Freitas et al OriginalArq Bras Article Cardiol Arterial hypertension in Catanduva 2001; 77: 16-21. Prevalence of Hypertension in the Urban Population of Catanduva, in the State of São Paulo, Brazil Olavo de Carvalho Freitas, Fabiano Resende de Carvalho, Juliana Marques Neves, Paula Karine Veludo, Ricardo Silva Parreira, Rodrigo Marafiotti Gonçalves, Simone Arenales de Lima, Reinaldo Bulgarelli Bestetti Catanduva, SP - Brazil Objective - To study the prevalence of systemic hyper- Several studies on prevalence of systemic hypertensi- tension and its control in the population of Catanduva, in on exist in the international medical literature 1-7. In Brazil, the state of São Paulo, Brazil. these values have ranged from 16.1% to 35.1% 8-16, depen- ding on the ethnic and social groups studied and on the pa- Methods - We carried out a randomized cross-sectio- rameters proposed as the defined limits of hypertension. nal population-based study of the urban population of Ca- In Brazil, some studies assess the association between tanduva with individuals above 18 years of age (688 indivi- systemic hypertension and demographic characteristics, duals accounting for 0.9% of the referred population). We such as age bracket, ethnic group, socioeconomic level, interviewed study participants to analyze the major qualita- smoking, alcohol consumption, salt ingestion, stress, dia- tive and quantitative variables that could influence the hy- betes, and obesity 8-16. However, little attention has focused pertensive scenario and the risk for systemic hypertension. on the control of antihypertensive treatment, which ac- Blood pressure was measured through the indirect method counts for therapeutical failure in more than 60% of the ca- according to the III Consenso Brasileiro de Hipertensão (III ses 13,17-19. Brazilian Consensus on Hypertension), which established In the Northwestern region of the state of São Paulo ≥ blood pressure levels 140/90 mm Hg as hypertensive. there are municipalities with a high socioeconomic level, such as Catanduva, and their economy are based on the Results - The prevalence of systemic hypertension was citric and sugar cane agroindustry and also on the tertiary higher in individuals with: (1) history of hypertension sector industry. Therefore, some of these municipalities (p<0.0001); (2) diabetes mellitus (p=0.05); (3) body mass have a quality of life similar to that observed in developed index (B. M. I) ≥ 25 kg/m² (p<0.001); (4) low educational level (p<0.0001); (5) familial income ranging from 1 to 5 minimum countries. Our study aims to assess the prevalence of syste- wages (p<0.05); (6) unmarried status (divorced/separated mic hypertension associated with some of the above-cited and widow(er)s) (p<0.0001). Of the interviewed individuals, factors in Catanduva. The total population estimated for the 27.6% (p=0.05) had blood pressure levels under control. city in 1998 was 103,889 inhabitants, 77,598 of whom were above 18 years of age. The prevalence of the male sex was Conclusion - Our study showed that the prevalence observed until the age of 50 years, according to the IBGE of systemic hypertension was 31.5%, and that 27.6% of the (Brazilian Institute of Geography and Statistics). individuals interviewed had blood pressure levels under control at the time of the interview. Methods Key words - hypertension, antihypertensive treatment, An analytical cross-sectional population-based study epidemiological study of hypertension with randomized sampling20 was carried out. The population analyzed comprised 688 essentially urban individuals (0.9% Faculdade de Medicina de Catanduva - FAMECA of the entire population) with ages above 18 years (74.7% of Mailing address: Olavo de Carvalho Freitas – FAMECA - Depto. de Ciências the entire population), who lived in the municipality of Ca- Fisiológicas – Disciplina de Fisiologia – Av. São Vicente de Paula, 1455 – 15800-000 tanduva, and whose origin was not important, according to – Catanduva, SP, Brazil – E-mail: [email protected] (English version by Stela Maris C. e Gandour) data of the 1996 census and the IBGE’s forecast for 1998. Of the 688 individuals interviewed, 286 were males and 402 Arq Bras Cardiol, volume 77 (nº 1), 16-21, 2001 16 Arq Bras Cardiol Freitas et al 2001; 77: 16-21. Arterial hypertension in Catanduva were females. The relative disproportion between males and practice of physical exercises 3 or more times a week for a mi- females was mainly due to the fact that more men than wo- nimum period of 45 minutes each time 18,21,22. All intervie- men are in the workforce and therefore men were not readily wees were asked about the above-cited items, in the that se- available to interview. To minimize this effect, the interviews quence. They received no questionnaire to fill out. were performed early in the morning to include men before After one medical student administered the question- they had to go to work. naire, the other medical student measured the blood pressu- To avoid sampling errors, the city was divided into 40 re level through the indirect method using an aneroid sectors, in which the number of dwellings and the social sphygmomanometer, which is less accurate than the mercu- groups contained did not matter. These sectors were selec- ry one, but more appropriate for field research because it is ted, and the study began with the first selected sector, and easier to handle and is less often rejected by the intervie- so on. In each sector, 3 dwellings per block were randomly wees 21,23. Before blood pressure measurement, the inter- chosen. No dwelling was excluded, not even those without viewee rested for 5 minutes in a calm environment with a sewage or electricity. If the inhabitants of the selected dwel- pleasant temperature, remaining seated on a chair with 1 of ling could not participate or if the dwelling was empty, the the arms resting on a table, at heart level. The brachial artery nearest dwelling was then chosen to meet the criterion esta- of the right arm was located by palpation. The cuff was firm- blished. ly placed 2 to 3 cm above the cubital fossa over the brachial The research team comprised 2 teachers (cardiolo- artery, centralizing the rubber bag above it. Korotkoff pha- gists), 6 medical students (interviewers), and 1software ses determined systolic and diastolic pressures as follows: specialist. The medical students were properly trained and phase I determined systolic pressure, and phase V determi- oriented to administer the questionnaires and to measure ned diastolic pressure. After 3 minutes, a new measurement the anthropometric parameters. The interviewers wore bad- of blood pressure was performed. The mean of both measu- ges of the Faculdade de Medicina de Catanduva to facilitate rements was obtained18. At the end, height was measured contact with the population and data collection 17. with a tape measure, and the interviewee was weighed for According to the III Brazilian Consensus on Hyper- calculating the body mass index. tension of 1998 18, systemic hypertension is defined as sys- For measuring blood pressure, the interviewee should tolic pressure >140mmHg and diastolic pressure >90mmHg not have performed the following activities in the 30 minu- (for individuals older than 18 years) 19. These criteria were tes prior to the interview: practiced physical exercises, adopted by the interviewers. drunk alcoholic beverages or coffee, ingested food, and The interview had a mean duration of 30 minutes, be- smoked 17-21. If the interviewer noticed any emotional ing performed from 6 to 10 a.m.19-23 daily from February 2 to change in the interviewee, the examination was postponed. April 4, 1998. The team was distributed in 3 pairs of intervie- After the assessment, the medical student provided a bro- wers, each pair comprising individuals of both sexes. The chure with information on systemic hypertension preven- pairs of interviewers were changed and the criteria of the tion and its predisposing factors to the interviewee. In addi- interview were reassessed weekly. tion, every hypertensive interviewee received recommen- After explaining to the interviewee the objectives and dations for more effective compliance with the antihyper- procedures of the study, 1 of the interviewers collected the tensive treatment 27-30. The individual who ignored his hy- personal data and, then, the other interviewer measured the pertensive condition was informed of his condition and ad- anthropometric data and the blood pressure level. The in- vised to get a more comprehensive assessment at the medi- terview comprised assessment of qualitative and quanti- cal service of the medical school of Catanduva 17. The ad- tative variables, such as age, sex, race, profession, daily dress of the hypertensive individual was recorded for futu- work load, marital status, educational level, familial income, re reassessments. use of medication that could positively influence hyperten- Aneroid sphygmomanometers of a single brand were sion (tricyclic antidepressants, monoamine oxidase inhibi- used, and they were properly calibrated every 15 days. Ste- tors, oral contraceptives), as well as antihypertensive drugs thoscopes, scales, and measuring tapes were also of a sin- and their use, regular or not. The following parameters were gle brand to avoid technical deviations in values because also assessed: dietary habits (amount of meat, number of of the material used 23. eggs, number of milk liters ingested per day or weekly), salt Software in the Delphi language for Windows was de- ingestion (quantification was based on the presence of the veloped for analyzing, formulating, and computing the salt container on the table, as no salt quantification in grams results. was performed because of the difficulty that this would im- Fisher exact test was used for comparing the proporti- ply), smoking (number of cigarettes smoked daily), ethanol in- on of noncontinuous variables between 2 groups. The sig- gestion (if higher than 30mL per day), number of annual me- nificance level adopted was lower than or equal to 0.05.