Whole-body impedance recording--a practical method for the diagnosis of sleep apnoea

The aim of this study was to evaluate the utility of whole-body impedance cardiography (ICGWB) in sleep studies, particularly in sleep apnoea detection. A comparison between simultaneous whole night ICGWB and standard polysomnographic recordings were made in 14 patients with a clinical suspicion of obstructive sleep apnoea, a mean age of 46 years (range 30-63 years) and a mean BMI of 29 kg m-2 (25-47). Obstructive apnoeas, central apnoeas and hypopnoeas all caused characteristic patterns in the ICGWB tracing. For an apnoea-hypopnoea index (AHI) > 15 events h-1, the sensitivity of ICGWB was 89% and the specificity 80%. In conclusion, ICGWB signal includes valuable physiological information that can be effectively used for the detection of sleep apnoea episodes. The method seems promising in cases where the multichannel polysomnography is not applicable or when ICGWB is used for haemodynamic monitoring in seriously ill and postoperative patients.     

Lack of predictability at work and risk of acute myocardial infarction: an 18-year prospective study of industrial employees

Objectives. We examined whether the distinctive components of job control—decision authority, skill discretion, and predictability—were related to subsequent acute myocardial infarction (MI) events in a large population of initially heart disease–free industrial employees.Methods. We prospectively examined the relation between the components of job control and acute MI among private-sector industrial employees. During an 18-year follow-up, 56 fatal and 316 nonfatal events of acute MI were documented among 7663 employees with no recorded history of cardiovascular disease at baseline (i.e., 1986).Results. After adjustment for demographics, psychological distress, prevalent medical conditions, lifestyle risk factors, and socioeconomic characteristics, low decision autonomy (P < .53) and skill discretion (P < .10) were not significantly related to subsequent acute MI. By contrast, low predictability at work was associated with elevated risk of acute MI (P = .02). This association was driven by the strong effect of predictability on acute MI among employees aged 45 to 54 years.Conclusions. Prospective evidence suggests that low predictability at work is an important component of job control, increasing long-term risk of acute MI among middle-aged employees.Cardiovascular diseases account for approximately 40% of deaths in developed countries.¹ Acute myocardial infarctions (MIs) account for nearly half of all the cardiovascular mortality.² According to current knowledge, acute MI is predicted by not only well-known risk factors, such as smoking and lack of physical activity, but also psychosocial factors.³Most working-age adults in industrialized countries spend about one third of their waking hours at work during an average period of more than 30 years.⁴ Work environments often entail various stressful characteristics.⁵ Correspondingly, recent reviews proposed that adverse work-related psychosocial risk factors may contribute to poor cardiac health.^6,7In occupational epidemiology, the job strain model⁸ has dominated research on cardiovascular risk factors. This model postulates that a combination of high work demands and low control at work (i.e., job strain), if prolonged, increases the risk of heart disease. Although some follow-up studies have supported this model,^9,10 many large-scale prospective studies with null findings also have been reported.^11–14 Poor job control may be more detrimental to heart health than high job demands,¹⁵ but evidence on the independent predictive role of job control in coronary heart disease is scarce and mixed.^13,16,17Several factors may explain the conflicting findings. First, dimensions of job control, such as decision authority (i.e., decision latitude concerning one''s work pace and phases, and independence from other workers while carrying out tasks) and skill discretion (i.e., the level of cognitive challenges and variety of tasks at work), could contribute differently to health outcomes.¹⁸ Predictability on the job (i.e., the clarity of work goals and opportunity to foresee changes and problems at one''s work) has been suggested to represent a further component of job control, but empirical research on this component is largely lacking.^19–21 Predictability involves relatively high stability of work and a lack of unexpected changes, which characterized the earlier industrial era which had stable production systems.²² Predictable outcomes are less common in today''s turbulent work life; thus, lack of predictability may represent a salient health hazard^23,24 and may contribute to myocardial risk.²⁵Second, research indicates that physiological stress, especially exposure to long-term environmental stressors, can cause detrimental prolonged neurohormonal reactions as well as pathological physiological changes by adversely affecting the process of atherosclerosis,^16,26,27 thereby increasing the risk of acute MI.^28,29 However, most prospective studies on stressful work environment and subsequent cardiovascular disease have used follow-up periods of less than 10 years^6,7 or have studied all-cause cardiovascular outcomes rather than mortality and morbidity resulting from acute MI.⁹ Thus, potential long-term effects of work-related psychosocial factors on acute MI events have not been examined.Third, age may play a role in the association between job strain and acute MI risk. Weaker effects have been found among older workers; plausible reasons for this are healthy worker survivor bias; retirement during follow-up may remove job strain and cause exposure misclassification (i.e., healthier older employees survive, retire, and are no longer exposed to work-related characteristics); and an increasing number of other age-related causes of acute MI.³⁰ Among younger employees, job strain may be associated with shorter exposures to harmful job characteristics than among middle-aged employees. Long-term prospective age-specific studies are therefore needed to determine whether current psychosocial risks of work environment predict acute MI events and whether the influence of work characteristics is stronger among middle-aged employees.The objective of our 18-year follow-up study was to examine whether the distinctive components of job control—decision authority, skill discretion, and predictability—were related to subsequent acute MI events in a large population of initially heart disease–free industrial employees after the effects of established risk factors were taken into account. We further tested age-specific vulnerability among these employees.     

Functional brain segmentation using inter‐subject correlation in fMRI

The human brain continuously processes massive amounts of rich sensory information. To better understand such highly complex brain processes, modern neuroimaging studies are increasingly utilizing experimental setups that better mimic daily‐life situations. A new exploratory data‐analysis approach, functional segmentation inter‐subject correlation analysis (FuSeISC), was proposed to facilitate the analysis of functional magnetic resonance (fMRI) data sets collected in these experiments. The method provides a new type of functional segmentation of brain areas, not only characterizing areas that display similar processing across subjects but also areas in which processing across subjects is highly variable. FuSeISC was tested using fMRI data sets collected during traditional block‐design stimuli (37 subjects) as well as naturalistic auditory narratives (19 subjects). The method identified spatially local and/or bilaterally symmetric clusters in several cortical areas, many of which are known to be processing the types of stimuli used in the experiments. The method is not only useful for spatial exploration of large fMRI data sets obtained using naturalistic stimuli, but also has other potential applications, such as generation of a functional brain atlases including both lower‐ and higher‐order processing areas. Finally, as a part of FuSeISC, a criterion‐based sparsification of the shared nearest‐neighbor graph was proposed for detecting clusters in noisy data. In the tests with synthetic data, this technique was superior to well‐known clustering methods, such as Ward's method, affinity propagation, and K‐means . Hum Brain Mapp 38:2643–2665, 2017. © 2017 Wiley Periodicals, Inc.     

Emotion regulation individual therapy for adolescents with nonsuicidal self-injury disorder: a feasibility study

Background

Nonsuicidal self-injury (NSSI) is a serious health risk behavior that forms the basis of a tentative diagnosis in DSM-5, NSSI Disorder (NSSID). To date, established treatments specific to NSSI or NSSID are scarce. As a first step in evaluating the feasibility, acceptability, and utility of a novel treatment for adolescents with NSSID, we conducted an open trial of emotion regulation individual therapy for adolescents (ERITA): a 12-week, behavioral treatment aimed at directly targeting both NSSI and its proposed underlying mechanism of emotion regulation difficulties.

Methods

Seventeen girls (aged 13–17; mean = 15.31) with NSSID were enrolled in a study adopting an uncontrolled open trial design with self-report and clinician-rated assessments of NSSI and other self-destructive behaviors, emotion regulation difficulties, borderline personality features, and global functioning administered at pre-treatment, post-treatment, and 6-month follow-up. Measures of NSSI and emotion regulation difficulties were also administered weekly during treatment.

Results

Ratings of treatment credibility and expectancy and the treatment completion rate (88%) were satisfactory, and both therapeutic alliance and treatment attendance were strong. Intent-to-treat analyses revealed significant improvements associated with large effect sizes in past-month NSSI frequency, emotion regulation difficulties, self-destructive behaviors, and global functioning, as well as a medium effect size in past-month NSSI versatility, from pre- to post-treatment. Further, all of these improvements were either maintained or further improved upon at 6-month follow-up. Finally, change in emotion regulation difficulties mediated improvements in NSSI over the course of treatment.

Conclusions

Results suggest the acceptability, feasibility, and utility of this treatment for adolescents with NSSID.

Trial registration

ClinicalTrials.gov (NCT02326012, December 22, 2014, retrospectively registered).

     

Achilles tendon length changes during walking in long-term diabetes patients

Background

Diabetes leads to numerous side effects, including an increased density of collagen fibrils and thickening of the Achilles tendon. This may increase tissue stiffness and could affect stretch distribution between muscle and tendinous tissues during walking. The primary aim of this study was to examine stretch distribution between muscle and tendinous tissues in the medial gastrocnemius muscle–tendon unit in long-term diabetes patients and control subjects during walking.

Methods

Achilles tendon length changes were investigated in 13 non-neuropathic diabetes patients and 12 controls, whilst walking at a self selected speed across a 10 m force platform. Electromyographic activity was recorded in the medial gastrocnemius, soleus and tibialis anterior muscles, goniometers were used to detect joint angle changes, and ultrasound was used to estimate tendon length changes.

Findings

Achilles tendon length changes were attenuated in diabetes patients compared to controls, and were inversely correlated with diabetes duration (r = −0.628; P < 0.05), as was ankle range of motion (r = −0.693; P < 0.01). Tendon length changes were also independent of walking speed (r = −0.299; P = 0.224) and age (r = 0.115; P = 0.721) in the diabetic group.

Interpretation

Stretch distribution between muscle and tendon during walking is altered in diabetic patients, which could decrease walking efficiency, a factor that may be exacerbated with increasing diabetes duration. Diabetes-induced changes in mechanical tendon properties may be at least partly responsible for attenuated tendon length changes during walking in this patient group.