Association of noise exposure with lipid metabolism among Chinese adults: mediation role of obesity indices.

PURPOSE: Noise exposure in the workplace has been linked to a number of health consequences. Our objectives were to explore the relationship between occupational noise and lipid metabolism and evaluate the possible mediating effect of obesity indices in those relationships with a cross-sectional study design. METHODS: Cumulative noise exposure (CNE) was used to measure the level of noise exposure. Logistic regression models or generalized linear models were employed to evaluate the association of occupational noise and obesity with lipid metabolism markers. Cross-lagged analysis was conducted to explore temporal associations of obesity with lipid metabolism. RESULTS: A total of 854 participants were included, with each one-unit increase in CNE, the values of total cholesterol/high-density lipoprotein cholesterol and low-density lipoprotein cholesterol/high-density lipoprotein cholesterol increased by 0.013 (95% confidence interval: 0.006, 0.020) and 0.009 (0.004, 0.014), as well as the prevalence of dyslipidemia increased by 1.030 (1.013, 1.048). Occupational noise and lipid metabolism markers were all positively associated with body mass index (BMI), waist circumference (WC), a Body Shape Index (ABSI) and a Body Shape Index and Body Roundness Index (BRI) (all P < 0.05). Moreover, BMI, WC, ABSI and BRI could mediate the associations of occupational noise with lipid metabolism; the proportions ranged from 21.51 to 24.45%, 23.84 to 30.14%, 4.86 to 5.94% and 25.59 to 28.23%, respectively (all P < 0.05). CONCLUSIONS: Our study demonstrates a positive association between occupational noise and abnormal lipid metabolism, and obesity may partly mediate the association. Our findings reinforce the need to take practical steps to reduce or even eliminate the health risks associated with occupational noise.

Osteoarthritis & stroke: a bidirectional mendelian randomization study.

OBJECTIVE: The epidemiological evidence on the link between osteoarthritis (OA) and stroke remains inconclusive. Herein, we adopted a two-sample bidirectional Mendelian randomization (MR) study to determine the causality relationship between OA and stroke. DESIGN: Summary-level data derived from the published genome-wide association studies (GWAS) were employed for analyses. The data for OA at any site (n = 455,211), knee OA (n = 403,124), and hip OA (n = 393,873) were obtained from a meta-analysis of GWAS available in the UK Biobank and Arthritis Research UK Osteoarthritis Genetics resources. The MEGASTROKE consortium provided data for stroke (n = 446,696), ischemic stroke (IS) (n = 440,328) and its subtypes, and intracerebral hemorrhage (ICH) (n = 3,026). The main MR analysis was conducted by the inverse variance weighted (IVW) method. MR-Egger regression, MR pleiotropy residual sum and outlier, weighted median, Cochran Q statistic, and leave-one-out analysis approach were leveraged as supplements. RESULTS: We detected that higher risk of hip OA was significantly associated with overall stroke [IVW odds ratio (OR): 1.12, 95% confidence interval (CI): 1.06-1.20, P = 0.0002], IS (OR: 1.13, 95%CI: 1.06-1.21, P = 0.0003), and small vessel IS (OR: 1.25, 95%CI: 1.10-1.42, P = 0.0006). However, we found no evidence that stroke and subtypes had casual effects on OA in the reverse MR analyses. CONCLUSIONS: The present study provides genetic support that hip OA is a potential risk factor for overall stroke, IS, and small vessel IS. Further studies are warranted to elucidate the underlying mechanisms of causal associations between site-specific OA and stroke subtypes.

Personal and household PM2.5 and black carbon exposure measures and respiratory symptoms in 8 low- and middle-income countries.

BACKGROUND: Household air pollution (HAP) from cooking with solid fuels has been associated with adverse respiratory effects, but most studies use surveys of fuel use to define HAP exposure, rather than on actual air pollution exposure measurements. OBJECTIVE: To examine associations between household and personal fine particulate matter (PM2.5) and black carbon (BC) measures and respiratory symptoms. METHODS: As part of the Prospective Urban and Rural Epidemiology Air Pollution study, we analyzed 48-h household and personal PM2.5 and BC measurements for 870 individuals using different cooking fuels from 62 communities in 8 countries (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Self-reported respiratory symptoms were collected after monitoring. Associations between PM2.5 and BC exposures and respiratory symptoms were examined using logistic regression models, controlling for individual, household, and community covariates. RESULTS: The median (interquartile range) of household and personal PM2.5 was 73.5 (119.1) and 65.3 (91.5) µg/m3, and for household and personal BC was 3.4 (8.3) and 2.5 (4.9) x10-5 m-1, respectively. We observed associations between household PM2.5 and wheeze (OR: 1.25; 95%CI: 1.07, 1.46), cough (OR: 1.22; 95%CI: 1.06, 1.39), and sputum (OR: 1.26; 95%CI: 1.10, 1.44), as well as exposure to household BC and wheeze (OR: 1.20; 95%CI: 1.03, 1.39) and sputum (OR: 1.20; 95%CI: 1.05, 1.36), per IQR increase. We observed associations between personal PM2.5 and wheeze (OR: 1.23; 95%CI: 1.00, 1.50) and sputum (OR: 1.19; 95%CI: 1.00, 1.41). For household PM2.5 and BC, associations were generally stronger for females compared to males. Models using an indicator variable of solid versus clean fuels resulted in larger OR estimates with less precision. CONCLUSIONS: We used measurements of household and personal air pollution for individuals using different cooking fuels and documented strong associations with respiratory symptoms.

Association of maternal gestational weight gain with intellectual developmental disorder in the offspring: a nationwide follow-up study in Sweden.

OBJECTIVES: To investigate the association between maternal gestational weight gain (GWG) and offspring's intellectual developmental disorders (IDD); how this association is modified by maternal early-pregnancy BMI. DESIGN: Population-based cohort study. SETTING AND POPULATION: All liveborn singletons with information on maternal GWG in the Swedish Medical Register during 1992-2006 (n = 467 485). METHODS: We used three GWG classifications, (1) Institute of Medicine (IOM) guidelines ('ideal' GWG: maternal underweight = 12.7-18.1 kg; normal = 11.3-15.9 kg; overweight = 6.8-11.3 kg; obesity = 5.0-9.1 kg), (2) LifeCycle project recommendation ('ideal' GWG: maternal underweight = 14.0-16.0 kg; normal = 10.0-18.0 kg; overweight = 2.0-16.0 kg; obesity class I = 2.0-6.0 kg; obesity class II ≤0.0-4.0 kg; obesity class III ≤0.0-6.0 kg) and (3) GWG centiles. Hazard ratio (HR) and 95% CI for offspring's IDD risk using Cox regression. MAIN OUTCOME MEASURES: IDD was extracted from Swedish National Patient Register (code ICD-9:317-319/ICD-10:F70-F79). RESULTS: Forty-one per cent of children were born to mothers with excessive GWG, 32.8% with ideal GWG and 26.2% with inadequate GWG according to IOM guidelines. Inadequate GWG was associated with 21% higher risk of offspring's IDD (95% CI 1.11-1.31) relative to ideal GWG. In contrast, when using the LifeCycle classification, children of mothers with inadequate GWG (HR 1.14, 95% CI 1.05-1.24) or excessive GWG (HR 1.09, 95% CI 1.01-1.17) had higher risks of IDD than those of mothers with ideal GWG. When using GWG centiles, extremely low GWG (<20th centile) and low GWG (20th-40th centile) were associated with elevated offspring's IDD risk. Further stratified analysis by maternal early-pregnancy body mass index (BMI) showed that overweight/obese mothers (BMI ≥25 kg/m2 ) with extremely excessive GWG (>25 kg) was associated with an increased offspring's IDD. CONCLUSION: Our findings suggest that inadequate maternal GWG may increase offspring's IDD risk, irrespective of maternal early-pregnancy BMI. Extremely excessive GWG (>25 kg) may increase offspring's IDD risk, but only among mothers with an early-pregnancy BMI ≥25 kg/m2 . TWEETABLE ABSTRACT: Inadequate maternal weight gain during pregnancy may increase the risk of offspring's intellectual disability, regardless of maternal BMI.

Measuring and predicting personal and household Black Carbon levels from 88 communities in eight countries.

Black Carbon (BC) is an important component of household air pollution (HAP) in low- and middle- income countries (LMICs), but levels and drivers of exposure are poorly understood. As part of the Prospective Urban and Rural Epidemiological (PURE) study, we analyzed 48-hour BC measurements for 1187 individual and 2242 household samples from 88 communities in 8 LMICs (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Light absorbance (10-5 m-1) of collected PM2.5 filters, a proxy for BC concentrations, was calculated via an image-based reflectance method. Surveys of household/personal characteristics and behaviors were collected after monitoring. The geometric mean (GM) of personal and household BC measures was 2.4 (3.3) and 3.5 (3.9)·10-5 m-1, respectively. The correlation between BC and PM2.5 was r = 0.76 for personal and r = 0.82 for household measures. A gradient of increasing BC concentrations was observed for cooking fuels: BC increased 53% (95%CI: 30, 79) for coal, 142% (95%CI: 117, 169) for wood, and 190% (95%CI: 149, 238) for other biomass, compared to gas. Each hour of cooking was associated with an increase in household (5%, 95%CI: 3, 7) and personal (5%, 95%CI: 2, 8) BC; having a window in the kitchen was associated with a decrease in household (-38%, 95%CI: -45, -30) and personal (-31%, 95%CI: -44, -15) BC; and cooking on a mud stove, compared to a clean stove, was associated with an increase in household (125%, 95%CI: 96, 160) and personal (117%, 95%CI: 71, 117) BC. Male participants only had slightly lower personal BC (-0.6%, 95%CI: -1, 0.0) compared to females. In multivariate models, we were able to explain 46-60% of household BC variation and 33-54% of personal BC variation. These data and models provide new information on exposure to BC in LMICs, which can be incorporated into future exposure assessments, health research, and policy surrounding HAP and BC.

Disparities of birth cohort effects on pancreatic cancer incidence between the United States and urban China.

BACKGROUND: Pancreatic cancer has been associated with lifestyle factors, but few comparative studies were conducted among countries of different culture and lifestyle habits. This study compared the trends of pancreatic cancer incidence and birth cohort effects in the United States and urban China and explored the potential discrepancies of risk patterns. MATERIALS AND METHODS: Age-standardized incidence rates (ASIRs) were calculated using data from national or regional cancer registries of the United States and two large cities of China (Shanghai, Hong Kong). The temporal trends of incidence were assessed by joinpoint regression. The effects of birth cohort and calendar period were identified through age-period-cohort modeling. RESULTS: The ASIR in the United States from 1976 to 2015 was 8.26/100 000, which was higher than that in Hong Kong (4.29/100 000) and Shanghai of China (6.63/100 000). Shanghai had lower incidence (4.41/100 000) in 1976-1980 but increased annually by 1.38% in males and 1.67% in females, with a sharper upward trend than the United States and Hong Kong. Males had higher risks than females, with a male-to-female ratio of 1.34, 1.44, and 1.37 in the United States, Hong Kong, and Shanghai, respectively. A significant and prominent increase in incidence rate was observed among successive generations in China particularly for Shanghai, but such a pattern was not apparent in the United States. CONCLUSIONS: The differences in pancreatic cancer incidence by sex may be multi-factorial involving known risk factors like tobacco smoking and alcohol consumption. The significant birth cohort effects among recent and early generations in the Shanghai population were in line with a society in socioeconomic transition and adoption of Western lifestyle mainly including consumption of calorie-rich foods and physical inactivity. Differences in these risk patterns will have implications on health care efforts and policies for cancer control.

The household economic burden of non-communicable diseases in 18 countries

BACKGROUND: Non-communicable diseases (NCDs) are the leading cause of death globally. In 2014, the United Nations committed to reducing premature mortality from NCDs, including by reducing the burden of healthcare costs. Since 2014, the Prospective Urban and Rural Epidemiology (PURE) Study has been collecting health expenditure data from households with NCDs in 18 countries. METHODS: Using data from the PURE Study, we estimated risk of catastrophic health spending and impoverishment among households with at least one person with NCDs (cardiovascular disease, diabetes, kidney disease, cancer and respiratory diseases; n=17 435), with hypertension only (a leading risk factor for NCDs; n=11 831) or with neither (n=22 654) by country income group: high-income countries (Canada and Sweden), upper middle income countries (UMICs: Brazil, Chile, Malaysia, Poland, South Africa and Turkey), lower middle income countries (LMICs: the Philippines, Colombia, India, Iran and the Occupied Palestinian Territory) and low-income countries (LICs: Bangladesh, Pakistan, Zimbabwe and Tanzania) and China. RESULTS: The prevalence of catastrophic spending and impoverishment is highest among households with NCDs in LMICs and China. After adjusting for covariates that might drive health expenditure, the absolute risk of catastrophic spending is higher in households with NCDs compared with no NCDs in LMICs (risk difference=1.71%; 95% CI 0.75 to 2.67), UMICs (0.82%; 95% CI 0.37 to 1.27) and China (7.52%; 95% CI 5.88 to 9.16). A similar pattern is observed in UMICs and China for impoverishment. A high proportion of those with NCDs in LICs, especially women (38.7% compared with 12.6% in men), reported not taking medication due to costs. CONCLUSIONS: Our findings show that financial protection from healthcare costs for people with NCDs is inadequate, particularly in LMICs and China. While the burden of NCD care may appear greatest in LMICs and China, the burden in LICs may be masked by care foregone due to costs. The high proportion of women reporting foregone care due to cost may in part explain gender inequality in treatment of NCDs. (AU)

Dietary sugar intake was associated with increased body fatness but decreased cardiovascular mortality in Chinese elderly: an 11-year prospective study of Mr and Ms OS of Hong Kong.

BACKGROUND/OBJECTIVES: Epidemiological studies suggest that sugar intake contributes to weight gain and increased risk of cardiovascular diseases (CVDs). However, this association is largely undefined in the elderly population. Our aim was to investigate the effect of sugar consumption on the subsequent changes in body fatness and CVD mortality in Chinese elderly. METHODS: A total of 2000 men and 2000 women aged ⩾65 years were recruited from 2001 to 2003. Dietary sugar intake was estimated based on a validated 329-item food frequency questionnaire and a local sugar database. Adiposity was measured using dual-energy X-ray absorptiometry at baseline and follow-up after 4 years. Mortality was ascertained by local death registry until March 2014. Multivariable linear and Cox regression were conducted to evaluate the association of sugar consumption on the changes in body fatness and CVD mortality. RESULTS: A total of 174 CVD deaths were documented within the total 37 999 person-years' follow-up. Significant positive association between sugar intake and increase in body fatness at follow-up after 4 years was found in men but not in women. After adjustment for potential confounders, men who consumed 1% increase in added sugar had an increase in whole body fat by 0.043 kg (P=0.006), central fat by 0.029 kg (P=0.016) and peripheral fat by 0.026 kg (P=0.006). However, in both genders, after an average of 11.1-year follow-up, compared with the lowest quintile, the highest intakes of added sugar were associated with significantly lowered CVD mortality by 74.9% (hazard ratio (HR) (95% confidence interval (CI)): 0.251(0.070, 0.899)) in a dose-response manner (Ptrend=0.011). This association was attenuated to non-significance by further adjustment of the change in body fatness (Ptrend=0.055). CONCLUSIONS: Thus higher sugar intake of the Chinese elderly was associated with increased adiposity in men but decreased CVD mortality. The current World Health Organization recommendation for the elderly should be reviewed.

Sleep Quality, Sleep Duration, and the Risk of Coronary Heart Disease: A Prospective Cohort Study With 60,586 Adults.

STUDY OBJECTIVES: There is limited information on the relationship between risk of cardiovascular disease and the joint effects of sleep quality and sleep duration, especially from large, prospective, cohort studies. This study is to prospectively investigate the joint effects of sleep quality and sleep duration on the development of coronary heart disease. METHODS: This study examined 60,586 adults aged 40 years or older. A self-administered questionnaire was used to collect information on sleep quality and sleep duration as well as a wide range of potential confounders. Events of coronary heart disease were self-reported in subsequent medical examinations. Two types of Sleep Score (multiplicative and additive) were constructed to reflect the participants' sleep profiles, considering both sleep quality and sleep duration. The Cox regression model was used to estimate the hazard ratio (HR) and the 95% confidence interval (CI). RESULTS: A total of 2,740 participants (4.5%) reported new events of coronary heart disease at follow-up. For sleep duration, participants in the group of < 6 h/d was significantly associated with an increased risk of coronary heart disease (HR: 1.13, 95% CI: 1.04-1.23). However, the association in the participants with long sleep duration (> 8 h/d) did not reach statistical significance (HR: 1.11, 95% CI: 0.98-1.26). For sleep quality, both dreamy sleep (HR: 1.21, 95% CI: 1.10-1.32) and difficult to fall asleep/use of sleeping pills or drugs (HR: 1.40, 95% CI: 1.25-1.56) were associated with an increased risk of the disease. Participants in the lowest quartile of multiplicative Sleep Score (HR: 1.31, 95% CI: 1.16-1.47) and of additive sleep score (HR: 1.31, 95% CI: 1.16-1.47) were associated with increased risk of coronary heart disease compared with those in the highest quartile. CONCLUSIONS: Both short sleep duration and poor sleep quality are associated with the risk of coronary heart disease. The association for long sleep duration does not reach statistical significance. Lower Sleep Score (poorer sleep profile) increases the risk of coronary heart disease, suggesting the importance of considering sleep duration and sleep quality together when developing strategies to improve sleep for cardiovascular disease prevention.

Meta-analysis on shift work and risks of specific obesity types.

AIMS: This systematic review and meta-analysis evaluated the associations between shift work patterns and risks of specific types of obesity. METHODS: PubMed was searched until March 2017 for observational studies that examined the relationships between shift work patterns and obesity. Odds ratio for obesity was extracted using a fixed-effects or random-effects model. Subgroup meta-analyses were carried out for study design, specific obesity types and characteristics of shift work pattern. RESULTS: A total of 28 studies were included in this meta-analysis. The overall odds ratio of night shift work was 1.23 (95% confidence interval = 1.17-1.29) for risk of obesity/overweight. Cross-sectional studies showed a higher risk of 1.26 than those with the cohort design (risk ratio = 1.10). Shift workers had a higher frequency of developing abdominal obesity (odds ratio = 1.35) than other obesity types. Permanent night workers demonstrated a 29% higher risk than rotating shift workers (odds ratio 1.43 vs. 1.14). CONCLUSION: This meta-analysis confirmed the risks of night shift work for the development of overweight and obesity with a potential gradient association suggested, especially for abdominal obesity. Modification of working schedules is recommended, particularly for prolonged permanent night work. More accurate and detailed measurements on shift work patterns should be conducted in future research.

Childhood obesity prevention through a community-based cluster randomized controlled physical activity intervention among schools in china: the health legacy project of the 2nd world summer youth olympic Games (YOG-Obesity study).

BACKGROUND: Childhood obesity has been becoming a worldwide public health problem. We conducted a community-based physical activity (PA) intervention program aiming at childhood obesity prevention in general student population in Nanjing of China, the host city of the 2nd World Summer Youth Olympic Games (YOG-Obesity study). METHODS: This was a cluster randomized controlled intervention study. Participants were the 4th (mean age±s.e.: 9.0±0.01) and 7th (mean age±s.e.: 12.0±0.01) grade students (mean age±s.e.: 10.5±0.02) from 48 schools and randomly allocated (1:1) to intervention or control groups at school level. Routine health education was provided to all schools, whereas the intervention schools additionally received an 1-year tailored multi-component PA intervention program, including classroom curricula, school environment support, family involvement and fun programs/events. The primary outcome measures were changes in body mass index, obesity occurrence and PA. RESULTS: Overall, 9858 (97.7%) of the 10091 enrolled students completed the follow-up survey. Compared with the baseline, PA level increased by 33.13 min per week (s.e. 10.86) in the intervention group but decreased by 1.76 min per week (s.e. 11.53) in the control group (P=0.028). After adjustment for potential confounders, compared with the control group, the intervention group were more likely to have increased time of PA (adj. Odds ratio=1.15, 95% confidence interval=1.06-1.25), but had a smaller increase in mean body mass index (BMI) (0.22 (s.e. 0.02) vs 0.46 (0.02), P=0.01) and BMI z-score (0.07 (0.01) vs 0.16 (0.01), P=0.01), and were less likely to be obese (adj. Odds ratio=0.7, 95% confidence interval=0.6, 0.9) at study end. The intervention group had fewer new events of obesity/overweight but a larger proportion of formerly overweight/obese students having normal weight by study end. CONCLUSIONS: This large community-based PA intervention was feasible and effective in promoting PA and preventing obesity among the general student population in a large city in China. Experiences from this study are the lessons for China to control the childhood obesity epidemic.

Reduced prostate cancer risk with green tea and epigallocatechin 3-gallate intake among Hong Kong Chinese men.

BACKGROUND: In vitro and in vivo studies suggested that polyphenol epigallocatechin 3-gallate (EGCG) in tea may have anti-carcinogenic effect on prostate cells, but this protective effect has less been examined in epidemiology studies. We aimed to investigate the association between prostate cancer (PCA) risk and habitual green tea intake among Chinese men in Hong Kong; meanwhile, the relationship with EGCG was also explored. METHODS: We consecutively recruited 404 PCA cases and 395 controls from the same hospital who had complete data on habitual tea consumption, including green, oolong, black and pu'er tea. We reconstructed the level of EGCG intake according to a standard questionnaire and the analytic values for EGCG extracted from the literature published by Lin et al. in 2003. We calculated odds ratios (ORs) for tea consumption and EGCG intake using unconditional multiple logistic regression, and examined their exposure--response relationships with PCA risk. RESULTS: A total of 32 cases and 50 controls reported habitual green tea drinking, showing an adjusted OR of 0.60 (95% confidence interval (CI): 0.37, 0.98). A moderate excess risk was observed among the habitual pu'er tea drinkers (OR=1.44, 95% CI: 1.02, 1.91). A significantly lower intake of EGCG was observed among cases (54.4 mg) than the controls (72.5 mg), which resulted in an inverse gradient of PCA risk with the increasing intake of EGCG (test for trend, P=0.015). CONCLUSION: PCA risk among Chinese men in Hong Kong was inversely associated with green tea consumption and EGCG intake, but these results need to be replicated in larger studies.

Effects of acrylonitrile on the pathological morphology and apoptosis of neurons in rats.

This study aimed to evaluate the effects of acrylonitrile (ACN) on neuronal morphology and apoptosis in rats. An ACN solution was administered to Wistar rats by gavage at doses of 0, 5, 10, or 20 mg/kg, 5 days a week for 13 weeks. The morphology of neurons and the presence of apoptosis was examined by light and electron microscope, DNA electrophoresis, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. Significant vacuolation and the widening of the interspaces around blood vessels were observed in the groups that received the highest dose. Disordered myelin sheaths, malformed neuronal nuclei, and chromatin condensation at the periphery of the nucleus that formed crescents were also observed in the treated rats. The number of apoptotic neurons was significantly decreased (P < 0.05) in the treated groups (5 mg/kg group: 1.5 ± 1.22 apoptotic neurons/slide; 10 mg/kg group: 2.5 ± 1.05 apoptotic neurons/slide; 20 mg/kg group: 2.34 ± 1.21 apoptotic neurons/slide) compared to the control group (4.5 ± 1.52 apoptotic neurons/slide). The number of Bcl-2-positive neurons and the levels of staining were increased in the treated rats compared to those of the control group. These results suggested that ACN may induce serious morphological changes in rat neurons and inhibit neuronal apoptosis in rats.

Exposure to air pollutants and mortality in hypertensive patients according to demography: a 10 year case-crossover study.

This study evaluated whether short term exposures to NO2, O3, particulate matter <10 mm in diameter (PM10) were associated with higher risk of mortality. A total of 223,287 hypertensive patients attended public health-care services and newly prescribed at least 1 antihypertensive agent were followed-up for up to 5 years. A time-stratified, bi-directional case-crossover design was adopted. For all-cause mortality, significant positive associations were observed for NO2 and PM10 at lag 0-3 days per 10 µg/m(3) increase in concentration (excess risks 1.187%-2.501%). Significant positive associations were found for O3 at lag 1 and 2 days and the excess risks were 1.654% and 1.207%, respectively. We found similarly positive associations between these pollutants and respiratory disease mortality. These results were significant among those aged ≥65 years and in cold seasons only. Older hypertensive patients are susceptible to all-cause and respiratory disease-specific deaths from these air pollutants in cold weather.

Meta-analysis on night shift work and risk of metabolic syndrome.

This study aims to quantitatively summarize the association between night shift work and the risk of metabolic syndrome (MetS), with special reference to the dose-response relationship with years of night shift work. We systematically searched all observational studies published in English on PubMed and Embase from 1971 to 2013. We extracted effect measures (relative risk, RR; or odd ratio, OR) with 95% confidence interval (CI) from individual studies to generate pooled results using meta-analysis approach. Pooled RR was calculated using random- or fixed-effect model. Downs and Black scale was applied to assess the methodological quality of included studies. A total of 13 studies were included. The pooled RR for the association between 'ever exposed to night shift work' and MetS risk was 1.57 (95% CI = 1.24-1.98, pheterogeneity = 0.001), while a higher risk was indicated in workers with longer exposure to night shifts (RR = 1.77, 95% CI = 1.32-2.36, pheterogeneity = 0.936). Further stratification analysis demonstrated a higher pooled effect of 1.84 (95% CI = 1.45-2.34) for studies using the NCEP-ATPIII criteria, among female workers (RR = 1.61, 95% CI = 1.10-2.34) and the countries other than Asia (RR = 1.65, 95% CI = 1.39-1.95). Sensitivity analysis confirmed the robustness of the results. No evidence of publication bias was detected. The present meta-analysis suggested that night shift work is significantly associated with the risk of MetS, and a positive dose-response relationship with duration of exposure was indicated.

Insomnia and associated factors among anaesthetists in Hong Kong.

The primary objective of this survey was to investigate the prevalence of insomnia among anaesthetists in Hong Kong. The use of sleeping aids, factors associated with insomnia and the effect of insomnia on work performance were also studied. We surveyed all locally registered anaesthesia specialists and trainees by post. The response rate was 50%. We found that the prevalence of insomnia among the respondents was 22.4% (95% confidence interval 16.7 to 28.1%). Insomnia was positively associated with the number of on-call shifts per month (P=0.002) and poor relationship with supervisors (P=0.009). Alcohol was the most frequently used aid to assist sleep, followed by zolpidem. The majority of respondents using sleeping medication obtained the drug over-the-counter, by self-prescription or prescription by colleagues. Only 4.3% (95% confidence interval 0 to 10.2%) of respondents suffering from insomnia had formal medical consultation for sleep disturbance. Insomnia was associated with increased subjective sleepiness at work (P=0.007) and subjective decline in work performance during both daytime (P <0.001) and night-time (P <0.001). However, it was not associated with the tendency to fall asleep at work. The results of this survey suggest that insomnia is a common problem among the anaesthetists of Hong Kong. By restricting the amount of on-call duty and improving relationships with supervisors, the prevalence of insomnia may be reduced and the quality of patient care improved.

A meta-analysis on dose-response relationship between night shift work and the risk of breast cancer.

This study aimed to conduct a systematic review to sum up evidence of the associations between different aspects of night shift work and female breast cancer using a dose-response meta-analysis approach. We systematicly searched all cohort and case-control studies published in English on MEDLINE, Embase, PSYCInfo, APC Journal Club and Global Health, from January 1971 to May 2013. We extracted effect measures (relative risk, RR; odd ratio, OR; or hazard ratio, HR) from individual studies to generate pooled results using meta-analysis approaches. A log-linear dose-response regression model was used to evaluate the relationship between various indicators of exposure to night shift work and breast cancer risk. Downs and Black scale was applied to assess the methodological quality of included studies. Ten studies were included in the meta-analysis. A pooled adjusted relative risk for the association between 'ever exposed to night shift work' and breast cancer was 1.19 [95% confidence interval (CI) 1.05-1.35]. Further meta-analyses on dose-response relationship showed that every 5-year increase of exposure to night shift work would correspondingly enhance the risk of breast cancer of the female by 3% (pooled RR = 1.03, 95% CI 1.01-1.05; Pheterogeneity < 0.001). Our meta-analysis also suggested that an increase in 500-night shifts would result in a 13% (RR = 1.13, 95% CI 1.07-1.21; Pheterogeneity = 0.06) increase in breast cancer risk. This systematic review updated the evidence that a positive dose-response relationship is likely to present for breast cancer with increasing years of employment and cumulative shifts involved in the work.

Pulmonary tuberculosis and lung cancer mortality in a historical cohort of workers with asbestosis.

OBJECTIVES: To examine pulmonary tuberculosis (PTB) infection and lung cancer mortality among workers with asbestosis in Hong Kong. STUDY DESIGN: Historical cohort study. METHODS: All 124 male incident cases of asbestosis registered at the Pneumoconiosis Clinic of the Tuberculosis and Chest Service of the Department of Health between 1981 and 2008 were recruited and followed-up until 2008 to ascertain vital status and underlying causes of death. Standardized mortality ratios (SMRs) were calculated using the person-year method. Axelson's indirect method was used to adjust for the potential confounding effect of cigarette smoking. RESULTS: Forty-five patients (36.29%) had a history of PTB at the time of asbestosis diagnosis. The SMR of lung cancer was 5.22 [95% confidence interval (CI) 1.08-15.25] for subjects with a history of PTB, and this was reduced to 2.35 (95% CI 0.49-6.85) after indirect adjustment for smoking. Among asbestosis workers without a history of PTB, the SMR after indirect adjustment for smoking was 4.25 (95% CI 1.55-9.25) and 5.92 (95% CI 1.92-13.79) for those with comorbidities and those without comorbidities, respectively. Compared with other workers, those with a history of PTB had the highest all-cause SMR (6.73, 95% CI 4.55-9.63) and very high mortality due to heart diseases. CONCLUSIONS: This historical cohort study revealed that the prevalence of PTB infection was high among workers with asbestosis in Hong Kong. An excess risk of lung cancer mortality was observed among workers with a history of PTB, but the risk was lower than that seen among workers without a history of PTB. These interesting findings need to be confirmed by future studies.