Associations Of Total Daily Steps And Aerobic Steps With Respiratory Impairment In Older Adults

PURPOSE: There are limited data on the association between daily steps and respiratory impairment (RI) in older adults. This study examined the associations of total daily and aerobic steps (continuous stepping at ≥60 steps/min for ≥10 minutes) with the prevalence of RI in older adults. METHODS: This cross-sectional study included 410 adults aged ≥65 years (58% women; mean age 74) with valid spirometry. Average total daily steps and aerobic steps were assessed by a tri-axial accelerometer-based pedometer for 7 days. RI was determined by spirometry and defined as any forced expiratory volume ≤ lower limit of normal for a person’s age, sex, and height using the Global Lung Function Initiative reference equations. Participants were categorized into tertiles of total daily steps (low, middle, and high) and three categories of aerobic steps: no aerobic steps, low, and high (lower and upper 50% of aerobic steps, respectively). We used logistic regression to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of RI across total daily and aerobic steps categories. We adjusted for age, sex, education, body mass index, smoking status, heavy alcohol consumption, arthritis, diabetes, hypertension, and cardiovascular disease. RESULTS: There were 46 cases (11%) of RI. Mean (SD) total daily steps for the entire sample was 5,862 (3,425), and mean (SD) aerobic steps were 2,672 (2,611) among 301 participants [73%] with >0 aerobic steps. Compared to the lower third of total daily steps, the ORs (95% CIs) of RI were 0.54 (0.25-1.19) and 0.39 (0.17-0.94) among the middle and high total daily step tertiles, respectively, after adjusting for confounders (p for trend <0.05). Compared to those with no aerobic steps (27% of sample), the ORs (95% CIs) of RI were 0.65 (0.30-1.40) and 0.34 (0.15-0.80) among those in the low and high aerobic steps, respectively, after adjusting for confounders (p for trend <0.05). CONCLUSIONS: These data suggest that high total daily steps and high aerobic steps are significantly associated with a lower prevalence of RI in older adults. However, due to our cross-sectional design, future prospective studies are needed to confirm the temporality of these findings.