The swallowing profile of healthy aging adults: Comparing noninvasive swallow tests to videofluoroscopic measures of safety and efficiency

Purpose: It has been widely reported that a proportion of healthy, community-dwelling seniors will develop dysphagia in the absence of a known neurological, neuromuscular, or structural cause. Our objective was to test whether various feasible, noninvasive measures of swallowing could differentiate safe versus unsafe and efficient versus inefficient swallowing on videofluoroscopy (VF) in a sample of healthy seniors. Method: VFs from 44 (21 male, 23 female) healthy community-dwelling seniors (> 65 years old) were compared with a series of feasible, noninvasive swallowing metrics: maximal tongue strength (anterior and posterior), hand grip strength, pharyngeal volume, age, body mass index, 3-oz water swallow challenge, the 10-item Eating Assessment Tool questionnaire, and the Frailty Index. The VF protocol included 9 liquid barium boluses (3 × 5 ml thin, 3 × 20 ml thin, and 3 × 5 ml nectar). Each swallow was rated (randomized and blind) for safety using the Penetration– Aspiration Scale score and for efficiency using the Normalized Residue Ratio Scale (NRRS). Participants were deemed “unsafe” if they had any single Penetration– Aspiration Scale scores ≥ 3 and “inefficient” if they had any NRRS valleculae score > 0.082 or NRRS pyriform sinus score > 0.067. Univariate analyses of variance were run for each continuous swallowing measure by swallowing safety and swallowing efficiency status. Pearson’s chi-square analyses were used to compare binary outcomes by swallow safety and efficiency status. Bonferroni corrections were applied to control for multiple comparisons. Results: None of the swallowing measures significantly differentiated safe from unsafe swallows. Although several variables trended to distinguishing efficient from inefficient swallows (age, 10-item Eating Assessment Tool, 3-oz water swallow challenge), only one variable, pharyngeal volume, was significantly different between efficient and inefficient swallows (p =.002). Conclusion: Our findings support the notion that larger pharyngeal volumes (measured using acoustic pharyngometry) are associated with worse swallowing efficiency, a finding we attribute to atrophy of the pharyngeal musculature in healthy aging.