Work-site hypertension prevalence and control in three Central European Countries

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1 (2004) 18, Nature Publishing Group All rights reserved /04 $ ORIGINAL ARTICLE Work-site hypertension prevalence and control in three Central European Countries JG Fodor 1, J Lietava 2, A Rieder 3, S Sonkodi 4, H Stokes 1, T Emmons 1 and P Turton 1 1 University of Ottawa Heart Institute, Heart Check, Ottawa, Ontario, Canada; 2 Second Medical Clinic, Bratislava, Slovakia; 3 Institute for Social Medicine, Faculty of Medicine, University of Vienna, Vienna, Austria; 4 Faculty of Medicine, University of Szeged, Albert Szent-Gyorgyi Medical University, Szeged, Hungary Compared to Austria, cerebrovascular stroke (CVS) mortality is three times higher in Hungary, and twice as high in Slovakia. We hypothesized that this is due to better treatment and control of hypertension in Austria. To test this hypothesis, we carried out a cross-sectional survey of blue collar employees on work sites in each of these countries. Blood pressure screening was carried out at three work sites in Austria, one in Hungary and one in Slovakia. A standardized protocol was followed in each of these countries. The Bp-TRU TM measuring instrument was used to provide accurate reproducible readings and eliminate interobserver error. After the exclusion of missing data and women, the study population included 323 males screened in Austria, 600 in Hungary, and 751 in Slovakia. The mean ages of the respondents ranged from 35 to 42 years. The prevalence of hypertension was 29% in Austria, 28% in Hungary and 40% in Slovakia. Of those identified as hypertensive, 73% in Austria, 45% in Hungary and 67% in Slovakia were newly diagnosed as a result of this screening. Of those treated for hypertension, 10% in Austria, 15% in Hungary and 5% in Slovakia were controlled. The differences in CVS mortality cannot be explained by better control of hypertension in Austria but indicate the involvement of other determinants. (2004) 18, doi: /sj.jhh Published online 19 February 2004 Keywords: blood pressure; cerebrovascular stroke; Central Europe; environmental factors Introduction Since the fall of communism in 1989 in Central and Eastern Europe, increasing attention is being paid to the poor state of health in postcommunist societies. The worst health indicators are found in areas of the former Soviet Union, where the probability of early mortality before 65 years is twice that of Western Europe. 1 In Central European countries, the overall health situation is somewhat better, albeit there are significant differences between countries. Life expectancy at birth is 75 years in the Czech Republic, somewhat less in the Slovak Republic (73 years) and worse in Hungary (71 years). 2,3 We were particularly interested in comparing data between Austria, the Slovak Republic and Hungary. Before World War I, these neighbouring countries were part of the Austria-Hungarian monarchy. At the end of World War II, the political system changed in Correspondence: JG Fodor, University of Ottawa Heart Institute, Heart Check, First Floor, 40 Ruskin St., Ottawa, Ontario, Canada, K1Y 4W7. gfodor@ottawaheart.ca Published online 19 February 2004 these countries. Austria remained a free country with a market economy that has enjoyed economic prosperity in contrast to Hungary and Slovakia. This is reflected in the differences between the gross national income per capita in these three countries, where Austrian incomes are six to eight times higher than in Slovakia or Hungary (Table 1). The standard death rate comparing all causes of death for all ages per population per year shows that Hungarian mortality rates are about 70% higher than Austrian rates, while mortality rates in the Slovak Republic are about 50% higher (Table 2). The mortality rates from cerebrovascular stroke (CVS) mortality are of particular interest. In Slovakia and even more in Hungary, CVS mortality is significantly higher than that of Austria or Canada (Figure 1). Since hypertension is the most important risk factor for CVS 4,5 and successful treatment of hypertension results in significant reduction of these events, 6 we hypothesized that the differences seen between these three countries are due either to differences in the prevalence of hypertension, or as a result of better treatment of hypertension in Austria compared to Hungary and Slovakia.

2 582 Table 1 Demographical overview of Austria, Hungary and Slovakia To gain a better insight into this problem, we decided to carry out a pilot study in these three countries. The primary objective was to establish the prevalence of hypertension and treatment status in each of these countries. The secondary objectives were to assess the awareness and the level of control of hypertension, and to test the feasibility of international comparative studies in this part of the world. Comparative studies of blood pressure levels in different populations attempted in the past have been difficult to evaluate because of large interand intraobserver error when using standard mercury manometers or random zero instruments. The availability of a new Canadian blood pressure measuring instrument, the Bp-TRUt, made it possible to avoid measurement errors and to obtain reliable BP values. 7 Methods Austria Hungary Slovakia Population (million) Life expectancy (years) Gross national income (per capita) (USD) $ $4 740 $3 700 Table 2 Standard death rate, all causes, all ages, per Country Standard death rate Austria 658 Hungary 1124 Slovakia 990 Figure 1 Male cerebrovascular stroke mortality, age standardized, per individuals (Source: WHO Europe, HFA Database, January 2002, Statistics Canada 2001). In all the three countries, the studies were carried out in blue collar work settings. In Austria, respondents were recruited from a large bakery in Vienna, from labourers in Vienna Harbour and from auxiliary staff from the Vienna General Hospital (orderlies, cleaners, etc). In Hungary, respondents were recruited from employees of the Pick salami factory in Szeged. The Slovak study was carried out in the city of Sala, in a factory for producing chemicals and fertilizers (Duslo). Respondents were invited to participate in examinations through announcements by the management, unions and posters that explained the purpose of the investigation. Ethical approval was obtained from the respective universities in the three countries. The investigation was carried out by a team of physicians and nurses. The respective teams in each country visited the worksites and held a special hypertension detection clinic. Upon arrival, the respondents were interviewed using a short, standardized questionnaire (see Appendix 1); these contained identical questions in all of the participating countries, translated into the Hungarian, Slovak and German languages. The subjects were asked not to eat or smoke for at least 30 min before their examination. Prior to the blood pressure measurement, they rested quietly for a minimum of 5 min. The participant s right arm was held at the level of the heart. The Bp-TRUt blood pressure measuring instrument was used to determine blood pressure. This instrument measured the systolic and diastolic blood pressure (SBP and DBP, respectively) six times at 1-min intervals, discarded the first value, and calculated the average SBP and DBP based on the remaining five consecutive measurements. The instrument also recorded the heart rate. All data were sent to the University of Ottawa Heart Institute and entered into a database. Standard parametric and nonparametric tests were applied using SAS and Excel statistical programs. Hypertensives were classified as those respondents who had an SBP X140 mmhg and/or DBP X90 mmhg, or those who were taking antihypertensive medication, regardless of their blood pressure level. Controlled hypertensives were classified as those treated with antihypertensive drugs and with SBPo140 mmhg and DBPo90 mmhg. Respondents who were identified as newly discovered hypertensives were referred to a physician for further treatment, as were those respondents who were treated but whose blood pressure was not controlled. Results In Austria, 372 respondents were screened in total (323 male, 48 female and one missing gender data); in Hungary, 1021 in total (600 male, 412 female and nine missing gender data); and in Slovakia, 1190 (751 male, 439 female). Given the small number of women screened in Austria, the comparative analyses were performed only on males. The mean ages

3 of the respondents ranged from 35 to 42 years. The prevalence of hypertension in males is 29% in Austria, 28% in Hungary and 40% in Slovakia (Table 3); of these, 73% in Austria were newly diagnosed as were 45% in Hungary and 67% in Slovakia. Of those aged 39 years or less, 19% were hypertensive and of those aged 40 years or more, 50% were hypertensive. There are significant differences (Po0.05) in the SBP and DBP between the three countries (Table 4). Of those who were classified as hypertensive and who were on antihypertensive medication, hypertension control was achieved in only 9.7% in Austria, 14.9% in Hungary and 5.3% in Slovakia (Table 5). Our results indicate that although Hungary has the highest level of CV mortality, it also had the best level of hypertension control (14.9%), demonstrated by mean SBP and DBP below 140/90 mmhg in the treated group (Table 4). Slovakia had the lowest level of control at 5.3% and the highest mean SBP and DBP at 152.2/95.8 mmhg in the treated group. Despite having the lowest CV mortality, Austria also had a low level of hypertension control with the mean SDP and DBP at 141.2/93.1 mmhg in the treated group (Table 4). Discussion This study set out to establish the prevalence of hypertension and treatment status in work sites in Austria, Hungary and Slovakia, and to test the feasibility of international comparative studies in this part of the world. We have documented that it is possible to implement such studies with relative ease and fast acquisition of valuable data. However, the primary objective of this study was to investigate whether the relatively low CVS mortality in Austria, as compared to Slovakia and Hungary, is a result of better awareness and treatment of hypertension in Austria. The work site settings were chosen with regard not only to the feasibility of the study but also because we expected that in low socioeconomic groups the lack of awareness and treatment would be more accentuated. The fact that the socioeconomic gradient is inversely related to health status is amply documented, 8 as is the fact that treatment of hypertension results in a significant reduction of stroke mortality and morbidity. 9 There were no significant differences in the control of hypertension between the three countries; in fact, the level of hypertension control was comparable to statistics in Canada. 10 The striking differences in morbidity and mortality of postcommunist societies have been studied in the past decade by many authors. Kesteloot 11 Table 5 Percentage of control in those identified with hypertension Country participants identified with hypertension (HT) participants treated for HT participants with HT controlled Austria (28%) 9 (9.7%) Hungary (32%) 25 (14.9%) Slovakia (33%) 16 (5.3%) 583 Table 3 Prevalence of hypertension Country numbers of male respondents Hypertensive (HT) Of those with HT, newly diagnosed Austria (29%) 68 (73%) Hungary (28%) a 76 (45%) Slovakia (40%) b 202 (67%) b a There were 2 HT variables missing for Hungary. b There was one HT variable and 28 newly diagnosed variables missing for Slovakia. Table 4 Mean systolic and diastolic blood pressure in those treated and those nontreated for hypertension Country Subgroup Treated Nontreated Austria Mean SBP (mmhg) Mean DBP (mmhg) Hungary Mean SBP (mmhg) Mean DBP (mmhg) Slovakia Mean SBP (mmhg) Mean DBP (mmhg) a a There was one DBP variable missing in the nontreated category for Slovakia. SBP represents systolic blood pressure and DBP, diastolic blood pressure.

4 584 considers nutritional factors as a major cause for the observed differences between Hungary, Austria and Switzerland. Hungarian authors, 12 comparing cardiovascular disease risk profile in a rural population sample in Hungary with German data from the PROCAM study, 13 concluded that, while the Hungarian population is more obese and nutrition is characterized by a high fat and meat content, the traditional cardiovascular disease risk factors are not strikingly different between the two countries. Our findings are in line with these observations in that the prevalence and control of hypertension, which is a significant cardiovascular disease risk factor, do not differ greatly between countries with a relatively low cardiovascular mortality (Austria) and countries with a high cardiovascular mortality (Hungary and Slovakia). Thus, our study indicates that neither the awareness of hypertension nor the intensity of treatment of hypertension provides an explanation for the differences in the CVS mortality between Austria, Hungary and Slovakia. It is evident that determinants such as nutrition, psychosocial stress and other as yet unidentified factors may play a role. In summary, despite dramatic differences in cerebrovascular stroke mortality between Austria, Hungary and Slovakia, our study establishes that this gradient is not due to better treatment and control of hypertension in Austria, and highlights the need for further research to determine the cause of this mortality gradient in Eastern Europe. Acknowledgements We gratefully acknowledge the significant support we have received from Dr A Dukat, Bratislava, Slovakia; Dr T Dorner, Wien, Austria; Dr G Lencse, Szeged, Hungary and Dr M Caprnda, Bratislava, Slovakia. This project was supported by CIDA Canada, the Austrian Red Cross Society, and the City of Wien Healthy Heart Program. The Bp-TRUt instruments to all participating sites were donated by Dr Mark Gelfer, Medical Director VSM Corporation, Vancouver, Canada. References 1 McKee M, Shkolnikov V. Understanding the toll of premature deaths among men in Eastern Europe. Br Med J 2001; 323: Statistics Canada. Canadian statistics information. Accessed May Available from: URL: World Health Organization, Regional Office for Europe. European health for all database. Accessed January Available from: URL: Kannel WB. Blood pressure as a cardiovascular risk factor. JAMA 1996; 275: MacMahon S et al. Blood pressure, stroke, coronary heart disease. Part 1, Prolonged differences in blood pressure: prospective observational studies corrected for the regression dilution bias. Lancet 1990; 335: Dahlöf B, Devereux RB, Kjeldsen SE. Cardiovascular morbidity and mortality in the losartan intervention for endpoint reduction in hypertension study (LIFE): a randomized trial against atenolol. Lancet 2002; 359: Wright JM, Mattu GS. Validation of a new algorithm for the BPM-100 electronic blood pressure monitor. Blood Pressure Monit 2001; 6: Ginter E. Cardiovascular risk factors in the former communist countries: Analysis of 40 European MON- ICA populations. Eur J Epidemiol 1995; 11: Blood Pressure Lowering Treatment Trialists Collaboration. Effects of ACE inhibitors, calcium antagonists, and other blood-pressure-lowering drugs: results of prospectively designed overviews of randomized trials. Lancet 2000; 355: Joffres M et al. Awareness, treatment and control of hypertension in Canada. Am J Hypertens 1997; 10: Kesteloot H. Regional differences in mortality: a comparison between Austria, Hungary and Switzerland. Acta Cardiol 1999; 54: Mark L, Kondacs A, Hanyecz V. Cardiovascular risk factor profile: Comparison of a Hungarian community with Germany. Wien Klin Wochenschr 1997; 109: Assmann G, Schulte H. The Prospective Cardiovascular Münster (PROCAM) study: prevalence of hyperlipidemia in persons with hypertension and/or diabetes mellitus and the relationship to coronary heart disease. Am Heart J 1988; 116: Appendix A CLINICAL CHART Austria Hungary Slovakia International Blood Pressure Study ID... Male Female Age (yr)... Body Weight (kg)... Body Height (cm)... Waist Circumference (cm)... Blood Pressure (as determined by VMS instrument according to protocol) Systolic BP (mmhg)... Diastolic BP (mm Hg)... HR (beats/min)... Have you had your blood pressure measured ever? Have you had your blood pressure measured in the past year? Have you been told that you have high blood pressure?

5 Have you been prescribed drugs to reduce high blood pressure? Do you know the name(s) of the prescribed drug(s)? What is/are the name(s) of the drug(s) you were prescribed for treating your high blood pressure? Do you take these drugs now? If you are currently on treatment with drugs to lower your blood pressure, tick one of the following statements which most accurately describes you: I take my blood pressure pills every day regularly. I never forget to take them. I take my blood pressure pills almost every day. Occasionally I forget. Sometimes I either forget or decide not to take my blood pressure pills, for short periods of time (days) I frequently forget or decide not to take my blood pressure pills for extended periods of time (weeks or months) and finally Did you smoke even one cigarette during the past 7 days? 585