Harri Lindholm

Sleep restriction increases the risk of developing cardiovascular diseases by augmenting proinflammatory responses through IL-17 and CRP

Background Sleep restriction, leading to deprivation of sleep, is common in modern 24-h societies and is associated with the development of health problems including cardiovascular diseases. Our objective was to investigate the immunological effects of prolonged sleep restriction and subsequent recovery sleep, by simulating a working week and following recovery weekend in a laboratory environment. Methods and Findings After 2 baseline nights of 8 hours time in bed (TIB), 13 healthy young men had only 4 hours TIB per night for 5 nights, followed by 2 recovery nights with 8 hours TIB. 6 control subjects had 8 hours TIB per night throughout the experiment. Heart rate, blood pressure, salivary cortisol and serum C-reactive protein (CRP) were measured after the baseline (BL), sleep restriction (SR) and recovery (REC) period. Peripheral blood mononuclear cells (PBMC) were collected at these time points, counted and stimulated with PHA. Cell proliferation was analyzed by thymidine incorporation and cytokine production by ELISA and RT-PCR. CRP was increased after SR (145% of BL; p<0.05), and continued to increase after REC (231% of BL; p<0.05). Heart rate was increased after REC (108% of BL; p<0.05). The amount of circulating NK-cells decreased (65% of BL; p<0.005) and the amount of B-cells increased (121% of BL; p<0.005) after SR, but these cell numbers recovered almost completely during REC. Proliferation of stimulated PBMC increased after SR (233% of BL; p<0.05), accompanied by increased production of IL-1β (137% of BL; p<0.05), IL-6 (163% of BL; p<0.05) and IL-17 (138% of BL; p<0.05) at mRNA level. After REC, IL-17 was still increased at the protein level (119% of BL; p<0.05). Conclusions 5 nights of sleep restriction increased lymphocyte activation and the production of proinflammatory cytokines including IL-1β IL-6 and IL-17; they remained elevated after 2 nights of recovery sleep, accompanied by increased heart rate and serum CRP, 2 important risk factors for cardiovascular diseases. Therefore, long-term sleep restriction may lead to persistent changes in the immune system and the increased production of IL-17 together with CRP may increase the risk of developing cardiovascular diseases.

Trends in prevalence of asthma and allergy in Finnish young men: nationwide study, 1966-2003.

Recent reports on time trends in atopic disease suggest that the prevalence of asthma and allergic rhinitis has levelled off in some European countries after several decades of increasing.1 2 We reported earlier that the prevalence of asthma in young Finnish men remained stable from 1926 to 1961 but started to rise steeply during the 1960s; a sixfold, virtually linear increase in asthma prevalence was found between 1966 and 1989, in parallel with increases in indicators of disabling asthma (on the basis of the percentage of men exempted from military service at call-up owing to asthma and of men discharged during service as a result of asthma).3 We examined whether similar trends have continued during the subsequent 13 years (1990-2003). As data on current trends in prevalence of allergic conditions are scarce, we also examined the trends in prevalence of allergic rhinitis and eczema from 1966 to 2003 among these young men.nnIn Finland, about 98% of all men aged 18-19 are examined to establish their fitness for …

Temporomandibular joint related painless symptoms, orofacial pain, neck pain, headache, and psychosocial factors among non-patients

The aims of this study were to assess the prevalence of temporomandibular joint related (TMJ) painless symptoms, orofacial pain, neck pain, and headache in a Finnish working population and to evaluate the association of the symptoms with psychosocial factors. A self-administered postal questionnaire concerning items on demographic background, employment details, perceived general state of health, medication, psychosocial status, and use of health-care services, was mailed to all employees with at least 5 years at their current job. The questionnaire was completed by 1339 subjects (75%). Frequent (often or continual) TMJ-related painless symptoms were found in 10%, orofacial pain in 7%, neck pain in 39%, and headache in 15% of subjects. Females reported all pain symptoms significantly more often than men (P < 0.001). Frequent pain and TMJ-related symptoms were significantly associated with self-reported stress, depression, and somatization (P < 0.001). Perceived poor general state of health (P < 0.001), health care visits (P < 0.001), overload at work (P < 0.001), life satisfaction (P < 0.05), and work satisfaction (P < 0.05) were also significantly associated with pain symptoms, but the work duty was not (P > 0.05). Our findings are in accordance with earlier studies and confirm the strong relationship between neck pain, headache, orofacial pain, TMJ-related painless symptoms, and psychosocial factors. Furthermore, TMJ-related symptoms and painful conditions seem to be more associated with work-related psychosocial factors than with type of work itself.

Associations of reported bruxism with insomnia and insufficient sleep symptoms among media personnel with or without irregular shift work.

BackgroundThe aims were to investigate the prevalence of perceived sleep quality and insufficient sleep complaints, and to analyze whether self-reported bruxism was associated with perceptions of sleep, and awake consequences of disturbed sleep, while controlling confounding factors relative to poor sleep.MethodsA standardized questionnaire was mailed to all employees of the Finnish Broadcasting Company with irregular shift work (n = 750) and to an equal number of randomly selected controls in the same company with regular eight-hour daytime work.ResultsThe response rate in the irregular shift work group was 82.3% (56.6% men) and in the regular daytime work group 34.3% (46.7% men). Self-reported bruxism occurred frequently (often or continually) in 10.6% of all subjects. Altogether 16.8% reported difficulties initiating sleep (DIS), 43.6% disrupted sleep (DS), and 10.3% early morning awakenings (EMA). The corresponding figures for non-restorative sleep (NRS), tiredness, and sleep deprivation (SLD) were 36.2%, 26.1%, and 23.7%, respectively. According to logistic regression, female gender was a significant independent factor for all insomnia symptoms, and older age for DS and EMA. Frequent bruxism was significantly associated with DIS (p = 0.019) and DS (p = 0.021). Dissatisfaction with current work shift schedule and frequent bruxism were both significant independent factors for all variables describing insufficient sleep consequences.ConclusionSelf-reported bruxism may indicate sleep problems and their adherent awake consequences in non-patient populations.

GSM mobile phone radiation suppresses brain glucose metabolism

We investigated the effects of mobile phone radiation on cerebral glucose metabolism using high-resolution positron emission tomography (PET) with the 18F-deoxyglucose (FDG) tracer. A long half-life (109 minutes) of the 18F isotope allowed a long, natural exposure condition outside the PET scanner. Thirteen young right-handed male subjects were exposed to a pulse-modulated 902.4 MHz Global System for Mobile Communications signal for 33 minutes, while performing a simple visual vigilance task. Temperature was also measured in the head region (forehead, eyes, cheeks, ear canals) during exposure. 18F-deoxyglucose PET images acquired after the exposure showed that relative cerebral metabolic rate of glucose was significantly reduced in the temporoparietal junction and anterior temporal lobe of the right hemisphere ipsilateral to the exposure. Temperature rise was also observed on the exposed side of the head, but the magnitude was very small. The exposure did not affect task performance (reaction time, error rate). Our results show that short-term mobile phone exposure can locally suppress brain energy metabolism in humans.

Physiological evaluation of chemical protective suit systems (CPSS) in hot conditions.

This job-related experiment investigated physiological strain in subjects wearing impermeable chemical protective suit systems (CPSSs) weighing about 28 kg. Two types of CPSSs were studied: the self-contained breathing apparatus was carried either inside or outside the suit. Eight healthy and physically fit male firefighter instructors aged 32 to 45 years volunteered for the study. The test drill, performed at a dry, windless ta of 40 °C, was divided into 2 consecutive work sessions of 14.5 min (a 20-min rest between) including typical operational work tasks. Considerable thermal and maximal cardiovascular strain and intense subjective discomfort measured in the firefighters emphasize the need to limit working time in hot conditions to only 10–12 min while wearing CPSSs. The present results indicate that the exceptionally heavy physical load and psychological stress during operations in chemical emergencies must be considered in the assessment of the cardiovascular capacity of ageing firefighters using CPSSs.

Reported bruxism and stress experience in media personnel with or without irregular shift work.

A standardized questionnaire was mailed to all employees of the Finnish Broadcasting Company with irregular shift work (n = 750) and to an equal number of randomly selected controls with regular 8‐hour daytime work. The aim was to analyze whether irregular shift work, workload in terms of weekly working hours, dissatisfaction with current workshift schedule, health‐care use, age and gender were associated with self‐reported bruxism and experienced stress. The response rates were 58.3% (n = 874, 53.7% men) overall, 82.3% (n = 617, 56.6% men) for irregular shift workers and 34.3% (n = 257, 46.7% men) for the regular daytime work group. Those with irregular shifts were more often dissatisfied with their current workshift schedule than those in daytime work (25.1% versus 5.1%, P < 0.01). Irregular shift work was significantly associated with more frequent stress (P < 0.001), but not with self‐reported bruxism. Workers dissatisfied with their current schedule reported both bruxism (P < 0.01) and stress (P < 0.001) more often than those who felt satisfied. In multivariate analyses, frequent bruxism was significantly associated with dissatisfaction with current workshift schedule (P < 0.05), number of dental visits (P < 0.05), and visits to a physician (P < 0.01), and negatively associated with age (P < 0.05), while severe stress was significantly positively associated with number of visits to a physician (P < 0.001). It was concluded that dissatisfaction with ones workshift schedule and not merely irregular shift work may aggravate stress and bruxism.

Nordic walking decreased circulating chemerin and leptin concentrations in middle-aged men with impaired glucose regulation

Abstract Background. Dysfunction of adipose tissue is one of the major factors leading to insulin resistance. Altered adipokine concentration is an early sign of adipose tissue dysfunction. The aim of this study was to assess the impact of exercise intervention on adipokine profile, glycemic control, and risk factors of the metabolic syndrome (MeS) in men with impaired glucose regulation (IGR). Methods. Overweight and obese men with IGR (n =144) aged 40–65 years were studied at baseline and at 12 weeks in a randomized controlled multicenter intervention study. BMI varied from 25.1 to 34.9. The subjects were randomized into one of three groups: 1) a control group (C; n =47), 2) a Nordic walking group (NW; n =48), or 3) a resistance training group (RT; n =49). Results. Leptin concentrations decreased in the NW group compared to both other groups. Both types of exercise intervention significantly decreased serum chemerin concentrations compared to the C group. In the NW group also body fat percentage, fatty liver index (FLI), and total and LDL cholesterol concentrations decreased compared to the RT group. Conclusions. Nordic walking intervention seems to decrease chemerin and leptin levels, and subjects in this intervention group achieved the most beneficial effects on components of MeS.

Electromagnetic interference with cardiac pacemakers and implantable cardioverter-defibrillators from low-frequency electromagnetic fields in vivo

AIMSnElectromagnetic interference (EMI) can pose a danger to workers with pacemakers and implantable cardioverter-defibrillators (ICDs). At some workplaces electromagnetic fields are high enough to potentially inflict EMI. The purpose of this in vivo study was to evaluate the susceptibility of pacemakers and ICDs to external electromagnetic fields.nnnMETHODS AND RESULTSnEleven volunteers with a pacemaker and 13 with an ICD were exposed to sine, pulse, ramp, and square waveform magnetic fields with frequencies of 2-200 Hz using Helmholtz coil. The magnetic field flux densities varied to 300 µT. We also tested the occurrence of EMI from an electronic article surveillance (EAS) gate, an induction cooktop, and a metal inert gas (MIG) welding machine. All pacemakers were tested with bipolar settings and three of them also with unipolar sensing configurations. None of the bipolar pacemakers or ICDs tested experienced interference in any of the exposure situations. The three pacemakers with unipolar settings were affected by the highest fields of the Helmholtz coil, and one of them also by the EAS gate and the welding cable. The induction cooktop did not interfere with any of the unipolarly programmed pacemakers.nnnCONCLUSIONnMagnetic fields with intensities as high as those used in this study are rare even in industrial working environments. In most cases, employees can return to work after implantation of a bipolar pacemaker or an ICD, after an appropriate risk assessment. Pacemakers programmed to unipolar configurations can cause danger to their users in environments with high electromagnetic fields, and should be avoided, if possible.

Associations of perceived pain and painless TMD-related symptoms with alexithymia and depressive mood in media personnel with or without irregular shift work.

The aim of the present study was to analyze whether previously emerged pain symptoms and painless temporomandibular disorder (TMD) symptoms are associated with alexithymia and self‐rated depression among media personnel in or not in irregular shift work. A standardized questionnaire was mailed to all employees of the Finnish Broadcasting Company in irregular shift work (n = 750) and to an equal number of randomly selected controls in regular 8‐h daytime work. The questionnaire covered demographic items, employment details, general health experience, physical status, psychosomatic symptoms, psychosocial status, stress, work satisfaction and performance, and health-care use. Studied age groups, marital status, gender or perceived health were not significantly associated with alexithymia in the bivariate analyses. Most studied painless TMD symptoms associated significantly with alexithymia. Alexithymia was also significantly more prevalent among those who reported having more often than average neck pain (P<0.05), head pain (P<0.01), and tender teeth (P<0.01). According to logistic regression, the probability of alexithymia was significantly positively associated with pain symptoms (P<0.01) and painless TMD-related symptoms (P<0.01), and significantly negatively associated with female gender (P<0.01). Additionally, depressive mood was significantly positively associated with dissatisfaction of ones work-shift schedule (P<0.05), and poorer health experience (P<0.01). Neither alexithymia nor depression was associated with irregular shift work in itself. In conclusion, depressive mood may be a sign of dissatisfaction and impaired well‐being. In the case of perhaps less disabling but common physical symptoms alexithymia as a possible underlying factor may be relevant in the diagnosis and management of such disorders.