ABC | Volume 113, Nº3, September 2019

Original Article Gerage et al. Physical activity in PAD patients Arq Bras Cardiol. 2019; 113(3):410-416 of intermittent claudication according to the recommendations for physical activity practice, providing objective information regarding the time spent in sedentary behavior, light physical activity and MVPA. Moreover, we tested the association between adherence to physical activity recommendations and sociodemographic and clinical factors in Brazilian patients with symptomatic PAD. Methods Study design and ethical issues This descriptive study was approved by Local Ethics Committee. Prior to data collection, patients were informed about the methodological and logistic procedures required to participate in the study, as well as the risks and benefits, and signed a written informed consent form before participation. Participants The overall sample consisted of symptomatic PAD patients, recruited at a tertiary center specialized in vascular disease, between September 2015 and November 2017. The tertiary center is a specific unit designed to treat PAD patients with intermittent claudication symptoms. There, physicians instruct patients to: stop smoking, control their risk factors, and increase their physical activity levels. In the present study, no additional instructions were given, and patients were asked to keep their physical activity routine. To be included in the present study, patients should: have PAD (Fontaine Stage II), ankle brachial index (ABI) <0.90 in one or both legs and undergo the six-minute walking test (6MWT). Patients with non-compressible vessels, amputated limbs and/or ulcers, previous diagnosis of neurological or psychiatric disorders, or those classified as illiterate were excluded. Measurements Clinical data A standardized face-to-face interview was performed, including assessment of social and demographic information, co-morbid conditions (self-reported), and medications. Social and demographic variables included age and gender (male or female). Time of disease diagnosis was obtained through the question “ How long have you had the disease? ”. Data on smoking habits (ex- or current smoker, or non-smoker), obesity (bodymass index (BMI) ≥30 kg/m²), diabetes (doctor-diagnosed or hypoglycemic drugs), hypertension (systolic/diastolic blood pressure >140/90 mmHg or antihypertensive drug use), dyslipidemia (doctor‑diagnosed or hypolipidemic drug use), coronary heart disease, heart failure and history of cancer (self‑reported or analysis of medical records) were obtained. Disease severity PAD severity was obtained by calculating the ABI in accordance with the guidelines. 10 All measures were carried out by a single and trained evaluator, using vascular Doppler (Medmega DV160, Brazil) and aneroid sphygmomanometer. Walking capacity The 6MWT was performed on a 30-meter long corridor, following the previously described protocol. 11 Briefly, patients were instructed to complete as many laps as possible. Patients were encouraged to “walk at the usual pace for six‑minutes and cover as much ground as possible”. Patients were informed that they could rest, if necessary. At the end of each minute, patients received feedback on the elapsed time and standardized encouragement in the formof statements such as “you are doing well, keep it up” and “do your best". Total walking distance was defined as the maximum distance which the patient could walk during the test, with or without leg pain. In addition, the self-reported ambulatory ability was assessed using the Brazilian versions of Walking Impairment Questionnaire (WIQ) 12 and the Walking Estimated-Limitation Calculated by History (WELCH) questionnaire. 13 Objectively measured physical activity Physical activity was assessed using a GT3X+ triaxial accelerometer (Actigraph, Pensacola, FL, USA). Each participant was instructed to use the accelerometer for seven consecutive days, removing it only for sleeping, bathing or performing activities in the water. The device was attached to an elastic belt and attached to the right side of the hip. Data reduction was performed using the Actilife software, version 6.02 (Actigraph, Pensacola, FL, USA), with a 60Hz sample frequency and 60s epochs. Periods with consecutive values of zero for 60 min or longer were interpreted as “accelerometer not worn” and excluded from the analysis. Physical activity data were included only if the participant had accumulated a minimum of 10 hours/day of recording for at least four days, including one weekend day. The average of total time spent in each intensity of physical activity was calculated using the cutoff points specific for elderly individuals, 14 adapted by Buman et al., 15 considering sedentary time (SED) as 0 – 99 counts/min; low‑light physical activities as 100–1040 counts/min, high‑light physical activities as 1041-1951 counts/min and MVPA as ≥1952counts/minusingtheverticalaxis,andanalyzedinmin/day, adjusting for the time and number of days the device was worn. The total time spent in SED bouts and the time spent in bouts of at least high-light physical activities and MVPA were analyzed by the sum of minutes spent in SED, high-light physical activities and MVPA, respectively, in periods lasting ≥10 minutes. Additionally, we calculated the percentage of patients that met the current physical activity recommendations (≥ 150 min/week) considering MVPA bouts. Statistical analysis The sample size was calculated by estimating an effect size of 0.3 in the chi-square analysis, considering an alpha error of 5% and a power of 80%. The sample size required for the study was 143 participants. The data were stored and analyzed using the Statistical Package for the Social Sciences (SPSS, version 17.0, SPSS Inc, Chicago, IL). Descriptive analysis was performed to summarize the patients’ data using means, standard deviation or frequency distribution (absolute and relative), as appropriate. Binary logistic regression was used to test the crude and adjusted (age, time of the disease 411