Journal of Human Hypertension (2005) 19, 255–256 & 2005 Nature Publishing Group All rights reserved 0950-9240/05 $30.00 www.nature.com/jhh
RESEARCH LETTER
Noncommunicable diseases in Africa: a silent hypertension epidemic in Eritrea Journal of Human Hypertension (2005) 19, 255–256. doi:10.1038/sj.jhh.1001802 Published online 23 December 2004
Gash Barka Anseba SRS Debub NRS Maekel 500.0 450.0 Incidence rate/100,000
There is limited literature on epidemiology of noncommunicable diseases (NCDs) in Africa.1 Most countries have not conducted national surveys of these diseases.2 NCDs have been neglected in developing countries particularly given the background of its coexistence with infectious diseases. The limited material and human resources available in the developing countries are directed towards infectious diseases. Several studies have reported higher prevalence of hypertension in urban compared with rural subjects.3,4 A number of factors have been attributed to this urbanization-related hypertension including increased psychosocial stress,5 dietary salt6 and Western-type lifestyles and diet.7 The relationship between risk factors and NCDs was reported from prospective epidemiological studies conducted mainly in Western populations.3 The objective of this study was to investigate the burden of NCDs in Eritrea. The Ministry of Health of Eritrea has created extensive data sets in the central registry through a health management information system. Health workers make clinical diagnoses of diseases and create records for all patients present for medical services, based on national guidelines for those diseases. The study was conducted in order to determine the extent of NCDs in the people from the State of Eritrea. The analysis is based on all patients who reported to health facilities for either outpatient or in-patient services. There have been no studies in Eritrea to examine and quantify the magnitude of the NCDs.2 As a result of the limited resources, most governments would tend to invest more resources in the management of infectious diseases leaving the NCDs unattended. The most striking finding was the increase in essential hypertension by 100% during the 6-year period of study. The incidence of hypertension more than doubled in just 6 years. The increase in essential hypertension matched the degree of urbanization of the zobas (regions) (Figure 1). There was a steady disease burden from heart failure and myocardial infarction while strokes suddenly increased from 2001 (Figure 2).
The impact of the risk factors is variable among different populations and racial groups.6,8 The observation of a 100% increase in the incidence of hypertension in a 6-year period in this study is exceptionally high. This hypertension disease ‘explosion’ is not accompanied by the usual risk factors for the disease such as obesity and increased psychosocial stress. There has been a relatively high incidence of myocardial infarction albeit stable over the study period, compared to the rest of Africa where cases of this disease while increasing are still limited to those in a high socioeconomic bracket.9
400.0 350.0 300.0 250.0 200.0 150.0 100.0 50.0 0.0 1998
1999
2000 2001 Year
2002
2003
Figure 1 Annual incidence of hypertension by Zoba.
Heart Failure Incidence rate/100,000
Dear Sir,
Myocardial Infarction
Stroke
50 45 40 35 30 25 20 15 10 5 0 1998
1999
2000
2001
2002
2003
Year
Figure 2 Annual incidence of heart failure, strokes and myocardial infarction.
Research Letter 256
During the period of study, the incidence of diabetes mellitus increased by about 40%. There is no risk factor profile examined to explain this sudden increased disease burden. The inter-relationship between diabetes mellitus and hypertension and adverse sequel are well recognized.10 The data shows a high incidence of hypertension. It is prudent to conduct a risk factor survey, which will be the basis for primary and secondary interventions to arrest this fast growing NCD case load. J Mufunda1, P Nyarango1, A Kosia2, A Obgamariam3, G Mebrahtu4, A Usman4, J Ghebrat2, S Gebresillosie3, S Goitom3, A Kifle3, A Tesfay3 and A Gebremichael1 1 Orotta School of Medicine, Asmara, Eritrea; 2 WHO Eritrea Country Office, Eritrea; 3 Department of Research and Human Resource Development, Eritrea; 4 Division of Disease Prevention and Control, Eritrea Correspondence: Professor J Mufunda, Orotta School of Medicine, PO Box 212, Asmara, Eritrea. E-mail:
[email protected]
References 1 Pobee JO. Community-based high blood pressure programs in sub-Saharan Africa. Ethn Dis 1993; 3: S38–S45.
Journal of Human Hypertension
2 Bonita R et al. Surveillance of Risk Factors for Non Communicable Disease: The WHO Stepwise Approach, WHO, 2001. 3 Kaufman JS et al. Determinants of hypertension in West Africa: contribution of anthropometric and dietary factors to urban-rural and socioeconomic gradients. Am J Epidemiol 1996; 143: 1203–1218. 4 Mufunda J, Chifamba J, Somova L, Sparks HV. Hypertension and cardiovascular disease in migrating population. Migration within Africa. High Blood Pressure 1995; 4: 46–49. 5 Strogatz DS et al. Social support, stress and blood pressure in black adults. Epidemiology 1997; 8: 482–497. 6 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: 361–364. 7 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: 463–473. 8 Luke 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. 9 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. 10 Omar MA, Seedat MA, Dyer RB, Motala AA. Diabetes and hypertension in South African Indians. A community study. S Afr Med J 1988; 73: 635–637.
