Development of chronic kidney disease influenced by serum urate and body mass index based on young-to-middle-aged Japanese men: a propensity score-matched cohort study.

OBJECTIVE: To investigate the association between serum uric acid (SUA) level and body mass index (BMI) on the development of chronic kidney disease (CKD) in working men aged 20-60 years. DESIGN: Retrospective cohort study. SETTING: Data from employees' annual health check-ups were collected from two companies in 2009 and 2014. PARTICIPANTS: A total of 16 708 working men were recruited. We excluded participants with missing essential data (N=7801), who had basal estimated glomerular filtration rate (eGFR) <60.0 mL/min/1.73 m2 and/or proteinuria (N=698) or with the absence of follow-up data (N=2). PRIMARY OUTCOME: eGFR <60 mL/min/1.73 m2 and/or proteinuria (≥1+) in 2014 (defined as incident CKD). RESULTS: The cut-off values of SUA for incident CKD were 6.6 mg/dL in both young (20-39 years old) and middle-aged (40-60 years old) men analysed by receiver operator characteristics. ORs for incident CKD were assessed on propensity score-matched (1:1) cohorts. In young participants (N=1938), after propensity score matching, a coexistence of high-level SUA (≥6.6 mg/dL) and overweight (BMI ≥25 kg/m2) was a significant risk factor of incident CKD (OR=2.18, 95% CI 1.10 to 4.31, p=0.025), but high-level SUA was not an independent risk factor without overweight status (p=0.174). In middle-aged participants (N=2944) after propensity score matching, high-level SUA was a significant risk factor of incident CKD both with or without overweight (OR=1.44, 95% CI 1.02 to 2.04, p=0.037; OR=1.32, 95% CI 1.01 to 1.73, p=0.041, respectively). CONCLUSION: These findings suggest that high-level SUA is strongly associated with incident CKD in overweight young adult men.

Alteration of normal level of serum urate may contribute to decrease in estimated glomerular filtration rate decline in healthy Japanese men.

INTRODUCTION: Serum uric acid (SUA) levels have a linear relationship with the estimated glomerular filtration rate (eGFR). It is unclear whether further changes, subsequent to normal level of SUA can attenuate eGFR decline in a healthy population, so we aimed to determine the normal level of SUA that can contribute to preventing kidney dysfunction. METHODS: In this retrospective cohort study from Japan, annual health checkup data from 2009 to 2014 was collected. After propensity score matching (1:1), data from 2,634 individuals with basal SUA ≤7.0 mg/dL (normal; mean age, 39 y; mean eGFR, 80.8 mL/min/1.73 m2) and 1,642 individuals with basal SUA >7.0 mg/dL (elevated; mean age, 42 y; mean eGFR, 75.0 mL/min/1.73 m2) were collected to determine the relationship between followed-up SUA level and the rate of change in eGFR. RESULTS: In individuals with normal level SUA at baseline, the elevation of SUA (>7.0 mg/dL) accelerated eGFR decline compared to those with normal SUA levels at 5-year follow-up (-4.1 ± 9.6% vs -9.9 ± 9.0%, p < .0001). Digression of SUA level (≤7.0 mg/dL) reduced eGFR decline compared with persistent SUA level over 7.0 mg/dL (-1.5 ± 11.5% vs -7.0 ± 10.1, p < .0001). In multiple linear regression analysis, there was strong association between the rate of change in SUA and eGFR in individuals with basal SUA ≤7.0 and >7.0 mg/dL (standardized coefficient; -0.3348, p < .001 and -.2523, p < .001, respectively). CONCLUSION: Subsequent to normal level of SUA (under 7.0 mg/dL) may contribute to a decrease in eGFR decline in apparently healthy men.

Work Environment-related Stress Factors are Correlated with Diabetes Development in Workers with Impaired Glucose Tolerance: A 5-year Follow-up Study Using the Brief Job Stress Questionnaire (BJSQ).

Several previous studies have investigated the effects of occupational stress on the onset of diabetes mellitus (DM), but there are few studies of occupational stress and DM using the Brief Job Stress Questionnaire (BJSQ), a standard stress check method in Japan. This study aimed to determine the relationship between occupational stress factors and the onset of DM using the BJSQ. We examined 6,620 male company workers aged 40 years and above in 2013, using the BJSQ. Overall, 2,604 subjects with impaired glucose tolerance who were free of mental disorders and DM were followed-up for 5 years and re-examined in 2017. A retrospective data analysis was conducted in 2019. We documented 241 new cases of DM in 2017 (diabetes group). Compared with the non-diabetes group, the subjects in the diabetes group had significantly decreased "skill utilization". A binomial logistic regression analysis (generalized linear model) revealed that "skill utilization" was associated with the risk of DM development in 2017 (odds ratio, 1.632; 95% confidence interval, 1.061-2.510). Our results showed that low skill utilization might increase the risk of diabetes development in Japanese male workers.

Workplace social capital and refraining from seeking medical care in Japanese employees: a 1-year prospective cohort study.

OBJECTIVES: We examined the association of workplace social capital (WSC), including structural and cognitive dimensions, with refraining from seeking medical care (RSMC) among Japanese employees. DESIGN: One-year prospective cohort study. SETTING AND PARTICIPANTS: We surveyed 8770 employees (6881 men and 1889 women) aged 18-70 years from 12 firms in Japan using a self-administered questionnaire comprising the WSC scale and the items on potential confounders (ie, age, educational attainment and equivalent annual household income) at baseline (from April 2011 to March 2013). OUTCOME MEASURES: At a 1-year follow-up, we measured RSMC using a single-item question 'In the past year, have you ever refrained from visiting a hospital, clinic, acupuncturist or dentist despite your sickness (including a slight cold or cavity) or injury?' RESULTS: The results of Cox regression with robust variance showed that, after adjusting for potential confounders, the low WSC group (ie, the lowest tertile group) had a significantly higher relative risk (RR) of RSMC compared with the high WSC group (ie, the highest tertile group) among both men and women (overall WSC: RR 1.09 (95% CI 1.01 to 1.17) and 1.20 (95% CI 1.06 to 1.37); structural dimension: RR 1.13 (95% CI 1.04 to 1.22) and 1.25 (95% CI 1.07 to 1.45); and cognitive dimension: RR 1.11 (95% CI 1.03 to 1.20) and 1.21 (95% CI 1.06 to 1.38), respectively). Trend analysis using a continuous score of the WSC scale also showed a significant association of low WSC with a higher risk of RSMC among both men and women. CONCLUSIONS: Our findings suggest that the lack of social capital in the workplace is associated with RSMC among Japanese employees.

Relationship between abdominal adiposity and incident chronic kidney disease in young- to middle-aged working men: a retrospective cohort study.

BACKGROUND: Obesity is a risk factor for the development of chronic kidney disease (CKD). However, it remains to be fully examined whether fatness is more useful in predicting incident CKD. We aimed this study to determine the association of body fat, body mass index and waist circumference (WC) with subsequent changes in estimated glomerular filtration rate (eGFR) and incident CKD in young- to middle-aged working men. METHODS: We analyzed data from annual health check-up in male workers aged from 20 to 60 years with basal eGFR of 60-90 mL/min/1.73 m2. Cut-off values of parameters and odds ratio (OR) for the incident CKD were calculated by receiver operator characteristics analysis andχ2 test, respectively. We also tested trends of changes in eGFR according to changes in WC in each age decade. RESULTS: There were 8,015 men participants. During the 5-year follow-up, 11.0% of the participants (N = 878) had developed to incident CKD. When basal WC was greater than 80.0 cm, which was decided by Youden's Index, there was a significantly higher risk of incident CKD [OR 1.57 (95% confident interval 1.35-1.84)]. Changes in WC over 5 years were significantly related to eGFR decline in young men (< 40 years old) with normal blood pressures and normoglycemia. CONCLUSIONS: These findings suggest that WC > 80.0 cm is a risk factor for incident CKD and strongly associated with a decline in eGFR in the young- to middle-aged working healthy men.

Impact of low-density lipoprotein cholesterol on decline in estimated glomerular filtration rate in apparently healthy young to middle-aged working men.

BACKGROUND: It remains to be fully clarified whether there is a relationship between uncontrolled dyslipidemia and decline in estimated glomerular filtration rate (eGFR) in the general population. Therefore, this study's aim was to test the association of dyslipidemia with changes in eGFR in apparently healthy working men. METHODS: We retrospectively examined the annual medical check-up list of 14,510 male workers aged 20-60 years with eGFR ≥ 60 mL/min/1.73 m2 at baseline, and then evaluated the association of the changes in the check-up parameters with a decline in eGFR during the 5-year observation period. RESULTS: Mean age and eGFR were 38.5 years and 82.3 mL/min/1.73 m2 at baseline, respectively. Evaluated low-density lipoprotein cholesterol (LDL-C) (≥140 mg/dL) was a strong indicator of CKD development in participants (basal eGFR 60-90 mL/min/1.73 m2) without hypertension [odds ratio (95% confidence interval): 1.46 (1.12-1.90)] or diabetes mellitus (DM) [1.49 (1.23-1.82)]. When LDL-C normalized under 140 mg/dL during follow-up, the decline in eGFR was smaller in non-hypertensive participants [-5.9 (-14.4 to -0.9) vs -13.4 (-18.4 to -4.5) mL/min/1.73 m2, p < 0.05]. There was an inverse correlation between change of LDL-C and decline in eGFR (p for trend <0.001). CONCLUSION: Increased LDL-C levels are associated with the development of incident CKD and eGFR decline in young to middle-aged working men without hypertension and/or DM.

Association of job demands with work engagement of Japanese employees: comparison of challenges with hindrances (J-HOPE).

OBJECTIVES: Recent epidemiological research in Europe has reported that two groups of job demands, i.e., challenges and hindrances, are differently associated with work engagement. The purpose of the present study was to replicate the cross-sectional association of workload and time pressure (as a challenge) and role ambiguity (as a hindrance) with work engagement among Japanese employees. METHODS: Between October 2010 and December 2011, a total of 9,134 employees (7,101 men and 1,673 women) from 12 companies in Japan were surveyed using a self-administered questionnaire comprising the Job Content Questionnaire, National Institute for Occupational Safety and Health Generic Job Stress Questionnaire, short 10-item version of the Effort-Reward Imbalance Questionnaire, short nine-item version of the Utrecht Work Engagement Scale, and demographic characteristics. Multilevel regression analyses with a random intercept model were conducted. RESULTS: After adjusting for demographic characteristics, workload and time pressure showed a positive association with work engagement with a small effect size (standardized coefficient [ß] = 0.102, Cohen's d [d] = 0.240) while role ambiguity showed a negative association with a large effect size (ß = -0.429, d = 1.011). After additionally adjusting for job resources (i.e., decision latitude, supervisor support, co-worker support, and extrinsic reward), the effect size of workload and time pressure was not attenuated (ß = 0.093, d = 0.234) while that of role ambiguity was attenuated but still medium (ß = -0.242, d = 0.609). CONCLUSIONS: Among Japanese employees, challenges such as having higher levels of workload and time pressure may enhance work engagement but hindrances, such as role ambiguity, may reduce it.

[Approach to easing occupational stress for high-stress workers: applying the brief job stress questionnaire to workplace mental health promotion].

We investigated job stress among 442 employees from 19 divisions in a Japanese company using the Brief Job Stress Questionnaire. Job stress of the employees was estimated by the score for total health risk. Among the 19 divisions, two divisions showed over 120 points of mean total health risk score. Intervention with a stress-reduction program was carried out in these 2 divisions. First, to assess the job stress, health care staff interviewed all workers in the 2 divisions. Second, the results of the interviews were reported to the divisions' managers. Third, the managers applied the best remedy for job stress in their workplaces. In addition, occupational health staff conducted mental health education as well as individual interviews for the workers from the 2 divisions. At reevaluation one year later, both divisions showed a decreased general health risk (under 120 points). No sick leaves for depression occurred within the 2 divisions during the intervention. The results of the present study suggest that the intervention was effective in easing occupational stress for high-stress workers. The stress reduction program also seemed to have helped managers to change their recognition of occupational mental health and enabled close cooperation with occupational health staff, which may improve mental health in the workplace.

Predisposing factors of sleep-disordered breathing in Japanese male workers.

The aim of this study was to elucidate the usable predisposing factors of sleep-disordered breathing (SDB) in the workplace. A total of 353 male workers who complained of SDB related symptoms such as witnessed snoring, recurrent awakening from sleep, urination during the night, morning headache, and excessive daytime sleepiness were included in the analysis. We examined hyoid-mental distance (HMD), modified Mallampati score (MMS), and the narrowness of the pharynx with tonsillar hypertrophy as the predisposing physical findings of SDB. We used the number of 3% or more oxygen desaturation events per hour (ODI3) as the indicator of SDB. The mean values (S.D.) of all subjects were 44.3 (8.9) yr (19-66 yr) of age, and 25.9 (3.8) Kg/m(2) body mass index (BMI). A significant difference in ODI3 was found between the HMD classes, and also between the subjects with and without tonsillar hypertrophy. Mean ODI3 adjusted for age, BMI, and alcohol consumption on the day of monitoring was high in the group of short HMD and the group of tonsillar hypertrophy (+). For MMS, though ODI3 did not appear to be significantly different, mean ODI3 was high in the MMS-IV. In conclusion, short HMD and tonsillar hypertrophy are the important findings predicting SDB identified by pulse oximetry. These findings would be beneficial in the workplace for selection of subjects who should be encouraged to undergo pulse oximetry for detection of SDB.

The usefulness of sleep apnea syndrome screening using a portable pulse oximeter in the workplace.

Sleep Apnea Syndrome (SAS) is a condition characterized by sleep-disordered breathing resulting in health impairment and sleep problems. From the viewpoints of the prevention of health impairment, accidents at work and traffic accidents, active implementation of screening for SAS in workplaces is necessary. Using a portable pulse oximeter, we conducted SAS screening for workers, who applied for the screening or who were instructed to participate by occupational physicians based on their symptoms at the time of medical check-up, in order to evaluate the effectiveness of a portable pulse oximeter as a screening device in the workplace. During the 2-yr study period from April 2002 to March 2004, 380 workers underwent overnight pulse oximetry at home; data on 367 of them were considered valid and included in the analysis. We deemed screening-positive as oxygen desaturation of the peripheral artery of 4% or greater if 10 or more events were observed per hour (ODI4> or =10); or oxygen desaturation of the peripheral artery of 3% or greater if 15 or more events were observed per hour (ODI3> or =15). Eighty-three subjects were identified as screening-positive and 54 of them underwent polysomnography. All of them were diagnosed as having SAS with an apnea hypopnea index (AHI)> or =5, of which continuous positive airway pressure (CPAP) therapy was indicated in 48 cases (88.9%) with AHI> or =20. On the other hand, 11 of the 284 screening-negative subjects with mild sleep disordered breathing underwent polysomnography and all of them were diagnosed as having SAS with AHI> or =5. However, CPAP therapy was indicated only for 5 with AHI> or =20 of the 11. Therefore, in total, 65 subjects were diagnosed with SAS in this study and for 53 of them CPAP therapy was indicated. The simplicity of the SAS screening by pulse oximetry makes it easy to use for screening of workers, and this method was highly effective in detecting individuals with severe SAS for whom CPAP therapy was indicated.

[A report on the inspection of the Shinkansen Multiple Inspection Train].

The multiple inspection train nicknamed "Doctor Yellow" is capable of taking necessary measurements of the track and electrical facilities, and maintains the safety and reliability of the Tokaido Shinkansen corridor. We performed a workplace inspection to examine environmental conditions in this train. The workers were engaged in VDT (visual display terminal) work including the inspection task. The labor environments such as vibration, noise, temperature and lighting, were comfortable. However, some of the working conditions while the Bullet train is running are inevitably restricted. The occupational physicians of the Central Japan Railway Company are expected to play important roles in providing effective health management for the employees under the characteristic work environments on the railroad.