Pharyngeal functional reserve (Jones & Colletti, 2021)

Purpose: Functional reserve represents the difference between an individual’s ability to produce a maximum output function and the ability to perform a functional task. Several studies have documented an age-related decrease in functional reserve with oral tongue pressure generation. Whether this pattern is seen in pharyngeal swallowing pressures is unknown. The aim of this study was to investigate pharyngeal functional reserve using high-resolution manometry during normal-effort and effortful swallows.

Method: Pharyngeal high-resolution manometry was performed on 38 younger healthy individuals (≤ 40 years) and 18 older healthy individuals (≥ 60 years) during normal-effort and effortful water swallows. Pressure metrics included maximum pressure in the velopharynx, tongue base, and hypopharynx, as well as pharyngeal contractile integral and minimum pressure in the upper esophageal sphincter (UES). Repeated-measures analysis of variance was used to determine the effects of swallow task, age, and pharyngeal region on pressure generation.

Results: Maximum pharyngeal pressures and pharyngeal contractile integral were significantly increased during the effortful swallows compared to normal-effort swallows (p < .001), but there were no interactions between task and age in pharyngeal pressures. In the UES, minimum pressures were significantly elevated in older individuals during effortful swallows compared to normal-effort swallows (p = .007) but did not follow a pattern consistent with reduced functional reserve.

Conclusions: Healthy individuals increase pharyngeal driving pressures during effortful swallows, without an age-related reduction in the magnitude of pressure increase. Thus, this study did not find evidence for an age-related reduction in pharyngeal functional reserve. The preserved ability to increase pharyngeal pressures during effortful swallowing in aging may support the use of behavioral swallowing interventions in older individuals without neuromuscular conditions.

Supplemental Material S1. Descriptive statistics for pharyngeal swallowing pressures in younger and older participants during normal effort and effortful swallows.

Supplemental Material S2. Comparative statistics for repeated-measures ANOVA evaluating impact of task, age, and pharyngeal region on pharyngeal maximum pressures.

Supplemental Material S3. Comparative statistics for repeated-measures ANOVA evaluating impact of task and age on pharyngeal contractile integral.

Supplemental Material S4. Comparative statistics for repeated-measures ANOVA evaluating impact of task and age on upper esophageal sphincter minimum pressure.

Jones, C. A., & Colletti, C. M. (2021). Age-related functional reserve decline is not seen in pharyngeal swallowing pressures. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2021_JSLHR-21-00164