Age-related sarcopaenia of the posterior pharynx in a cadaveric population
Date
2021
Authors
Fitchat, Nicolas Allyn
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Abstract
Sarcopaenia is the loss of muscle associated with ageing. Dysphagia is a disruption in the
correct functionality of the pharyngeal muscles with significant implications.
Objective
To investigate the degree of Sarcopaenia in the posterior pharynx in a cadaveric population
and its correlation with age at the time of death and sex as a possible contributing factor
leading to the development of dysphagia.
Methods
Retrospective review of data collected from 109 cadavers was analysed, 52 males and 57
females. A total of 86 cadavers met the inclusion criteria, 42 males and 44 females. Mean
measurements at four aspects of the posterior laryngopharynx at the level of the inferior
pharyngeal constrictor were analysed and correlated with age. These means were further
compared in cadavers 65 years and younger, and those older than 65 years. This mean was
also compared between the two sexes. A paired student’s T test and a one sample T test were
used to test for significance.
Results
A positive correlation was found between age and the mean of the muscle thicknesses of the
posterior laryngopharynx. A significant difference was found between the groups of cadavers
divided between those 65 years and younger and older than 65 years. No significant
difference was found between the muscle thickness of the posterior laryngopharynx and sex
of the cadaver.
Conclusion
There was a positive correlation between age and the mean muscle thickness of the posterior
laryngopharynx. Showing that the muscle is thicker in older cadavers. Furthermore, the
muscle thickness is significantly thicker in those more than 65 years than those 65 years and
less.
It has been shown by multiple previous studies that have shown that constriction of the
pharynx appears to decline with age. Other studies have however shown that the force
generated during swallowing in the pharynx does appear to increase with age. This has been
postulated to be a compensatory response to the decrease in compliance of the
cricopharyngeus muscle, as the upper oesophageal constrictor (UES), due to a replacement of
normal muscle and connective by fibroadipose tissue.
As a part of sarcopaenia where there is a complex interplay between atrophy and
hypertrophy, hypertrophy appears to be the most prominent feature in the posterior
laryngopharynx of the elderly as is demonstrated by a thicker muscle layer in our older
individuals. This hypertrophy may be a compensatory effect due to the loss of muscle fibres
due to atrophy as has been previously explored by other authors. There appears to be no
statistically significant difference in this muscle thickness between sexes.
This hypertrophy may be a compensatory effect due to the loss of muscle fibres due to
atrophy as has been previously explored by other authors. This may also be a possible reason
to explain the increase in the force of contraction during swallowing to overcome the
resistance that a food bolus requires to overcome the resistance within the UES, which has
been shown to be less compliant in aged individuals, in order to pass into the proximal
oesophagus.
Description
A dissertation submitted in fulfilment of the requirements for the degree of Master of Science in Medicine (Internal Medicine) to the Faculty of Health Sciences, School of Internal Medicine, University of the Witwatersrand, Johannesburg, 2021