Bond University
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Assessing thermoregulatory deficits of trained
individuals with a spinal cord injury exercising in
the heat
CRN-AESS Research Methodology Library
2017
Heat activated sweat gland density
Peta Forsyth
University of Canberra and Australian Institute of Sport
Ollie Jay
University of Sydney
Follow this and additional works at: http://epublications.bond.edu.au/crn_assess
Part of the Sports Medicine Commons, and the Sports Sciences Commons
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Forsyth, P., & Jay, O. (2017). Heat activated sweat gland density. Retrieved from http://epublications.bond.edu.au/crn_assess/3
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AIS/USyd: heat activated sweat gland density
Last saved: 15-May-17
Heat activated sweat gland density
Contributed by: Peta Forsyth1 and Ollie Jay2
1
University of Canberra and Australian Institute of Sport; 2University of Sydney
Project: Assessing thermoregulatory deficits of trained individuals
with a spinal cord injury exercising in the heat
Author: Peta Forsyth & Ollie Jay
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AIS/USyd: heat activated sweat gland density
Last saved: 15-May-17
Table of contents
1 Introduction/Background ........................................................................................................ 3
1.1 References............................................................................................................................... 3
2 Facility and Equipment ............................................................................................................ 3
2.1 Testing facility requirements .................................................................................................. 3
2.2 Equipment ............................................................................................................................... 4
2.2.1 Smaller equipment/instruments ....................................................................................... 4
2.2.2 Consumables ..................................................................................................................... 4
2.2.3 Personal Protective Equipment (PPE) ............................................................................... 4
3 Training/qualifications/competencies...................................................................................... 4
4 Workflow ................................................................................................................................ 5
4.1 Before the participant arrives ................................................................................................. 5
4.2 Participant preparation ........................................................................................................... 5
4.3 Data collection ........................................................................................................................ 5
4.4 Data analysis ........................................................................................................................... 5
5 Supplier and ordering information ........................................................................................... 8
Author: Peta Forsyth & Ollie Jay
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1 Introduction/Background
Sweat production is determined by the sweat output from each gland and the number of active
sweat glands. When we measure sweat rate (whole-body or local) we are measuring the sweat rate
from a large number of sweat glands within the defined surface area. An estimation of the number
of heat-activated sweat glands, in conjunction with measurements of local sweat rate, can be used
to determine average sweat gland output. Quantifying the number of heat-activated sweat glands
can be used, for example, to compare sweat gland function between populations or to characterize
the extent of neuropathy.
Traditional methods to determine the number of active sweat glands includes macrophotography1,
starch-iodine2, and iodine-paper3. A description of each technique may be found in the references
provided. The validity and reliability of a new modified iodine-paper technique has been recently
established4. The protocol for this new method is described in this document.
1.1 References
1. Kenney W.L, and Fowler S.R (1988). Methylcholine-activated eccrine sweat gland density and
output as a function of age. Journal of Applied Physiology, 65(3), 1082-6.
2. Inoue Y (1996). Longitudinal effects of age on heat-activated sweat gland density and output
in healthy active older men. European Journal of Applied Physiology and Occupational
Physiology, 74(1-2), 72-7.
3. Sato K, and Sato F (1983). Individual variations in structure and function of human eccrine
sweat gland. American Journal of Physiology, 245(2), R203-8.
4. Gagnon, D, Ganio, M.S, Lucas, R.A, Pearson, J, Crandall, C.G, & Kenny, G.P (2012). Modified
iodine-paper technique for the standardized determination of sweat gland activation.
Journal of Applied Physiology, 112(8), 1419-1425.
2 Facility and Equipment
2.1 Testing facility requirements
No specific facilities required.
Author: Peta Forsyth & Ollie Jay
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2.2 Equipment
2.2.1 Smaller equipment/instruments
Equipment
Photo/description
Iodine crystals
Aluminium toolbox
For storing plastic container with iodine crystals
and paper (being saturated with iodine)
Plastic ruler
Use to ensure the iodine soaked squares of
paper are pressed against the skin uniformly
Double sided tape
To attach the iodine soaked paper to the plastic
ruler when taking a measurement
2.2.2 Consumables
Item
Photo/description
Zip lock bags
For storing saturated cotton paper prior to
being used in a trial
100% cotton paper
2.2.3 Personal Protective Equipment (PPE)
Item
Photo/description
Gloves
For handling the iodine soaked paper
Protective glasses
When working with the iodine crystals
3 Training/qualifications/competencies
Please indicate (check the box) to indicate which of the following is required prior to undertaking this
method:
Yes
No
Health and Safety training
Laboratory induction
Current First Aid / CPR
Immunisation
Method-specific training
If yes, please provide details:
Although this method does not require formal training, it will require practice to become
skilled at the technique
Formal qualification required
Other specific requirements
Author: Peta Forsyth & Ollie Jay
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4 Workflow
4.1 Before the participant arrives
The paper used to measure heat-activated sweat gland density must be prepared in advance.
To prepare the paper, 100 % cotton paper (Moab Entrada Bright 190, Legion Paper, NY, USA)
should be cut to size (3cm x 3cm) then placed in an airtight box containing iodine crystals. A
smaller size (e.g. 1.5cm x 1.5cm) may be more appropriate for smaller areas of the body such as
the forehead. Iodine saturation takes ~48 h, at which point the cotton paper will turn from white
to brown. The paper should then be removed and placed in a new airtight container or ziplock
bag until it is needed. For the preparation and storage of starch-iodine paper, it is important to
handle the paper with gloves and keep it away from any moisture to ensure it remains stain-free
prior to being used. In addition, protective glasses should be worn when working with the iodine
crystals.
4.2 Participant preparation
Minimal preparation is required on the participant’s behalf, as this measure is taken while the
participant is exercising or immediately following exercise. Prior to the participant commencing
exercise, the researcher should inform the participant that they will be taking this measurement
by pressing paper against the skin, however there will be no discomfort in this process and it will
take < 10 seconds at each site.
4.3 Data collection
Before taking a measurement with the paper, the skin at the location of interest should be wiped
down using a dry tissue or cloth. The square of paper should then be held against the skin for 110 seconds, depending on the sweat rate of the individual. It is suggested to attach the paper to
a hard and flat surface (such as a ruler) using double sided tape to ensure the paper is applied
uniformly to the skin. If the participant is sweating profusely, the paper should only be pressed
against the skin for 1-2 seconds, however if there is little or no visible sweat, a longer period of
time against the skin will be required (8-10 seconds). The active sweat glands will produce dark
purple spots on the paper from the sweat expulsion. The sample should then be stored in an
airtight bag until it is ready to be analysed.
4.4 Data analysis
For analysis, the individual sweat glands can be counted using a computer-aided analysis
program, freely available for download on any operating system (ImageJ,
https://imagej.nih.gov/ij/index.html). Research by Gagnon et. al (2012) has validated the
Author: Peta Forsyth & Ollie Jay
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computer-aided analysis as a reliable method for counting sweat glands with the starch iodine
paper technique1.
The following instructions detail how to analyse heat activated sweat gland density samples
using the computer aided analysis software ImageJ (taken from Gagnon et. al, J Appl Physiol.
2012):
1. Step 1. To analyze a sample, determine the edges of the scanned image using the “Find
edges” option (Process toolbar–Find edges).
2. Step 2. Next, set the image type to 8-bit grayscale (Image toolbar–Type–8-bit) before
converting the image to a binary (black and white) image (Process toolbar–Binary–Make
binary). Once this step is complete, the dots produced by the active glands are displayed
in black, with the background being white.
3. Step 3. To perform a count of the number of active glands, select the “Analyze particles”
(Analyze toolbar–Analyze particles) and first define a lower and upper size limit for the
pixel area, which is the minimum/maximum size allowable for a dot to be considered in
the count. Before running the analysis, ensure that the following options are chosen:
display results, clear results, exclude on edges, record starts. Also, ensure that the
“Outlines” option is selected under the “Show” menu to visually examine which particles
have been included by the software during the analysis.
4. Step 4. Once the analysis performed, the software generates a count of the particles
present in the image, which is the number of active glands for that sample. It also
provides an image in which each individual count included in the analysis has been circled
in red. If the number of particles included in the analysis is inadequate, return to step 3
and adjust the lower and upper size limit of the pixel area accordingly.
5. Step 5. The number of particles is divided by the surface area of the paper to give a value
of active sweat glands per square centimeter.
Figure. Sample of heat-activated sweat glands using the modified iodine-paper technique
(left). The image is converted to 8-bit greyscale and then binary, that is, black dots on a white
background (middle). Following analysis using ImageJ software, the counted sweat glands
are defined in black and numbered in red (right). Adapted from Gagnon et al., 2012.
Author: Peta Forsyth & Ollie Jay
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Reference: Gagnon, D., Ganio, M. S., Lucas, R. A., Pearson, J., Crandall, C. G., & Kenny, G. P. (2012).
Modified iodine-paper technique for the standardized determination of sweat gland activation.
Journal of Applied Physiology, 112(8), 1419-1425.
Author: Peta Forsyth & Ollie Jay
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5 Supplier and ordering information
Item description
Product code
Supplier
Notes
100% cotton paper
Moab Entrada
Bright 190
Company name: Legion Paper
Specifications:
Web: http://moabpaper.com/entrada-rag/
190 gsm / 15.5 mil
Brightness D65 103
100% cotton / machine made
Double Sided
Bright White / Contains OBAs (surface)
Water-resistant
Pigment (recommended) / Dye
Author: Peta Forsyth & Ollie Jay
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