IJCS | Volume 31, Nº6, November / December 2018

595 Rissardi et al. Effects of physical inactivity on blood glucose Int J Cardiovasc Sci. 2018;31(6)594-602 Original Article risk of disease. The health benefits of moderate or vigorous intensity physical activity include lower risk of developing or dying from chronic diseases, such as type 2 diabetes mellitus (T2DM), hypertension (HT), coronary artery disease (CAD), stroke, kidney disease and some types of cancers. 4-9 Admittedly, physical activity improves lipid profiles and glycemic control; it reduces the risk of developing insulin resistance and glucose intolerance, and it plays an important role in the treatment of hypertension. The prevalence of physical inactivity in the population is variable, depending of the assessed world region and of age. 10,11 Generally, older adults are more physically inactive than younger adults, showing about 55% versus 23% of inactivity, respectively. 10 About one in every three American adults (30.4%) do not engage in physical activity. 11 However, in Brazil, there is a lack of consistent data on the prevalence of physical inactivity and its effect on clinical andmetabolic parameters in the general population at different age groups. Therefore, this study aimed to evaluate the prevalence of physical inactivity in a Brazilian urban adult population stratified by age groups, correlating it to demographic, anthropometric and biochemical parameters. Materials and methods Study design setting, and participants This study was approved by the Research Ethics Committee of the Medical School (057/2004). All participants were informed about the purpose of the study and provided informed consent before starting it. This was a cross-sectional, population-based study with simple random sampling and stratified by age groups, which was carried out from March 2004 to November 2005 in the urban adult population (≥ 18 years) of São José do Rio Preto, São Paulo, Brazil. 12 The sampling was stratified according to age groups, based on the data provided by the Brazilian Institute of Geography and Statistics ( Instituto Brasileiro de Geografia e Estatística , IBGE). At the time the survey, the city had a population of 370,000 inhabitants, predominantly white (82.8%) and with a balanced distribution between men (48.4%) and women (51.6%). 13 The groups were divided by age ranges: 18-39, 40-49, 50-59, 60-69 and ≥ 70 years. The parameters used to calculate the stratum sample sizes were number of inhabitants, expected prevalence of hypertension for each age group, a confidence interval of 95% and a maximum error of 3%. 14 The city was divided into census sections according to IBGE. In each sector, the number of individuals was determined according to the proportionality of the population. For each region, streets, homes, an adult living for more than six months in a house, who met the inclusion criteria, was randomly chosen. After the visit to the first residence, houses located on alternating sides of the street, after skipping two households, were visited. If the selected individual did not agree to participate, the next-door neighbor was randomly chosen. Exclusion criteria included pregnancy, severe degenerative diseases, incapacitating mental disorders, severe psychiatric diseases or mental disability and bedridden patients. 12 Interviewers were previously trained and monitored by a field coordinator. The participants answered a questionnaire that included their personal data, income and assets, in order to assess their socioeconomic status, formal education (number of years of schooling), personal and familymedical history, lifestyle, awareness of hypertension and diabetes medication being used. After that, body mass index (BMI), pulse rate and blood pressure (BP) were assessed. Data collection The BPmeasurement technique was that standardized by the VII Joint National Committee: 15 1) measurements were taken with a recently calibrated aneroid sphygmomanometer (Welch Allyn / Tycos) known to be accurate; 2) the cuff was placed so that the lower edge was 3 cm above the elbow crease and the bladder was centered over the brachial artery; 3) a standard, a large, and a small bladder were available for thicker and thinner arms, respectively; 4) the arm was bare and supported, with the blood pressure cuff positioned at the heart level 6) phase I and V (disappearance) Korotkoff sounds were used to identify systolic and diastolic BP, respectively; 7) the pressure was rapidly increased to 30 mmHg above the level at which the radial pulse was extinguished; 8) a cuff deflation rate of 2 mmHg per beat was used; 9) a minimum of 1-minute intervals were recommended between readings to prevent venous congestion; 10) BP was measured in both arms to detect possible differences due to peripheral vascular disease; in this case, the higher value was taken. Arterial hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg or with the use of antihypertensivemedications. For individuals with