Björn Karlson

Inducing physiological stress recovery with sounds of nature in a virtual reality forest — Results from a pilot study

Experimental research on stress recovery in natural environments is limited, as is study of the effect of sounds of nature. After inducing stress by means of a virtual stress test, we explored physiological recovery in two different virtual natural environments (with and without exposure to sounds of nature) and in one control condition. Cardiovascular data and saliva cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group subjected to sounds of nature in a virtual natural environment, suggesting enhanced stress recovery may occur in such surroundings. The group that recovered in virtual nature without sound and the control group displayed no particular autonomic activation or deactivation. The results demonstrate a potential mechanistic link between nature, the sounds of nature, and stress recovery, and suggest the potential importance of virtual reality as a tool in this research field.

Cognitive performance in patients with burnout, in relation to diurnal salivary cortisol.

This study investigated cognitive performance in patients with burnout, in relation to the flexibility of the hypothalamic–pituitary–adrenal (HPA) axis. Clinical cases with work stress-induced burnout (n = 65), and demographically matched, healthy reference subjects (n = 65), were given six neuropsychological tests and a self-rating scale for cognitive problems. Diurnal salivary cortisol was measured among burnout cases and an external reference group (n = 174), including a dexamethasone suppression test (DST) among burnout cases. Compared with referents, the burnout group under-performed in a cognitive speed test (Wechsler Adult Intelligence Scale-Revised (WAIS-R) Digit Symbol), but not in any other test of sustained attention, episodic memory, or vocabulary. Burnout cases had considerably more subjective cognitive problems, but ratings were unrelated to test performance. Compared with referents, burnout cases had similar morning salivary cortisol levels and similar awakening response, but lower evening cortisol. Among burnout cases, lower diurnal cortisol variability was related to slower performance in several tests. The DST response showed no consistent relationship with any cognitive parameter. Hence, despite considerable subjective cognitive problems, the burnout group showed only a partial, mild deviation in cognitive performance. A flatter diurnal cortisol profile was related to lower cognitive processing speed, but diurnal cortisol pattern and DST response were normal, suggesting a maintained HPA axis flexibility.

Cardiovascular and cortisol reactivity and habituation to a virtual reality version of the Trier Social Stress Test: A pilot study

The Trier Social Stress Test (TSST) is a widely used protocol to induce stress in laboratory settings. Briefly, in the TSST, the test participant is asked to hold a speech and to do an arithmetic task in front of an audience. In the present pilot study, we examined endocrine and autonomic reactivity and habituation to repeated stress provocations using a virtual reality (VR) version of TSST. The VR system was a CAVE™ system with three rear projected walls (4 m×3 m), and one floor projection. The system also included a head tracking system and passive stereoscopy. The virtual audience consisted of one woman, and two men. Ten healthy men, mean age 28.3 years (24-38 years), were confronted with the test twice (1 week between sessions), during which salivary cortisol, heart rate (HR), high frequency heart rate variability (HF-HRV, parasympathetic activity), and T-wave amplitude (TWA, suggested to be related to sympathetic influence on myocardial performance) were assessed. Cortisol secretion showed a marked increase (88% vs. baseline) during the first stress provocation, but habituated in the second session. The magnitude of HR and TWA reactivity during stress provocation was approximately the same at both sessions, implying a stable increase in sympathetic activity. Heart rate showed a maximum increase of 40% at the first session, and 32% at the second. TWA showed a maximum decrease of 42% at the first session, and 39% at the second. The results resemble those obtained in prior studies using the real-life TSST. If these results can be replicated with larger samples, VR technology may be used as a simple and standardized tool for social stress induction in experimental settings.

Seasonal Variation in Human Salivary Cortisol Concentration

Measurement of cortisol concentration can contribute important information about an individuals ability to adjust to various environmental demands of both physical and psychosocial origin. However, one uncertainty that affects the possibilities of correctly interpreting and designing field studies is the lack of observations of the impact of seasonal changes on cortisol excretion. For this reason, the month‐to‐month changes in diurnal cortisol concentration, the awakening cortisol response (ACR), maximum morning concentration, and fall during the day were studied in a group of 24 healthy men and women 32 to 61 yrs of age engaged in active work. On one workday for 12 consecutive months, participants collected saliva at four time points for determination of cortisol: at awakening, +30 min, +8 h, and at 21:00 h. Data were analyzed by a repeated measures design with month (12 levels) and time‐of‐day (4 levels) as categorical predictors. Cortisol concentrations were analyzed on a log scale. The diurnal pattern of cortisol was similar across months (interaction between month and time of day: p>0.4). The main effects of month and time‐of‐day were statistically significant (p <0.001). Highest concentrations were observed in February, March, and April, and lowest concentrations were observed in July and August. There were no statistically significant effects in any of the other measures, or between men and women. In conclusion, a seasonal variation in salivary cortisol concentrations was detected in an occupationally active population. Thus, seasonal variation needs to be taken into account when designing and evaluating field studies and interventions and when making comparisons across studies.

Return to work after a workplace-oriented intervention for patients on sick-leave for burnout - a prospective controlled study

BackgroundIn the present study the effect of a workplace-oriented intervention for persons on long-term sick leave for clinical burnout, aimed at facilitating return to work (RTW) by job-person match through patient-supervisor communication, was evaluated. We hypothesised that the intervention group would show a more successful RTW than a control group.MethodsIn a prospective controlled study, subjects were identified by the regional social insurance office 2-6 months after the first day on sick leave. The intervention group (n = 74) was compared to a control group who had declined participation, being matched by length of sick leave (n = 74). The RTW was followed up, using sick-listing register data, until 1.5 years after the time of intervention.ResultsThere was a linear increase of RTW in the intervention group during the 1.5-year follow-up period, and 89% of subjects had returned to work to some extent at the end of the follow-up period. The increase in RTW in the control group came to a halt after six months, and only 73% had returned to work to some extent at the end of the 1.5-year follow-up.ConclusionsWe conclude that the present study demonstrated an improvement of long-term RTW after a workplace-oriented intervention for patients on long-term sick leave due to burnout.Trial registrationCurrent Controlled Trials NCT01039168.

Burden of illness, metabolic control, and complications in relation to depressive symptoms in IDDM patients

Relationships between demographic‐, treatment‐, and sickness‐related factors, metabolic control (HbA1c), perceived burden of illness, and degree of depressive symptoms were examined in a group of 155 insulin‐dependent diabetic patients, aged 35.3 ± 8.9 years. The patients completed a questionnaire measuring depressive symptoms and three aspects of perceived burden of illness. No gender differences in HbA1c level or occurrence of late diabetic complications were found. Both men and women showed a modestly elevated degree of depression compared with norm groups. Self‐reported burden of illness was strongly related to depression but was largely unrelated to objective disease‐related measures. Level of depression was correlated neither with degree of metabolic control nor with the presence of such late diabetic complications as retinopathy and nephropathy. Some 44 % of the variance in depression could be explained by worries about complications in those patients with the lowest HbA1c levels, by perceived restrictions in everyday life in patients with intermediate metabolic control, and by problems of glycaemic regulation in patients with poor metabolic control. Degree of depression was largely unrelated to disease severity, but was found to be related to the perceived daily burden of living with the disease, the specific worries and concerns associated with a depressed mood varying with degree of metabolic control.

EUROQUEST—A Questionnaire for Solvent Related Symptoms: Factor Structure, Item Analysis and Predictive Validity

The study evaluates the factor structure and predictive validity of the symptom questionnaire EUROQUEST (EQ) that had been developed with the goal of simplifying the evaluation of health effects associated with long-term solvent exposure. The EQ was added to the normal evaluation procedures for 118 male patients with suspected solvent-induced toxic encephalopathy (TE) referred to seven Swedish clinics of occupational medicine during an 18-month period. EQ was also completed by 239 males from a random sample of 400 Swedish males aged 25-64 years selected from the general population and a sample of 559 occupationally active male spray painters aged 25-64 years. Factor and item analyses of EQ responses were performed. Ordinary least square regression analysis was used to evaluate sensitivity and correlation to evaluate the specificity of EQ and the separate components. Questions concerning memory and concentration symptoms alone showed better sensitivity than the other five EQ dimensions singly or combined for the entire EQ and for a subset of questions approximating Q16, a widely used organic solvent symptom screening questionnaire. However, the diagnosis of TE required information in addition to exposure and responses to EQ and Q16-like questions. The results indicate that the subset of EQ questions concerning memory and concentration might replace the more cumbersome EQ and less sensitive Q16 in screening for TE, although none of the screening instruments alone replaces current clinical diagnostic procedures.

Pain Recollection after Chest Pain of Cardiac Origin

Memory for pain is an important research and clinical issue since patients ability to accurately recall pain plays a prominent role in medical practice. The purpose of this prospective study was to find out if patients, with an episode of chest pain due to suspected acute myocardial infarction could accurately retrieve the pain initially experienced at home and during the first day of hospitalization after 6 months. A total of 177 patients were included in this analysis. The patients rated their experience of pain on a numerical rating scale. The maximal pain at home was retrospectively assessed, thereafter pain assessments were made at several points of time after admission. After 6 months they were asked to recall the intensity of pain and once again rate it on the numerical rating scale. The results from the initial and 6-month registrations were compared. In general, patients rated their maximal intensity of chest pain as being higher at the 6-month recollection as compared with the assessments made during the initial hospitalization. In particular, in patients with a high level of emotional distress, there was a systematic overestimation of the pain intensity at recall.

Exhaustion measured by the SF-36 vitality scale is associated with a flattened diurnal cortisol profile

The possible association between stress-related exhaustion and reduced activity in the hypothalamo-pituitary-adrenal (HPA) axis is increasingly in focus. The aim of the present study was to examine whether exhaustion measured in a non-patient population is associated with alterations in diurnal cortisol profile. The study population included 78 working individuals. The study group was dichotomised into exhausted and non-exhausted groups by means of the SF-36 vitality scale. Salivary cortisol was measured at three times during 1 workday: at awakening, 30min after awakening, and in the evening. The results showed that diurnal cortisol variation was significantly reduced in exhausted individuals. The difference in cortisol variation was mainly due to lowered morning cortisol in the exhausted group. Differences in cortisol levels at each sampling time or in mean diurnal output of cortisol were not statistically significant. The results would support the notion that exhaustion is associated with HPA axis hypoactivity as assessed by salivary cortisol. Furthermore, the SF-36 vitality provides a measure of exhaustion that may be useful in epidemiological studies in order to explore long-term health effects of stress-related exhaustion.

The influence of different insulin regimens on quality of life and metabolic control in insulin-dependent diabetics

Administration of insulin with premeal boluses of short-acting insulin using a new injection device (Novopen) was compared with a conventional three times daily injection regimen regarding aspects of quality of life and metabolic control in insulin-dependent diabetes mellitus (IDDM). Eighteen C-peptide-negative patients with IDDM (16 men, two women, aged 31.0 +/- 7.4 years, duration of diabetes 13.0 +/- 4.6 years; mean +/- SD) participated in the study. All patients had been treated with three daily insulin injections for at least 1 year prior to the study. The patients were randomized into two groups. Group A started a 3-month treatment period with premeal injections of short-acting insulin and intermediate-acting insulin at bedtime. This period was followed by another 3 months using the initial three times daily injection regimen. Group B completed the study in the reverse order. Quality of life was assessed by using questionnaires and personal interviews by the same clinical psychologist. Metabolic control was assessed by measuring the levels of glycosylated hemoglobin. The results show that both treatment groups experienced a general improvement in mood and well-being during the period with multiple insulin injection treatment. Furthermore, during the periods of insulin pen treatment, an increased experience of freedom and less dependence on fixed meal times were noted. Overall metabolic control, insulin dosage, body weight, and number of hypoglycemic episodes did not change during the study. It is concluded that metabolic control, safety, and number of hypoglycemic episodes using premeal doses of short-acting insulin using Novopen were not different from those seen during conventional treatment.(ABSTRACT TRUNCATED AT 250 WORDS)