Association Between Employment Status and Short Sleep Duration Among Middle-Aged Japanese: the Survey on Time Use and Leisure Activities

BACKGROUND

Short sleep duration (SSD) is reported to be highly associated with socio-economic status. There are few studies on the relationship between employment status and SSD in Japan.

METHOD

The authors used the 2006 Survey on Time Use and Leisure Activities conducted by the Ministry of Internal Affairs and Communications Japan, which provides representative samples of Japanese people. The anonymous data of 120,783 people aged 30-59 years were analyzed. Authors defined five categories of employment status: "unemployed," "regularly employed," "non-regularly employed," "self-employed," and "other." Authors also defined a sleep duration shorter than 5 h per night as SSD. Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of SSD using regular employment as the reference group were calculated using the logistic regression model, adjusting for potential confounding factors, i.e., age, marital status, education level, communication device use, and the amount of time spent on various daily activities.

RESULTS

The prevalence of SSD was 2.8% (1639/58,308) in men and 3.2% (1976/62,475) in women. The multivariable-adjusted OR (95% CI) of SSD for the self-employed was 0.78 (0.65-0.92) in men and 1.78 (1.43-2.21) in women after adjustment for potential confounding factors, i.e., age, marital status, education level, and communication device use. Further adjustment for the time spent on daily activities revealed that the OR (95% CI) of SSD for the self-employed was 0.78 (0.65-0.92) in men and 1.89 (1.52-2.36) in women.

CONCLUSION

Self-employed women had a higher prevalence of SSD. By contrast, self-employed men had a lower prevalence of SSD.

[Sleep-disordered breathing in occupational places: from screening to Health and Productivity Management]

BACKGROUND

Sleep-disordered breathing (SDB), represented by sleep apnea, is highly prevalent in the general population and is associated with alcohol intake and obesity. Since SDB is further associated with hypertension, diabetes, and future cardiovascular diseases, as well as accidents and injuries in workplaces, there is a need for complete SDB assessment in workers, including screening and the application of diagnostic and therapeutic approaches.

RESULTS

Currently, it appears that SDB assessment is not sufficiently conducted, even among commercial motor vehicle (CMV) drivers, despite CMV drivers with SDB being at a high risk of serious traffic accidents. Based on a discussion conducted in The Study Group for Sleep Disordered Breathing in Work Places, we summarized the current situation in Japan and tried to elucidate the bottleneck of these approaches. Then, the situation in Japan was compared with that in South Korea; Professor Chol Shin substantiated that the situation in South Korea was similar to that in Japan. However, recently published data on CMV drivers in the United States showed that appropriate treatment of SDB reduced the risk of traffic accidents among CMV drivers. This will encourage the implementation of the required processes, from screening to maintenance of treatment.

CONCLUSION

We propose a new approach based on "harmonizing work with treatment and prevention" and "Health and Productivity Management (HPM)" as a solution for implementing SDB programs.

Impact of sleep disordered breathing on performance in judo players

Objective

Previous studies have suggested that young sports players may suffer from sleep disordered breathing (SDB). It was hypothesised that SDB in heavy-class judo players was far more prevalent than expected and that it could reduce judo performance, which could be improved by appropriate therapies. To address this, the present study estimated the percentage of heavy-class judo players with SDB and investigated the effect of SDB treatment on judo performance.

Methods

We enrolled 19 young judo players from a university judo team with body weight >100 kg and/or body mass index >30 kg/m². Both excessive daytime sleepiness (EDS) and respiratory disturbance index (RDI) were evaluated using the Epworth Sleepiness Scale (ESS) and an overnight type 3 sleep monitor.

Results

The percentages of young heavyweight-class judo players with EDS (ESS ≥11) and those with SDB (RDI ≥5) were both 63%, which was unexpectedly high for the age class. Seven of the participants underwent continuous positive airway pressure therapy, which improved both RDI and ESS scores (p<0.05 for each) and subsequently the sleep quality and judo performance of the participants.

Conclusions

Our study indicates that young judo players might silently suffer from SDB, leading to poorer judo performance and to future cardiovascular diseases. Clinicians should be aware of the possible presence of SDB in young sports players and consider the application of diagnostic and therapeutic remedies.

Evaluation of three-dimensional iterative image reconstruction in C-arm-based interventional cone-beam CT: A phantom study in comparison with customary reconstruction technique

We compared images obtained using a three-dimensional iterative image reconstruction (3D-IIR) algorithm for C-arm-based interventional cone-beam computed tomography (CBCT) with that using the customary reconstruction technique to quantify the effect of reconstruction techniques on image quality.We scanned 2 phantoms using an angiography unit with digital flat-panel system-an elliptical cylinder acrylic phantom to evaluate spatial resolution and a Catphan phantom to evaluate CT number linearity, image noise, and low-contrast resolution. Three-dimensional imaging was calculated using Feldkamp algorithms, and additional image sets were reconstructed using 3D-IIR at 5 settings (Sharp, Default, Soft+, Soft++, Soft+++). We evaluated quality of images obtained using the 6 reconstruction techniques and analyzed variance to test values of the 10% value of each MTF, mean CT number, and contrast-to-noise ratio (CNR), with P < .05 considered statistically significant.Modulation transfer function curves and CT number linearity among images obtained using the customary technique and the 5 3D-IIR techniques showed excellent agreement. Noise power spectrum curves demonstrated uniform noise reduction across the spatial frequency in the iterative reconstruction, and CNR obtained using all but the Sharp 3D-IIR technique was significantly better than that using the customary reconstruction technique (Sharp, P = .1957; Default, P = .0042; others, P < .0001). Use of 3D-IIR, especially the Soft++ and Soft+++ settings, improved visualization of low-contrast targets.Use of a 3D-IIR can significantly improve image noise and low-contrast resolution while maintaining spatial resolution in C-arm-based interventional CBCT, yielding higher quality images that may increase safety and efficacy in interventional radiology.

Harmonizing work with the treatment and prevention of sleep disordered breathing in commercial motor vehicle drivers: implications for health and productivity management

The desastrous traffic accidents to date have provided the relevance for promotion of harmonization of work with treatment and prevention of sleep disordered breathing (SDB) in transport sectors. SDB is highly prevalent in commercial motor vehicle (CMV) drivers and is one cause of cognitive impairment and consequent traffic accidents, potentially costing billions and leading to many deaths. Various screening, diagnostic, and therapeutic approaches, some well established, are explored in this paper. Although drivers with SDB need to be appropriately diagnosed and treated, some are reluctant to continue their treatment or never submit to screening because of a lack of information. Thus, CMV drivers need to be well informed and screened, in addition to being encouraged to continue the treatment. The harmonization of work with treatment and prevention aids these objectives, providing benefits not only for individual health but also for transport companies, and further being an essential step towards uptake of "health and productivity management" in the transport sectors.

Bronchial epithelial cells produce CXCL1 in response to LPS and TNFα: A potential role in the pathogenesis of COPD

RATIONALE

Neutrophilic airway inflammation plays a central role in chronic obstructive pulmonary disease (COPD). CXC chemokine ligand (CXCL)1 is a neutrophil chemokine involved in the pathogenesis of COPD. However, its clinical significance in COPD patients is poorly understood.

AIM OF THE STUDY

To assess the production of CXCL1 by bronchial epithelial cells in response to lipopolysaccharide (LPS) and tumor necrosis factor (TNF)α.

MATERIALS AND METHODS

We measured sputum CXCL1 and CXCL8 levels in patients with COPD, asthma, and asthma-COPD overlap (ACO), and compared them to those of patients with interstitial pneumonia (IP). Using primary human bronchial epithelial cells and BEAS-2B cells, CXCL1 protein release and mRNA expression were measured after LPS or TNFα stimulation. We evaluated signal transduction mechanisms for CXCL1 production using nuclear factor-κ B (NF-kB) and mitogen-activated protein kinase (MAPK) inhibitors, and examined the effects of anti-inflammatory agents on CXCL1 production in BEAS-2B cells.

RESULTS

Sputum CXCL1 levels in COPD and ACO patients were higher than in IP patients, whereas sputum CXCL8 levels were not. Sputum CXCL1 levels were not affected by inhaled corticosteroid usage, whereas sputum CXCL8 levels tended to be affected. LPS and TNFα stimulated CXCL1 production and mRNA expression in bronchial epithelial cells. NF-kB and MAPK p38 were involved in LPS-induced CXCL1 production. Therapeutic anti-inflammatory agents minimally attenuated CXCL1 production and considerably inhibited CXCL8 production in BEAS-2B cells.

CONCLUSIONS

Sputum CXCL1 levels is a potentially better diagnostic marker for COPD than sputum CXCL8 levels, which is explained by that CXCL1 production in bronchial epithelial cells is less affected by therapeutic anti-inflammatory agents than CXCL8 production.

Changes in bone metabolism after gastric cancer surgery in male patients: a prospective observational study

BACKGROUND

Several retrospective studies have shown that bone disorders occur after gastric cancer surgery. This study was designed to prospectively evaluate the changes in bone metabolism after gastrectomy for gastric cancer.

METHODS

We prospectively enrolled 39 men with early gastric cancer who underwent gastrectomy. We excluded women to avoid the effects of menopause. We employed dual energy X-ray absorptiometry (DEXA) to measure bone mineral density (BMD) of the lumbar spine. DEXA was performed before and 1 and 2 years after surgery. The serum levels of alkaline phosphatase (ALP), 1,25-dihydroxy vitamin D [1,25(OH)₂VD], 25-hydroxy vitamin D [25(OH)VD], and estradiol were measured before surgery and every 3 months until 2 years after surgery.

RESULTS

DEXA revealed that BMD significantly decreased by 0.036 ± 0.033 g/cm² 12 months after gastrectomy (P < 0.001) and by 0.046 ± 0.040 g/cm² 24 months after gastrectomy (P < 0.001). The serum ALP level significantly increased by 38.31 ± 103.8 IU/L 24 months after surgery (P = 0.013). The serum 25(OH)VD level significantly decreased by 4.88 ± 6.42 ng/ml 24 months after surgery (P < 0.001), whereas the serum 1,25(OH)₂VD levels were consistently in the normal range. The serum estradiol level significantly increased by 2.94 ± 7.49 pg/ml 12 months after gastrectomy (P = 0.035). A lower preoperative body mass index (BMI) significantly correlated with the reduction in BMD 12 months after surgery; the correlation coefficient was 0.37 (P = 0.025).

CONCLUSIONS

This study showed that a significant decrease in BMD was observed for up to 24 months after gastrectomy, not only 12 months.

Nocturnal enuresis and sleep disordered breathing in primary school children: Potential implications

INTRODUCTION

The association between nocturnal enuresis (NE) and sleep disordered breathing (SDB) has been repeatedly reported, but has primarily been focused on clinical cohorts. The purpose of this study, was to assess whether SDB-related symptoms such as snoring and unrefreshing sleep in the morning are associated with NE in a large-scale community school-based survey.

METHODS

A cross-sectional assessment using a standard questionnaire was conducted on nearly 20 000 primary school children (5-12 years old) in Matsuyama, Japan. Associations between NE and the frequencies of snoring and unrefreshing sleep were evaluated using multivariate logistic and regression analyses.

RESULTS

Multivariate adjusted odds ratios (95% confidence intervals) for enuresis were 1.21 (1.04 to 1.40) and 1.36 (1.07 to 1.73) in boys who snored 1 or 2 nights per week and ≥3 nights per week, respectively (P for trend <0.0001). Those for enuresis were 1.67 (1.41 to 1.99) and 1.96 (1.63 to 2.36) in boys who showed unrefreshing sleep 1 or 2 nights per week and ≥3 nights per week, respectively (P for trend <0.0001). Significant associations between NE and snoring frequency emerged among children who did not report unrefreshing sleep (P-trend for boys and girls were <0.0001 and <0.01, respectively), while significant associations between NE and frequency of unrefreshing sleep were detected among children who snored ≥1 nights per week (P for trend >0.1).

CONCLUSIONS

The pathogenic mechanisms linking snoring and unrefreshing sleep to increased risk of NE are unknown. However, snoring, a surrogate reporter of SDB, is associated with increased urine production, while unrefreshing sleep may result from disrupted sleep facilitating increased sleep pressure and elevated arousal thresholds. Thus, both SDB and unrefreshing sleep are potential independent risk factors of NE in school age children.

Sleep apnea and type 2 diabetes

The aim of the present review was to clarify the association between obstructive sleep apnea (OSA) and type 2 diabetes, and discuss the therapeutic role of continuous positive airway pressure (CPAP) in type 2 diabetes. OSA patients are more likely than non-OSA populations to develop type 2 diabetes, while more than half of type 2 diabetes patients suffer from OSA. Similar to Western countries, in the East Asian population, the association between these two disorders has also been reported. CPAP is the primary treatment for OSA, but the effect of CPAP on comorbid diabetes has not been established. CPAP improved glucose metabolism determined by the oral glucose tolerance test in OSA patients, and several studies have shown that CPAP improves insulin resistance, particularly in obese populations undergoing long-term CPAP. Diabetes is associated with other sleep-related manifestations as well, such as snoring and excessive daytime sleepiness. Snoring is associated with the development of diabetes, and excessive daytime sleepiness appears to modify insulin resistance. Well-designed studies are required to clarify the therapeutic effect of CPAP on diabetes. As both diabetes and OSA lead to cardiovascular disease, clinicians and healthcare professionals should be aware of the association between diabetes and OSA, and should take CPAP and health-related behaviors into consideration when treating patients with diabetes and/or OSA.