Are subjective measures the answer to assess physical inactivity on a daily basis in patients with resistant hypertension?

Abstract

TO THE EDITOR: Physical activity (PA) has indisputable benefits to prevent, control, and treat hypertension. An inverse dose–response relationship between PA and incident hypertension has been reported among adults with normal blood pressure and a reduction of the risk of cardiovascular disease progression has been found with increased PA among adults with hypertension [1]. Although vast research and guidelines strongly recommend PA for the prevention and management of hypertension, population levels of PA have remained flat [2]. Estimates indicate that ~25–30% of the global population fails to meet physical PA guidelines [3]. Physical inactivity and sedentary behavior are a persistent public health problem and a major modifiable risk factor worldwide for cardiovascular disease (CVD) and all-cause mortality. The 2018 European hypertension guidelines [4] recommend lifestyle advice, including PA, as a first line treatment for patients with hypertension. Nonetheless, the appropriate and regular assessment of PA is determinant for an effective promotion of active lifestyles. Indeed, the American Heart Association recommends that PA assessment should be a priority in all visits to health settings [2]. Two typically suggested methods for capturing PA levels are self-reports and wearable devices such as accelerometers [2]. Accelerometers allow an objective and continuous measure of PA [5]. However, data collection is very dependent on compliance by the participant to wear the device [5]. Also, the duration of the protocol, equipment cost, and necessary time to download, process and treat all the PA data, make the objective assessment of PA impractical on a daily basis in a clinical practice setting. Self-reported measures, such as questionnaires, are generally feasible and can assess all types of PA, including stationary activities and water activities [6]. They can also cover long time frames. However, PA questionnaires may also overor underestimate participants’ PA [5, 6]. Some systematic reviews have reported the agreement between accelerometers and selfreported measures and have found weak to moderate correlations in healthy adult populations [5, 6]. The Brief Physical Activity Assessment Tool (BPAAT) is a short, 2-question tool, originally developed to enable family doctors to identify insufficiently active adults [7]. Given the scarcity of consultation time, a fast and easy to apply tool is a key factor for daily use. The BPAAT classification categories showed good construct validity (0.40 ≤ Kappa ≤ 0.64 [7–9]; sensitivity= 0.75 95%CI: 0.70–0.79, and specificity= 0.74 95%CI: 0.71–0.77 [9]) in patients with various health conditions, when compared to accelerometry and to other PA questionnaires [9, 10]. Nonetheless, to the best of our knowledge, no data is yet available for participants with resistant hypertension. Hence, this study aims to determine if the BPAAT is a valid instrument to detect inactive patients with resistant hypertension. In this cross-sectional study, sixty patients, aged between 40 and 75 years, with resistant hypertension (according to the American Heart Association scientific statement [11]) were prospectively recruited from the hypertension outpatient clinic in two hospitals in Portugal. Exclusion criteria were secondary hypertension, evidence of target organ damage, heart failure, acute cardiovascular event in the previous year, peripheral artery disease, renal failure, chronic obstructive pulmonary disease, change of antihypertensive medication in the past 3 months before inclusion in the study, limitations to PA and regular engagement in exercise training. The hospital ethics committee approved the study (N/Ref. 073619, 21/ 09/2016). The participants provided written informed consent, and all the procedures were conducted according to the Declaration of Helsinki. Outcome measures included clinical data, blood pressure and daily PA (questionnaire and accelerometry). PA was objectively measured over a 7-day period with an accelerometer (Actigraph GT1M; ActiGraphLLC, Pensacola, USA) positioned on the right hip during the day; sedentary time, and time spent at light, moderate and vigorous PA was computed with the Actilife software (ActiGraphLLC, Pensacola, USA), using the criteria developed by Freedson et al. [12]. Data were considered valid with ≥5 days recorded and ≥10 wear-time hours per day. Self-reported PA was assessed by the BPAAT (Fig. 1A) [7]. This questionnaire consists of two questions, assessing the frequency of 20-min and 30-min of vigorous and moderate PA (including walking), respectively in a “usual” week. Scoring combines the results of the questions and patients are classified as “sufficiently active” if they report ≥3 days performing at least 20 min of vigorous PA, ≥5 days performing