Sickness Behavior
Conditions
Keywords
Sickness behavior, Cytokines, Psychoneuroimmunology
Brief summary
In this randomized double blind cross-over study 8 healthy persons were injected with 0.8 ng/kg body weight lipopolysaccharide (LPS) /endotoxin and placebo at two different occasions. The aim was to investigate how pain sensitivity and health perception change in response to an acute immune activation.
Detailed description
Eight healthy participants were included in this randomized and balanced double blind cross-over study. They were injected two times, once with the active component and once with placebo. Participants were recruited by advertising and screened through questionnaires and a health examination by a physician. They were asked not to engage in strenuous physical activities, sleep regular hours and refrain from alcohol the day before the experiment. If the participants felt ill, e.g. coming down with a cold, they were instructed to call and were rescheduled for a later appointment. C-reactive protein (CRP) was assessed to exclude participants having an ongoing infection on the experimental day. Pregnancy was also an exclusion criteria and a pregnancy test was administered for all female participants on arrival. Several pain sensitivity measures were performed baseline and at peak inflammatory response 1-2 hours after injection. Subjects filled out questionnaires at baseline, 90 minutes and 4,5 hours after injection. The study and the procedures used in the study are described in detail here: https://openarchive.ki.se/xmlui/bitstream/handle/10616/44650/Thesis\_Bianka\_Karshikoff.pdf?sequence=8&isAllowed=y The following papers have been published using data from this study: Olsson MJ, Lundstrom JN, Kimball BA, Gordon AR, Karshikoff B, Hosseini N, Sorjonen K, Olgart Hoglund C, Solares C, Soop A, Axelsson J & Lekander M. The Scent of Disease: Human Body Odor Contains an Early Chemosensory Cue of Sickness. Psychol Sci. 2014 Jan 22. Sundelin T, Karshikoff B, Axelsson E, Hoglund CO, Lekander M, Axelsson J. Sick man walking: Perception of health status from body motion. Brain Behav Immun. 2015;48:53-6. Karshikoff B, Lekander M, Soop A, Lindstedt F, Ingvar M Kosek E, Olgart Höglund C, & Axelsson J. Modality and sex differences in pain sensitivity during human endotoxemia. Brain, Behavior, and Immunity. 2015 May;46:35-43
Interventions
BIOLOGICALLipopolysaccharide
Endotoxin at 0.8 ng/kg of body weight administered intravenously (Escherichia Coli, Lot nr G3E0609, United States Pharmacopeia Rockville, MD)
BIOLOGICALPlacebo
Saline administered intravenously
Sponsors
University of California, San Francisco
The Swedish Society of Medicine
Swedish Heart Lung Foundation
The Swedish Research Council
Swedish Council for Working Life and Social Research
Stockholm University
Karolinska Institutet
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy subjects
Exclusion criteria
* Diagnosed physiological or psychiatric disease * Needle anxiety or blood phobia * Regular medication (excluding contraceptive pill) * Infection in the last two weeks * Pregnancy or breastfeeding * Smoking * Excessive alcohol use * Body mass index in the range of obesity (\>30 kg/m2) or underweight (\<18.5 kg/m2) * Invisible veins in the antecubital area of the arms
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in interoceptive vs exteroceptive focus | 7 hours | Rating of concordance of heartbeat vs signal and change in tone of signal |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in facial apparence | 2 hours | Photos were taken under standardised conditions before and after injection |
| Change in gait | 2 h | The participants were filmed walking before and after injection |
| Change in self-rated health | 7 hours | Two questions were used to assess self-rated health 1how do you rate your general health status rated on a 5 grade Likert scale very good to very poor and 2how is your health right now rated on a 7 grade Likert scale from excellent to very poor |
| Change in pain perception | 7 hours | Both deep and cutaneous pain at threshold and suprathreshold noxious levels. Heat- and cold (cutaneous) pain sensitivity was assessed for threshold stimuli and intense noxious stimuli, as well as pressure (deep) pain thresholds and CPM (descending pain inhibition). |
Outcome results
None listed