Stress Response Pattern of Heart Rate Variability in Patients with Functional Somatic Syndromes.

Functional somatic syndromes (FSSs) represent a clinically important group of disorders that are often stress-related. Their autonomic pathophysiology, including reduced heart rate variability (HRV), has been reported. However, the response pattern to mental stress and recovery in FSSs remains unclear. Thus, we aimed to clarify the pattern of autonomic stress response and recovery to mental arithmetic stress in patients with FSS compared to that in healthy controls. This cross-sectional study included 79 patients with FSS who visited the Department of Psychosomatic Medicine at a university hospital in Japan and 39 healthy controls. Following a mood questionnaire and obtaining epidemiologic information, HRV was measured during three periods (5 min each): relaxation baseline resting, stress (mental arithmetic task), and post-stress recovery period. The HRV analysis included inter-beat interval, low frequency power, and high frequency power. Compared to healthy controls, patients with FSS exhibited significantly higher scores on the mood questionnaire, prolonged duration of illness, and decreased functionality in daily activities. While the healthy control group showed a pronounced stress response pattern with a significant decrease in vagal HRV and recovery, the FSS group showed a "flat" vagal stress response pattern, and the HRV in the FSS group was lower at relaxation baseline, remained low during the stress, and did not change post stress. Patients with severe FSS exhibit an altered stress response pattern. Our results could provide significant clues for the diagnosis and treatment of such patients, as well as useful insights into the relationship between stress and illness.

The relationship between salivary amylase and the physical and psychological changes elicited by continuation of autogenic training in patients with functional somatic syndrome.

BACKGROUND: The aim of this study was to clarify the changes in biological measures during autogenic training (AT) sessions and the relationship between these biological measures and the changes in physical and psychological measures induced by continuation of AT in patients with functional somatic syndrome (FSS). We used the salivary amylase (SAMY) level, skin temperature of the finger (TEMP), subjective symptom scores, and psychological characteristics to assess these changes. METHODS: We assessed 24 patients with FSS and 23 healthy controls before and after AT. We then conducted the same tests after the participants had practiced AT at home 1 and 2 months later. RESULTS: The baseline SAMY levels in the first session were significantly higher in the FSS group than in the control group. However, this difference was not significant in the second and third sessions. The pattern of changes in TEMP induced by AT was not different between the FSS and control groups. Tension-anxiety and somatic symptoms in patients with FSS were improved by AT. In the FSS group, the baseline SAMY levels in the first session showed a significant negative correlation with the changes in the subjective symptom score and tension-anxiety score at baseline. CONCLUSIONS: The practice of AT, both during the first session and after 1 month of continuation, eased the dysregulation of the autonomic nervous system that is reflected in SAMY in patients with FSS. AT also contributed to decreases in the tension-anxiety and somatic symptoms in patients with FSS. We suggest that SAMY is related to both physical and psychological effects of AT in patients with FSS.

Pain threshold reflects psychological traits in patients with chronic pain: a cross-sectional study.

BACKGROUND: Chronic pain enhances sensory sensitivity and induces the biased development of psychological traits such as depression and pain catastrophizing, leading to the formation of heterogeneous conditions. Fluctuations in the sensory-related thresholds of non-injured sites (with normal peripheral tissue) in patients with chronic pain are thought to be related to central sensitization. The objectives of this study were to analyze the association between pain tolerance thresholds (PTTs) in non-injured sites and the psychological traits of patients with chronic pain and to evaluate the usefulness of PTT measures in assessments of pathological conditions related to chronic pain. METHODS: This study included 57 patients with chronic pain. The PTTs were measured in non-injured sites with quantitative sensory testing (QST) with electrical stimulation and then classified with cluster analysis. The Short-Form McGill Pain Questionnaire was used to subjectively assess pain in the injured sites. The Minnesota Multiphasic Personality Inventory (MMPI) was used to assess the patients' psychological traits. RESULTS: Based on the cluster analysis of PTTs, the patients were classified into a High-Sensitivity group and an Others group consisting of the remaining patients. The results of the MMPI profiles showed that the High-Sensitivity group included significantly more patients with the Neurotic Triad pattern and no patients with the Conversion V pattern. The scores of the hypochondriasis and hysteria scales were significantly lower in the High-Sensitivity group than in the Others group. CONCLUSIONS: This study indicated that patients with chronic pain can be classified according to PTTs in non-injured sites and suggests that patients with High-Sensitivity have characteristic psychological traits. Assessment of PTTs in non-injured sites would be useful for evaluating the psychological condition of patients with chronic pain.

Saliva amylase as a measure of sympathetic change elicited by autogenic training in patients with functional somatic syndromes.

The aim of this study was to discuss the effect of autogenic training (AT) on patients with functional somatic syndrome (FSS) using salivary amylase, the skin temperature of the finger, subjective severity of symptoms, and psychological characteristics as measures. We assessed 20 patients with FSS and 23 healthy controls before and after AT. Baseline levels of salivary amylase prior to an AT session were significantly higher in the FSS group than in the control group. However, this difference was not significant after AT. The skin temperature of the finger increased after AT in both the FSS and control groups. AT contributed to the improvement of somatic symptoms in patients with FSS. Our results regarding psychological characteristics suggest that mood disturbances are deeply involved in the pathology of FSS. Individuals with FSS exhibited elevated levels of sympathetic activity compared with healthy controls. Our data indicates that AT eased dysregulation of the autonomic nervous system in patients with FSS. Thus, salivary amylase may be a useful index of change induced by AT in patients with FSS.