title: Are Cardiac Autonomic Nervous System Activity and Perceived Stress Related to Functional Somatic Symptoms in Adolescents? The TRAILS Study.
abstract: OBJECTIVE
  Stressors have been related to medically insufficiently explained or functional somatic symptoms (FSS). However, the underlying mechanism of this association is largely unclear. In the current study, we examined whether FSS are associated with different perceived stress and cardiac autonomic nervous system (ANS) levels during a standardized stressful situation, and whether these associations are symptom-specific.
  
  
  METHODS
  We examined 715 adolescents (16.1 years, 51.3% girls) from the Dutch cohort study Tracking Adolescents' Individual Lives Sample during the Groningen Social Stress Test (GSST). FSS were assessed by the Youth Self-Report, and clustered into a cluster of overtiredness, dizziness and musculoskeletal pain and a cluster of headache and gastrointestinal symptoms. Perceived stress levels (i.e. unpleasantness and arousal) were assessed by the Self-Assessment Manikin, and cardiac ANS activity by assessing heart rate variability (HRV-HF) and pre-ejection period (PEP). Perceived stress and cardiac ANS levels before, during, and after the GSST were studied as well as cardiac ANS reactivity. Linear regression analyses were used to examine the associations.
  
  
  RESULTS
  Perceived arousal levels during (beta = 0.09, p = 0.04) and after (beta = 0.07, p = 0.047) the GSST, and perceived unpleasantness levels before (beta = 0.07, p = 0.048) and during (beta = 0.12, p = 0.001) the GSST were related to FSS during the past couple of months. The association between perceived stress and FSS was stronger for the FSS cluster of overtiredness, dizziness and musculoskeletal pain than for the cluster of headache and gastrointestinal symptoms. Neither ANS activity levels before, during, and after the GSST, nor maximal HF-HRV and PEP reactivity were related to FSS.
  
  
  CONCLUSIONS
  This study suggests that perceived stress levels during social stress are related to FSS, whereas cardiac ANS activity and reactivity are not related to FSS.
authors.affiliation: University of Groningen, University Medical Center Groningen, Interdisciplinary Center for Psychopathology and Emotion regulation, Groningen, The Netherlands.
authors.forename: Karin A M
authors.initials: KA
authors.lastname: Janssens
authors.affiliation: University of Groningen, University Medical Center Groningen, Interdisciplinary Center for Psychopathology and Emotion regulation, Groningen, The Netherlands.
authors.forename: Harriëtte
authors.initials: H
authors.lastname: Riese
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Internal Medicine, Groningen, The Netherlands.
authors.forename: Arie M
authors.initials: AM
authors.lastname: Van Roon
authors.affiliation: Erasmus Medical Center Rotterdam, Department of Medical Psychology & Psychotherapy, Rotterdam, The Netherlands.
authors.forename: Joke A M
authors.initials: JA
authors.lastname: Hunfeld
authors.affiliation: Academic Medical Center, Department of Radiology, Amsterdam, The Netherlands.
authors.forename: Paul F C
authors.initials: PF
authors.lastname: Groot
authors.affiliation: University of Groningen, University Medical Center Groningen, Interdisciplinary Center for Psychopathology and Emotion regulation, Groningen, The Netherlands.
authors.forename: Albertine J
authors.initials: AJ
authors.lastname: Oldehinkel
authors.affiliation: University of Groningen, University Medical Center Groningen, Interdisciplinary Center for Psychopathology and Emotion regulation, Groningen, The Netherlands.
authors.forename: Judith G M
authors.initials: JG
authors.lastname: Rosmalen
mesh_terms: D000293:Adolescent; D001143:Arousal / Q000502:physiology; D001341:Autonomic Nervous System / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D006321:Heart / Q000502:physiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D010146:Pain / Q000209:etiology / Q000523:psychology; D057566:Self Report; D013315:Stress, Psychological / Q000503:physiopathology*; D013997:Time Factors