sectional baseline survey of the principal risk factors for the major NCDs in Eritrea that was conducted in 2004. The WHO STEPwise approach for surveillance of NCD risk factors was used.2

The STEPwise approach provides a framework for surveillance of NCD risk factors, NCD-specific morbidity and mortality. The approach is based on the concept that surveillance systems require standardized data collection to ensure comparability over time and across locations. It is also sufficiently flexible to be appropriately adaptable in a variety of country situations and settings.

STEPS is a sequential process starting with gathering information on key risk factors by the use of questionnaires (Step 1), then moving to simple physical measurements (Step 2), and only then recommending the collection of blood samples for biochemical assessment (Step 3). In this study, Steps 1 and 2 were used.

Study design

A sample size of 2304 subjects (N) in the six zones was calculated using the formula:

where Z is the Z-score, P is the proportion of the factor under investigation,

and E is the maximum error allowed.

A two-stage stratified cluster sampling procedure with primary sampling unit (PSU)=cluster selected from all six zones was used. The PSU (cluster) was selected with probability proportional to the size of the village (PPS) in terms of households. A cluster could correspond to a village or cut across villages. In some instances, a village could contain more than one cluster.

In all, 123 clusters were selected from the six zones and 20 individuals aged 15–64 years old were targeted from each cluster for interview. A total of 20 × 123 (2460) was thus targeted. (Note: WHO recommends a minimum of 400 subjects per age group, that is, 200 male and 200 female; thus, 2000 for the five 10-year age groups).

Systematic sampling of households was carried out using the given sampling interval for that village. The first household was selected by spinning a bottle at the middle of every village and all eligible subjects per household (15–64 years) were enlisted and one was randomly selected per age group. Each time a subject was selected for interview and physical examination, that individual was crossed out from the age group checklist till the total sample size was attained.

Data collection procedure

Training of data collectors

The data collectors were given a 2-day training session that included interview techniques, introduction to NCDs, detailed introduction to the data collection instruments and physical measurement instruments.

There were sessions to practice with the questionnaire and the physical measurement equipment. Field guidelines were likewise developed and given to each team.

Questionnaire

The questionnaire was developed from the STEPs standard questionnaire and adapted for Eritrea pretested and modified according to pretesting findings. It was also translated into the local Tigrinya language.

Height measurement

The SECA body metre (206 seca Vogel and Halke GmbH and Co. Sonke Vogel Geschalfsfuhrer) was used for this measurement. The following procedures were followed in a chronological sequence: assembling of the instrument on a vertical solid surface; the respondents standing on the board without footwear or head wear, facing the interviewer, placing their feet together, heels against the back of the board, knees straight and looking straight ahead; and the interviewer moving the measuring stick down and placing it on top of the head and recording the height in centimetres.

Weight measurement

A TANITA digital scale (2003 Tanita Corporation of America Inc., Arlington Heights, IL, USA) was used for weight measurement. The sample was subdivided into three categories based on the body mass index (BMI, kg/m2): lean less than 18.9, normal 19–24.9 and high BMI greater than 25.

Waist circumference measurement

The tension measuring tape graduated to 1 mm was used for measurement. A private area was chosen for this. The sequential steps followed were as follows: identification of the inferior margin of the last rib and the superior border of the iliac crest in the mid-axillary plane with a pen; identification and marking of the midpoint between the two was found with a tape measure; application of the tension tape over the marked point making sure that the tape was horizontal across the back; and making the recording at the point of normal expiration.

Blood pressure (BP) measurement

The measurements were taken using the OMRON digital sphygmomanometer (OMRON M7 Duo 773 OMRON Healthcare Europe B.V. Kruisweg 577, 2132 NA Hoofddorp) as recommended.2

Before taking the measurements, the respondent was advised to sit quietly and rest for 5 min with the legs uncrossed and the right arm free of clothing. Then, the right arm was placed on the table with the palm facing upwards. The appropriate cuff size was selected. The artery position mark (ART) was aligned with the brachial artery. The cuff was wrapped snugly and fastened securely. The cuff was kept at the same level as the heart during measurement. Taking measurement involved the following steps: Pushing the ‘START’ button enabled automatic inflation of the cuff and display of the reading of systolic blood pressure (SBP) and diastolic blood pressure (DBP) readings, which were recorded. A second reading was taken after the first. If the difference between the first and second readings was >10 mmHg, then a third reading was taken and recorded and the average of the closest two was used for analysis.

Data management and analysis

Questionnaires collected from the field were reviewed by team leaders assigned to each team before submitting them to the headquarters for data entry. Double entry of the questionnaires was performed using EPI-INFO 2000 software and EpiData software developed by the Menzes centre for validation. After data entry, data cleaning was conducted.

New variables were defined by adopting the standard Steps variables (STEPS Data Management Manual, Draft version v1.5, October 2003).

Data analysis was conducted using EPI_INFO 2002 and SPSS software.

Regression analysis was used to ascertain associations between BMI and BPs. Three forms of BP were used: SBP, DBP and mean arterial pressure (MAP). MAP was calculated from the formula MAP=(SBP−DBP)/3+DBP.

Quality assurance of the data

To ensure quality of data collection, the interviewers and the supervisors were carefully selected. The supervisors were senior staff from the WHO, Orotta School of Medicine and the Ministry of Health. The interviewers were recruited from public health students of Asmara University who had previous research experience and included final year nursing students as well as medical students from the Orotta School of Medicine.

The questionnaire was translated into the local Tigrinya language and pretested.

Intensive training was given to the data collectors, which included practical sessions and questionnaire and equipment testing.

A guideline was prepared and given to the teams for easy reference. Also, in order to minimize error, digital equipment was used for measuring weight and BP. The training was focused on application of the cuff and position of the machine at the level of the heart and accurate recording of the displayed figures. On the second day, all data collectors were evaluated on the procedure for BP measurement. Each team was accompanied by one of the trainers who oversaw the measurement throughout the survey as a quality assurance exercise.

In order to minimize data entry errors, double data entry was carried out and checks were instituted into the databases.

Ethical clearance and confidentiality

The survey was cleared by the Ministry of Health and had the full support of the Orotta School of Medicine.

A letter from the Ministry of Health signed by the Director General detailing the survey objectives and seeking cooperation and support from all stakeholders was carried by each survey team.

In the field, clearance was always obtained from the zonal and village administration.

Verbal informed consent was obtained from all respondents before administering the questionnaire or taking measurements.

Major challenges from the survey

The major constraints encountered during the survey included absence of selected candidates from the houses because of the farming season, making the interviewers return many times before getting responses, and the data were too extensive for analysis to be run in Epi Info. We had to export it to SPSS for better analysis.

Results

Altogether, 2352 respondents participated in the study, giving a response rate of 95.6%, which is quite good for surveys of this nature. All age groups were equally represented (Table 1).

Table 1 Distribution of respondents by age group and gender

All the nine ethnic groups, namely Tigrinya (63), Tigre (6.4), Saho (6), Bilen (5.5), Afar (3.8), Nara (2.5), Hadareb (0.7), Rashida (0.7), Kunama (0.6) and others (0.8), in Eritrea were included in the survey, at the percentages given in brackets after each group. These ethnic proportions were consistent with estimated population subgroupings with the majority of the respondents from the Tigrinya ethnic group (Table 1).

The prevalence of age-adjusted obesity defined as a BMI of 30 kg/m2 was 3.3% in the general population. BMI was consistently higher in females than in males throughout the entire age group range, especially in the 35–44 and 55–64 age groups, where it was more than double in females (Table 2). In all, 32% of the population was lean, 51% normal and the remaining 17% in the high BMI (overweight and obese) category.

Table 2 Prevalence of obesity by sex and age group

The prevalence of hypertension in the general population was 16%, with the highest levels in unemployed people and local merchants (24%) and the lowest levels in students (7.1%). The prevalence of hypertension steadily increased with age in both sexes. The overall prevalence was slightly higher in males (16.88%) than in females (15.28%). However, below the 35–44 year age group, the prevalence was higher in males, and above that age group, the prevalence became higher in females (Figure 1).

Figure 1
figure1

Prevalence of hypertension by sex and age group.

The prevalence of hypertension tended to be higher in urban than in rural environments. In all, 80% of the newly diagnosed hypertensive cases were not aware of their condition.

The prevalence of hypertension was higher in urban settings (16.5%) than in rural settings (14.5%). However, this difference was not significant (P-value=0.26).

Using regression analysis on the whole sample, BMI positively correlated with all the three forms of BP, SBP, DBP and MAP.

There was no significant difference among the regression coefficients between BMI and each of the three forms of BP, SBP, DBP and MAP (Table 3).

Table 3 Regression analysis between different blood pressures and BMI

The effect of BMI was greater in males than in females, especially in the >45 year age groups.

In lean people, there was no significant effect of BMI on BP. In normal BMI women <45 years, there was a significant correlation between all forms of BP and BMI (P0.05), but this significance disappears for those women >45 years (Table 4). For normal BMI men, there was a positive correlation between BMI and SBP in men >45 years (P0.05), but no significance with other BPs and in those <45 years.

Table 4 Regression analysis between SBP and BMI in two age groups

There was a trend for a negative correlation between all forms of BP and BMI in both females and males and in both age groups <45 and >45 years, although this did not reach significance.

Discussion

The study was conducted in order to establish the correlates of BP through a national survey in the State of Eritrea in 2004 according to the WHO STEPwise protocol. The main objective of the survey was to establish a baseline that would be used to identify the risk factors and in measuring the impact of risk factor reduction interventions. The cardinal findings of the study were that BP and hypertension prevalence increased with age and were higher in urban than in rural settings. Hypertension prevalence was slightly higher in males than in females up to the 35–44 year age group, after which there was a crossover, when it was slightly higher in females than in males. There was a positive correlation between BMI and BP in the overall sample; however, when the sample was analysed further, important differences emerged. In lean people, there was no significant correlation, while in normal BMI women <45 years, the association was strong. In the high BMI groups, there was a negative correlation, which was not significant. Given the relatively high levels of hypertension evident from this survey, there is need to set up a programme whose strategy is to harness and mobilize resources that will be used to develop and implement risk factor reduction interventions to curb the further increase in hypertension prevalence.

This survey was national in terms of regional and racial distribution of the country, making it representative of the population of Eritrea. The response rate was higher than levels achieved in similar surveys, which is commendable and also made the generated sample reflective of the population racial grouping and composition at national level. A high participation rate coupled with a randomized sampling procedure made results of the study generalizable to people of Eritrea.

The equipment and technique for BP measurement and definition of hypertension (140/90 mmHg) used were according to the WHO STEPwise approach, which allowed for interstudy comparisons.2 The overall prevalence of hypertension was higher than the levels generated in some Western African countries, but lower than those in Southern Africa and Egypt and the Indian Ocean Island countries.26 The prevalence of hypertension among black subjects has demonstrated a gradient of risk factor pattern across the diaspora with reported values of 14% in Western Africa, 26% in the Caribbean and 33% in the USA. In Africa, some of the highest prevalence rates of hypertension were reported in Egypt27 and Zimbabwe,16 especially in the urban environment. In this study, BP and hypertension prevalence increased with age and were both higher in urban than in rural settings, which is consistent with findings reported in other African-based studies and in Caucasians.26

Awareness of hypertension among the respondents was less than 20%, making the majority of the newly diagnosed patients unaware of their condition. The level of awareness was similar to that reported in Zimbabwe,28 but much lower than that reported in South Africa,29 and USA.30 In addition to the low level of awareness, there was another challenge waiting, that of convincing the new patients to regularly take medications for life for a disease, which does not have any presenting symptoms. Patients will therefore tend to present late with morbidity and mortality from target organ damage such as strokes, heart and renal failure, all of which consume larger resources to manage than to prevent. Already there has been a recent report of high incidence of strokes in one region of Eritrea for reasons still inexplicable.25 It is therefore very critical that an aggressive community-based health education and promotion programme be set up to reduce the morbidity from hypertension in Eritrea.

Analysis of the data revealed a complex relationship between all the three forms of BP that were examined, SBP, DBP and MAP, and BMI. There was an overall positive correlation between these two variables as has been reported previously.20, 31 Although the level of BMI was higher in women, the effect was stronger in men. This is difficult to explain, although it has been suggested that the BMI and BP relationship is stronger in lean people, our findings did not support this explanation. On the contrary, in our study, there was no significant relationship between BP and BMI in the lean subjects. It has been demonstrated that the threshold for the positive relationship BMI–BP at 21.5 kg/m2 was higher than the cutoff value for lean populations, which was <19 kg/m2.20 Paradoxically, there was a negative correlation between BP and BMI in the high BMI group, which did not reach statistical significance, and which would tend to provide protection rather than contribute to the increase in BP. Interestingly, it was in the normal BMI group that the BMI–BP relationship had a significant positive correlation for females <45 years and males >45 years.

Although hypertension prevalence was higher in males than in females <45 years, there was a crossover effect of BP curves for people >45 years, where the opposite was true. If increased BMI were a critical factor in the pathogenesis of increased BP, given that a negative correlation does not provide support for its role in the crossover effect in BP between males and females, there is a need to further investigate the mechanisms of this crossover effect in the future. It is probable, for example, that the BP–BMI relationship is sigmoid shaped, whereas at low BMI, there is no relationship, but this is followed by a gradual build up in the association in the normal BMI group, and then finally plateaus or even decreases at high BMI. The proportion of the lean population of 32% is quite high in Eritrea. There is no normogram of physiological variables including weight and height among the population under study. It is therefore possible that part of the lean population may actually be malnourished, creating another confounding variable. This is speculative as our study did not address the issues.

BP patterns between females and males in Africa exhibit a heterogeneous pattern. On the one hand, some studies from Southern Africa,10, 16 Morocco32 and Egypt27 have recorded higher BP in females than in males, which is the opposite of what is obtained in Caucasian populations. This observation has been referred to as reversed gender dichotomy. On the other hand, studies in other countries, notably Nigeria,4 DRC20 and Ghana,4 have shown higher BPs in males than in females. In Caucasians and Afro-Americans, studies of BPs generally reported higher levels in males than in females.30, 33 It appears this heterogeneity may be a reflection of different socioeconomic stressors and related factors rather than of pure physiological origin.19, 22 One explanation cited for reversed gender dichotomy was higher indices of obesity and elevated level of insulin resistance in the females.17

The prevalence of hypertension was higher in the urban than in the rural setting, representing what has been termed urbanization-related hypertension. This is a near universal finding in many African-based studies, with a few exceptions.10, 16, 19, 20 A number of factors have been implicated in the development of this form of hypertension, notably adoption of Western-type lifestyles, especially diet, and increased psychosocial stress. There is a confounding variable on the BP pattern in Eritrea. The majority of urban settings are geographically sited on high altitude with rural areas predominantly located in the low-lying areas including some sub-sea-level areas. BPs are known be influenced by altitude with conflicting results, some reporting higher pressures in lowlands34 and others observing higher pressures in highlands.35 A normogram for BP has not been established in Eritrea. Through extrapolation, it is possible that pressures in the participants from the lowlands are low. The prevalence of hypertension in the lowlands may therefore be artificially low. The definition of hypertension may require modification downwards after the development of a normogram to include people at risk of hypertensive cardiovascular disease.

References

  1. 1

    Pobee JO . Community-based high blood pressure programs in sub-Saharan Africa. Ethn Dis 1993; 3: S38–S45.

    PubMed  Google Scholar 

  2. 2

    Bonita R, de Courten M, Dwyer T, Jamrozik K, Winkelmann R . Surveillance of Risk Factors for Non Communicable Disease. The WHO Stepwise approach: WHO, 2001.

    Google Scholar 

  3. 3

    Murray CJL, Lopez AD . The global burden of disease. In: Murray CJL, Lopez AD (eds). The global burden of disease: A Comprehensive Assessment of Mortality and disability from disease, Injuries and Risk in 1990 and projected to 2020. USA: Harvard School of Health, 1996, pp. 1–52.

    Google Scholar 

  4. 4

    Kaufman JS, Owoaje EE, James SA, Rotimi CN, Cooper RS . Determinants of hypertension in West Africa: contribution of anthropometric and dietary factors to urban–rural and socio-economic gradients. Am J Epidemiol 1996; 143 (12): 1203–1218.

    CAS  Article  Google Scholar 

  5. 5

    Forrester T, Cooper RS, Weatherall D . Emergence of Western diseases in the tropical world: the experience with chronic cardiovascular diseases. Br Med Bull 1998; 54 (2): 463–473.

    CAS  Article  Google Scholar 

  6. 6

    Mensah GA, Barkey NL, Cooper RS . Spectrum of hypertensive target organ damage in Africa: a review of published studies. J Hum Hypertens 1994; 8: 799–808.

    CAS  PubMed  Google Scholar 

  7. 7

    Seedat YK, Mayet FG, Latiff GH, Joubert G . Study of risk factors leading to coronary heart disease in urban Zulus. J Hum Hypertens 1993; 7: 529–532.

    CAS  PubMed  Google Scholar 

  8. 8

    Davidson MH . Emerging therapeutic strategies for the management of dyslipidemias in patients with the metabolic syndrome. Am J Cardiol 2004; 93: 3c–11c.

    CAS  Article  Google Scholar 

  9. 9

    Domanski M, Proschan M . The metabolic syndrome. J Am Coll Cardiol 2004; 43: 138–139.

    Google Scholar 

  10. 10

    Seedat YK, Seedat MA, Hackland DB . Prevalence of hypertension in the urban and rural Zulu. J Epidemiol Commun Health 1982; 36 (4): 256–261.

    CAS  Article  Google Scholar 

  11. 11

    Pauletto P, Caroli M, Pessina AC, Dal Palu C . Hypertension prevalence and age-related changes of blood pressure in semi-nomadic and urban Oromos of Ethiopia. Eur J Epidemiol 1994; 10 (2): 159–164.

    CAS  Article  Google Scholar 

  12. 12

    Sparks BT, Mufunda J, Musabayane C, Sparks HV, Mahomed K, Hunter JM . Prevalence of hypertension among women in rural Zimbabwe: a comparison of pregnant and non-pregnant women. Cent Afr J Med 1996; 42 (4): 93–97.

    CAS  PubMed  Google Scholar 

  13. 13

    Mufunda J, Chifamba J, Somova L, Sparks Jr HV . Hypertension and cardiovascular disease in migrating population. Migration within Africa. High Blood Pressure 1995; 4: 46–49.

    Google Scholar 

  14. 14

    Mufunda J, Fink GD, Sparks HV . Blood pressure responses to dietary salt in rural and urban African men. Ethn Dis 1993; 3: S46–S58.

    PubMed  Google Scholar 

  15. 15

    Mufunda J, Chifamba J, Chitate N, Vengesa PM . Salt sensitivity is not associated with hyperinsulinemia in a sample of rural black Zimbabweans. S Afr Med J 1998; 88 (3): 361–364.

    CAS  PubMed  Google Scholar 

  16. 16

    Mufunda J, Scott LJ, Chifamba J, Matenga J, Sparks B, Cooper RS et al. Correlates of blood pressure in an urban Zimbabwean population and comparison to other populations of African region. J Hum Hypertens 2000; 14: 65–73.

    CAS  Article  Google Scholar 

  17. 17

    Mufunda J, Sigola LB, Chifamba J, Vengesa PM . Hyperinsulinemia: possible cause of high blood pressure in unemployed urban black women. High Blood Pressure 1995; 4: 137–140.

    Article  Google Scholar 

  18. 18

    Diamanti-Kandaraski E, Kaili C, Alexandraki K, Spina G . Failure of mathematical indices to accurately assess insulin resistance in lean, overweight or obese women with polycystic ovary syndrome. J Clin Endocrinol Metab 2004; 89: 1273–1276.

    Article  Google Scholar 

  19. 19

    Simmons D, Barbour G, Congelton J, Levy J, Meacher P, Saul H et al. Blood pressure and salt intake in Malawi: an urban rural study. J Epidemiol Community Health 1986; 40 (2): 188–192.

    CAS  Article  Google Scholar 

  20. 20

    M’Buyamba-Kabangu JR, Fagard R, Staessen J, Lijnen P, Amery A . Correlates of blood pressure in rural and urban Zaire. J Hypertens 1987; 5 (3): 371–375.

    Article  Google Scholar 

  21. 21

    Nair P, Nyamphisi M, Yarnell JW . Lack of difference in blood pressure between the urban and rural population in Lesotho, Africa. Cent Afr J Med 1994; 40 (10): 278–281.

    CAS  PubMed  Google Scholar 

  22. 22

    Strogatz DS, Cruft JB, James SA, Keenan NL, Browning SR, Garrett JM et al. Social support, stress and blood pressure in black adults. Epidemiology 1997; 8: 482–497.

    CAS  Article  Google Scholar 

  23. 23

    Dressler WW, Santos JED, Viteri FE . Blood pressure, ethnicity and psycho-social resources. Psychosom Med 1986; 48: 509–519.

    CAS  Article  Google Scholar 

  24. 24

    Kelemen L, Jain M, Anand S, Yusuf S . Dietary differences in ethnic groups in Canada. Can J Cardiol 1997; 13: 13–24.

    Google Scholar 

  25. 25

    Mufunda J, Nyarango P, Kosia A, Ogbamariam A, Mebrahtu G, Usman A et al. Non-communicable diseases in Africa: a silent hypertension epidemic in Eritrea. J Hum Hypertens 2004; 19: 1–2.

    Google Scholar 

  26. 26

    Cooper R, Rotimi C . Hypertension in blacks. Am J Hypertens 1997; 10: 804–812.

    CAS  Article  Google Scholar 

  27. 27

    Ibrahim MM, Rizk H, Appel LJ, el Arousy W, Helmy S, Sharaf Y et al. Hypertension prevalence, awareness, treatment, and control in Egypt. Results from the Egyptian National Hypertension Program (NHP). NHP Investigative team. Hypertension 1995; 26: 886–890.

    CAS  Article  Google Scholar 

  28. 28

    Matenga JA, Allain TJ, Gomo Z, Wilson AO, Ndemera B, Adamchak DJ et al. Hypertension management in Zimbabwe-awareness, treatment and blood pressure control. A community based study. S Afr Med J 1997; 10: 1371–1373.

    Google Scholar 

  29. 29

    Steyn K, Gaziano TA, Bradshaw D, Laubscher R, Fourie J . Hypertension in South African adults: results from the Demographic and Health survey, 1998. J Hypertens 2001; 19: 1717–1725.

    CAS  Article  Google Scholar 

  30. 30

    Whelton PK, Muntner P . Prevalence, awareness, treatment and control of hypertension in North Africa and Asia. J Hum Hypertens 2004; 18: 545–551.

    CAS  Article  Google Scholar 

  31. 31

    Kaufman JS, Asuzu MC, Mufunda J, Forrester T, Wilks R, Luke A et al. The relationship between blood pressure and body mass index in lean populations. Hypertension 1997; 30: 1511–1516.

    CAS  Article  Google Scholar 

  32. 32

    Tazi MA . Prevalence of the main cardiovascular risk factors in Morocco. Results of a National Survey, 2000. J Hypertens 2003; 21: 897–903.

    CAS  Article  Google Scholar 

  33. 33

    Luke A, Durazo-Arvizu R, Rotimi C, Prewett TE, Forrester T, Wilks R et al. Relation between body mass index and body fat in black population samples from Nigeria, Jamaica and the United State. Am J Epidemiol 1997; 145: 620–628.

    CAS  Article  Google Scholar 

  34. 34

    Ruiz L, Renaloza D . Altitude and hypertension. Mayo Clin Proc 1977; 52: 442–445.

    CAS  PubMed  Google Scholar 

  35. 35

    Arsalan S, Arsalan N, Soylu A, Akgun C, Tepebasili I, Turkmen M et al. High altitude and blood pressure in children. Yale J Biol Med 2003; 76: 145–148.

    Google Scholar 

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Acknowledgements

We are indebted to the Ministry of Health of the State Eritrea for permission to conduct the survey and publish this manuscript. We acknowledge with thanks the provision of the financial resources provided by the Italian Government through the WHO Country Office to facilitate the survey. The contribution of the Orotta School of Medicine and Asmara University for providing the research assistants is recognized. We are appreciative of the financial assistance for the survey, received from the Public Health And Rehabitation Programme for Eritrea (PHARPE) funded by the Italian Government through The World Health Organization.

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Mufunda, J., Mebrahtu, G., Usman, A. et al. The prevalence of hypertension and its relationship with obesity: results from a national blood pressure survey in Eritrea. J Hum Hypertens 20, 59–65 (2006). https://doi.org/10.1038/sj.jhh.1001924

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Keywords

  • National Blood Pressure Survey
  • NCDs
  • BP
  • obesity
  • Eritrea
  • Africa

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