Prevalence of cardiovascular risk factors in the Republic of ... - Nature

Journal of Human Hypertension (1999) 13, 243–247  1999 Stockton Press. All rights reserved 0950-9240/99 $12.00 http://www.stockton-press.co.uk/jhh

ORIGINAL ARTICLE

Prevalence of cardiovascular risk factors in the Republic of Georgia CE Grim1, CM Grim2, JR Petersen3, J Li2, F Tavill3, NN Kipshidze4, PS Chawla1 and N Kipshidze1 1

Medical College of Wisconsin, Milwaukee WI, 2Shared Care Inc, Los Angeles, CA, USA; 3Milwaukee International Health Training Center, Milwaukee, WI, USA; 4Institute of Clinical and Experimental Therapy, Tbilisi, Georgia

Background: Eastern Europe is experiencing an epidemic of deaths from cardiovascular diseases with an increase since the early 1990s approaching 50%. The ability to survey the risk factors associated with this striking rise is severely hampered by the current disarray of the area’s public health system. We used a rapid survey method to describe the epidemiology of cardiovascular risk in the capital of the Republic of Georgia, Tbilisi. Methods: A two-stage cluster design, ‘rapid survey method’ developed by the Chronic Disease Center was used to estimate the frequency of hypertension, a major cardiovascular risk factor. Local personnel were trained and certified in blood pressure measurement and rapid survey techniques. The training and survey were conducted over a period of 14 days at which time a prelimi-

nary report of the survey was presented to the Ministry of Health. Results: A total of 321 subjects were surveyed. The frequency of high blood pressure (⬎140/⬎90 mm Hg) at the time of the examination was 58% in men and 56% in women. The major correlates for blood pressure were gender and age. In addition we found that 31% of the population had a total cholesterol ⭓220 mg% and a similar number had a low high density lipoprotein ⭐35 mg%. Smoking was present in 60% of men and none were taking aspirin daily to prevent premature coronary artery disease. Conclusions: The rapid survey method is feasible in the former Soviet Union and can quickly provide estimates of the risk factors associated with the epidemic of cardiovascular disease in this area.

Keywords: cardiovascular risk factors; high blood pressure; epidemiology; former Soviet Union

Introduction Cardiovascular disease (CVD) death rates show striking geographical variation in Europe with areas of the former Soviet Union showing the highest rates.1 For example in the Ukraine the 1990–1992 CVD deaths were 4.5 times higher in men and 6.8 times higher in women than in France. High blood pressure is the major underlying cause of cardiovascular morbidity and mortality in industrialised countries as well as in less developed countries.2–4 Major reductions in cardiovascular deaths and disability have been proven to be a direct result of detection and treatment of high blood pressure (HBP) including studies showing that the provision of free care for hypertensives lowers blood pressure better than co-pay systems in the US.5 The rapidly changing psychosocial milieu and disintegration of the health care system in the former Soviet Union countries has resulted in an increase in uncontrolled CVD risk factors and is likely the explanation for the sudden increase in CVD deaths in Eastern Europe.6 The use Correspondence: Dr Nicholas Kipshidze, Division of Cardiovascular Medicine, 9200 W Wisconsin Ave, Milwaukee, WI 53226, USA Received 7 March 1998; revised 24 June and 23 October 1998; accepted 7 December 1998

of classical survey methods is difficult in these areas owing to political, administrative and financial problems. Implementing strategies aimed at improving the public health requires that risk factors be defined and quantified. The purpose of this report is to describe the use of the rapid survey method developed by the Chronic Disease Center in Atlanta, GA, USA, for the assessment of diseases in children to assess the prevalence of high blood pressure and other cardiovascular risk factors in the Republic of Georgia.

Subjects and methods The rapid survey method (RSM) The method was developed for the Expanded Program on Immunization (EPI) and has been termed the ‘rapid survey methodology’ (RSM).7,8 The RSM is a two-stage, probability-proportional-to-size (PPS), cluster sampling technique not requiring random selection at the second stage. With the conventional RSM 30 clusters are chosen for the first stage, we chose 48 clusters to increase our sample size. At the second stage, an equal number of persons (n = 7) are selected from each cluster. PPS sampling at the first stage, coupled with a constant number per cluster at the second stage, results in a self-weighted

Prevalence of CV risk factors in Republic of Georgia CE Grim et al

244

sample in which all persons in the population have the same probability of being selected. As there were no up-to-date population density estimates on which to base our sampling we chose to use the last published telephone directory (1991) as our sampling frame. It is estimated that 99% of persons living in apartment buildings and homes in this area had a telephone in 1991. We randomly chose 48 pages from the 621 residential pages. We sampled the area of the city of Tbilisi south of the Mtkvari River inhabited by an estimated 700 000 persons of all social classes. On each page of the telephone book we randomly choose a starting point and then selected the first address in which the telephone number contained the first three digits of our target areas. The team went to the address listed with the telephone number and this was the starting site of the cluster. After a signed informed consent to the interview and blood sampling, we used a standardised questionnaire and examination procedure to test all unrelated (by descent) in the household who were between the ages of 40 and 65 years. Blood was obtained for the measurement of total cholesterol and high density lipoprotein (HDL) cholesterol by standard techniques. When the subjects in the house were completed the team went to the next nearest house or apartment and repeated the process. When seven subjects had been studied the team moved to another starting address (cluster) and repeated the procedure. On the average it took 3 h to complete each cluster.

seated blood pressure all three blood pressure measurements were averaged. Hypertension was defined as in the JNC-VI guidelines: systolic blood pressure ⬎140 mm Hg or diastolic blood pressure ⬎90 mm Hg, or on antihypertensive medication.

The survey teams

Consent

Each survey team consisted of two Georgian physicians, a Georgian nurse, a person to perform venipuncture and one of the authors from the US. The overall supervision of each team was the responsibility of the US team member. Survey teams arrived at their first cluster by about 10 am and many continued their survey until after 8 pm in order to sample more working people. The survey team used a two-page questionnaire which was modelled after the one we have previously used.9

The project was reviewed and approved by the Human Subject’s Committee at the Institute of Clinical and Experimental Therapy and informed consent was obtained in writing from each subject.

Blood pressure All investigators in the study who measured blood pressure were trained and certified in sphygmomanometry by the Shared Care (Shared Care Research and Education, Inc, Torrance, CA, USA) blood pressure certification programme according to the guidelines of the American Heart Association.10 In the field, height, weight, arm circumference, waist and hip circumference were measured in duplicate and the average used. Room temperature was recorded. Body mass index (BMI) was calculated as the body weight in kilograms divided by the square of the height in metres. Blood pressure was measured in the right arm in a seated position after having rested for 5 min timed by one observer. The cuff was chosen based on the arm circumference.11 Two trained observers listened simultaneously and took three readings. The subjects then stood upright and another pressure was taken at exactly 1 min. For the

Other measures Blood pressure is known to vary by the temperature of the examining room. As there was no heat in many homes we measured temperature with a mercury thermometer. The average room temperature was 16.8° ± 3.6°C. The coldest room was 8°C. Data analysis To facilitate analysis of the data we brought our own personal computer (Macintosh Powerbook 170) and printer with us. Key data was entered into a Filemaker Pro Database (Claris Corporation, USA) and analysis was performed by Statview programs (Abacus Concepts, Inc, USA) on site so that each day’s results could be reviewed and a preliminary report provided to the Ministry of Health upon our departure. Descriptive statistics and confidence intervals were calculated by standard methods. Factors influencing blood pressure were analysed by regression and analysis of variance (ANOVA). The determinates of blood pressure were analysed by univariate and multivariate correlation and linear regression modelling as well as ANOVA.

Results Population response to the survey We were welcomed into 85% homes for the survey and 91% of the people asked allowed us to take blood samples. Indeed we had been informed that it would be unlikely that anyone would give us blood at the home visit. Because there was a limited supply of vacutainer tubes or syringes to use to draw blood we obtained blood samples from 116 of 321 subjects. The fact that we examined twice as many women as men reflects the fact that most of our surveys were performed during the day. Blood pressure and it correlates Overall the blood pressure observers tended to have terminal digit bias for 0 with about 24% of readings ending in zero (expected would be 20%). Table 1 lists the mean and 95% confidence limits for the major terms included in the data set. At an average age of 55, the average BMI was 29 (obese ⬎28). Table 2 gives the blood pressure by age and gender. On the average systolic blood pressure increased about 10 mm Hg in each decade while diastolic blood


Table 1 Demographics of the sample Mean (95% Cl) Age (years) Height (cm) Weight (kg) BMI (kg/m2) Waist (cm) Hip (cm) Arm circumference (cm) Pulse (bpm) Blood pressure (mm Hg) Systolic seated Diastolic seated Systolic standing Diastolic standing Room temperature (°C)

more than two packs per day. Smoking was not associated with elevated blood pressure.

55 (54 –56) 163 (16.2–16.4) 78 (76–80) 29 (29–30) 94 (92–95) 112 (111–114) 32 (31–32) 79 (78–80)

Aspirin ingestion

146 (141–147) 84 (82–85) 140 (138–142) 84 (83–85) 16.8 (16.4 –17.2)

A history of diabetes was present in 11% (10/92) of males and 10% (22/229) of females. There was no difference in blood pressure between those with or without a history of diabetes.

Cl = confidence limits.

Daily aspirin ingestion plays a powerful role in preventing heart disease in men. Only one person surveyed (a woman) took aspirin regularly. Diabetes

Alcohol

pressure did not change. Univariate analysis (not shown) revealed correlations of systolic and diastolic blood pressure only with age and gender. In simple and stepwise regression analysis (Tables 3 and 4) of variance with age, gender, and education only age was significant (P ⬍ 0.0001). For neither systolic nor diastolic blood pressure was there a significant correlation with BMI, waist or hip circumference. The prevalence of high blood pressure (⭓140 or ⭓90 mm Hg) at the time of the visit was 58% (53/92) in men vs 56% (128/229) in women. Including those who had been previously told they had high blood pressure but were now normal increased the frequency of hypertensives to 73% in women (167/229) and 67.4% (62/92) in men. A total of 154 persons said they were taking some antihypertensive medication at the time of the survey. Of those on treatment only 25% (35/154) had a blood pressure of less than 140/90 mm Hg suggesting inadequate treatment regimens or non-compliance.

Alcohol intake was assessed by the number of grams of vodka, bottles of beer, glasses of wine and grams of cognac consumed per day and per weekend. The most common alcoholic beverage consumed was wine. Moderate drinkers consumed ⬍2 drinks per day while heavy drinkers consumed an average of ⭓2 drinks per day. In women 83% (190/229) were non-drinkers, 15% (34/229) were moderate and only 2% (4/229) were heavy drinkers. In men 46% (42/92) were non-drinkers, 42% (36/92) were moderate drinkers and 12% (11/92) were heavy drinkers. There was no relationship between alcohol intake and blood pressure in both sexes. Hyperlipidaemia Blood samples were available for analysis in 116 subjects. If one defines an elevated cholesterol as ⭓220, then 31% (36/116 tested) had a high cholesterol and 31% also had a low HDL cholesterol (⭐35). Room temperature

Smoking Smoking was assessed by the question, ‘do you smoke now?’ and ‘how many packets of cigarettes do you smoke per day?’ In men 60% (55/92) were current smokers while only 15% (34/229) of women smoked. Of those who smoked 33% (29/89) smoked less than one pack per day, 47% (42/89) smoked one to two packs per day and only 10% (9/89) smoked

There was no relationship between blood pressure and room temperature.

Discussion Our study demonstrated the feasibility of the rapid survey method to estimate cardiovascular risk factors that might account for the recent striking

Table 2 Mean ± s.d. and range of blood pressure by age and gender Age

Male

Female

n

mean ± s.d.

Range

n

Mean ± s.d.

Range

40– 49

SBP DBP

33

137 ± 25 85 ± 16

104 –196 60–132

58

132 ± 20 144 ± 11

103–187 62–111

50–59

SBP DBP

25

144 ± 21 87 ± 14

109–179 61–121

94

144 ± 28 85 ± 13

98–238 60–137

60–69

SBP DBP

34

160 ± 30 88 ± 16

102–212 60–124

97

151 ± 26 83 ± 13

98–239 61–118

n = number in each cell; SBP = systolic blood pressure; DBP = diastolic blood pressure.

245


246

Table 3 Simple regression systolic blood pressure with nine variables Variables Age Sex Smoking Car own Hx DM BMI TC HDL Temperature

r

n

F

P

0.322 0.29 0.068 0.006 0.054 0.105 0.153 0.005 0.023

317 321 226 309 314 311 115 115 317

36.326 2.736 1.047 0.011 0.906 3.461 2.711 0.003 0.171

0.0001 0.0991 0.3074 0.9153 0.342 0.0638 0.1024 0.955 0.6798

Hx DM = History of diabetes mellitus; TC = total cholesterol.

increase in cardiovascular disease in the eastern European countries. Data from the survey suggests that other areas planning to assess health risk factors rapidly and at a minimum cost can do so by using similar Public health implications The virtual absence of a health care system in Georgia, combined with the stress of living in a city in which the lights, heat, telephone, public transportation and roadways frequently do not work, as well as the stress of adapting to a major change in the political and economic climate likely play a large role in the health status of the population. The low rate of employment at the time of our survey, due to severe economic problems in the Republic of Georgia may have some effect on our results: (i) the stress of these circumstances may increase blood pressure; (ii) home surveys done during the day normally sample those not at work and this may account for higher number of women being surveyed than men. When the high frequency of high blood pressure and hypercholesterolaemia is combined with the high smoking rate in men and the absence of the use of aspirin to prevent myocardial infarction, it becomes easy to understand why the Republic of Georgia and other republics of the former Soviet Union lead the world in cardiovascular death and disability.6 As there are no other recent reports from this area and little reliable data on the prevalence of high blood pressure in the Republic of Georgia before the dissolution of the former Soviet Union we do not Table 4 Stepwise regression systolic blood pressure with nine variables Variables

Par. Corr

F to Enter:

Age Sex Smoking Car Hx DM BMI TC HDL Temperature

0.43 2.047 E-4

10.666 1.979E-6 1.047 0.085 3.272 0.746 1.338 0.07 0.097

−0.043 −0.258 0.126 0.168 −0.039 −0.046

Hx DM = History of diabetes mellitus; TC = total cholesterol.

know if this very high frequency of disease is new. Most persons who had high blood pressure, at least in this urban area, had been previously diagnosed. Thus new case finding may not be a major issue. Getting those who know they have high blood pressure to get it under control should be a major focus. Many patients were monitoring their own pressure. Most medications are available without a prescription at many street kiosk pharmacies. Most patients bought their medications themselves. Virtually no patients were taking diuretics or beta-blockers, the least expensive and effective form of therapy. The majority of patients took their medications only when they ‘felt’ like their blood pressure was high. This was in part due to the very high cost of antihypertensive medications being taken. Thus they were purchasing expensive medications, but were not getting a good cost/benefit effect because they were taking them sporadically. Source and quality control of drugs merit study. The good news is that high blood pressure is a cardiovascular risk factor that is easily detected and usually simply and effectively managed. However, it should be noted that even in an affluent society such as the United States, according to the most recent JNC-VI report only 27% of patients with hypertension have adequate control of their blood pressure. The benefits of controlling hypertension have been documented in many studies. A 60% reduction in the 10-year risk of mortality from cardiovascular diseases was shown in patients with hypertension who were treated compared to those who were not treated.12 Also, epidemiological evidence indicates that for a 6 mm Hg lowering of diastolic blood pressure there is a 35– 40% decrease in stroke mortality.13 The disease is easy and in expensive to diagnose and inexpensive to treat in the great majority of instances. For example, hydrochlorothiazide 25 mg can be purchased for less than 1 Cent US per tablet and based on experience in the US it is likely that this single drug would control perhaps 50% of all hypertensives. These data suggest that national public health programmes to detect and treat high blood pressure should be developed and implemented to bring about a rapid reversal of this epidemic. These programmes can be implemented with minimum investment in equipment and without the need for highly skilled medical personnel.

Intervention strategies Our survey’s findings of widespread, inadequately treated hypertension in Tbilisi, an urban area in the Republic of Georgia and related cardiovascular disease risk factors strongly supports the need for a population level comprehensive hypertension control programme. Targeting the ‘at risk’ populations in the Republic of Georgia (75% of the adult population between 40 and 65 years of age) a programme should offer systematic screening for hypertension and the identification of associated risk factors; conduct follow-up assessment of screening findings for diagnostic and disease severity classification pur-


poses; prescribe antihypertensive treatment and monitor compliance and control. Population level hypertension control programmes are preferentially conducted through the public health and primary care systems of a community. The Republic of Georgia’s public health services could be strengthened if resources were made available for the conduct of such a programme.

Fund, Suite 1106, 1800 N. Kent Street, Arlington, VA, 22209, USA. The help offered by participating physicians and nurses from the Institute of Clinical and Experimental Therapy of Georgia is highly appreciated. Special appreciation is given to the Minister of Health Republic of Georgia, A Jorbenadze, and Karen Lerner from Milwaukee International Health Center.

Study limitations

References

(1) Rapid survey methods lack the precision and reliability of the standard random survey methods. Nevertheless in conditions where standard random survey methods are difficult to conduct as in most of the former Soviet Union, these methods allows a rapid estimate of the disease burden of the population and provides public health and government agencies information useful for programme planning and subsequent public health intervention. (2) The persons living in Tbilise, in the Republic of Georgia probably represent a more highly educated group less likely to exercise and under more stress than those living in rural areas. For these reasons the prevalence of hypertension may be greater in this group of people. (3) The fact that our survey was mostly performed during the daytime might have resulted in fewer men than women being assessed, therefore the confidence of estimates in men is less precise.

1 Sans S, Kesteloot H, Kromhout D. The burden of cardiovascular disease mortality in Europe. Eur Heart J 1997; 18: 1231–1248. 2 Nissinen A, Bothig S, Granroth H, Lopez AD. Hypertension in developing countries. World Health Statistics Quarterly 1988; 41: 141–154. 3 Manton KG. The global impact of noncommunicable diseases: estimates and projections. World Health Statistics Quarterly 1988; 41: 255–266. 4 Korv J, Roose M, Kaasik AE. Changed incidence and case-fatality rates of first-ever stroke between 1970 and 1973 in Tartu, Estonia. Stroke 1996; 27: 199–203. 5 Brook RH et al. Does free care improve adult’s health? N Engl J Med 1983; 309: 1426–1434. 6 Ginter E. The epidemic of cardiovascular disease in Eastern Europe. N Engl J Med 1997; 336: 1915–1916. 7 Rothenberg RB, Lobanov A, Singh KB, Stroh G, Jr. Observations on the application of EPI cluster survey methods for estimating disease incidence. Bull of the WHO 1985; 63: 93–99. 8 Frerichs RR, Tar KT. Use of rapid survey methodology to determine immunization coverage in rural Burma. J Tropical Pediatrics 1988; 34: 125–130. 9 Wilson TW et al. Effects of socioeconomic status on blood pressure in the commonwealth of Dominica, the West Indies. Am J Hypertens 1995; 8: 47A. 10 Grim CM, Grim CE. A curriculum for the training and certification of blood pressure measurement for health care providers. Can J Cardiol 1995; 11 (Suppl H): 38H– 42H. 11 Perloff D, Grim CM, Flack J. Recommendations for human blood pressure determination by sphygmomanometry. Circulation 1993; 88(5ptl); 2460–2470. 12 Sytkowski PA, D’Agostino RB, Belanger AJ, Kannel WB. Secular trends in long-term sustained hypertension, long-term treatment, and cardiovascular mortality. Circulation 1996; 93: 697–703. 13 MacMohan S et al. Blood pressure, stroke, and coronary heart disease. Part I: Prolonged differences in blood pressure: prospective observational studies corrected for the regression dilutional bias. Lancet 1990; 335: 765–774.

Conclusion The rapid survey method proved to be feasible in this area of the former Soviet Union. The striking finding that 58% of the men and 56% of the women screened in this study have uncontrolled hypertension suggests that this is the major cause for the epidemic of cardiovascular disease in the Republic of Georgia. The relatively low cost and the ability to get reliable results using a rapid survey method in a matter of days suggests that other health care systems that need to assess risk factors for cardiovascular disease should consider using this method.

Acknowledgements This research project was supported by a preliminary grant from Civilian Research and Development

247