ShiftWork and Impaired Glucose Metabolism: A 14-Year Cohort Study on 7104 Male Workers

The aim of this study was to assess the effect of shiftwork on hemoglobin A1c (HbA1c) level, as an index of glucose metabolism. A 14 yr prospective cohort study was conducted on day (n?=?4219) and alternating shiftworkers (n?=?2885) who received annual health checkups between 1991 and 2005 at a Japanese steel company. The endpoints were either a 10%, 15%, 20%, 25%, or 30% increase in HbA1c during the period of observation, compared to HbA1c at entry to the study. The association between the type of job schedule and increase in HbA1c was investigated after adjusting for age, body mass index, mean arterial pressure, total serum cholesterol, creatinine, alanine aminotransferase, γ-glutamyl transpeptidase, uric acid, drinking habit, smoking habit, and habitual exercise using multivariate pooled logistic regression analyses. Shiftwork was significantly associated with the various HbA1c endpoints (≥10% HbA1c increase, odds ratio 1.35 [95% confidence interval 1.26–1.44]; ≥15% HbA1c increase, odds ratio 1.29 [95% confidence interval, 1.19–1.40]; ≥20% HbA1c increase, odds ratio 1.23 [95% confidence interval 1.11–1.37]; and ≥25% HbA1c increase, odds ratio 1.19 [95% confidence interval 1.03–1.36]). Age, body mass index, alanine aminotransferase, and γ-glutamyl transpeptidase were associated positively with all five HbA1c endpoints. Uric acid was associated negatively with all five HbA1c endpoints. Our study on male Japanese workers revealed alternating shiftwork (in addition to other established factors, such as age and body mass index) was a consistent risk factor for impaired glucose metabolism.     

Estimation of the benchmark duration of shiftwork associated with weight gain in male Japanese workers

The authors estimated the benchmark durations (BMDs) and their 95% lower confidence limit (BMDL) for the reference duration of shiftwork for weight gain. A 14-yr prospective cohort study was conducted in male workers at a Japanese steel company (n?=?7254) who had received annual health check-ups between 1991 and 2005. The endpoints in the study were either a 5%, 7.5%, or 10% increase in body mass index (BMI) during the period of observation, compared to the BMI at entry. The association between the duration of shiftwork and weight gain was investigated using multivariate pooled logistic regression analyses with stepwise selection of covariates, including age, BMI measured during the study, drinking and smoking habits, and habitual exercise. The BMDL/BMD for shiftwork in subjects aged in their 40s or ≥50 yrs was estimated using benchmark responses (BMRs) of 5% or 10% and parameters for the duration of shiftwork and other covariates. For workers aged in their 40s, the BMDL/BMD for shiftwork with a BMR of 5% was 18.6/23.0 yrs (≥7.5%) and 16.9/19.4 yrs (≥10%). For workers aged ≥50 yrs, the BMDL/BMD with a BMR of 5% was 22.9/28.2 yrs (≥7.5%) and 20.6/23.6 yrs (≥10%). The reference duration of shiftwork that associated with weight gain was shown to be at least 17 yrs in middle-aged workers. Special attention should be paid to prevent weight gain at an earlier stage and not when this increase in weight has become apparent.     

ESTIMATION OF THE BENCHMARK DURATION OF SHIFTWORK ASSOCIATED WITH WEIGHT GAIN IN MALE JAPANESE WORKERS

The authors estimated the benchmark durations (BMDs) and their 95% lower confidence limit (BMDL) for the reference duration of shiftwork for weight gain. A 14-yr prospective cohort study was conducted in male workers at a Japanese steel company (n?=?7254) who had received annual health check-ups between 1991 and 2005. The endpoints in the study were either a 5%, 7.5%, or 10% increase in body mass index (BMI) during the period of observation, compared to the BMI at entry. The association between the duration of shiftwork and weight gain was investigated using multivariate pooled logistic regression analyses with stepwise selection of covariates, including age, BMI measured during the study, drinking and smoking habits, and habitual exercise. The BMDL/BMD for shiftwork in subjects aged in their 40s or ≥50 yrs was estimated using benchmark responses (BMRs) of 5% or 10% and parameters for the duration of shiftwork and other covariates. For workers aged in their 40s, the BMDL/BMD for shiftwork with a BMR of 5% was 18.6/23.0 yrs (≥7.5%) and 16.9/19.4 yrs (≥10%). For workers aged ≥50 yrs, the BMDL/BMD with a BMR of 5% was 22.9/28.2 yrs (≥7.5%) and 20.6/23.6 yrs (≥10%). The reference duration of shiftwork that associated with weight gain was shown to be at least 17 yrs in middle-aged workers. Special attention should be paid to prevent weight gain at an earlier stage and not when this increase in weight has become apparent. (Author correspondence: suwa@faculty.chiba-u.jp)     

Predictive Power of a Body Shape Index for Development of Diabetes,Hypertension, and Dyslipidemia in Japanese Adults: A Retrospective Cohort Study

Background/Objectives

Recently, a body shape index (ABSI) was reported to predict all-cause mortality independently of body mass index (BMI) in Americans. This study aimed to evaluate whether ABSI is applicable to Japanese adults as a predictor for development of diabetes, hypertension, and dyslipidemia.

Subjects/Methods

We evaluated the predictive power of ABSI in a retrospective cohort study using annual health examination data from Chiba City Hall in Japan, for the period 2008 to 2012. Subjects included 37,581 without diabetes, 23,090 without hypertension, and 20,776 without dyslipidemia at baseline who were monitored for disease incidence for 4 years. We examined the associations of standardized ABSI, BMI, and waist circumference (WC) at baseline with disease incidence by logistic regression analyses. Furthermore, we conducted a case-matched study using the propensity score matching method.

Results

Elevated BMI, WC, and ABSI increased the risks of diabetes and dyslipidemia [BMI-diabetes: odds ratio (OR) = 1.26, 95% confidence interval (95%CI) = 1.20−1.32; BMI-dyslipidemia: OR = 1.15, 95%CI = 1.12−1.19; WC-diabetes: OR = 1.24, 95%CI = 1.18−1.31; WC-dyslipidemia: OR = 1.15, 95%CI = 1.11−1.19; ABSI-diabetes: OR = 1.06, 95%CI = 1.01−1.11; ABSI-dyslipidemia: OR = 1.04, 95%CI = 1.01−1.07]. Elevated BMI and WC, but not higher ABSI, also increased the risk of hypertension [BMI: OR = 1.32, 95%CI = 1.27−1.37; WC: OR = 1.22, 95%CI = 1.18−1.26; ABSI: OR = 1.00, 95%CI = 0.97−1.02]. Areas under the curve (AUCs) in regression models with ABSI were significantly smaller than in models with BMI or WC for all three diseases. In case-matched subgroups, the power of ABSI was weaker than that of BMI and WC for predicting the incidence of diabetes, hypertension, and dyslipidemia.

Conclusions

Compared with BMI or WC, ABSI was not a better predictor of diabetes, hypertension, and dyslipidemia in Japanese adults.     

Shift Work and the Relationship with Metabolic Syndrome in Chinese Aged Workers

Background

Shift work is indicated to be associated with adverse metabolic disorders. However, potential effects of shift work on metabolic syndrome (MetS) and its components have not been well established.

Methods

In total, 26,382 workers from Dongfeng-Tongji Cohort were included in this study. Information on shift work history was gathered through questionnaires and metabolic traits were measured. Logistic regression models were used to calculate the odds ratio (OR) and 95% confidence interval (CI) for long-term shift work related with MetS and each component, respectively. Further stratification analysis was performed to detect the differences on MetS between female and male shift workers.

Results

Long-term shift work was associated with MetS without adjusting for any confounders. Compared with the group of non-shift work, the multivariate-adjusted ORs (95%CI) of MetS associated with 1–10, 11−20, and ≥20y of shift work were 1.05 (0.95−1.16), 1.14 (1.03−1.26), 1.16 (1.01−1.31), respectively. In female workers, we found a dose-response relationship that every 10 years increase in shift work was associated with a 10% (95% CI: 1%−20%) elevated OR of MetS, while no significant dose-response trend was found among male workers. Furthermore, shift work duration was significantly associated with ORs of high blood pressure (1.07, 1.01−1.13), long waist circumference (1.10, 1.01−1.20) and high glucose levels (1.09, 1.04−1.15). No significant association was observed between shift work and low HDL cholesterol) and raised triglyceride levels.

Conclusions

Long-term shift work was associated with metabolic syndrome and the association might differ by gender in retired workers. Applicable intervention strategies are needed for prevention of metabolic disorders for shift workers.     

Objective working hour characteristics and work–life conflict among hospital employees in the Finnish public sector study

This epidemiological cohort study, based on Finnish public sector data, investigated the associations between objective working hour characteristics and work–life conflict in day and shift work. The comprehensive data of hospital workers (n = 8 931, 92% women, average age 45 years), consisted of survey responses from 2012, linked with the payroll data of working hour characteristics from 91 days preceding the survey. Logistic regression analysis was used to investigate the associations between working hour characteristics and experiencing work–life conflict often/very often. The analyses were adjusted for age (< 39, 40–49 and >50 years), sex, level of education, marital status, number of small (0–6 years) and school-aged (7–18 years) children, and the overall stressfulness of the life situation. We also conducted stratified analyses of age and sex on the basis of significant interactions. Difficulties in combining work and life were more often associated with shift work without night shifts and shift work with night shifts than with day work (41% and 34 versus 27%; OR for shift work with night shifts 1.78, 95% CI 1.59–2.00, OR for shift work without night shifts 1.42, 95% CI 1.26–1.60). A high proportion (> 25%) of long (> 40h, (OR 1.26, 95% 1.14–1.39) and very long (> 48h, OR 1.31, 95% CI 1.15–1.49) weekly working hours were associated with work–life conflict, and in the stratified analysis, the latter was also true among women (OR 1.54, 95% CI 1.25–1.89). Of the unsocial working hour characteristics, a relatively large amount (> 10% of all shifts) of evening (OR 1.56, 95% CI 1.41–1.72) and night shifts (OR 1.46, 95%CI 1.32–1.61), a high proportion (> 25% of all shifts) of quick returns (< 11h) (OR 1.46, 95% CI 1.31–1.63), and weekend work (OR 1.44, 95% CI 1.31–1.58) were associated with work–life conflict. A large amount of single days off (> 25% of all days off) was associated with work–life conflict among men (OR 1.90, 95% CI 1.11–3.25), but not in the whole sample. When the two types of shift work were analyzed separately, shift work without night shifts and very long work weeks had higher odds (OR 1.47, 95% CI 1.20–1.80) of work–life conflict than shift work with night shifts. Conversely, weekend work and evening shifts had higher odds of work–life conflict among shift workers with night shifts (OR 1.74, 95% 1.55–1.96; (OR 1.57, 95% CI 1.40–1.77) than among those without night shifts. To conclude, this study shows that shift workers with and without night shifts more often have difficulties combining work and life than day workers. Several unsocial working hour characteristics, including long work weeks, evening and night shifts, weekend work, and quick returns, are associated with work–life conflict.     

Association of Sickness Absence with Poor Sleep and Depressive Symptoms in Shift Workers

A cross-sectional study was conducted to evaluate the contribution of daily sleep habits and depressive symptoms to sickness absences of shift workers. A self-administered questionnaire that solicited answers about sleep, symptoms of depression, sickness absence, diseases/injuries, and lifestyle factors was submitted to a sample of 522 rotating shift workers between the ages of 18–59 (mean 27) yrs of an electric equipment manufacturing company. The seven features of sleep queried were daily hours of sleep, time to fall asleep, awakening during sleep, early morning awakening, sleep well at night, sufficiency of sleep, and excessive daytime sleepiness at work. The responses were assessed over the subject's previous 1-yr period. Each sleep feature, except daily sleeping hours, was dichotomized by the following responses: (1) taking more than 30 min to fall asleep (difficulty initiating sleep; DIS), (2) awakening during sleep almost every day (difficulty maintaining sleep; DMS), (3) early morning awakening almost every day (EMA), (4) sleeping very poorly or not so well at night, (5) definite or somewhat insufficient nightly sleep, and (6) excessive daytime sleepiness at work almost every day (EDS). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Sickness absence was calculated by asking subjects “How many days in total have you been absent from work due to sickness, including paid vacation, in the last 1-yr period?” The responses were divided into three groups that included no (0 days) sickness absences (reference group, n = 235 subjects), 1 to 4 days (short-term, n = 199 subjects), and 5 days or more (long-term, n = 88 subjects). Compared to the prevalence of sleep features of the reference group, workers with short-term absence showed a significantly higher prevalence of EMA with an odds ratio (OR) of 5.3, 95% confidence interval (CI) 1.3–22.0. Long-term absence was significantly associated with DMS (OR = 2.1, 95%CI 1.0–4.6), EMA (OR = 5.6, 95%CI 1.0–28.7), sleeping poorly at night (OR = 2.6, 95%CI 1.4–5.0), and high depressive symptoms (OR = 2.0, 95%CI 1.0–3.7) according to the CES-D score of ≥16, after adjusting for multiple confounding variables. These data point to an association between both the parameters of poor sleep and symptoms of deep depression when self-reported sickness absence is frequent. The association is particularly strong with long-term absence in male shift workers.     

Body mass index and weight gain after middle adulthood are associated with risk of papillary thyroid cancer: A case–control study

BackgroundIt is unclear whether weight change after middle adulthood influences the risk of thyroid cancer. The aim of this study was to investigate associations between the risk of papillary thyroid cancer (PTC) and body mass index (BMI) and weight change after middle adulthood (age 35).MethodsA matched case–control study based on three hospitals included 516 pairs of cases newly diagnosed with PTC and controls. Current height and weight after defecation in the morning were measured by trained nurses. During measurement, all subjects were requested to wear lightweight clothing and no shoes. Weight at age 35 was self-reported. BMI and weight change were modeled as continuous and categorical variables. Conditional and unconditional logistic regression models were used to estimate the odds ratio (OR) and 95% confidence interval (95%CI) for the association between BMI and weight change after middle adulthood and PTC.ResultsAfter adjustment for covariates, measured BMI at the time of current diagnosis was positively associated with PTC (OR 1.16, 95%CI 1.10–1.21). According to WHO BMI guidelines for Asia-Pacific populations, the OR (95%CI) for PTC risk in obesity was 2.99 (1.92–4.67) compared to normal weight (p-trend <0.001). Moreover, PTC was positively associated with BMI at age 35; the OR (95%CI) for PTC risk per unit increase in BMI was 1.06 (1.02–1.11). Compared to stable weight (changed <0.5 kg/year), weight gain ≥1.0 kg/year after middle adulthood was positively associated with PTC (OR 2.57, 95%CI 1.39–4.76, p-trend <0.001). Compared to maintaining non-overweight status, the PTC risk was significantly increased in those individuals who gained weight and became overweight after middle adulthood (OR 3.82, 95%CI 2.50–5.85).ConclusionThis study showed that high BMI and obesity were positively associated with increased risk of PTC, and weight gain after middle adulthood also could elevate the PTC risk.     

Potential Risk Factors of Persistent Low Back Pain Developing from Mild Low Back Pain in Urban Japanese Workers

Study Design

Two-year, prospective cohort data from the Japan epidemiological research of occupation-related back pain study in urban settings were used for this analysis.

Objective

To examine the association between aggravated low back pain and psychosocial factors among Japanese workers with mild low back pain.

Summary of Background Data

Although psychosocial factors are strongly indicated as yellow flags of low back pain (LBP) leading to disability, the association between aggravated LBP and psychosocial factors has not been well assessed in Japanese workers.

Methods

At baseline, 5,310 participants responded to a self-administered questionnaire including questions about individual characteristics, ergonomic work demands, and work-related psychosocial factors (response rate: 86.5%), with 3,811 respondents completing the 1-year follow-up questionnaire. The target outcome was aggravation of mild LBP into persistent LBP during the follow-up period. Incidence was calculated for the participants with mild LBP during the past year at baseline. Logistic regression was used to explore risk factors associated with persistent LBP.

Results

Of 1,675 participants who had mild LBP during the preceding year, 43 (2.6%) developed persistent LBP during the follow-up year. Multivariate analyses adjusted for individual factors and an ergonomic factor found statistically significant or almost significant associations of the following psychosocial factors with persistent LBP: interpersonal stress at work [adjusted odds ratio (OR): 1.96 and 95% confidence interval (95%CI): 1.00–3.82], job satisfaction (OR: 2.34, 95%CI: 1.21–4.54), depression (OR: 1.92, 95%CI: 1.00–3.69), somatic symptoms (OR: 2.78, 95%CI: 1.44–5.40), support from supervisors (OR: 2.01, 95%CI: 1.05–3.85), previous sick-leave due to LBP (OR: 1.94, 95%CI: 0.98–3.86) and family history of LBP with disability (OR: 1.98, 95%CI: 1.04–3.78).

Conclusions

Psychosocial factors are important risk factors for persistent LBP in urban Japanese workers. It may be necessary to take psychosocial factors into account, along with physical work demands, to reduce LBP related disability.     

Association of sickness absence with poor sleep and depressive symptoms in shift workers

A cross-sectional study was conducted to evaluate the contribution of daily sleep habits and depressive symptoms to sickness absences of shift workers. A self-administered questionnaire that solicited answers about sleep, symptoms of depression, sickness absence, diseases/injuries, and lifestyle factors was submitted to a sample of 522 rotating shift workers between the ages of 18-59 (mean 27) yrs of an electric equipment manufacturing company. The seven features of sleep queried were daily hours of sleep, time to fall asleep, awakening during sleep, early morning awakening, sleep well at night, sufficiency of sleep, and excessive daytime sleepiness at work. The responses were assessed over the subject's previous 1-yr period. Each sleep feature, except daily sleeping hours, was dichotomized by the following responses: (1) taking more than 30min to fall asleep (difficulty initiating sleep; DIS), (2) awakening during sleep almost every day (difficulty maintaining sleep; DMS), (3) early morning awakening almost every day (EMA), (4) sleeping very poorly or not so well at night, (5) definite or somewhat insufficient nightly sleep, and (6) excessive daytime sleepiness at work almost every day (EDS). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Sickness absence was calculated by asking subjects "How many days in total have you been absent from work due to sickness, including paid vacation, in the last 1-yr period?" The responses were divided into three groups that included no (0 days) sickness absences (reference group, n=235 subjects), 1 to 4 days (short-term, n=199 subjects), and 5 days or more (long-term, n = 88 subjects). Compared to the prevalence of sleep features of the reference group, workers with short-term absence showed a significantly higher prevalence of EMA with an odds ratio (OR) of 5.3, 95% confidence interval (CI) 1.3-22.0. Long-term absence was significantly associated with DMS (OR = 2.1, 95%CI 1.0-4.6), EMA (OR = 5.6, 95%CI 1.0-28.7), sleeping poorly at night (OR= 2.6, 95%CI 1.4-5.0), and high depressive symptoms (OR = 2.0, 95%CI 1.0-3.7) according to the CES-D score of >16, after adjusting for multiple confounding variables. These data point to an association between both the parameters of poor sleep and symptoms of deep depression when self-reported sickness absence is frequent. The association is particularly strong with long-term absence in male shift workers.     

Nutritional status and eating habits of bus drivers during the day and night

The aim of this study was to compare anthropometry and food intake patterns in bus drivers working during the day and night. One hundred and fifty males (81 night workers and 69 day workers) participated in the study. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. Measurements of height, weight, waist circumference (WC), systolic and diastolic blood pressure, blood glucose, and lipid profile were obtained. A significant difference between groups was observed for mean WC (98.5?±?10.7?cm in day workers versus 103.2?±?9.7?cm in night workers; p?=?0.005). Night workers had higher prevalence of being overweight and obese (BMI?≥?25?kg/m²) than day workers (78.2% day workers versus 90.2% night workers; p?=?0.004) and increased WC (>94?cm) (72.4% day workers versus 86.4% night workers; p?=?0.03). Significant differences were found for meat consumption (2.3 servings ±0.9 for night workers versus 2.0 servings ±0.7 day workers, p?=?0.04) and fruit intake (0.9 servings ±0.4 for night workers versus 0.7 servings for day workers ±0.5; p?=?0.006). Night workers had a lower intake of vegetables than recommended compared to day workers (100 versus 92.7%, respectively, p?=?0.01) and higher intake of oil (40.7 versus 24.6%, p?=?0.03). Multivariate logistic regression analysis indicated that night work was associated with being overweight (OR?=?2.94, 95% IC: 1.14–7.66, p?=?0.03) and abnormal values of WC (OR?=?2.82, 95% IC: 1.20–6.69, p?=?0.009) after adjusting for potential confounders. It is concluded that night workers had a higher prevalence and risk of being overweight/obese and increased WC compared with day workers. Night workers also presented a higher proportion of inappropriate intakes of food groups when compared to day workers, even though both groups were eating poor diets. These results demonstrate the need of lifestyle-intervention programs in these workers.     

Relationship between shift work schedule and self-reported sleep quality in Chinese employees

Few studies have reported on the effects of fixed and rotating shift systems on the prevalence of sleep disturbance. Thus, in this study, the relationships between different work schedules and sleep disturbance in Chinese workers were investigated. A total of 2180 workers aged 19–65 years responded to the self-report questionnaire on shift work schedule (fixed day-shift, fixed night-shift, two-shift or three-shift system), working hours a day, and working days a week, physical effort, subjective sleep quality and subjective mental state. It was found that the rotating shift workers, namely, two- and three-shift workers, exhibited higher risks of sleep disturbance than with the fixed day-shift workers did (OR 1.37; 95% CI 1.07to 1.74; and OR 2.19; 95% CI 1.52 to 3.15, respectively). The risk was particularly high among two- or three-shift workers who worked more than 8 hours a day or more than 5 days a week and among three-shift workers who reported both light and heavy physical effort at work. Moreover, the two- and three-shift workers (rotating shift workers) suffered from poorer sleep quality than the fixed night shift workers did (OR 1.84; 95% CI 1.01 to 3.32; and OR 2.94; 95% CI 1.53 to 5.64, respectively). Consequently, rotating shift work (two- and three-shift work) is a risk factor for sleep disturbance, and the fixed work rhythm may contribute to the quality of sleep.     

Electronic Games and Environmental Factors Associated with Childhood Obesity in Switzerland

Objective: Environmental factors and behaviors associated with obesity have not been well described in children living in Europe. Although television watching has been repeatedly associated with obesity, it is unclear whether other sedentary activities, such as use of electronic games, are independently associated with obesity in children. The hypothesis was that various types of sedentary activities are associated with obesity in children living in Switzerland. Research Methods and Procedures: This was a cross‐sectional study of children (grades one to three) from four communities in the Greater Zurich Area (Switzerland). Obesity was defined as a combination of overweight (BMI) and overfat (skinfold thicknesses). Environmental factors were assessed by questionnaire. The children's physical activity was estimated by their teacher (scale 0 to 10). Results: Of 922 eligible subjects, 872 (94.6%) took part in the study. Use of electronic games [odds ratio (OR) = 2.03 per hour per day, 95% confidence interval (CI): 1.57 to 2.61, p < 0.001], television (OR = 2.83 per hour per day, 95% CI: 2.08 to 3.86, p < 0.001), physical activity (OR = 0.80 per unit, 95% CI: 0.72 to 0.88, p < 0.001), maternal work (OR = 1.93, 95% CI: 1.13 to 3.29, p = 0.02), and paternal smoking (OR = 1.78, 95% CI: 1.07 to 2.96, p = 0.03) were independently associated with obesity. Further adjustment for socioeconomic status, when available, did not change these results. Discussion: In this sample of children living in Switzerland, the use of electronic games was significantly associated with obesity, independently of confounding factors. The association of obesity with television use and lack of physical activity confirms results from other populations and points to potential strategies for obesity prevention.     

MTHFR C677T and A1298C polymorphisms and cervical carcinoma susceptibility: meta-analyses based on 4421 individuals

MTHFR polymorphisms have been implicated as risk factors for several cancers. Studies have conducted on the associations of MTHFR polymorphisms with cervical carcinoma risk and have generated inconclusive results. The aim of the present study was to increase power demonstrating the possible relations. Meta-analyses examining the association between MTHFR C677T and A1298C polymorphisms and cervical carcinoma risk were performed. Separate analyses on ethnicity and source of controls were also implemented. Eligible studies were identified for the period up to Dec 2011. Eleven case-control studies containing 1859 cases and 2562 controls regarding MTHFR C677T polymorphisms were selected, of which four studies containing 461 cases and 832 controls described A1298C polymorphisms. For the overall data, no associations of MTHFR C677T polymorphisms with cervical carcinoma were observed (TT vs CC: OR = 1.07; 95 %CI = 0.73-1.58; dominant model: OR = 0.89; 95 %CI = 0.66-1.18; recessive model: OR = 1.13; 95 %CI = 0.84-1.52). In the subgroup analysis by ethnicity, MTHFR 677T allele was associated with decreased cervical cancer susceptibility among Caucasians (TT vs CC: OR = 0.65; 95 %CI = 0.45-0.93; dominant model: OR = 0.70; 95 %CI = 0.58-0.86) but not Asians. As for A1298C polymorphism, no marked associations of A1298C genetic variation with cervical cancer risk were observed (CC vs AA: OR = 1.01; 95 %CI = 0.60-1.73; dominant model: OR = 1.17; 95 %CI = 0.91-1.49; recessive model: OR = 0.99; 95 %CI = 0.60-1.63). Collectively, the results of the present study suggest that MTHFR 677T allele might play a preventive role for cervical carcinoma among Caucasians. A1298C polymorphisms might exert little effect on cervical cancerigenesis.     

The Impact of PNPLA3 rs738409 Genetic Polymorphism and Weight Gain ≥10 kg after Age 20 on Non-Alcoholic Fatty Liver Disease in Non-Obese Japanese Individuals

Non-alcoholic fatty liver disease (NAFLD) in non-obese individuals is inadequately elucidated. We aim to investigate the impact of known genetic polymorphisms on NAFLD and the interaction between genetic risks and weight gain on NAFLD in obese and non-obese Japanese individuals. A total of 1164 participants who received health checkups were included. Participants with excessive alcohol consumption, with viral hepatitis or other inappropriate cases were excluded. Fatty liver was diagnosed by ultrasonography. Participants with a body mass index (BMI) of <18.5 kg/m², 18.5–22.9 kg/m², 23.0–24.9 kg/m² and ≥25 kg/m² were classified underweight, normal weight, overweight and obese, respectively. Self-administered questionnaire for lifestyle was assessed and a total of 8 previously reported genetic polymorphisms were chosen and examined. In all, 824 subjects were enrolled. The overall prevalence of NAFLD was 33.0%: 0% in underweight, 15.3% in normal weight, 41.1% in overweight and 71.7% in obese individuals. The prevalence of NAFLD is more affected by the G allele of patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 in normal weight (odds ratio (OR) 3.52; 95%-CI: 1.42–8.71; P = 0.0063) and in overweight individuals (OR 2.60; 95%-CI: 1.14–5.91; P = 0.0225) than in obese individuals (not significant). Moreover, the G allele of PNPLA3 rs738409 and weight gain ≥10 kg after age 20 had a joint effect on the risk of NAFLD in the normal weight (OR 12.00; 95% CI: 3.71–38.79; P = 3.3×10⁻⁵) and the overweight individuals (OR 13.40; 95% CI: 2.92–61.36; P = 0.0008). The G allele of PNPLA3 rs738409 is a prominent risk factor for NAFLD and the interaction between the PNPLA3 rs738409 and weight gain ≥10 kg after age 20 plays a crucial role in the pathogenesis of NAFLD, especially in non-obese Japanese individuals.     

Shiftwork and Sickness Absence Among Police Officers: The BCOPS Study

Shiftwork, regarded as a significant occupational stressor, has become increasingly prevalent across a wide range of occupations. The adverse health outcomes associated with shiftwork are well documented. Shiftwork is an integral part of law enforcement, a high-stress occupation with elevated risks of chronic disease and mortality. Sickness absence is an important source of productivity loss and may also serve as an indirect measure of workers’ morbidity. Prior studies of shiftwork and sickness absenteeism have yielded varying results and the association has not been examined specifically among police officers. The objective of this study was to compare the incidence rate of sick leave (any, ≥3 consecutive days) among day-, afternoon-, and night-shift workers in a cohort of police officers and also examine the role of lifestyle factors as potential moderators of the association. Participants (N?=?464) from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) study examined between 2004 and 2009 were used. Daily work history records that included the shift schedule, number of hours worked, and occurrence of sick leave were available for up to 15 yrs starting in 1994 to the date of the BCOPS study examination for each officer. Poisson regression analysis for ungrouped data was used to estimate incidence rates (IRs) of sick leave by shift, and comparison of IRs across shifts were made by computing incidence rate ratios (IRRs) and their 95% confidence intervals (CIs). Sick leave occurred at a higher rate on the night shift (4.37 per 10?000 person-hours) compared with either day (1.55 per 10?000 person-hours) or afternoon (1.96 per 10?000 person-hours) shifts. The association between shiftwork and sickness absence depended on body mass index (BMI). For overweight individuals (BMI?≥?25?kg/m²), the covariate-adjusted incidence rate of sick leave (≥1 day) was twice as large for night-shift officers compared with those working on the day (IRR?=?2.29, 95% CI: 1.69–3.10) or afternoon (IRR?=?1.74, 95% CI: 1.29–2.34) shift. The IR of three or more consecutive days of sick leave was 1.7 times larger for those working on night shift (IRR?=?1.65, 95% CI: 1.17–2.31) and 1.5 times larger for those working on afternoon shift (IRR?=?1.50, 95% CI: 1.08–2.08) compared with day shiftworkers. For subjects with normal BMI (<25?kg/m²), the incidence rates of sick leave did not differ significantly across shifts. In conclusion, shiftwork is independently associated with sickness absence, with officers who work the night shift having elevated incidence of sick leave. In addition, overweight officers who work the night shift may be at additional risk for sickness absence.     

The impact of obesity to antioxidant defense parameters in adolescents with increased cardiovascular risk

BackgroundThe goal of this study was to assess the oxidative stress status through the values of antioxidant defense parameters: superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and total antioxidant status (TAS), as well as cardiovascular risk factors (total cholesterol, LDL-cholesterol, VLDL-cholesterol, non-HDL-cholesterol and triglycerides), anthropometric parameters (Body mass index-BMI, waist circumference-WC, hipp circumferemce-HC, waist-to-hipp ratio-WHR and inflammatory markers (high sensitive C-reactive protein) in a group of obese adolescents.MethodsA total of 238 students of both sexes, age of 22.32 ± 1.85 yr. were included in the study. According to the values of BMI lower and higher than 25 kg/m2 and WC higher and lower than 94 cm (males)/80 cm (females) the tested group of students was divided into 2 subgroups: Group 1 (increased risk for CVD) and Group 2 (lower risk for CVD).ResultsSignificantly reduced SOD and GPx with increased GR, TAS, inflammatory and lipoprotein parameters were obtained in Group 1 compared to Group 2. Significant positive association of hsCRP (OR:1.41; 95%CI 1.08-1.83; P=0.007), TAS (OR:827.2; 95%CI 19.27-35498; P=0.007) and GR (OR:1.13; 95%CI 1.05-1.21; P=0.002) and negative association of GPx (OR:0.97; 95%CI 0.94-1.003; P=0.043) and HDL-cholesterol (OR:0.41; 95%CI 0.176-0.963; P=0.0014) with cardiovascular risk factors were found in obese students. According to the ROC analysis GR>44.8 U/L, TAS>1.35 mmol/L, hsCRP>1.71 mg/L and HDL-cholesterol <1.13 mmol/L have sufficient predictive ability for cardiovascular disease in obese students.ConclusionsSignificant association of antioxidant defense parameters with anthropometric, lipid and inflammatory markers in obese students with increased cardiovascular risk suggest that screening of these parameters is necessary and highly recommended.     

Permanent night workers´ sleep and psychosocial factors in hospital work. A comparison to day and shift work

ABSTRACT

We aimed to study whether permanent night workers sleep and psychosocial factors differ from day workers and shift workers. The participants (n = 9 312, 92% females, average age 45 years, most commonly nurses and departmental secretaries) were day workers (DW, n = 2 672), shift workers (SW, n = 6 486) and permanent night workers (PNW, n = 154). The Finnish Public Sector survey responses from six hospital districts from 2012 were combined to payroll data from 91 days preceding the survey. The data were analyzed using Pearson χ²-test, one-way ANOVA and multinomial logistic regression analysis. The PNWs reported slightly longer average sleep length than the SWs or the DWs (7:27 vs. 7:13 and 7:10 h, p < 0.001). The PNWs reported least often difficulties in maintaining sleep (p < 0.001) compared to the SWs and the DWs. The PNWs reported most often difficulties to fall asleep and fatigue during free-time (p-values <0.001). The DWs and PNWs experienced less often work-life conflict than the SWs (25 and 26 vs. 38%, p < 0.001). The PNWs were more often satisfied with autonomy at work and appreciation and fair treatment by colleagues than the DWs or the SWs (p < 0.001). The SWs and PNWs reported remarkably higher occurrence of verbal (p < 0.001, OR 3.71, 95% CI 3.23–4.27 and OR 7.67, 95% CI 5.35–10.99, respectively) and physical workplace violence (p < 0.001, OR 9.24, 95% CI 7.17–11.90 and OR 28.34, 95% CI 16.64–43.06, respectively) compared to DWs. Conclusively, PNWs reported contradictory differences in sleep quality compared to DWs and SWs. PNWs are more often satisfied with their colleagues and autonomy at work than DWs or SWs but face workplace violence remarkably more often.     

Shift work and sleep disorder comorbidity tend to go hand in hand

Taking into consideration that shift work has a wide-ranging impact on circadian and sleep functioning, it seems likely that shift work increases the risk of a general sleep disturbance, spread out over a multitude of comorbid sleep disorders. The aim of the present study is to analyze and present the sleep disorder data of 250 shift workers and 971 permanent day workers, taken from a nationally representative sample. Additional data concerning duration, timing, and quality of sleep, daytime functioning and social/family variables were added to the analyses. The results showed that the shift workers experienced significantly more difficulties with the variability of their sleep times, reported more napping and considered themselves more as poor sleepers than the day workers. Most importantly, shift work, in comparison with day work, appeared associated with a significantly higher prevalence of the clinical, International Classification of Sleep Disorders’ defined symptoms of nearly all main sleep disorders (including shift work disorder). For shift workers, the prevalence of a general sleep disturbance was 39.0% (95%CI 33.2 – 45.2), significantly higher than for day workers (24.6%, 95%CI 22.0 – 27.4). Moreover, shift workers were characterized by high levels of sleep disorder comorbidity. In addition, exclusively for shift workers, the prevalence of disordered sleep systematically decreased across decades of life and was considerably higher for single versus partnered shift workers. This study adds to the insight into the interacting factors that determine shift work coping and may play a role in occupational health interventions aimed at reducing sleep problems and thus improving the resilience and tolerance of the shift worker.     

Major Increase in Prevalence of Overweight and Obesity between 1987 and 2001 among Danish Adults

Objective: The aim of the study was to examine the secular trends in the prevalence of obesity (BMI ≥ 30.0 kg/m²) and overweight (25.0 ≤ BMI < 30.0 kg/m²) in Danish adults between 1987 and 2001. Research Methods and Procedures: The study included self‐reported weight and height of 10, 094 men and 9897 women 16 to 98 years old, collected in a series of seven independent cross‐sectional surveys. Prevalence and changes in prevalence of obesity and overweight stratified by sex and age groups were determined Results: The prevalence of obesity more than doubled between 1987 and 2001, in men from 5.6% to 11.8% [odds ratio (OR) = 2.3, 95% confidence interval (CI) = 1.9 to 2.8, p < 0.0001] and in women from 5.4% to 12.5% (OR = 2.6, 95% CI = 2.1 to 3.2, p < 0.0001), with the largest increase among the 16‐ to 29‐year‐old subjects (men, from 0.8% to 7.5%, OR = 10.2, 95% CI = 4.1 to 25.3, p < 0.0001; women, from 1.4% to 9.0% OR = 7.0, 95% CI = 3.5 to 14.1, p < 0.0001). Between 1987 and 2001, the prevalence of overweight increased from 34% to 40% in men and from 17% to 27% in women. Discussion: The prevalence of overweight and obesity in Denmark has increased substantially between 1987 and 2001, particularly among young adults, a development that resembles that of other countries. There is clearly a need for early preventive efforts in childhood to limit the number of obesity‐related complications in young adults.