Projects: Work and stress, physiological responses
The group focuses on stress reactions at work and risk perception of new environmental exposures.
We evaluate physiological markers of psychological stress in relation to individual and work related risk factors as well as to assess intervention programs e.g. offered by occupational health services. Sleep quality is estimated by sleep diary and actigraph recordings and heart rate variability is analysed based on 24-hour recordings. On-going research also includes studies on sleep quality as a prognostic marker of wellbeing and sickness absence. WASP is a partner in Stockholm Stress Center.
Radiofrequency fields from UMTS phone and sleep and cognitive functions
The number of mobile phone users has increased rapidly during the last 15 years, but there is a remaining concern for negative health effects. Effects on the brain’s electrical activity (EEG), sleep and cognitive functions have been reported in some studies, while other studies have failed to identify any influence of radiofrequency fields (RF). In an earlier study we observed an effect on sleep (decreased time for deep sleep) and spatial memory after three hours exposure to RF (884 MHz, SAR 1,4 W/kg). In the present study we will build on these results and study possible effects of a three hour exposure to UMTS (3G) in a group of teenagers. The study is performed in collaboration with the Stress Research Institute, Stockholm University.
Specific hypotheses to be tested are that exposure to UMTS leads to decrease in deep sleep, increase in power density in EEG alpha and spindle frequency bands, improved performance in cognitive tests and headache. The study has a double blind crossover-design as the earlier study, but with an increase in the number of exposure sessions (UMTS or sham) per participant. The study group will be 20 subjects age 16 to 19.
Universitetslektor/överläkare Lena Hillert
Sleep quality and multisite pain
Sleep problems are associated with sickness absence and with pain. By analyzing data from the MUSIC-Norrtälje study we will study a possible association between self-reported sleep quality and multisite pain five years later. The MUSIC-Norrtälje study was initiated in order to identify and quantify risk factors and protective factors for LBP and NSP, and to investigate the prognoses of these disorders. The Norrtälje Study was at baseline case-referent study (1994-1996), with five-year follow-up including men and women, 20-59 years old living and working in Norrtälje. The present study consists of 2329 subjects who participated both at baseline and at follow-up. The questionnaire at baseline and follow-up includes questions on sleep (Karolinska Sleep Questionnaire) and on musculoskeletal pain (Von Korff and The Standard Nordic Questionnaire). Hypotheses tested in this study are whether good or bad sleep will predict onset of or restoration from multisite pain five years later.
Sleep quality and sickness absence among individuals with low-back or neck-shoulder pain
Sleep problems are associated with sickness absence and with pain. By analyzing data from the MUSIC-Norrtälje study we will study a possible association between self-reported sleep quality and sickness absence during five subsequent years. The MUSIC-Norrtälje study was initiated in order to identify and quantify risk factors and protective factors for LBP and NSP, and to investigate the prognoses of these disorders. The Norrtälje Study was at baseline case-referent study (1994-1996), with five-year follow-up including men and women, 20-59 years old living and working in Norrtälje. Census data from the National Social Insurance Board on sickness absence were linked to each of the 2329 subjects who participated in both the baseline study and follow-up. The questionnaire at baseline and follow-up includes questions on sleep (Karolinska Sleep Questionnaire) and on musculoskeletal pain (Von Korff and The Standard Nordic Questionnaire). The hypothesis tested in this study is whether bad sleep predicts sickness absence during the five subsequent years in subjects who reported low back pain and/or neck shoulder pain at baseline.
HRV and sleep quality exposure to stressors
There is a known association between tinnitus on one hand and depression, anxiety and stress on the other. In addition to this, hearing disabilities are associated to an increased risk of mood disorders among adults. In this study, tinnitus, hearing problems as well as questionnaire data concerning common symptoms of stress will be regarded as indicators of stress and analyzed in relation to nocturnal HRV (heart rate variability). By studying twins we will also be able to investigate the relative importance of stress and genetic factors on HRV and the sympatho-vagal balance.
This cross-sectional study is a collaboration with the Twin Hearing Study. Male twins born 1926 to 1958 and who participated in a prior study published 1997 are recruited from the Swedish Twin Registry. Data on self-reported sleep (Karolinska Sleep Diary), 24 hour heart rate variability (HRV) and reported stress during the day prior the measurements has been assessed during 2010-2013. Subjective and objective data on hearing are assessed as part of the Twin Hearing Study. Correlations between self-reported sleep quality and stress, hearing disabilities, tinnitus and HRV parameters will be analyzed. In a first step, twin analysis will be conducted with tests for correlation of HRV traits for monozygotic twins and dizygotic twins, according Falconer`s formula. Further analysis with structural equation models will be conducted if number of subjects can assume enough power. In total, data have been assessed in 202 individuals (44 monozygotic pairs, 28 dizygotic pairs, 58 singletons).
Sleep quality in patients with work-related psychological disorders
MiiNA is a new short term individually targeted intervention program based on interviews and diagnostic tools for patients with new onset work-related psychological disorders. For evaluation of the intervention program, data on subjective sleep (Karolinska Sleep diary) and objective sleep (Actiwatch) is assessed together with a self-administered questionnaire concerning psychological health including HAD (Hospital Anxiety and Depression scale), EQ-5D, SMBM - Shirom, Melamed Burnout Measure and WAI (Work Ability Index). Data is assessed before the intervention, directly after the intervention and six months after intervention. In all, data from approximately 30 individuals participating in MiiNA and 30 controls (receiving treatment as usual) will be assessed. The intervention program (MiiNA) is targeted towards occupational health care units, and participants (patients) are recruited through caregivers who have received training for MiiNA. The correlation between sleep (objective and subjective) and self-rated changes of psychological health will also be calculated in order to investigate whether sleep quality will influence the effect of the intervention program.