Changes of pain perception, autonomic function, and endocrine parameters during treatment of anorectic adolescents.
OBJECTIVE
The underlying mechanisms of reduced pain perception in anorexia nervosa (AN) are unknown. To gain more insight into the pathology, the authors investigated pain perception, autonomic function, and endocrine parameters before and during successful treatment of adolescent AN patients.


METHODS
Heat pain perception was assessed in 15 female adolescent AN patients and matched controls. Results were correlated with autonomic and endocrine parameters (free triiodothyronine, free cortisol). Autonomic function was studied using heart rate variability and pupillary light reflex assessment. To investigate the influence of therapy on these parameters, data were obtained at three different time points.


RESULTS
Heat pain thresholds were significantly increased in the acute state and decreased after weight had been regained for 6 months. Similarly, an increased parasympathetic tone was present in the acute state only. The relative amplitude of the pupillary light reflex showed a positive correlation to pain thresholds over time and predicted disease progression. In addition, the authors found a negative correlation between increased pain thresholds and low free cortisol.


CONCLUSIONS
Increased pain thresholds are associated with increased parasympathetic tone and a hypothyroid state in AN. This may either indicate common central mechanisms or suggest a causative interaction.
Bär
Karl-Jürgen
KJ
Drs. Bär, Boettger, Wagner, Sauer and Ms. Wilsdorf are with the Department of Psychiatry; Drs. Gerhard and Blanz are with the Department of Child and Adolescent Psychiatry; and Dr. Boettger is with the Institute of Physiology, Friedrich-Schiller-University, Jena, Germany. Electronic address: Karl-Juergen.Baer@med.uni-jena.de.
Boettger
Silke
S
Drs. Bär, Boettger, Wagner, Sauer and Ms. Wilsdorf are with the Department of Psychiatry; Drs. Gerhard and Blanz are with the Department of Child and Adolescent Psychiatry; and Dr. Boettger is with the Institute of Physiology, Friedrich-Schiller-University, Jena, Germany.
Wagner
Gerd
G
Drs. Bär, Boettger, Wagner, Sauer and Ms. Wilsdorf are with the Department of Psychiatry; Drs. Gerhard and Blanz are with the Department of Child and Adolescent Psychiatry; and Dr. Boettger is with the Institute of Physiology, Friedrich-Schiller-University, Jena, Germany.
Wilsdorf
Christine
C
Drs. Bär, Boettger, Wagner, Sauer and Ms. Wilsdorf are with the Department of Psychiatry; Drs. Gerhard and Blanz are with the Department of Child and Adolescent Psychiatry; and Dr. Boettger is with the Institute of Physiology, Friedrich-Schiller-University, Jena, Germany.
Gerhard
Uwe Jens
UJ
Drs. Bär, Boettger, Wagner, Sauer and Ms. Wilsdorf are with the Department of Psychiatry; Drs. Gerhard and Blanz are with the Department of Child and Adolescent Psychiatry; and Dr. Boettger is with the Institute of Physiology, Friedrich-Schiller-University, Jena, Germany.
Boettger
Michael K
MK
Drs. Bär, Boettger, Wagner, Sauer and Ms. Wilsdorf are with the Department of Psychiatry; Drs. Gerhard and Blanz are with the Department of Child and Adolescent Psychiatry; and Dr. Boettger is with the Institute of Physiology, Friedrich-Schiller-University, Jena, Germany.
Blanz
Bernhard
B
Drs. Bär, Boettger, Wagner, Sauer and Ms. Wilsdorf are with the Department of Psychiatry; Drs. Gerhard and Blanz are with the Department of Child and Adolescent Psychiatry; and Dr. Boettger is with the Institute of Physiology, Friedrich-Schiller-University, Jena, Germany.
Sauer
Heinrich
H
Drs. Bär, Boettger, Wagner, Sauer and Ms. Wilsdorf are with the Department of Psychiatry; Drs. Gerhard and Blanz are with the Department of Child and Adolescent Psychiatry; and Dr. Boettger is with the Institute of Physiology, Friedrich-Schiller-University, Jena, Germany.
D000293:Adolescent; D000856:Anorexia Nervosa / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D001294:Attitude to Health; D015992:Body Mass Index; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D010146:Pain / Q000453:epidemiology* / Q000523:psychology*; D010147:Pain Measurement