IJCS | Volume 33, Nº2, March / April 2020

135 c) absence of any other chronic disease; d) not having performed physical exercise in the last six months. Subjects that did not adequately answer the quality-of-life questionnaire were excluded from the study. Data collection The data collection occurred betweenAugust 2015 and August 2016. The dependent variables of the study are the quality-of-life domains. Demographic data and clinical conditions were considered as independent variables. We evaluated the patients’ sex, age and educational level, as well as health history (time of hypertension and medications). Before all cardiovascular evaluations, the patients were instructed to a) have a light meal before arriving at the laboratory; b) avoid physical activities of moderate to vigorous intensity for at least 24h before the laboratory visit; and c) avoid smoking, caffeine and alcohol consumption for at least 12h. In the laboratory, the subjects initially remained in the supine position for a period of rest of 10 min to perform the measurements with a controlled temperature between 22 and 24ºC. Quality of life Quality of life was measured through the SF-36 questionnaire 27 after an individual interview with the hypertensive subjects by a trained researcher. For each of the SF-36 domains (functional capacity, physical aspects, pain, general health, vitality, social aspects, emotional aspects and mental health), the respective scores were calculated, which varied from0 to 100, where 0 corresponds to the worst health status and 100 to the best health status. Anthropometric measurements Body mass, height and waist circumference were obtained. Body mass was measured in a digital scale, Filizola brand, with 0,1 kg precision and height was determined in a stadiometer coupled to the scale with 0,1 cm precision. Waist circumference was obtained using the umbilical scar as reference. 28 The body mass index was calculated by dividing body mass by square height in meters. Muscle strength Muscle strength was measured through a digital hand dynamometer (CAMRY, United States) adjustable and calibrated with a 0 to 100 kg/f scale. The test was performed three times, for each arm, with a 1-minute interval between each try and the highest value found was considered the result. This procedure showed an intraclass correlation coefficient (test and retest with a 1-week interval) from 0,986 to 0,989. 29 Clinical blood pressure Clinical blood pressure was obtained in an Omron HEM 742 device. All the procedures followed the recommendations of the 7 th Brazilian Guidelines of Hypertension 30 and showed good reproducibility indicators. 31 The intraclass correlation coefficient for systolic blood pressure was 0,85 and, for diastolic blood pressure, 0,92. 31 Statistical analysis To analyze the factors associated with quality of life, we performed the crude and adjusted linear regression analysis. Initially, the crude analysis was performed to establish the variables included in the multiple models. Therefore, only the variables that showed p ≤ 0.30 were included. The significance level adopted and the criteria for the variable to remain in the model was p < 0.05. Multicollinearity analysis was performed to identify the existence of a strong correlation between two (or more) independent variables, which could affect the relationshipwith the dependent variable. Thus, Variance Inflation Factors (VIF) lower than five were assumedwith tolerance lower than 0.20. All analyses were performed in the Statistical Package for the Social Sciences (SPSS), version 20, and the data are presented as mean±standard deviation and relative frequency. Results Table 1 shows the general characteristics of the hypertensive patients included in the study. Tables 2 and 3 show the relationship between the demographic, clinical and physical fitness variables with the quality of life of hypertensives in the physical and emotional domains. Figure 1 shows the variables that presenteda statistically significant relationship. It was found that individualswith lower educational level, higher body mass index and lower muscle strength showed the worse quality of life in the functional capacity domain (p < 0.05 for all). Higher systolic blood pressure was related to higher values in the physical aspects domain (p < 0.05). Women presented Silva et al. Factors associated with quality of life Int J Cardiovasc Sci. 2020; 33(2):133-142 Original Article