Salivary alpha amylase not chromogranin A reflects sympathetic activity: exercise responses in elite male wheelchair athletes with or without cervical spinal cord injury
Background: Salivary alpha-amylase (sAA) and chromogranin A (sCgA) have both
been suggested as non-invasive markers for sympathetic nervous system (SNS)
activity. A complete cervical spinal cord injury leading to tetraplegia is accompanied
with sympathetic dysfunction; the aim of this study was to establish the exercise
response of these markers in this in vivo model.
Methods: Twenty-six elite male wheelchair athletes (C6-C7 tetraplegia: N=8, T6-L1
paraplegia: N=10 and non spinal cord injured controls: N=8) performed treadmill
exercise to exhaustion. Saliva and blood samples were taken pre, post, and 30 min
post exercise and analysed for sAA, sCgA and plasma adrenaline concentration,
respectively.
Results: In all three subgroups, sAA and sCgA were elevated post exercise (P<0.05).
Whilst sCgA was not different between subgroups, a group x time interaction for sAA
explained the reduced post exercise sAA activity in tetraplegia (162±127 vs 313±99
(paraplegia) and 328±131 U∙mL-1 (controls), P=0.005). The post exercise increase in
adrenaline was not apparent in tetraplegia (P=0.74). A significant correlation was found
between adrenaline and sAA (r=0.60, P=0.01), but not between adrenaline and sCgA
(r=0.06, P=0.79).
Conclusions: The blunted post-exercise rise in sAA and adrenaline in tetraplegia
implies that both reflect SNS activity to some degree. It is questionable whether sCgA
should be used as a marker for SNS activity, both due to the exercise response which
is not different between the subgroups and its non-significant relationship with
adrenaline.
Funding
This work was funded by the Peter Harrison Centre for Disability Sport.
History
School
Sport, Exercise and Health Sciences
Published in
Sports Medicine - Open
Citation
LEICHT, C.A., 2017. Salivary alpha amylase not chromogranin A reflects sympathetic activity: exercise responses in elite male wheelchair athletes with or without cervical spinal cord injury. Sports Medicine, 3, article 1, DOI: 10.1186/s40798-016-0068-6
This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/
Acceptance date
2016-12-07
Publication date
2017
Notes
This is an Open Access article it is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
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the Creative Commons license, and indicate if changes were made.