Arterial Hypertension and other risk factors associated with cardiovascular diseases among adults

OBJECTIVE: to identify the prevalence of arterial hypertension and its association with cardiovascular risk factors among adults. METHOD: cross-sectional, population-based, descriptive study conducted with 408 adult individuals. Data were collected through a questionnaire and measurements of weight, height and waist circumference. Person's Chi-square and multiple logistic regression were used in the data analysis. RESULTS: 23.03% of the individuals reported hypertension with a higher prevalence among women. Odds Ratio indicated that smoking, body mass index, waist circumference, diabetes mellitus and dyslipidemia were positively associated with arterial hypertension. CONCLUSION: high self-reported hypertension and its association with other cardiovascular risk factors such as diabetes, obesity and dyslipidemia show the need for specific nursing interventions and the implementation of protocols focused on minimizing complications arising from hypertension, as well as to prevent the emergence of other cardiovascular diseases.


Introduction
Cardiovascular diseases (CVD) are currently the leading cause of deaths worldwide. These diseases accounted for more than 17 million deaths in 2008, three million of which occurred before the age of 60. Most could have been avoided. The World Health Organization estimates that around 23.6 million people will die of cardiovascular diseases in 2030 (1) .
Among the CVD, systemic arterial hypertension (SAH) is an important risk factor for cardiac and cerebrovascular complications (1) . It is considered a public health problem around the world. In 2000, the prevalence of SAH in the world population was 25% and the estimate for 2025 is 29% (2) . The prevalence of hypertension verified in studies conducted in Brazil ranged from 22.3% to 43.9%, with an average of 32.5% (3)(4) .
In virtually all nations, the prevention and control of SAH has important implications and the use of new strategies and approaches to identify with greater accuracy the individuals at risk benefit both the individuals with hypertension and society (5) . Because SAH is a chronic disease, however, it requires monitoring and treatment for life, involving both pharmacological and non-pharmacological measures (6) . To define the sample size, a prevalence of 50% of cardiovascular risk factors was considered together with an estimated error of 5% and reliability and precision of the sample is set at 95%, adding 10% for potential losses, resulting in 415 individuals. A total of 408 individuals aged between 20 and 59 years old, both sexes, participated in this study, while only valid data were considered for some variables.
The individuals were selected in a systematic random sample in which the streets, blocks and households were randomly drawn. Systematically and with a predefined interval, one individual living in the fourth household on the right side of the street was addressed. When no individuals within the selected age group lived in the house, we moved to the subsequent house in which only one individual was interviewed.
Data were collected from September 2010 to February 2011 through interviews and measurements of weight, height, and waist circumference (WC).
The instrument used for the interviews is part of an instrument adopted in a household survey addressing behavioral risk and morbidity of non-communicable diseases (7) . This questionnaire was previously tested SAH was considered for self-reported cases. Sociodemographic variables were the predictor variables of sex, age, marital status, and economic status, which was used to estimate the purchasing power of individuals and families (8) , who were grouped into: A1-A2, B1-B2, were considered to be inactive (9) . Diet was considered inadequate when the intake of fruits and/or vegetables and/or legumes was below five times a week (7) .
Body mass (in kilograms) was assessed using a portable anthropometric digital scale (150 kilograms maximum capacity and accuracy to 0.1 kilograms). An anthropometric tape was used to measure height (in meters). The individual's weight (in kilograms) divided by the squared height (in meters) was used to compute body mass index (BMI). The values were classified into: normal weight, when BMI >18.50 to 24.99 kg/m 2 ; overweight, when BMI ≥25 to 29.99 kg/m 2 ; and obese when BMI ≥30 kg/m 2 (9) . Abdominal obesity (excessive fat in the abdominal region) was determined when WC was above 102 cm for men and 88 cm for women (9) , measured at the midpoint between the costal margin and the iliac crest.

Discussion
The prevalence of SAH identified in this study was similar to that found in a study conducted in Pelotas, in the Southern region of Brazil (10) , and less than that observed in other Brazilian studies (4,11) and in studies conducted in the United States (12) . It is, however, greater than the prevalence identified in a more comprehensive study conducted in all the Brazilian capitals using selfreported information, which ranged from 14.7% (in Palmas) to 29.5% (Rio de Janeiro), with an average of 21.6% (13) . Hypertension was more frequently found among women, which corroborates the findings of other studies conducted with adult (4,(13)(14) and elderly individuals (4,(13)(14)(15) , though no statistically significant association was observed between sexes, confirming the results reported for Nobres, MT (4) and Firminópolis, GO, Brazil (11) .
This study also shows that the prevalence of hypertension increased with age, as reported by another study (16) , while individuals aged between 50 and 59 years old were 5.35 times more likely to present hypertension that individuals aged from 20 to 29 years old.
The variable exercise was not significantly associated with SAH, similar to the results found in one study conducted in Sinop, MT, Brazil, though the authors report that longitudinal studies are more appropriate to assess the effects of exercise on blood pressure (17) .
Regular exercise is a non-pharmacological measure recommended for the treatment of SAH, not only for its beneficial effect on blood pressure, but also to reduce other cardiovascular risk factors (18) .
Likewise, diet was not significantly associated with SAH. Such a result may be associated with the type of methodology employed to assess diet. Only the intake of vegetables, greens and fruits was considered, though the intake of salt and fat is also an important indicator of SAH. Appropriate food intake and the importance of a balanced diet should be stressed and recommended by health professionals with hypertensive patients (14) for its benefit of reducing cardiovascular risks.
In regard to smoking, former smokers presented the highest prevalence of hypertension, which corroborates the findings of other studies (10)(11) . This study also shows that former smokers and smokers presented significant association with SAH. One study conducted in Japan reports that smoking and SAH are the two main factors of mortality due to non-communicable diseases among adults (19) .
This study found significant association in regard to BMI, similar to the findings of other studies that also show a significant association with SAH (20)(21) . The obese individuals in this study were 2.35 times more likely to present hypertension compared to those within a weight range considered to be normal. WC also was an important anthropometric indicator, showing significant association with SAH, corroborating the results reported by a study addressing Chinese individuals (22) .
The prevalence of obesity has grown around the world and is considered an important risk factor for SAH. One study conducted in the northern part of China reports that increased BMI is strongly linked to hypertension; however, it only represents the total body weight and is unable to distinguish between excess fat tissue and a large amount of muscle mass (22) .
This study shows that individuals with DM are almost three times more likely to develop SAH than individuals without DM. One epidemiological study indicates that DM and hypertension are usually associated conditions (16) , confirming data found in this study, that is, that 50% of the individuals with DM also have hypertension. Self- associated with hypertension account for more than 50% of the risk attributed to coronary disease, so that therapeutic measures can reduce morbidity and mortality in diverse conditions of risk (23) . We also observed that most individuals with SAH presented more than three cardiovascular risk factors. Additionally, an increase in the number of associated factors was maintained with aging.
This study's limitations are related to three aspects: a) the fact that the participants were selected according to which individuals were present at home at the time of the visit, which resulted in a sample predominantly composed of women; b) SAH was selfreported; and c) the fact that leisure activities were not considered exercise, which led to a high prevalence of sedentariness. In regard to the last two questions, however, it is important to note that self-reported hypertension is considered appropriate to estimating the prevalence of various health conditions in populations and has also been used by the Ministry of Health in the VIGITEL (13) survey. Also, in regard to exercise, we note that an evaluation of a population as being sedentary should generally be viewed with caution, especially when making journeys, domestic and work activities are not taken into account (24) .

Conclusion
The results show that the prevalence of selfreported SAH was higher among women aged between 50 and 59 years old. In regard to risk factors, the most prevalent were DM, obesity, and dyslipidemias, while these are considered important risk factors for arterial hypertension.
The identification of SAH and its association with