High intensity endurance training is associated with better quality of life, but not with improved cognitive functions in elderly marathon runners.

Impairment of cognitive functions in advanced age leads to a reduced quality of life and impaired ability to perform everyday tasks. The positive impact of physical exercise on the quality of life and well-being, also at a later age, is well established. However, the effect of endurance exercises, including long distance running and cycling, on cognitive function and mental health within the elderly population has still to be elucidated. To this end, elderly active marathoners (N = 50) aged over 60 years and non-athlete controls (N = 49) were followed for four years. Cognitive function was assessed using the CERAD test battery. In addition, the Short Form Health Survey (SF-36) was applied to assess self-reported physical, mental, and emotional health. Except for age, sex and education-corrected z-values of the test "Word list recall", with marathon runners showing a decline compared to an improvement in controls (p < 0.05), there was no statistically significant difference in time trend between groups. In contrast, concerning self-reported health, scores in all eight domains of the SF-36 remained stable over time and, in nearly all of them, marathon runners showed higher self-reported health than controls. The results indicated that extensive endurance exercise is associated with improved subjective health but does not lead to better scores in cognitive performance tests in elderly persons.

Myeloperoxidase levels predict executive function.

The main purpose of the study was to investigate whether baseline myeloperoxidase (MPO) levels are associated with executive cognitive function in individuals with high physical activity. Baseline serum MPO levels of 56 elderly marathon runners and 58 controls were assessed by ELISA. Standardized tests were applied to survey domain-specific cognitive functions. Changes in brain morphology were visualized by magnetic resonance imaging (MRI). High baseline serum MPO levels correlated with worse outcome in tests assessing executive cognitive function in athletes but not in the control group (NAI maze test p<0.05, Trail Making Test ratio p<0.01). In control participants, subcortical white matter hyperintensities were associated with higher scores on the Geriatric Depression Scale (p<0.05), whereas athletes seem to be protected from this effect. During strenuous exercising, MPO as well as its educts may be elevated due to increased oxygen intake and excretion of pro-inflammatory mediators inducing host tissue damage via oxidative stress. This outweighs the potential benefits of physical activity on cognitive function.

Association of cardio-ankle vascular index with physical fitness and cognitive symptoms in aging Finnish firefighters.

PURPOSE: Monitoring cardiovascular risk factors is important in health promotion among firefighters. The assessment of arterial stiffness (AS) may help to detect early signs of atherosclerosis. The aim of this study was to analyze associations between aerobic fitness, cognitive symptoms and cardio-ankle vascular index (CAVI) as a measure for AS among Finnish firefighters. METHODS: The data are one part of a large 13-year follow-up study of the health and physical and mental capacity of Finnish professional firefighters. The subjects in this substudy comprised 65 male firefighters of a mean age of 48.0 (42-58) years in 2009. Their maximal oxygen uptake was successfully measured in two cross-sectional studies in 1996 and 2009, and they responded to questionnaires at both sessions, and their CAVI was measured in 2009. CAVI was calculated from the pulse waveform signal and pulse wave velocity. The lifestyle habits and subjective cognitive stress-related symptoms were collected via a standardized questionnaire. Muscular fitness was measured by the routine test battery used for Finnish firefighters. RESULTS: CAVI was related to age. About one-fifth of the firefighters had a CAVI of >8. Aerobic fitness was the main physiological factor correlating with increased CAVI. Interestingly, VO(2)max and the accelerated decrease in VO(2)max during a 13-year follow-up were associated with signs of impaired vascular function. The cognitive symptoms derived from the Profile of Mood States questionnaire (POMS) were mainly associated with stress and sleeping difficulties. No clear association with physical fitness was found in this population of fit firefighters. CONCLUSIONS: Among firefighters, the decrease in aerobic fitness predicts increased arterial stiffness. The speed of the age-related decline in maximal oxygen consumption is as important as absolute level. Against expectations, the cognitive function did not correlate with vascular health parameters. The cognitive symptoms, however, were only mild.

A meta-analysis for neurobehavioural effects due to electromagnetic field exposure emitted by GSM mobile phones.

BACKGROUND AND OBJECTIVE: Numerous studies have investigated the potential effects of electromagnetic fields (EMFs) emitted by GSM mobile phones ( approximately 900 MHz to approximately 1800 MHz) on cognitive functioning, but results have been equivocal. In order to try and clarify this issue, the current study carried out a meta-analysis on 19 experimental studies. DESIGN: Meta-analysis. METHODS: Nineteen studies were taken into consideration. Ten of them were included in the meta-analysis as they fulfilled several minimum requirements; for example, single-blind or double-blind experimental study design and documentation of means and standard deviation of the dependent variables. The meta-analysis compared exposed with non-exposed subjects assuming that there is a common population effect so that one single effect size could be calculated. When homogeneity for single effect sizes was not given, an own population effect for each study and a distribution of population effects was assumed. RESULTS: Attention measured by the subtraction task seems to be affected in regard to decreased reaction time. Working memory measured by the N-back test seems to be affected too: under condition 0-back target response time is lower under exposure, while under condition 2-back target response time increases. The number of errors under condition 2-back non-targets appears to be higher under exposure. CONCLUSION: Results of the meta-analysis suggest that EMFs may have a small impact on human attention and working memory.

Prolonged asystole provoked by head-up tilt testing.

We describe a patient with a history of neurocardiogenic syncopes who had a positive headup tilt test that resulted in an lasting asystole lasting 34 seconds. However, the previously carried out Schellong test with a 30-min phase of standing showed a normal result. The patient showed typical orthostatic symptoms while tilted at the angle of 75 degrees. Shortly before asystole occurred, heart rate variability showed high frequency bands, indicating vagal stimulation. The pathophysiology of neurocardiogenic syncope (NCS) in context with heart rate variability is discussed. This patient was successfully treated with propranolol. This case shows the utility of a provocative head-up tilt test in establishing the diagnosis of NCS. If the Schellong test is normal, still further examination by tilt-table test is indispensable.

Lead exposure levels and duration of exposure absence predict neurobehavioral performance.

OBJECTIVES: We investigated cognitive functions in currently lead exposed and formerly lead exposed men. The aim of the study was to verify the hypothesis that lead induced cognitive deficits are reversible. METHODS: Forty-seven lead exposed subjects with a mean blood level (PbB) of 30.8 microg/100 ml and 48 formerly exposed aged-matched subjects (PbB: 5.5 microg/100 ml) with the same socio-economic background were investigated. Both groups were matched on verbal intelligence. Cognitive functions were assessed by using the Modified Wisconsin Card Sorting Test, Block Design Test, Visual Recognition Test, Simple Reaction Time, Choice Reaction and Digit Symbol Substitution. Lead exposure was assessed by using current and cumulative measures. The sample was divided according to their exposure duration versus exposure absence into four groups for subsequent ANOVA models analyses. RESULTS: Currently exposed men performed significantly worse in the Wisconsin Test and Block Design Test. No differences were found in the Visual Recognition Test, Simple Reaction Time, Choice Reaction and Digit Symbol Substitution. Splitting the sample according to their exposure duration versus exposure absence resulted in better cognitive performance of subjects with shorter exposure duration and longer exposure absence in the Block Design Test and the Wisconsin Test. CONCLUSIONS: Our results provide further evidence that cognitive deficits induced by occupationally lead are most likely reversible.

Reproductive toxicology in occupational settings: an update.

OBJECTIVE: This article mainly attempts to review the recent human literature on the adverse effects of occupational factors on fertility, developmental effects and genetic changes in the germ line, which lead to genetic malformations or to genetic disease. The secondary study aim is to answer whether occupational exposures are quantitative momentously for 15% involuntarily childless couples, 10-20% spontaneous abortions and 3% birth defects. METHODS: A literature survey was conducted for publications on these subjects focusing on the latest publications. PubMed (Medline. 2005) was used for this literature search. RESULTS: Publication bias and a large amount of confounding factors, which have to be controlled, make the design of human fertility studies difficult. Epidemiologic studies using time to conception techniques have been useful in identifying substances and exposure scenarios with proven toxic effect on fertility. The collected studies suggest that the exposure to the following substances or occupational settings may affect fertility function: lead, organic mercury compounds, manganese, carbon disulfide, 2-bromopropane and dibromochloropropane, welding, professional driving and working with heat. Concerning developmental effects even for methyl mercury, which was in group A of the German MAK list, to date no reliable evidence of the damaging effect on the human fetus under actual work conditions has been obtained. It is also difficult to classify substances according to their mutagenic potential for the germ cell, since no direct evidence of an association between exposure against a physical or chemical pollutant and the occurrence of a hereditary disorder has been found yet. CONCLUSION: In conclusion there are only a few substances which may affect reproductive function in the workplace without a doubt. The decreasing fertility of women in Western countries can be explained by the increasing female reproduction age, rather than by occupational exposures. Also the rates for spontaneous abortions and birth defects cannot be explained by industrial exposures at the workplace.

Functional adrenergic receptor polymorphisms and idiopathic orthostatic intolerance.

OBJECTIVES: Idiopathic orthostatic intolerance (IOI) is a common disorder that is characterized by chronic orthostatic symptoms and substantial increases in heart rate and plasma norepinephrine concentrations that are disproportionately high while standing. Several features of the syndrome, including the tachycardia, tremulousness, and exaggerated norepinephrine have been considered potentially due to hypoactive or hyperactive states of adrenergic receptors of the sympathetic nervous system. The aim of this study was therefore to ascertain whether genotypes at eight polymorphic loci within five relevant adrenergic receptor genes (alpha2A, alpha2B, alpha2C, beta1 and beta2) influence the risk for IOI. METHODS: We studied 80 young men in military service (20 patients with IOI and 60 age-matched controls). All participants underwent a tilt table test including monitoring of blood pressure, heart rate and plasma catecholamines, in the supine position and during 30 min of standing. Genotyping at the eight loci (alpha2ALys251, alpha2BDel301-303, alpha2CDel322-325, beta1Gly49, beta1Arg389, beta2Arg16, beta2Glu27, beta2Ile164) was performed in all participants. Chi-square tests of independence were used to test for associations between IOI and genotype. In addition, an association of the polymorphisms with haemodynamic variables (heart rate, supine and upright blood pressure) was ascertained using one-way variance analysis. RESULTS: For the beta1Gly49 polymorphism we found a decrease in the risk of IOI among persons who were homozygous (odds ratio, 0.88; 95% confidence interval, 0.81-0.97). In addition, we found an association between beta1Gly49 and decreased heart rate in the upright position, regardless of IOI diagnosis. There were no associations with the other studied polymorphisms and IOI. CONCLUSIONS: Our current results suggest that the beta1Gly49 polymorphism is protective for IOI. This is likely one of several common genetic loci that may represent modifiers of IOI phenotypes.

Effects of parathyroidectomy on lead mobilization from bone in patients with primary hyperparathyroidism.

Since lead (Pb) accrued from environmental exposure accumulates in bone with a half life time between 6 and 10 years, a release of bone Pb into the circulation and/or urine (PbU) should be expected in diseases with increased bone metabolism such as hyperparathyroidism. We studied 60 patients with primary hyperparathyroidism (pHPT, 50 women, 10 men, aged 61.4 +/- 10.6 and 64.1 +/- 9.9 years, respectively) (a) before, (b) 1-6 months, and (c) 6-12 months after parathyroidectomy. Besides lead in blood (PbB) and lead in 24-h urine samples (PbU), parathyroid hormone (PTH), serum Ca2+, osteocalcin (OC), phosphate (PO4), and serum pyridinoline cross-linked telopeptide (cTP) were determined. Control data were determined in 20 healthy age-matched subjects. As expected, Ca2+ decreased after parathyroidectomy. Mean PbB in patients with pHPT was in the same range as in controls. A decrease of PbB after parathyroidectomy was found in the interval beyond 6 months. In contrast, mean PbU initially increased after surgery (3.05 +/- 1.94 vs. 4.25 +/- 2.65 microg/l, P = 0.004) and was not different beyond 6 months in comparison with preoperative values at (c). Investigating only patients with PTH < 150 ng/l, no significant PbB or PbU alterations were detected before and after parathyroidectomy. In patients with PTH > 150 ng/l, the decrease of PbB at (c) was more pronounced as was the increase of PbU at (b). In these patients, PbB and OC as well as PbB and cTP were correlated preoperatively. In conclusion, our data show that in environmentally lead-exposed (by food or by pollution) hyperparathyroid individuals, there is no hazardous PbB release from bone. The preoperative correlation between PbB and OC in pHPT patients with PTH > 150 ng/l provides evidence that in fact there is a Pb release from bone into the blood-pool by bone remodeling. The increase of PbU after parathyroidectomy is suspected to be caused by PTH-dependent Pb accumulation in the kidney, which seems to be restored with decreasing PTH. Moreover, our data confirm prior findings that bone remodeling seems to be normalized 6 months after parathyroidectomy.

Diagnostic management of orthostatic intolerance in the workplace.

OBJECTIVE: Orthostatic intolerance (OI) is a syndrome that is characterised by headache, concentration difficulties, palpitation of the heart, dizziness associated with postural tachycardia and plasma norepinephrine concentrations that are disproportionately high when the sufferer is in the upright posture. In contrast to other forms of orthostatic dysregulation - orthostatic hypotension (OH) and postural orthostatic tachycardia syndrome (POTS) - OI, hitherto, could be diagnosed only by a tilt table examination, with high expenditure. In this paper we examine the reliability and validity of a questionnaire as a screening instrument for OI. METHODS: We studied 138 young men (mean age 21.6 years) who were undergoing military service. After a medical check and filling in the questionnaire, the participants underwent a tilt table test including monitoring of blood pressure, heart rate and plasma catecholamines, in the supine position and during 30 min of standing. The questionnaire consisted of ten items registering presence and frequency of typical OI symptoms. RESULTS: Probands (104) showed normal tilt table test results. OI was diagnosed in 14 probands, OH in 6 and POTS in 14. The OI participants scored significantly higher in the questionnaire than the healthy subjects did: the mean score of the OI group was 22.6, the healthy participants had a mean score of 3.9. Participants with POTS had a mean score of 13.5 and subjects with OH had a mean score of 17.0. Reliability analysis showed a Cronbach's alpha of 0.888. Validity analysis showed that 93.5% of the probands with any kind of orthostatic dysregulation can be detected. CONCLUSIONS: We were able to establish a short questionnaire as a reliable and valid screening instrument for OI. Usage of this questionnaire can simplify enormously the diagnostic management of patients with suspected OI.

Health consequences of an intravenous injection of metallic mercury.

BACKGROUND: Mercury poisoning presents a variety of clinical pictures depending on chemical structure, the route of exposure, amount absorbed and individual factors. Thus, an injection of metallic mercury can be considered relatively harmless in contrast to inhalation of mercury vapor. Injection of elemental mercury is rare, and a total of only 78 cases have been reported in the literature over the period 1923-2000. CASE REPORT: We report a suicide attempt by intravenous injection of approximately 8 g metallic mercury. By X-ray examination widespread multiple mercury shadows were visible in the whole lung and also in the subcutaneous region of the cubital fossa, the small pelvis and the right hypogastrium. Mercury excretion after treatment with 2,3-dimercaptopropane-1-sulfonate (DMPS) was significantly higher than in occupationally exposed workers. CLINICAL SYMPTOMS: The patient showed symptoms typical of acute mercury intoxication, including gastroenteritis, ulceromembranous colitis and stomatitis mercuralis. No biochemical abnormalities in hepatic or renal function occurred, despite the persistence of metallic densities in the body. The patient's lung function was normal. The patient transitionally developed erethismus and tremor mercuralis. After 1 month of DMPS treatment, the mercury levels in blood were still high and the tremor was persistent. Three years after the suicide attempt the surgical removal of residual mercury in the left fossa cubitalis was performed. The extirpation of residual mercury was successful in cutting the mercury levels to almost half. After the operation the patient showed no symptoms of chronic mercury intoxication. CONCLUSIONS: Since only 1 mg of mercury per day could be removed with DMPS treatment, it can be calculated, that it would take about 8,000 daily treatments to remove a total of 8 g solely by DMPS. Although DMPS itself does not dissolve the metallic deposits, it may considerably reduce the blood level of mercury and may therefore mitigate clinical symptoms, albeit transitorily. We therefore recommend that in cases of symptomatic metallic mercury injections, where the mercury cannot be removed by surgery, the patient's condition should be managed by repeated long-term DMPS treatment in order to control blood mercury levels.

Neurobehavioral effects of vanadium.

It was our aim to study whether chronic exposure to vanadium reduces cognitive abilities. We investigated effects on attention, visuospatial and visuomotor functioning, reaction time, short-term memory, and prefrontal functioning. Forty-nine vanadium exposed subjects with a mean vanadium level in urine (VanU) of 14.4 micro/L and 49 controls (VanU: 0.8 microg/L) with the same socioeconomic background were investigated. Neuropsychological tests were done using a modified Wisconsin Card Sorting Test (WCST), Block Design Test (BDT), Visual Recognition Test (VRT), Simple Reaction Time (SRT), Choice Reaction (CR), Digit Symbol Substitution (DSS), and Digit Span (DS). Exposure was assessed by using the vanadium level in urine and serum. While there were significant differences in BDT and DSS, no differences were found in WCST, SRT, CR, and DS. Significant correlations existed between the vanadium levels in urine and serum and the cognitive deficits. Vanadium concentrations around 14.2 microg/L in urine reduce neurobehavioral abilities, particularly visuospatial abilities and attention.

Decreased secretion of Th2 cytokines precedes Up-regulated and delayed secretion of Th1 cytokines in activated peripheral blood mononuclear cells from patients with insulin-dependent diabetes mellitus.

Recent evidence suggests that autoimmune animal diabetes is associated with an imbalance between the Th1 and Th2 arms of the cellular immune system. However, limited data is available regarding the Th1/Th2 imbalance in human Insulin dependent diabetes mellitus (IDDM) patients. Therefore, we examined the peak levels, secretory pattern and total cytokine production (calculated as the area under the curve, AUC) of the Th1 cytokines, IL-2 and IFN-gamma, and Th2 cytokines, IL-4 and IL-10, from stimulated peripheral blood mononuclear cells, from 17 IDDM patients and 24 normal controls. In contrast to controls, diabetic patients were characterized by an early, uniformly low secretion of Th2 cytokines, followed by a late increased secretion of Th1 cytokines. This resulted in significant differences in secretory patterns of IFN-gammaIL-2, IL-4 and IL-10 between the two groups; P<0.001, P<0.005, P<0.005 and P<0.001, respectively. No correlation was found in the diabetic patients between any profiles of the cytokines and their various clinical parameters, including age, gender, disease duration, insulin requirements or glycated hemoglobin levels. In conclusion, our data provides the first comprehensive evidence for an independent and persistent impairment of both Th1 and Th2 cytokine secretory patterns in IDDM patients.