Daily step counts in a US cohort with COPD

Abstract

Background Baseline values for daily step counts in US adults with COPD and knowledge of its accurate measurement, natural change over time, and independent relationships with measures of COPD severity are limited. Methods 127 persons with stable COPD wore the StepWatch Activity Monitor (SAM) for 14 days, and 102 of them wore it a median 3.9 months later. SAM counts were compared to manual counts in the clinic. We assessed change over time, the effect of season, and relationships with forced expiratory volume in one second (FEV1) % predicted, 6-minute walk test (6MWT) distance, the modified Medical Research Council (MMRC) dyspnea score, and the St. George’s Respiratory Questionnaire Total Score (SGRQ-TS). Results 98% of subjects were males, with mean age 71 ± 8 years and FEV1 1.48 ± 0.54 L (52 ± 19 % predicted). All 4 GOLD stages were represented, with the most subjects in GOLD II (44%) and GOLD III (37%). The SAM had > 90% accuracy in 99% of subjects. Average step count was 5,680 steps/day, which decreased with increasing GOLD stage (p=0.0046). Subjects walked 645 fewer steps/day at follow-up, which was partly explained by season of monitoring (p=0.013). In a multivariate model, FEV1 % predicted, 6MWT distance and MMRC score were weakly associated with daily step counts, while SGRQ-TS was not. Conclusions These findings will aid the design of future studies using daily step counts in COPD. Accurately measured, daily step counts decline over time partly due to season and capture unique information about COPD status.

An Internet-Mediated Pedometer-Based Program Improves Health-Related Quality-of-Life Domains and Daily Step Counts in COPD

“…3 However, people with COPD are signifi cantly less physically active than healthy people. 4,5 Decreased physical activity (PA) is associated with higher levels of systemic infl ammation and increased risk of acute exacerbations, hospital admissions, and death, independent of lung function in COPD. [6][7][8][9][10][11] Physical inactivity is a major contributor to skeletal muscle dysfunction in COPD.…”

Performance of a pedometer to measure physical activity in a U.S. cohort with chronic obstructive pulmonary disease

“…We studied participants with COPD recruited from the general pulmonary clinics at the Department of Veterans Affairs (VA) Boston Healthcare System from January 2009 through September 2011 and enrolled in an observational research study to characterize daily step count [5][6][7][21][22]. Eligible participants were over 40 yr of age and had a clinical diagnosis of COPD.…”

“…The SAM is a lightweight (38 g) microprocessor-controlled accelerometer designed for persons with mobility limitations [21,[37][38]. Attached to the ankle with a Velcro strap, the SAM responds to time, acceleration, and position to detect walking motion [21,[37][38].…”

“…Commercially available pedometers have gained popularity and may be a simple alternative to accelerometers [20]. Walking, measured by daily step count, is a PA that is relevant to patients, is easy to understand, and potentially can be modified [12,[21][22][23]. Daily step count reflects overall daily PA [24], can be a surrogate for PA level [25], and relates to COPD outcomes of exacerbations and hospitalizations regardless of intensity [7][8][9][10].…”

Evaluation of physical activity in patients with chronic obstructive pulmonary disease: recommendations of European Respiratory Society

“…При сильных жаре, холоде и / или вы сокой концентрации пыли или других поллютан тов в воздухе могут усиливаться симптомы ХОБЛ, бронхоконстрикция, провоцироваться обострения ХОБЛ [104][105][106], препятствуя ФА [107,108]. Также имеются сообщения и о сезонных колебаниях по вседневной ФА [93,[109][110][111] с тенденцией к ее сни жению в периоды с более низкой температурой воз духа. Большая высота над уровнем моря также может…”