Cost-Effectiveness of Virtual Reality Cognitive Behavioral Therapy for Psychosis: Health-Economic Evaluation Within a Randomized Controlled Trial

Background

Evidence was found for the effectiveness of virtual reality-based cognitive behavioral therapy (VR-CBT) for treating paranoia in psychosis, but health-economic evaluations are lacking.

Objective

This study aimed to determine the short-term cost-effectiveness of VR-CBT.

Methods

The health-economic evaluation was embedded in a randomized controlled trial evaluating VR-CBT in 116 patients with a psychotic disorder suffering from paranoid ideation. The control group (n=58) received treatment as usual (TAU) for psychotic disorders in accordance with the clinical guidelines. The experimental group (n=58) received TAU complemented with add-on VR-CBT to reduce paranoid ideation and social avoidance. Data were collected at baseline and at 3 and 6 months postbaseline. Treatment response was defined as a pre-post improvement of symptoms of at least 20% in social participation measures. Change in quality-adjusted life years (QALYs) was estimated by using Sanderson et al’s conversion factor to map a change in the standardized mean difference of Green’s Paranoid Thoughts Scale score on a corresponding change in utility. The incremental cost-effectiveness ratios were calculated using 5000 bootstraps of seemingly unrelated regression equations of costs and effects. The cost-effectiveness acceptability curves were graphed for the costs per treatment responder gained and per QALY gained.

Results

The average mean incremental costs for a treatment responder on social participation ranged between €8079 and €19,525, with 90.74%-99.74% showing improvement. The average incremental cost per QALY was €48,868 over the 6 months of follow-up, with 99.98% showing improved QALYs. Sensitivity analyses show costs to be lower when relevant baseline differences were included in the analysis. Average costs per treatment responder now ranged between €6800 and €16,597, while the average cost per QALY gained was €42,030.

Conclusions

This study demonstrates that offering VR-CBT to patients with paranoid delusions is an economically viable approach toward improving patients’ health in a cost-effective manner. Long-term effects need further research.

Trial Registration

International Standard Randomised Controlled Trial Number (ISRCTN) 12929657; http://www.isrctn.com/ISRCTN12929657

Ultrahigh risk for developing psychosis and psychotic personality organization

AIMS

Childhood adversities combined with unsafe parenting may disturb personality development. This study investigated whether psychotic personality organization as defined by Kernberg and assessed with de Dutch Short Form of the MMPI (DSFM) is more prevalent in ultrahigh risk (UHR) for psychosis compared with non-psychotic psychiatric control patients (NPPC).

METHODS

A total of 73 UHR and 119 NPPC patients were assessed with the DSFM and the Comprehensive Assessment of at Risk Mental States (CAARMS).

RESULTS

The results showed that the psychotic personality organization (PPO) was not associated to UHR status. The UHR group showed more severe symptoms, particularly higher scores on DSFM subscales negativism (negative affect) and somatization (vague somatic complaints) and severe psychopathology (psychotic symptoms and dissociation).

CONCLUSION

The PPO profile is not associated to the risk of developing psychosis.

Individualized Prediction of Transition to Psychosis in 1,676 Individuals at Clinical High Risk: Development and Validation of a Multivariable Prediction Model Based on Individual Patient Data Meta-Analysis

Background: The Clinical High Risk state for Psychosis (CHR-P) has become the cornerstone of modern preventive psychiatry. The next stage of clinical advancements rests on the ability to formulate a more accurate prognostic estimate at the individual subject level. Individual Participant Data Meta-Analyses (IPD-MA) are robust evidence synthesis methods that can also offer powerful approaches to the development and validation of personalized prognostic models. The aim of the study was to develop and validate an individualized, clinically based prognostic model for forecasting transition to psychosis from a CHR-P stage. Methods: A literature search was performed between January 30, 2016, and February 6, 2016, consulting PubMed, Psychinfo, Picarta, Embase, and ISI Web of Science, using search terms ("ultra high risk" OR "clinical high risk" OR "at risk mental state") AND [(conver* OR transition* OR onset OR emerg* OR develop*) AND psychosis] for both longitudinal and intervention CHR-P studies. Clinical knowledge was used to a priori select predictors: age, gender, CHR-P subgroup, the severity of attenuated positive psychotic symptoms, the severity of attenuated negative psychotic symptoms, and level of functioning at baseline. The model, thus, developed was validated with an extended form of internal validation. Results: Fifteen of the 43 studies identified agreed to share IPD, for a total sample size of 1,676. There was a high level of heterogeneity between the CHR-P studies with regard to inclusion criteria, type of assessment instruments, transition criteria, preventive treatment offered. The internally validated prognostic performance of the model was higher than chance but only moderate [Harrell's C-statistic 0.655, 95% confidence interval (CIs), 0.627-0.682]. Conclusion: This is the first IPD-MA conducted in the largest samples of CHR-P ever collected to date. An individualized prognostic model based on clinical predictors available in clinical routine was developed and internally validated, reaching only moderate prognostic performance. Although personalized risk prediction is of great value in the clinical practice, future developments are essential, including the refinement of the prognostic model and its external validation. However, because of the current high diagnostic, prognostic, and therapeutic heterogeneity of CHR-P studies, IPD-MAs in this population may have an limited intrinsic power to deliver robust prognostic models.

CBT in the prevention of psychosis and other severe mental disorders in patients with an at risk mental state: A review and proposed next steps

Patients with an 'At risk mental state' (ARMS) for developing psychosis can be treated successfully with CBT to postpone and prevent the transition to a first psychotic episode. A characteristic of individuals that meet ARMS criteria is that they are still open for multiple explanations for extraordinary experiences. CBT aims to normalize extraordinary experiences with education and to prevent delusional explanations. The treatment is not only effective, but also cost-saving in averting psychosis as well as in reducing disability adjusted life years at 18- and 48-month follow-up. Profiling within the ARMS group results in a personalized treatment. The screening and early treatment for ARMS fulfills all the criteria of the World Health Organization and is ready to be routine screening and treatment in mental health care. At the same time, ARMS patients are complex patients with multi-morbid disorders. Especially childhood trauma is associated to ARMS status, together with co-morbid PTSD, depression, substance abuse and anxiety disorders. Psychotic symptoms appear to be severity markers in other non-psychotic disorders. Preventing psychosis in ARMS patients should be broadened to also address other disorders and aim to reduce chronicity of psychopathology and improve social functioning in general. Several mechanisms play a part in psychopathology in ARMS patients such as stress sensitivity as a result of adverse experiences, dopamine sensitivity that is associated with salience and aggravates several cognitive biases, dissociation mediating between trauma and hallucinations, and low self-esteem and self-stigma. New avenues to treat the complexity of ARMS patients will be proposed.

Predicting trauma-focused treatment outcome in psychosis

OBJECTIVE

Although TF treatments are effective in patients with psychosis, it is unknown whether specific psychosis-related obstacles limit the effects, and what determines good outcome.

METHODS

Baseline posttraumatic stress disorder (PTSD) symptom severity and seven psychosis-specific variables were tested as predictors in patients with a psychotic disorder and PTSD (n=108), who received eight sessions of TF treatment (Prolonged Exposure, or Eye Movement Desensitization and Reprocessing therapy) in a single-blind randomized controlled trial. Multiple regression analyses were performed.

RESULTS

Baseline PTSD symptom severity was significantly associated with posttreatment PTSD symptom severity, explaining 11.4% of the variance. Additionally, more severe PTSD at baseline was also significantly associated with greater PTSD symptom improvement during treatment. After correction for baseline PTSD symptom severity, the model with the seven baseline variables did not significantly explain the variance in posttreatment PTSD outcome. Within this non-significant model, the presence of auditory verbal hallucinations contributed uniquely to posttreatment outcome but explained little variance (5.4%). Treatment completers and dropouts showed no significant difference on any of the psychosis-related variables.

CONCLUSIONS

Given the low predictive utility of baseline psychosis-related factors, we conclude that there is no evidence-based reason to exclude patients with psychotic disorders from TF treatments. Also, we speculate that patients with psychosis and severe baseline PTSD might derive more benefit if given more than eight sessions. Trial registration current controlled-trials.com | Identifier: ISRCTN79584912 | http://www.isrctn.com/ISRCTN79584912.

[Prognostic modelling and proactive intervention in psychosis: efficacy and cost-effectiveness]

Diagnoses have heterogeneous outcomes, varying from good to extremely poor. There is a need to single out an ultra-high-risk group of individuals who have illnesses that might well end unfavourably or who might later develop serious psychopathology.<br/> AIM: To devise a screening instrument that can identify a group of individuals who run a very high risk of developing a first-episode psychosis, and to create a type of intervention that can modify the course of the illness.<br/> METHOD: We developed a short screening instrument (PQ-16) and were able to ascertain its predictive value. We also tested an intervention that could influence risk factors and deal with emerging symptoms thereby achieving a better outcome for the patient.<br/> RESULTS: We developed a two-step detection instrument with a positive predictive value of 44%. The intervention, involving cognitive behavioural therapy for ultra-high-risk patients, was effective and led to a risk reduction of about 50%. Using the ultra-high-risk group of patients, we were able to model three prognostic profiles, each carrying a 4%, 13%, and 70% risk of subsequently developing psychosis. The intervention was cost-effective, reducing the financial burden on the health care services and on society as a whole.<br/> CONCLUSION: Prognostic modelling and proactive intervention can achieve improvements in health at lower costs.

Exposing therapists to trauma-focused treatment in psychosis: effects on credibility, expected burden, and harm expectancies

BACKGROUND

Despite robust empirical support for the efficacy of trauma-focused treatments, the dissemination proves difficult, especially in relation to patients with comorbid psychosis. Many therapists endorse negative beliefs about the credibility, burden, and harm of such treatment.

OBJECTIVE

This feasibility study explores the impact of specialized training on therapists' beliefs about trauma-focused treatment within a randomized controlled trial.

METHOD

Therapist-rated (n=16) credibility, expected burden, and harm expectancies of trauma-focused treatment were assessed at baseline, post-theoretical training, post-technical training, post-supervised practical training, and at 2-year follow-up. Credibility and burden beliefs of therapists concerning the treatment of every specific patient in the trial were also assessed.

RESULTS

Over time, therapist-rated credibility of trauma-focused treatment showed a significant increase, whereas therapists' expected burden and harm expectancies decreased significantly. In treating posttraumatic stress disorder (PTSD) in patients with psychotic disorders (n=79), pre-treatment symptom severity was not associated with therapist-rated credibility or expected burden of that specific treatment. Treatment outcome had no influence on patient-specific credibility or burden expectancies of therapists.

CONCLUSIONS

These findings support the notion that specialized training, including practical training with supervision, has long-term positive effects on therapists' credibility, burden, and harm beliefs concerning trauma-focused treatment.

Detection of people at risk of developing a first psychosis: comparison of two recruitment strategies

OBJECTIVE

Better recruitment strategies are needed to improve the identification of people at ultra-high risk of developing psychosis. This study explores the effectiveness of two recruitment strategies: a screening method in a consecutive help-seeking population entering secondary mental health services for non-psychotic problems vs. a population referred to the diagnostic center of an early-psychosis clinic.

METHOD

From February 2008 to February 2010, all general practitioner and self-referrals (aged 18-35 years) to the secondary mental healthcare service in The Hague and Zoetermeer were screened with the Prodromal Questionnaire; patients who scored above the cutoff of 18 and had a decline in social functioning were assessed using the Comprehensive Assessment of At-Risk Mental States (CAARMS). All referrals (aged 14-35 years) to the diagnostic center in Amsterdam were also assessed with the CAARMS.

RESULTS

The screening detected a three-fold higher prevalence of at-risk mental states: these subjects were older and more often female. manova showed significantly higher scores for the screened population on depression, social anxiety, distress with positive symptoms, and a higher rate of transition to psychosis within 12 months.

CONCLUSION

The screening method detects more patients with at-risk mental states than the referral method. The latter method is biased to young male patients in an earlier prodromal stage and a lower transition rate.

Ethnicity and baseline symptomatology in patients with an At Risk Mental State for psychosis

BACKGROUND

Ethnicity has been associated with different incidence rates and different symptom profiles in young patients with psychotic-like disorders. No studies so far have examined the effect of ethnicity on symptoms in people with an At Risk Mental State (ARMS).

METHOD

In this cross-sectional study, we analysed the relationship between ethnicity and baseline data on the severity of psychopathology scores in 201 help-seeking patients who met the ARMS criteria and agreed to participate in the Dutch Early Detection and Intervention (EDIE-NL) trial. Eighty-seven of these patients had a non-Dutch ethnicity. We explored the possible mediating role of ethnic identity.

RESULTS

Higher rates of negative symptoms, and of anhedonia in particular, were found in the ethnic minority group. This result could be attributed mainly to the Moroccan-Dutch and Turkish-Dutch subgroups, who also presented with more depression symptoms when the groups were examined separately. The ethnic minority group displayed a lower level of ethnic group identity compared to the immigrants of the International Comparative Study of Ethnocultural Youth (ICSEY). Ethnic identity was inversely related to symptoms in the Moroccan-Dutch patient group.

CONCLUSIONS

The prevalence of more severe negative symptoms and depression symptoms in ethnic minority groups deserves more attention, as the experience of attenuated positive symptoms when accompanied by negative symptoms or distress has proven to be predictive for transition to a first psychotic episode.

Predictors of persistence of ultrahigh risk symptoms and predictors of transition into psychosis

Aims

To determine predictors of transition from ultrahigh risk into psychosis.

Method

The Dutch EDIE trial has included 201 people with an ultrahigh risk for psychosis. These were included with both a referral based strategy and a screening all help-seeking people strategy. The study had a 24 month inclusion period and an 18 mont follow-up period with each patient. The preliminary results are presented.

Results

A loogistic regression was performed over 164 cases. 29 patients developed a psychosis.

Predictor variables were depression, social intercation anxiety, positive symptoms on the CAARMS, negative symptoms on the CAARMS, quality of life, social functioning, genetic risk, and the personal beliefs about illness.

The backward logistice regression (likelyhood ratio) discarded four variables. Predictors of psychosis were depression, positive symptoms, genetic liability and beliefs about illness at basline.

Conclusions

People with hihd scores on depression and positive symptoms are likely to develop a psychosis. Also those who have a psychotic parent and positive symptoms a more lekly to make a transition. Interestingly people that consider their condition as hopeless, feel entrapped by their condition, excluded by other pople and not in control of symptoms also have a heightened chance for developing psychosis in this sample.

A single blind randomized controlled trial of cognitive behavioural therapy in a help-seeking population with an At Risk Mental State for psychosis: the Dutch Early Detection and Intervention Evaluation (EDIE-NL) trial

Background

Psychotic disorders are a serious mental health problem. Intervention before the onset of psychosis might result in delaying the onset, reducing the impact or even preventing the first episode of psychosis. This study explores the effectiveness of cognitive behavioural therapy (CBT) in targeting cognitive biases that are involved in the formation of delusions in persons with an ultra-high risk for developing psychosis. A single blind randomised controlled trial compares CBT with treatment as usual in preventing or delaying the onset of psychosis.

Method/design

All help seeking patients aged 14 to 35 years referred to the mental health services in three regions in the Netherlands are pre-screened with the Prodromal Questionnaire during a period of two years. Patients with a score of 18 or more on the sub-clinical positive symptoms items (45 items in total) will be assessed with the Comprehensive Assessment of At Risk Mental State (CAARMS). In a different pathway to care model all referrals from the mental health services in Amsterdam to the specialized psychosis clinic of the Academic Medical Centre in Amsterdam are also assessed with the CAARMS. The primary outcome is the transition rate to psychosis according to the CAARMS-criteria. Group differences will be analysed with chi-square tests and survival analyses.

Discussion

CBT is a highly tolerated treatment. The psycho-educational CBT approach may prove to be a successful strategy since most people with an At Risk Mental State (ARMS) are distressed by odd disturbing experiences. Giving explanations for and normalising these experiences may reduce the arousal (distress) and therefore may prevent people from developing a catastrophic delusional explanation for their odd experiences and thus prevent them from developing psychosis.

Screening the entire help-seeking population referred to community mental health services with a two-stage strategy, as compared with traditional referral to a specialist clinical psychosis centre, might detect more ultra-high-risk (UHR) patients. This type of screening could be implemented in mental health care as routine screening. The trial is registered at Current Controlled trials as trial number ISRCTN21353122.

Air pollution exposure potentiates hypertension through reactive oxygen species-mediated activation of Rho/ROCK

OBJECTIVE

Fine particulate matter <2.5 microm (PM(2.5)) has been implicated in vasoconstriction and potentiation of hypertension in humans. We investigated the effects of short-term exposure to PM(2.5) in the angiotensin II (AII) infusion model.

METHODS AND RESULTS

Sprague-Dawley rats were exposed to PM(2.5) or filtered air (FA) for 10 weeks. At week 9, minipumps containing AII were implanted and the responses studied over a week. Mean concentration of PM(2.5) inside the chamber was 79.1+/-7.4 microg/m(3). After AII infusion, mean arterial pressure was significantly higher in PM(2.5)-AII versus FA-AII group. Aortic vasoconstriction to phenylephrine was potentiated with exaggerated relaxation to the Rho-kinase (ROCK) inhibitor Y-27632 and increase in ROCK-1 mRNA levels in the PM(2.5)-AII group. Superoxide (O(2).(-)) production in aorta was increased in the PM(2.5)-AII compared to the FA group, inhibitable by apocynin and L-NAME with coordinate upregulation of NAD(P)H oxidase subunits p22(phox) and p47(phox) and depletion of tetrahydrobiopterin. In vitro exposure to ultrafine particles (UFP) and PM(2.5) was associated with an increase in ROCK activity, phosphorylation of myosin light chain, and myosin phosphatase target subunit (MYPT1). Pretreatment with the nonspecific antioxidant N-acetylcysteine and the Rho kinase inhibitors (Fasudil and Y-27632) prevented MLC and MYPT-1 phosphorylation by UFP suggesting a O(2)(.-)-mediated mechanism for PM(2.5) and UFP effects.

CONCLUSIONS

Short-term air pollution exaggerates hypertension through O(2)(.-)-mediated upregulation of the Rho/ROCK pathway.

Reduction in noise-induced temporary threshold shift in humans following oral magnesium intake

A previous study demonstrated the prophylactic effects of magnesium on noise-induced permanent threshold shift in humans. For the first time, this study explores the effects of magnesium on temporary threshold shift in 20 human subjects, all men (16-37 years, mean age 21 years). The study was conducted in a double-blind manner on the same subjects tested in three different phases (placebo, magnesium, no-drug). The cochlear changes were assessed using both behavioural (audiograms) and objective (otoacoustic emission) measures. Blood samples were collected at the beginning and end of each phase. Amongst subjects and phases, magnesium intake was associated with significantly lower temporary threshold shift, compared with the other two phases, which were reflected both by the behavioural and cochlear measures. A correlation was found between the blood magnesium levels and temporary threshold shift reduction. No side-effects were associated with the oral ingestion of the magnesium. Magnesium provides significant protection against temporary threshold shift, complementing the previous permanent threshold shift human study. Both human noise-induced hearing loss studies introduced a novel, biological, natural agent for prevention and possible treatment of noise-induced cochlear damage in humans.

Stress effects of noise in a field experiment in comparison to reactions to short term noise exposure in the laboratory

Reactions to noise-induced communication disturbance of 42 men during a seminar were investigated. Stress reactions with or without road traffic noise (Lm = 60 dBA) were compared. Traffic noise was played back via loudspeakers during one day in the seminar room. The following parameters were measured: Fatigue and mental tension by questionnaire; blood pressure and heart rate; excretion of adrenaline, noradrenaline and cAMP from the collected urine. The same subjects participated in a laboratory test where the blood pressure was measured during 5 minutes of rest and after 5 minutes of exposure to intermittent white noise (Lm=97 dBA). It was found that the noise in the field experiment caused psychological and physiological stress effects in half of the subjects. Increased mental tension was correlated to increases as well as decreases of the blood pressure. Systolic blood pressure reactions were stronger than the reactions of diastolic blood pressure. Noise sensitive subjects reacted stronger than the others. In the short-term laboratory test, systolic blood pressure increases were smaller than the diastolic increases. At the end of the 5 minutes noise exposure only the diastolic blood pressure increases were significant. There was no correlation between the blood pressure reactions in the two different noise exposure experiments. There existed a positive correlation between noise sensitivity and the systolic blood pressure increases during the seminar, whilst the correlation, between noise sensitivity and systolic blood pressure increases in the laboratory exposure, was negative. From these results we conclude that short-term noise exposure experiments do not provide information about the effects of long-term real life exposure to environmental noise. Potential health effects of chronic noise-induced disturbances of activities are discussed.

Low frequency noise and stress: bronchitis and cortisol in children exposed chronically to traffic noise and exhaust fumes

A correlation of respiratory diseases to traffic related air pollution and noise was observed in an interview study. Since in that study the exposure was subjectively assessed, in the present field study nitrogen dioxide as indicator for vehicle exhausts and the mean night-time noise level were measured outside the children's windows in representative locations. Based on these measurements each child was placed in one of the following categories: low, medium or high traffic immission (ambient emissions). The physician contacts due to bronchitis of 68 children were assessed retrospectively from the files of the participating paediatricians. Saliva samples were collected from all children and the cortisol concentration was estimated. Children under high noise exposure (L(night, 8h) = 54-70dB(A)) had in comparison to all other children significantly increased morning saliva cortisol concentrations, indicating an activation of the hypothalamus-pituitary-adrenal (HPA) axis. Analysing a subgroup of children without high noise exposure showed, that children with frequent physician contacts due to bronchitis did not have increased morning saliva cortisol. However, multiple regression analysis with stepwise exclusion of variables showed that bronchitis was correlated more closely to morning salvia cortisol than to traffic immissions. On the other hand, the rate of physician contacts due to bronchitis increased in a dose dependent manner and significantly with increasing traffic immissions. From these results it can be concluded that high exposure to traffic noise, especially at nighttime, activates the HPA axis and this leads in the long term to an aggravation of bronchitis in children. This seems to be more important than the effect of exhaust fumes on bronchitis symptoms. The results of the present study should be subjected to further investigation using specially designed studies.

Health effects caused by noise: evidence in the literature from the past 25 years

Traffic noise is the most important source of environmental annoyance. According to the Environmental Expert Council of Germany, severe annoyance persistent over prolonged periods of time is to be regarded as causing distress. Previously, extraaural noise effects were mostly assessed using a paradigm in which the sound level played the major role. On the basis of this paradigm the relatively low sound level of environmental noise was not considered to be a potential danger to health. In contrast to this numerous empirical results have shown long-term noise-induced health risks. Therefore a radical change of attitude - a change of paradigm - is necessary. For an immediate triggering of protective reactions (fight/flight or defeat reactions) the information conveyed by noise is very often more relevant than the sound level. It was shown recently that the first and fastest signal detection is mediated by a subcortical area - the amygdala. For this reason even during sleep the noise from aeroplanes or heavy goods vehicles may be categorised as danger signals and induce the release of stress hormones. In accordance with the noise stress hypothesis chronic stress hormone dysregulations as well as increases of established endogenous risk factors of ischaemic heart diseases have been observed under long-term environmental noise exposure. Therefore, an increased risk of myocardial infarction is to be expected. The results of individual studies on this subject in most cases do not reach statistical significance. However, according to the Environmental Expert Council, these studies show a consistent trend towards an increased cardiovascular risk if the daytime immission level exceeds 65 dB(A). Most of the previous studies on the extraaural effects of occupational noise have been invalidated by exposure misclassifications. In future studies on health effects of noise a correct exposure assessment is one of the most important preconditions.

Health status as a potential effect modifier of the relation between noise annoyance and incidence of ischaemic heart disease

AIMS

Traffic noise is a psychosocial stressor. Epidemiological studies suggest chronic noise stress to be a risk factor for cardiovascular disorders.

METHODS

In a prospective cohort study, the association between annoyance and disturbances due to road traffic noise and the incidence of ischaemic heart disease (IHD) was studied in 3950 middle aged men.

RESULTS

Depending on the questionnaire item, non-significant odds ratios for IHD incidence ranging from 0.9 to 1.4 were found for the highly noise annoyed/disturbed subjects when compared with the less annoyed/disturbed subjects, over the six year follow up period. However, this relation was strongly modified by the prevalence of pre-existing chronic diseases. In subjects free of any chronic disease at the beginning of the follow up, significant odds ratios between 1.7 and 3.0 were seen. In the subgroup with chronic diseases no such noise effects were seen. This surprising result of no effect in the group of people with a potential risk, due to pre-existing health problems, may be because of the dilution of the true effect due to recall bias.

CONCLUSIONS

Annoyance and disturbance due to road traffic noise is associated with a higher incidence of IHD. Prevalence of disease can be an important effect modifier of the relation between noise annoyance and health outcomes.

Acute and chronic endocrine effects of noise: Review of the research conducted at the Institute for Water, Soil and Air Hygiene

This is a review of the research into endocrine effects of noise since the early 1980s at the Institute for Water, Soil and Air Hygiene. According to our knowledge, no other group has studied systematically the endocrine effects of acute and chronic noise exposure. Mechanisms of acute noise-induced stress reactions as well as long-term increase of stress hormones in animal and persons under chronic noise exposure were studied. Our theoretical background was Henry's psychophysiological stress model with the two reaction alternatives : (i) The fight-flight reaction, characterised by an increase in adrenalin and noradrenaline (ii) The defeat reaction with increased cortisol. Extremely intense acute noise exposure near the threshold of pain caused an increased release of cortisol from the suprarenal cortex but acute noise exposure with levels between 90 and 100 dB(A) caused an increase of catecholamines. Non-habituated noise increased primarily the release of adrenalin from the suprarenal medulla, whereas habituated noise caused a chronic increase of noradrenaline from the sympathetic synapses under longterm noise exposure at work. Environmental noise exposure (Leq >/= 60 dB(A)) caused catecholamine increase if activities such as conversation, concentration, recreation etc were disturbed through noise. In sleeping persons, traffic noise with only Leq >/= 30 dB (A) and Lmax >/= 55 dB(A) caused significant acute increase of cortisol, which developed into chronic increase if the noise exposure was repeated consistently. Parallel to cortisol, chronic noradrenaline increase was also observed. Based upon the empirical results, a noise stress model was developed which is a first step forward in the theoretical understanding of endocrine noise effects.

Ear damage caused by leisure noise

Noise is a health risk. Recent findings suggest that leisure noise is a substantial danger especially to children, teenagers and young adults. Epidemiological studies of teenagers with no occupational noise exposure show an increasing number with a substantial and measurable irreversible inner ear damage. This is basically due to the wide spread exposition to very loud toys (pistols and squibs), crackers and exposure to electronically amplified music, e.g. from personal cassette players (PCP), at discos or concerts etc. Protection against irreversible ear damage by leisure noise has an important impact in preventive medical care. Therefore the general public must be informed that loud leisure activities may cause damage to the ear. In order to protect children, young people and adults, the legislature ought to set limits for sound levels in discos, concert halls and for music equipment and toys by establishing the necessary standards and regulations.

Respiratory and dermatological diseases in children with long-term exposure to road traffic immissions

The pathogenesis of allergies can be stimulated by adjuvant effects--i.e. air pollutants such as NO(2) and particles from diesel exhausts as well as noise--the latter especially during night-time. During sleep, noise signals which are associated with danger (i.e. lorry noise) have the potential to trigger stress reactions even if the noise level is low. Increases of cortisol in the first half of the night seem to play an important role. In a blind interview study, the combined effects of chronic exposure to traffic related air pollution and noise, upon the risk of skin and respiratory diseases in children were studied. All children between 5-12 years, who had consulted one of two participating paediatricians were included in the study. The paediatricians diagnoses of 400 children were analysed together with their parents answers regarding the density of road traffic on their street and several confounding factors. Multiple regression analyses resulted in relative risks of asthma, chronic bronchitis and neurodermitis, which increased significantly with increasing traffic load. A comparison with the literature on such effects caused by air pollution alone, showed that traffic noise during the night might have an adjuvant effect on the pathogenesis of the mentioned diseases.

Community noise exposure and stress in children

Although accumulating evidence over the past two decades points towards noise as an ambient stressor for children, all of the data emanate from studies in high-intensity, noise impact zones around airports or major roads. Extremely little is known about the nonauditory consequences of typical, day-to-day noise exposure among young children. The present study examined multimethodological indices of stress among children living under 50 dB or above 60 dB (A-weighted, day-night average sound levels) in small towns and villages in Austria. The major noise sources were local road and rail traffic. The two samples were comparable in parental education, housing characteristics, family size, marital status, and body mass index, and index of body fat. All of the children were prescreened for normal hearing acuity. Children in the noisier areas had elevated resting systolic blood pressure and 8-h, overnight urinary cortisol. The children from noisier neighborhoods also evidenced elevated heart rate reactivity to a discrete stressor (reading test) in the laboratory and rated themselves higher in perceived stress symptoms on a standardized index. Furthermore girls, but not boys, evidenced diminished motivation in a standardized behavioral protocol. All data except for the overnight urinary neuroendocrine indices were collected in the laboratory. The results are discussed in the context of prior airport noise and nonauditory health studies. More behavioral and health research is needed on children with typical, day-to-day noise exposure.

Preventive effect of magnesium supplement on noise-induced hearing loss in the guinea pig

The effect of magnesium (Mg) on noise-induced hearing loss was investigated in two groups of adult pigmented guinea pigs maintained either on optimal or suboptimal (physiologically high or low) Mg produced by different diets. The total Mg concentrations of the perilymph (PL), cerebrospinal fluid, blood plasma and red blood cells were measured by atomic absorption spectrometry and were found to differ significantly between the two groups (P < 0.01). One ear of each animal was exposed to either a single shooting impulse at a peak pressure level of 187 dB or two impulse noise series at a rate of 1/s and peak pressure levels of 150 dB (1,000 impulses) and 167 dB (2,280 impulses), respectively. Temporary (TTS) and permanent (PTS) hearing threshold shifts in anesthetized animals were measured 2 h and 1 week after the noise exposure, using auditory brain stem response (ABR) audiometry at a frequency range from 3.75 to 30 kHz. Exposure to the single noise impulse resulted in a mean TTS that was significantly lower in the high Mg group than that in the low Mg group (P < 0.05), although no substantial PTS was observed in either group. In the animals exposed to 150 dB noise, the TTS showed a tendency towards an Mg-related reduction at the higher frequencies. A small difference in PTS was found between the low Mg and high Mg groups, but was not significant. Exposure to the 167-dB noise series caused a considerable TTS, which was significantly lower in the high Mg group at 7.5 and 15 kHz than in the low Mg group (P < 0.05). The mean PTS showed a significant difference between the two Mg groups over the whole frequency range (P < 0.05) and was found to correlate negatively with the total Mg concentrations of both PL and plasma (P < 0.05). Moreover, the high Mg group showed a faster recovery from the hearing threshold shift than the low Mg group. The present findings show that preventive oral Mg supplements can significantly reduce the rate of acoustic trauma caused by high-level impulse noise exposure in the guinea pig.

Total magnesium concentrations of perilymph, cerebrospinal fluid and blood in guinea pigs fed different magnesium-containing diets

The total magnesium (Mg) concentrations of the perilymph (PL), cerebrospinal fluid (CSF), plasma and red blood cells (RBCs) of anesthetized guinea pigs separated into three groups and fed different Mg-containing diets were determined by atomic absorption spectrometry. Due consideration was given to the significant sources of error connected with the sampling procedure, particularly contamination of PL with CSF. The Mg levels of the individuals fluids differed significantly (P < 0.05/0.01) within each group. In the normal Mg group, the mean values of the PL, CSF and plasma were 0.66, 0.81 and 0.97 mmol/l, respectively, and 7.83 mmol/kg dry weight for RBCs. The analytical data were found to depend on the Mg content of the animals' diet, but to a different degree in the individual specimens (plasma > PL > CSF). A correlation was found to exist between all specimens tested (P < 0.05/0.01), except for CSF and RBCs, with the closest relation being that between plasma and PL. These findings suggest that the perilymphatic Mg equilibrates with the Mg level of plasma rather than with that of CSF. This is the first report showing Mg data of PL, CSF, plasma and RBCs obtained from the same subject, and the dependency on the Mg content of the animals' diet.

Traffic noise and cardiovascular risk: the Caerphilly and Speedwell studies, third phase--10-year follow up

The authors tested the hypothesis that prolonged exposure to road traffic noise causes ischemic heart disease in a 10-y follow-up cohort study of middle-aged men. In the Caerphilly and Speedwell studies, 2512 and 2348 men, respectively, who were 45-59 y of age were seen in the initial cross-sectional phase and at follow-up intervals of 10 y. Adjusted odds ratios of 1.1 (95% confidence interval = 0.6, 1.9) and 0.9 (95% confidence interval = 0.6, 1.4) were found in the total cohorts. However, the relative risk was 1.3 (95% confidence interval = 0.8, 2.2) in the pooled reconstructed cohort of men who were followed for 6 y (i.e., from phase 2 to phase 3) and for whom room orientation and window-opening habits could be considered. Furthermore, the relative risk increased to 1.6 (95% confidence interval = 0.9, 3.0) in the subsample of men who had lived at least 15 y in their present homes at the time of recruitment. Living adjacent to streets with high traffic noise levels was associated with an adjusted (for covariates) increase in relative risk of 1.01-1.02/y in residence--a result that was only borderline significant (p < .10).

[Hearing loss caused by leisure noise]

Although noise in general can induce hearing loss, environmental noise represents an important risk for children, teenagers and young adults. Epidemiological investigations now support the occurrence of an increasing number of irreversible hearing losses in these groups. Major causes of hearing loss are toys (guns), explosives and electroacoustically amplified music delivered by head sets or heard in discotheques and open air concerts. Clinical indications are discussed.

Subjective work noise: a major risk factor in myocardial infarction

The relationship between subjective work noise exposure and the risk of myocardial infarction (MI) was assessed in a population based case-control study. 395 MI patients (31-65 years) were compared to 2148 controls from a random population sample with the same agelsex distribution. The relative risk (RR) for MI-adjusted for control variables (smoking, age, social status, etc.)-was found to increase significantly and steadily with noise category. Subjective work noise exposure was the second greatest risk factor for MI after smoking. Possible bias due to overreporting of subjective noise exposure is discussed. Interdisciplinary studies on the relationship between cardiovascular diseases and work-related stressors including subjective and objective noise assessment are needed to quantify the risk of MI due to work noise.

Dietary magnesium does not predict ischaemic heart disease in the Caerphilly cohort

OBJECTIVES

To examine the association between dietary magnesium intake and the risk of an ischaemic heart disease (IHD) event.

DESIGN

Estimates were made of dietary magnesium intake from food frequency records, supplemented by seven-day weighted intake records. The subsequent incidence of ischaemic heart disease events was recorded. The relative odds of an IHD event was related to base-line magnesium intake.

SETTING

Data on dietary magnesium intakes are available for 2172 men aged 45-59 y in the Caerphilly cohort. These have now been followed for ten years since base-line dietary data were collected, and during this time a total of 269 IHD events occurred. Of these, 96 were acute deaths (ICD 410) and 136 were non-fatal myocardial infarctions.

RESULTS

The overall mean dietary intake of magnesium was estimated to be 279 (s.d. 83) mg/day. The daily intake of those men who later experienced any IHD event was 266 (s.d. 84) mg/day and this differs from that in men who experienced no IHD event during this time (281 mg, P < 0.05). Men who suffered an acute IHD death had even lower intakes (mean 253 (s.d. 79); P < 0.005). Age, smoking habit, energy intake and alcohol consumption are all significantly associated with both Mg intake and IHD risk and are therefore possible confounding factors. Standardisation for these factors reduces the difference for all IHD events to 2.9 (s.e.m. 3.6) mg Mg/day, P > 0.05, and to 0.9 (s.e.m. 5.8) mg for acute IHD death. Similarly, when the men are ranked into fifths by their daily Mg intake, 70 of the 434 men with the lowest intakes went on to experience an IHD event, compared with only 41 of the 434 men with the highest Mg intakes. The relative odds (RO) for the fifth of men with the lowest intakes, compared with the fifth with the highest intakes, is 1.86 (P < 0.005), but standardisation for the confounding factors leads again to a loss of significance (RO 1.52, P > 0.05).

CONCLUSION

Although trends in the data are suggestive, data from the Caerphilly cohort give no certain evidence that dietary magnesium intake is independently predictive of ischaemic heart disease in the population studied.

Changes of ionized magnesium and free fatty acids in serum after acute myocardial infarction

The most feared early complications after an acute myocardial infarction are ventricular arrhythmias. These may be initiated by changed concentrations of catecholamines and electrolytes. The present study shows a reduction of total serum magnesium after acute myocardial infarction which is normalized within a few days. Further, it could be shown that a more significant decrease of ionized Mg2+ (iMg2+) takes place at the day of acute myocardial infarction in the total group of myocardial infarction patients (n = 36). A closer investigation reveals that iMg2+ was considerably decreased in one third of the patients, whereas two thirds showed minor changes of iMg2+ in both directions. The pronounced decrease of iMg2+ in the first sub-group can be explained by the time course of free fatty acids in serum. On the day of the myocardial infarction free fatty acids in serum were increased. This is probably caused by beta-adrenergic-induced lipolysis due to catecholamines released by the stressful situation of an acute myocardial infarction. The increased free fatty acids in serum bind Mg2+, thus reducing iMg2+. As long as a beneficial effect of a general Mg infusion in all acute myocardial infarction patients is controversial, iMg2+ should be measured and Mg infusion therapy should be applied only in patients with low iMg2+.

Measurement of free magnesium in blood, serum and plasma with an ion-sensitive electrode

The fraction of total magnesium bound to protein and other substances depends upon the pH. pH-dependency of ionized free magnesium (iMg2+) in serum is expressed by the Siggaard-Andersen equation: iMg2+ (pH) = iMg2+ (7.4) x 10x(7.4 - pH). During preparation of serum or plasma, considerable pH changes occur which have to be corrected on the basis of the above mentioned equation. For pH correction of iMg2+, x < 0.1 has so far been used. However, this is correct only for new Mg(2+)-sensitive electrodes. During the lifetime of Mg2+ electrodes used in the "Microlyte Magnesium" (Kone Instruments, Finland) x increases and x = 0.2 was found to be a suitable approximation for most of the lifetime. By instantaneous iMg2+ measurements in whole blood samples pH changes and the uncertainty of x can be avoided. Dilution of blood by intravenous infusions decreases x nearly proportionally to the decrease of protein concentration in blood. Various methodological influences such as temperature and delay time before centrifugation, storage of serum and venous occlusion were studied. The circadian rhythm of iMg2+ was found to be considerably more pronounced than that of total Mg and was negatively correlated to changes of free fatty acids. To avoid variations of iMg2+ due to circadian changes, blood collection should be carried out between 6 and 10 a.m. The normal range of iMg2+ in blood of 179 healthy subjects was found to be between 0.46 and 0.60 mmol/l and the quotient of free and total Mg between 0.59 and 0.71. The accuracy of "Microlyte Magnesium" (Kone Instruments, Finland) is sufficient in a wide range of iMg2+.

[Empirical studies of music listening habits of adolescents. Optimizing sound threshold limits for cassette players and discoteques]

The music habits of 569 pre-teens and teenagers, between 10 and 17 years of age, were examined and exposure to music from portable music players was compared to that in discotheques. Using a questionnaire we determined the length of time spent listening to portable music players and the frequency of disco visits. The individual level of the music heard through portable music players was measured as a free-field corrected short term mean level. The total music exposure (related to 40 hours per week) was calculated from the data and different assumed disco sound levels. We estimated the risk of ear damage according to ISO 1999 standards on the basis of the total music exposure, whereby the mean disco level was varied as a parameter in the range of 95 to 110 dB(A). Taking only the portable music players into account, one can expect that even after 5 years of music, approximately 5% of the total group would have a hearing loss of 20 dB. This percentage clearly rises when additional exposure is given in discotheques having music levels above 100 dB(A). We suggest therefore that for safety reasons the following sound levels should be observed: 90 dB(A) for portable music players and 95 dB(A) for discos. Through adherence to these levels we would expect that 1% of the young people in our study would have a hearing loss > 10 dB, whereas momentary exposure would result in a hearing loss > 10 dB of 10-20%. Therefore we believe that sound level limitations should be enacted immediately for portable music players and in discotheques.

[Sensorineural hearing loss in children starting school. Results of a representative hearing screening study]

Audiograms in the 0.5-6 kHz frequency range were taken, using improved audiometric screening methods, in 2032 children, 6-7 years old, who were undergoing their pre-school medical examinations. In 151 children (7.4%), the threshold for hearing was above 20 dB for at least one frequency. Of these, 82 children (4% of the overall sample) had a hearing impairment defined as a difference of > or = 10 dB between at least one frequency (3, 4 or 6 kHz) and the mean value from 1+2 kHz. This was evaluated as a sensorineural hearing loss. Unilateral losses (lateral difference > or = 10 dB) were more common than bilateral losses (2.5% vs 1.6% of the overall sample). These unilateral hearing losses in the high-frequency range are essentially regarded as the result of playing with impulse-noise producing toys, such as toy guns with caps.

[Risk of hearing loss caused by listening to music with head phones]

Sound levels of music played from mini-cassette players via headphones were measured in a nonrepresentative group of 681 pupils whose ages were between 10 to 19 years. Each pupil completed a questionnaire giving the total time spent listening to music each day. The pupils set the music levels (free field corrected short time Leq) between 60 dB(A) and 110 dB(A). In the age group from 12-16 years, 10% chose 110 dB(A). Nearly 50% of the total group usually listened to music less than one hour per day, and just less than 10% listened for four or more hours. The energy equivalent of continuous sound pressure level for an exposure time of 8 h per day was for 55% Leq 8 h < 66 dB(A) and for 7% Leq 8 h > 95 dB(A) while 4% had an Leq 8 h > 105 dB(A). Estimation of the expected hearing losses (HL) were based on ISO 1999: about 10% of the total group were predicted to have a HL > 10 dB at 4 kHz after 5 years. After listening to sound in this manner 0.3% were expected to develop hearing losses at age 25 years that would be severe enough to substantially impair speech intelligibility.

Oral magnesium intake reduces permanent hearing loss induced by noise exposure

INTRODUCTION

Following animal experiments where correlations were observed between serum magnesium level and noise-induced permanent hearing threshold shifts (NIPTS), we tested the prophylactic effect of magnesium in human subjects exposed to hazardous noise.

METHODS

Subjects were 300 young, healthy, and normal-hearing recruits who underwent 2 months of basic military training. This training necessarily included repeated exposures to high levels of impulse noises while using ear plugs. During this placebo-controlled, double-blind study, each subject received daily an additional drink containing either 6.7 mmol (167 mg) magnesium aspartate or a similar quantity of placebo (Na-aspartate).

RESULTS

NIPTS was significantly more frequent and more severe in the placebo group than in the magnesium group, especially in bilateral damages. NIPTS was negatively correlated to the magnesium content of blood red cells but especially to the magnesium mononuclear cells. Long-term additional intake of a small dose of oral magnesium was not accompanied by any notable side effect.

CONCLUSION

This study may introduce a significant natural agent for the reduction of hearing damages in noise-exposed population.

Comparative findings on serum IMg2+ of normal and diseased human subjects with the NOVA and KONE ISE's for Mg2+

It is clear now that although different ionophores for ionized Mg (IMg2+) have been designed by several groups, each of these has a distinctly different KMgCa. In view of this, it is important to determine whether each of these ion selective electrodes (ISE's) yield identical results for IMg2+ in sera from healthy and diseased humans. Using such an approach, we determined, in a blinded-and random manner, IMg2+ with both the NOVA and KONE ISE's for IMg2+ in two independent laboratories. No significant differences were found either for sera from healthy human volunteers or diseased patients. We did, however, note several interesting findings: 1. randomly, selected hospitalized patients exhibit a much higher incidence of abnormalities for IMg2+ (57-71%) than that noted previously for total Mg (TMg) measurements; and 2. coronary heart disease, rectal cancer and multiple sclerosis patients exhibit extracellular deficits in ionized free Mg.

Traffic noise and cardiovascular risk: the Caerphilly and Speedwell studies, second phase. Risk estimation, prevalence, and incidence of ischemic heart disease

As part of the Caerphilly and the Speedwell collaborative heart disease studies, associations between outdoor traffic noise level, risk factors for ischemic heart disease, and prevalence and incidence of ischemic heart disease were studied in two samples of 2,512 and 2,348 men, respectively, who were 45-63 y of age. Compared with the lowest noise category [Leq,6-22 h = 51-55 dB(A)], the subjects in the highest noise category [Leq,6-22 = 66-70 dB(A)] showed a slightly worse risk factor profile with respect to 9 identified endogenous risk factors. Logistic regression analysis suggested a marginal increase in risk (relative risk = 1.1) for ischemic heart disease incidence for these men based on risk factors. The prevalence of ischemic heart disease was slightly higher (relative risk = 1.2) in this noise group. The observed incidence of major ischemic heart disease within an observation period of approximately 4 y was slightly lower (relative risk = 0.8) for men in the highest noise group.

Traffic noise and cardiovascular risk: the Speedwell study, first phase. Outdoor noise levels and risk factors

As part of the Speedwell study, traffic noise exposure and risk factors for ischemic heart disease were studied in a sample of 2,348 men whose ages ranged from 45 to 63 y. The road traffic noise emission level, Leq, ranged between 51 and 70 dB(A) (6-22 h, 10-m distance). Significant associations were found between noise and potential ischemic heart disease risk factors, including total triglycerides, platelet count, plasma viscosity, glucose (increases), and systolic and diastolic blood pressure (decreases). Not all results support the hypothesis that traffic noise increases ischemic heart disease risk. The results were controlled for a number of potential confounding factors.

Noise-induced hypertension and magnesium in rats: relationship to microcirculation and calcium

It has been demonstrated that audiogenic stress (AS) can induce elevation of arterial blood pressure (ABP) in animals and humans and that noise-induced hearing loss may be associated with alterations in Mg metabolism. Experiments were designed to determine whether 1) there is a causal relationship among environmental noise stress, serum and vascular tissue (aortas and portal veins) Mg contents, and development of hypertension and 2) such noise-induced hypertension has a microcirculatory basis and what the mechanism may be. Rats maintained on normal Mg-containing diets for 12 wk (plasma [Mg] = 0.96 +/- 0.02 mM) and subjected to AS (85 dB(A), 12 h/day for 8 wk; 95 dB(A), 16 h/day for 4 wk) demonstrated significant elevation in systolic and diastolic ABP; plasma [Mg] showed a 15% deficit, whereas aortic and portal vein muscle exhibited slight reductions in Mg content and elevation in Ca. Moderate and more severely Mg-deficient animals not subjected to AS also exhibited significant elevations in systolic and diastolic ABP; vascular tissue Mg content decreased, whereas Ca content rose. Animals subjected to combined Mg deficiency and AS for 12 wk exhibited the greatest deficits in plasma and vascular muscle Mg and the greatest elevations in systolic and diastolic ABP; vascular tissue Ca contents also showed the greatest increases. In situ measurements of mesenteric arterioles, venules, and precapillary sphincters in the various subgroups revealed that the lower the plasma [Mg], the more constricted the microvessels, and the higher the ABP, the lower the plasma [Mg]. Capillary blood flow velocities were decreased in relation to the degree of plasma Mg deficit.(ABSTRACT TRUNCATED AT 250 WORDS)