Control of hypertension in the population. Strategies in affluent and developing countries.

Control of hypertension in population. Strategies in affluent and developing countries. The control of hypertension encompasses primary prevention, early detection and adequate treatment of high blood pressure. Primary prevention involves action at the population level to reduce obesity, alcohol and salt consumption, and to increase physical activity. The management of hypertension involves diagnostic work-up, assessment of overall cardiovascular disease risk, non-pharmacological and pharmacological treatment. The majority of community control programmes emphasized detection and treatment, rather than primary prevention. There are limitations to pharmacological treatment of hypertension, as shown by various studies, where a significant proportion of hypertensives have not been controlled by the treatment applied. In addition, the blood pressure-cardiovascular risk relationship is continuous and progressive and, even within the conventionally defined "normotensive" range, complications occur with escape control. Developing countries will encounter the problem of prohibitive costs of care and drug treatment for hypertension. Therefore greater emphasis must be put on primary prevention in population control of hypertension.

Development of public policy and physical activity initiatives internationally.

Epidemiological, pathological, clinical, and experimental studies over the past 40 years convincingly show that physical inactivity and low physical fitness contribute substantially to the major chronic diseases prevalent in industrialised societies. Several industrialised countries around the world report increases in physical activity participation among adults in recent years, but the prevalence of inactivity remains high. These increases in voluntary exercise are at least partially offset by decreasing daily energy demands due to increased mechanisation at home, at work and during leisure-time. In developing countries, physical inactivity is becoming a prevalent lifestyle due to rapid social and economic changes. Clinical interventions and mass appeals to be more physically active are limited in effectiveness against the background of increasingly sedentary lifestyles. Exercise scientists and public health officials need to turn attention to public policy and legislative initiatives to restructure physical and social environments to encourage more physical activity and discourage sedentary habits.

Lessons from worldwide experience with hypertension control.

Control of hypertension encompasses primary prevention, early detection and adequate treatment of high blood pressure. Primary prevention involves action at the community level to reduce obesity, alcohol and salt consumption, and increase physical activity. Management of hypertension involves diagnostic work-up, assessment of overall CVD risk, nonpharmacological and pharmacological treatment. The concept of community control was introduced to WHO's cardiovascular programme in the late 1960s, with hypertension as a spearhead. Once it had been demonstrated that the community approach was feasible, activities were extended to other cardiovascular, and later to noncommunicable, diseases. Outcome and process evaluations were made. A decrease in mortality and morbidity from stroke and myocardial infarction was demonstrated in most studies. As a result of these programmes, hypertension awareness, treatment and control rates increased remarkably and mean blood pressure levels decreased. The WHO/WHL Hypertension Management Audit Project attempted more complex analyses in various European populations. The majority of community control programmes emphasized detection and treatment, rather than primary prevention. Therefore, despite a decline in age-adjusted average blood pressures in various populations, the incidence of hypertension did not follow this trend. The decline observed in average blood pressure was achieved mainly by widespread drug treatment. Since cardiovascular risk grows with increasing blood pressure continuously and progressively, events occurring in the "normotensive' blood pressure range escape control. Developing countries will encounter the problem of prohibitive costs of care and drug treatment for hypertension. Therefore greater emphasis must be put on primary prevention in community control programmes.

Review of community intervention studies on cardiovascular risk factors.

The concept of community intervention in the field of cardiovascular disease prevention was introduced in the late sixties and early seventies. The WHO European Collaborative Trial in the multifactorial prevention of coronary heart disease used communities (factories) in a traditional controlled trial. The intervention used in this trial was an extension of a medical care model with preventive elements. The first two major community intervention projects in CVD prevention--the North Karelia Project and the Stanford Heart Disease Prevention Programme--were the basis of further WHO and NHLBI coordinated projects. They have used community-based population-wide strategies including existing community leadership, social networks, mass campaigns and extensive direct education for the general population. In the evaluation of those projects quasi-experimental models are used because "perfect experiments" are not possible. Some projects have proven the feasibility of community intervention and its positive impact on lifestyles and cardiovascular risk factors in a whole population and that such a development is associated with reduced cardiovascular mortality rates.

Lifestyle for preventing cardiovascular disease.

The World Health Organization (WHO) Expert Committee recommends dietary changes together with the smoking-control programs for prevention of cardiovascular diseases in the population. Promoting habitual physical activity is an important part of the population strategy. The lifestyle changes proposed in the population strategy require professional education, community leader education, public education, mass media education, community organization, and environmental changes. Effective population prevention of cardiovascular diseases needs national commitment, policy, planning, and development.

The role of health promotion in prevention policy against cardiovascular diseases in Hungary.

The development of public health has been a high priority in recent years in Hungary. In spite of concentrated efforts to establish a more advanced health service, the health status of the population has not improved and trends in mortality and morbidity are still unfavourable. Risk factors from the environment and from health-damaging behaviour are generally accepted as the main causes of cardiac diseases, yet lay people still think that progress in therapy can compensate for the effects of an unhealthy, overstrained and self-exploiting way of life. We might have well-educated experts and well-equipped institutes but two in three victims of myocardial infarction do not even reach hospital. A reorientation of health policy to a more prevention-focused approach and joint activities of all administrative, economic and social sectors coordinated at government level are necessary to put health in a more favourable position in the pattern of values in our society. The medical and sociological research work and the community level prevention activities began in 1982 in the 17th district of Budapest. The data of 1,611 residents of the district aged 25-64 were analysed. From data on nutrition, leisure-time physical activity, obesity, blood pressure distribution, and smoking habits it was established that socially unfavourable conditions cause a higher risk of cardiovascular diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of stable high blood pressure in adolescents.

We studied the relative importance of the initial BP and associated factors in adolescents to predict stable high BP. Out of 17,634 children aged 12-13 yrs an upper group/the upper 5% of the distribution curves for both SBP and DBP/a lower group/10% random from the remainder/were yearly followed for 4 yrs/boys: 1680, girls: 1643/. About 2/3 of children remained at the same percentile point: less than 30% and greater than or equal to 70% of SBP and half of them of DBP distribution. Significant positive tracking correlations were found both for SBP and DBP between the initial BP and follow-up BP readings in the same individual. Stepwise regression analysis showed that the SBP taken at the fourth follow-up can be explained by 29% in boys, 24% in girls on the basis of screening SBP and by 47% in boys, 42% in girls on the basis of SBP measured at the four previous examinations. Using discriminant analysis, 6-9 variables out of 18 studied could correctly allocate adolescents with stable SBP or DBP/less than 70% or greater than or equal to 70% at least 3 examinations/. Our study shows the importance of initial BP and a number of factors associated with stable high BP.

Factors associated with stable high blood pressure in adolescents.

Our aim was to study the relative importance of the factors associated with stable high blood pressure (BP) in adolescents. Out of 17 634 children born in 1964 and screened in 1977, two samples, an upper group [the upper 5% of the distribution curves for both systolic (SBP) and diastolic (DBP) blood pressures] and a lower group (a 10% random sample from the remainder), were chosen for yearly follow-up (1680 boys and 1143 girls) from 1978 to 1981. A multiple logistic function was used to analyse the factors associated with stable high SBP and DBP (with at least three different measurements of BP at or above the 95th percentile). Different sets of variables were studied. Of the boys with stable high SBP, 55% were found in the upper quintile of risk distribution when Quetelet's index was taken into consideration, 63% when Quetelet's index + age + heart rate+sexual maturation, 67% when Quetelet's index + age + heart rate + serum uric acid and 74% when Quetelet's index + age + heart rate + cardiothoracic index + heart volume index were taken into consideration. Of the girls with a stable high SBP, 68% were found in the upper quintile of risk distribution when any of the following variables was added to Quetelet's index + age + heart rate: R and S waves, serum cholesterol or post-load blood sugar. Similar but smaller effects of associated factors on DBP were observed. Our study shows that Quetelet's index and heart rate are the most important factors associated with stable high BP in adolescents.

Blood pressure in childhood and adolescence. Results from an international collaborative study on juvenile hypertension.

A total of 17,130 children of both sexes born in 1964 and living in Hungary, USSR, GDR and Cuba were examined in 1977. The children were grouped in upper (U) and lower (L) blood pressure groups and 3,640 children were re-examined in 1978-1981. The parents' age, smoking habits, marital status, the children's order of birth, number of siblings, and proportion of twins did not differ between U and L. The prevalence of hypertension and diabetes in the medical history of the children, and the prevalence of hypertension and stroke and diabetes in the medical history of the parents were significantly higher in U than in L. Signs of left ventricular hypertrophy and systolic murmurs, the magnitude of R and S waves in the ECG, and mean values of cardiothoracic and heart volume indices were higher in U than in L. Children in U were sexually more developed, taller, more obese (greater Quetelet's index and skinfold thickness) and less active physically. Average values of blood sugar and serum uric acid were also higher in U than in L. No difference was found between the two groups in the proportion of smokers and in mean cholesterol values. These differences between U and L were strengthened in comparison of children who showed repeatedly low (below the 30th percentile) or high (at or above the 70th, 90th and 95th percentile) readings in the SBP and DBP distribution curves. Since we did not find important differences when we related various factors to blood pressure taken on one or two separate occasions we emphasize the importance of casual blood pressure measurement in childhood.

International collaborative study on juvenile hypertension. 1. Study procedures and screening data.

The study procedures and the results of blood pressure screening from 8 centres are reported. Data are also presented on age, sex, sexual maturity for girls, height, weight, Quetelet's index, smoking, and use of antihypertensive drugs for 92.1% of the 18 609 children born in 1964 in the 8 districts and surveyed in 1977. The girls who had reached sexual maturity had the highest means for blood pressure, height, weight, and Quetelet's index. The proportion of girls who had attained menarche differed geographically. Certain differences were found among the 8 centres in the variables measured, but when age-specific comparisons were made most of the differences in the variables disappeared. Nevertheless a lower systolic blood pressure and height and a higher pulse rate were observed in Havana, Cuba, than in the European cities. Using multivariate analysis, height, weight, pulse rate, age at survey, and sexual maturity together explained somewhat less than 20% and 10% of the variation of systolic and diastolic blood pressures, respectively. These screening data provide a baseline for a longitudinal study that will continue until 1982.