Influence of age on swallows of a highly viscous liquid bolus

Swallow function has a decline with aging, mainly in those over 80 years old. In the population over 69 years, about 11% of subjects reported symptoms indicative of significant dysphagia.

Our objective was to evaluate the hypothesis that older asymptomatic subjects before 80 years old have compensations to sustain a safe and efficient swallow, at least with swallows of liquid bolus.

We performed videofluoroscopic evaluation of swallows in 55 normal volunteers, a younger group with 33 subjects (16 men and 17 women) aged 19 to 55 years, mean 35.5±9.8 years, and an older group with 22 subjects (15 men and 7 women) aged 56 to 77 years, mean 64.8±6.8 years. The subjects swallowed in duplicate 5 mL and 10 mL of liquid barium with a pH of 7.9, density of 1.82 g/cm3, and viscosity of 895 cp. Results The mean duration of pharyngeal transit, pharyngeal clearance, upper esophageal sphincter opening, hyoid movement and oral-pharyngeal transit were longer in the younger group compared with the older group. The relation between pharyngeal clearance duration and hyoid movement duration was similar in younger and older subjects, for 5 mL and 10 mL bolus volumes.

On average, a highly viscous liquid bolus crosses the pharynx faster in older subjects (56-77 years old) than in younger subjects (19-55 years old), which suggested an adaptation to the aging process to maintain a safe swallow.