The role of pre-morbid diabetes on developing amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

The literature on the association between diabetes and amyotrophic lateral sclerosis (ALS) consists of a limited number of studies. This cohort study was developed in order to assess the role of diabetes on the risk of developing ALS.

METHODS

The study population was represented by all residents in Turin (Italy) at the beginning of 1996 who participated in the 1991 census, over 14 years of age (n = 727 977) and followed up for ALS occurrence from 1998 to 2014. Presence of diabetes at baseline or during follow-up was ascertained through two Piedmont regional sources: the Diabetes Registry and the Anatomical Therapeutic Chemical Drug Prescription Archive. The risk of ALS was estimated using the Piedmont and Valle d'Aosta ALS Registry (PARALS). The association of diabetes, treated as a time-dependent variable, with ALS onset was estimated through Cox proportional hazard regression models adjusted for age, gender, education and marital status.

RESULTS

During follow-up, 397 subjects developed ALS, 24 of whom were already diabetic before ALS onset. Diabetes was associated with a significantly decreased risk of ALS [hazard ratio, 0.30 (95% confidence interval, 0.19-0.45)] without differences in risk by gender, age class or ALS phenotype.

CONCLUSION

The results support the protective role of diabetes toward ALS.

Exposure to psychosocial factors at work and mental well-being in Europe

BACKGROUND

Depression among workers is a major health concern and psychological work factors are considered important risk factors.

OBJECTIVES

To investigate exposure to psychosocial work risk factors and prevalence of depressive symptoms in the European working population, and to identify the psychosocial work characteristics that predict them.

METHODS

The study is a secondary data analysis based on a sample of 33,907 European employees from the last edition of the European Working Condition Survey (EWCS 2010). The relationship between the outcome variable (depressive symptoms) and the predictors (psychosocial work factors) was analyzed using a multi-stage Poisson model, estimating gender-specific relative risks (RR) and 95 percent confidence intervals.

RESULTS

After adjustment for individual and work characteristics, countries and other psychosocial factors, among men the RR of depressive symptoms was significantly increased for exposure to intermediate psychological demands and to high demands for hiding emotions, whereas high skill discretion, high support from colleagues, high support from managers, high job rewards and high job security significantly decreased the risk. Among women, high psychological demands and intermediate emotional demands significantly enhanced the risk of depressive symptoms while high decision authority, intermediate support from colleagues, high support from managers, high social climate, high job rewards and high job security protected against risk.

CONCLUSIONS

A high prevalence of depressive symptoms was found in the EWCS 2010, although with wide variations between countries. Several psychosocial factors at work were identified as risk factors for depressive symptoms, even after adjusting for workplace co-exposures and other potential confounders.

Occupational risk factors for sinonasal inverted papilloma: a case-control study

OBJECTIVES

Sinonasal inverted papilloma (IP) is an uncommon benign tumour characterised by frequent recurrence and, in approximately 10% of cases, by neoplastic transformation. IP aetiology is unknown but human papillomavirus is detectable in about one quarter of tumours. As some occupational hazards have been reported to be possible risk factors for IP, the aim of this study was to assess risk for sinonasal IP associated with prior exposure to suspected occupational risk factors for sinonasal malignancies.

METHODS

Between 1996 and 2007, data on incident cases were collected from hospitals throughout the Piedmont region of Italy by the regional sinonasal cancer registry. A questionnaire on occupational history, completed by 127 cases and 337 hospital controls, was used to assign previous exposure to a list of 17 occupational hazards. The relationship between IP and cumulative exposure to these hazards was explored using unconditional logistic regression to statistically adjust for age, sex, area of residence, smoking and co-exposures.

RESULTS

The risk of IP was significantly increased for ever exposure to welding fumes (OR 2.14) and organic solvents (OR 2.11) after controlling for potential confounders. For organic solvents only, a significant association with continuous cumulative exposure and a significant trend in risk across ordered cumulative exposure categories was found.

CONCLUSIONS

The present study revealed a significant association and a significant dose-response relationship between occupational exposure to organic solvents and IP. The lack of a dose-response relationship for welding fumes suggests that the observed association with ever exposure should be interpreted with caution.

A case-control study on occupational risk factors for sino-nasal cancer

OBJECTIVES

Sino-nasal cancer has been consistently associated with exposure to wood dust, leather dust, nickel and chromium compounds; for other occupational hazards, the findings are somewhat mixed. The aim of this study was to investigate the risk of sino-nasal epithelial cancer (SNEC) by histological type with prior exposure to suspected occupational risk factors and, in particular, those in metalworking.

METHODS

Between 1996 and 2000, incident cases were collected on a monthly basis from hospitals throughout the Piedmont region of Italy by the regional Sino-nasal Cancer Registry. A questionnaire on occupational history, completed by 113 cases and 336 hospital controls, was used to assign exposure to occupational hazards. The relationship between SNEC and cumulative exposure to these hazards was explored using unconditional logistic regression to statistically adjust for age, sex, smoking and co-exposures, allowing for a 10-year latency period.

RESULTS

The risk of adenocarcinoma was significantly increased with ever-exposure to wood dust (odds ratio; OR = 58.6), and to leather dust (OR = 32.8) and organic solvents (OR = 4.3) after controlling for wood dust, whereas ever-exposure to welding fumes (OR = 3.7) and arsenic (OR = 4.4) significantly increased the risk for squamous cell carcinoma. For each of these hazards, a significant increasing trend in risk across ordered cumulative exposure categories was found and, except for arsenic, a significantly increased risk with ever-exposure at low intensity. Treating cumulative exposure on a continuous scale, a significant effect of textile dusts was also observed for adenocarcinoma. For a mixed group of other histological types, a significant association was found with wood dust and organic solvents.

CONCLUSIONS

Some occupational risk factors for SNEC were confirmed, and dose-response relationships were observed for other hazards that merit further investigation. The high risk for adenocarcinoma with low-intensity exposure to wood dust lends support for a reduction in the occupational threshold value.

An international prospective general population-based study of respiratory work disability

BACKGROUND

Previous cross-sectional studies have shown that job change due to breathing problems at the workplace (respiratory work disability) is common among adults of working age. That research indicated that occupational exposure to gases, dust and fumes was associated with job change due to breathing problems, although causal inferences have been tempered by the cross-sectional nature of previously available data. There is a need for general population-based prospective studies to assess the incidence of respiratory work disability and to delineate better the roles of potential predictors of respiratory work disability.

METHODS

A prospective general population cohort study was performed in 25 centres in 11 European countries and one centre in the USA. A longitudinal analysis was undertaken of the European Community Respiratory Health Survey including all participants employed at any point since the baseline survey, 6659 subjects randomly sampled and 779 subjects comprising all subjects reporting physician-diagnosed asthma. The main outcome measure was new-onset respiratory work disability, defined as a reported job change during follow-up attributed to breathing problems. Exposure to dusts (biological or mineral), gases or fumes during follow-up was recorded using a job-exposure matrix. Cox proportional hazard regression modelling was used to analyse such exposure as a predictor of time until job change due to breathing problems.

RESULTS

The incidence rate of respiratory work disability was 1.2/1000 person-years of observation in the random sample (95% CI 1.0 to 1.5) and 5.7/1000 person-years in the asthma cohort (95% CI 4.1 to 7.8). In the random population sample, as well as in the asthma cohort, high occupational exposure to biological dust, mineral dust or gases or fumes predicted increased risk of respiratory work disability. In the random sample, sex was not associated with increased risk of work disability while, in the asthma cohort, female sex was associated with an increased disability risk (hazard ratio 2.8, 95% CI 1.3 to 5.9).

CONCLUSIONS

Respiratory work disability is common overall. It is associated with workplace exposures that could be controlled through preventive measures.

[Working conditions and health problems among call-centre operators: a study on self-reported data in the Piedmont Region (Italy)]

BACKGROUND

Currently, about 250,000 workers are employed in the call-centre sector in Italy. The nature and the organization of the work exposes workers to a variety of psychosocial and ergonomic hazards, with a potential impact on physical and psychological health.

OBJECTIVE

The aim of the study was to investigate working conditions and health status among call-centre operators, in order to estimate the prevalence of exposure to psychosocial and ergonomic risk factors, and of potentially work-related health problems.

METHODS

Workers from seven call-centres operating in the Torino area were invited to participate in the survey. During the period 2005-2006, 775 subjects working in telecommunications (70%), telemarketing (14%) and finance (16%) completed a standardized questionnaire on socio-demographics and lifestyle, working conditions, symptoms and diseases.

RESULTS

Poor microclimatic conditions, elevated noise, high levels of exposure to psychosocial factors and a high prevalence of unfavourable ergonomic working conditions were observed With regard to health conditions, the mental health index was lower than that expected for the Italian population. Overall, 60%, of the subjects reported headache, 57% musculoskeletal symptoms and 46% voice disorders, for which they consulted a physician and/or took medication.

CONCLUSION

A high proportion of call-centre operators were exposed to organizational and psychosocial risk factors, while the self-reported prevalence of potentially work-related health conditions was also high, as has been reported by other authors. Although further epidemiological studies are needed to meaningfully evaluate these associations, it also appears necessary to implement interventions on the most frequently encountered hazards in this sector.

Hospital injury rates in relation to socioeconomic status and working conditions

OBJECTIVES

To describe the risk of work injury by socioeconomic status (SES) in hospital workers, and to assess whether SES gradient in injury risk is explained by differences in psychosocial, ergonomic or organisational factors at work.

METHODS

Workforce rosters and Occupational Safety and Health Administration injury logs for a 5-year period were obtained from two hospitals in Massachusetts. Job titles were classified into five SES strata on the basis of educational requirements and responsibilities: administrators, professionals, semiprofessionals, skilled and semiskilled workers. 13 selected psychosocial, ergonomic and organisational exposures were assigned to the hospital jobs through the national O*NET database. Rates of injury were analysed as frequency records using the Poisson regression, with job title as the unit of analysis. The risk of injury was modelled using SES alone, each exposure variable alone and then each exposure variable in combination with SES.

RESULTS

An overall annual injury rate of 7.2 per 100 full-time workers was estimated for the two hospitals combined. All SES strata except professionals showed a significant excess risk of injury compared with the highest SES category (administrators); the risk was highest among semiskilled workers (RR 5.3, p<0.001), followed by nurses (RR 3.7, p<0.001), semiprofessionals (RR 2.9, p = 0.006) and skilled workers (RR 2.6, p = 0.01). The risk of injury was significantly associated with each exposure considered except pause frequency. When workplace exposures were introduced in the regression model together with SES, four remained significant predictors of the risk of injury (decision latitude, supervisor support, force exertion and temperature extremes), whereas the RR related to SES was strongly reduced in all strata, except professionals.

CONCLUSIONS

A strong gradient in the risk of injury by SES was reported in a sample population of hospital workers, which was greatly attenuated by adjusting for psychosocial and ergonomic workplace exposures, indicating that a large proportion of that gradient can be explained by differences in working conditions.

[Occupational mortality in the population employed at 1991 Census]

BACKGROUND

Despite limitations and problems connected to occupational surveillance systems based on mortality data, mortality from specific causes continues to be a crucial indicator for evaluating the differences in health among various occupations.

OBJECTIVES

To evaluate the potential of a surveillance system of occupational mortality based on census and mortality data obtained from ISTAT (Italian Central Statistics Institute).

METHODS

By means of record-linkage between Census data and death records from ISTAT, occupational mortality was assessed during the twelve month period following the 1991 census, limited to subjects aged 18-64 years for whom occupational information was available. The study population consisted of deceased subjects, 19,527 of whom were men and 3,547 were women. A cross-sectional model was used to evaluate odds ratios for cause-specific mortality. The risk estimates were then compared to the results obtained in a previous analysis on Census data gathered in the 1981 census.

RESULTS

Among the significantly increased risks observed both in 1981 and 1991, of particular interest are the excesses of mortality from liver cirrhosis in caretakers, janitors, and cleaning staff; and the excess of breast cancer in teachers. Mortality from cirrhosis in masons, porters, and waiters, and from violent causes in transport workers and bar and restaurant workers, was instead significantly in excess only in 1991.

CONCLUSIONS

The data on mortality by occupation does not permit inferences about occupational risks, though they can be useful to highlight socio-economic differences in premature death in the employed segment of the population and to draw attention to possible trends over time.

[Use of pension records for occupational health surveillance: example of record-linkage with hospital discharge records to study the association between work and the incidence of leukaemias, lung and bladder cancer, and miscarriage]

BACKGROUND

Epidemiologic surveillance of occupational health based on routinely collected data allows groups of workers to be studied, whose type of work (e.g. small enterprises, self-employed workers, artisans) makes it difficult to use a traditional cohort study design.

OBJECTIVE

To evaluate the validity of a study design based on the record-linkage between hospital discharge records and INPS social security records (National Institute for Social Security), in order to investigate the association between past employment in an economic sector and occurrence of diseases with a low fraction attributable to occupation and a high frequency in the population, where it is too costly to perform retrospective interviews to gather data from each recruited subject.

METHODS

A case-control study design was used in which hospital discharge records from 1995 in the Piedmont Region represented the source of subjects enrolled. Four series of cases were identified: males aged 40-75 years, with first hospital admission for leukaemia, lung or bladder cancer; and women aged 18-39 years, admitted for miscarriage. The controls were a random sample of patients admitted in the same year and matched by sex and age. The exposure variable was the prevalent economic sector in the occupational history of the subjects enrolled, as inferred from INPS social security records.

RESULTS

No economic sector examined showed a significant excess of incidence of bladder cancer or leukaemia. There was a significant excess of lung cancer in subjects with longest employment in the building industry, in metal working, and in the "foundries, heat pressing, forging, and rolling mills" sector. A significant excess of miscarriages was present only in women working in commerce.

DISCUSSION

The results demonstrated overall a low consistency compared with those obtained via other surveillance systems of occupational morbidity and mortality, as well as by means of analytical studies. The results appear more plausible for the sectors characterized by a low number of job tasks, or by a more homogenous exposure to risk factors among workers in different jobs. Among the limitations of this study the lack of a complete occupational history, the absence of information on potential confounders like smoking and alcohol consumption, and the probable non-differential misclassification of the longest held job need to be stressed

[Occupational mortality in Italy during 1992, assessed through record-linkage between pension records and death certificates]

BACKGROUND

The creation of a surveillance system of occupational mortality in Italy is limited by the low quality of information on occupation in death certificates, since the information is often incomplete or lacking and because only the occupation at the time of death is registered.

OBJECTIVE

To evaluate the possible use of INPS (National Institute of Social Security) records for the purpose of surveillance of occupational mortality, in terms of feasibility of setting up a system and of validity of the results obtained.

METHODS

Death records of 218,510 subjects aged 18-74, deceased in the 12 months following the 1991 census, were obtained from ISTAT (Central Statistics Institute). These were combined through record-linkage with the INPS social security archives, which contain the employment records by economic sector going back to 1974, in order to assign these deaths the sector in which they had worked the longest. Mortality by specific causes was evaluated by industry by means of a proportional mortality analysis stratified by sex and occupational status, and adjusted for age, education, marital status, geographical area of birth, drawing a disability pension, employment status at the time of death and work instability.

RESULTS

Record-linkage allowed attribution of the longest held job to 70% of the deaths recorded. Results are presented and discussed only on mortality in men due to asbestosis and silicosis, and causes of death with a substantial proportion attributable to occupation: chronic obstructive pulmonary disease (COPD); cancers of the bladder, nasal cavity, larynx, lung and pleura; leukaemia and lymphoma; accidental causes. Among the economic sectors with a significant excess mortality, the following are well documented in the literature: mortality due to COPD in the coal and peat-bog sectors; due to leukaemia among farmers; due to sino-nasal tumours in wood-working and furniture production; due to cancer of the larynx, lung, and pleura in occupations where there was probable exposure to asbestos (fishing and maritime transport, non-metal mining, building industry, and naval, train and aircraft construction); due to silicosis in industries with potential exposure to crystalline silica; due to accidental causes in the building industry and farming. Other mortality excesses and deficits, especially those due to bladder and lympho-haemopoietic cancers, appear to be only partly consistent with those described by other authors.

DISCUSSION

The feasibility of developing a surveillance system of occupational mortality based on the INPS source was found to be good, and, at least among males, for 75% of the deceased subjects historical information existed concerning the economic sectors registered in the INPS records. The results obtained would appear to indicate that the system is capable of highlighting risk excesses due to widespread exposure in the industries examined, regarding diseases for which there is a strong association with exposure. On the other hand, due to the inherent limits of the study's design (lack of a complete work history and of precise information on the jobs held) its use is not recommended in the surveillance of diseases with a low proportion attributable to a risk factor, or with wide exposure variability in a given sector among the various jobs.

[Occupational differences in exposure to hazardous work conditions]

BACKGROUND

Few studies have been aimed at describing organizational and psychosocial conditions of the Italian workforce by occupational group, and they have been mainly conducted within specific occupations.

OBJECTIVES

The present study aimed at identifying specific groups of occupations which have unfavourable profiles from the point of view of exposure to specific organizational factors and psychosocial risks, and to physical, chemical and ergonomic risks, and analyzing their distribution by worker age.

METHODS

The analysis was conducted on a sample of 4,195 workers in the Piedmont Region who were members of the CGIL Trade Union (Italian General Confederation of Labour), who answered a self-administered questionnaire in 2000, aimed at assessing chemical, physical, and ergonomic risks, accidents, and psychosocial factors connected with work organization and work tasks. Psychosocial risks were assessed via three scales aimed at measuring the degree of control, psychophysical demands, and worker satisfaction. The proportion of workers exposed to the above mentioned risks was analysed according to occupational group. This group was then compared with all other groups taken together, according to prevalence of high strain condition (combination of high demand and low control) and HSUR condition (High Strain Unfairly Rewarded; combination of high strain and low satisfaction).

RESULTS

Among males aged 25-44 years, restricted to the occupation groups with more than ten workers in high strain condition, significantly higher proportions of stress were observed in leather workers and shoemakers, paper factory workers, rubber workers, crane and bridge crane operators, plastic workers, painters, transport drivers and carpenters. For many of these groups, excesses were confirmed for the HSUR condition. Among subjects aged over 44 years, a higher risk for high strain was confirmed in rubber workers, transport drivers and carpenters. In addition, machine tool operators, assembly line and mechanical workers in this age group were exposed to higher risk of stress. In younger women there was a significantly higher risk of both high strain and HSUR conditions in workers employed in the rubber, plastic and the food industries, and in machine tool workers. Such excess risk was confirmed in the latter three categories also among older women. In general, the proportion of male workers classified as working in high strain conditions decreased as age increased, while in women it remained stable.

CONCLUSIONS

The study allowed evaluation of the differential impact of exposure to physical, chemical, and psychosocial risk factors among occupational groups, thus contributing to the identification and classification of exhausting jobs. The results further showed, particularly among men, a smaller proportion of older workers, compared to younger ones, exposed to harmful physical, chemical, ergonomic and psychosocial conditions, indicating a possible propensity of companies to adapt workplace conditions, organization and internal mobility to worker age.

Mortality of a cohort of road construction and maintenance workers with work disability compensation

BACKGROUND

Surveillance systems of occupational mortality are useful tools to identify cases of diseases suspected as occupational and to monitor their occurrence over time, in space and in population subgroups. Many surveillance systems make use of administrative data in which information about occupations and/or economic sectors of the subjects enrolled is reported, such as death certificates, hospital discharge data, census data, tax and pension records, and workers' compensation archives.

OBJECTIVES

In the present study we analyzed the mortality of a cohort of road construction and maintenance workers enrolled through the Italian national archive of work disability compensations, also in order to evaluate the possible use of this administrative source to monitor occupational mortality.

METHODS

8,000 subjects (7,879 males) receiving a disability compensation while working in the "road construction and maintenance" sector were identified from INAIL (National Institute for Insurance of Accidents at Work) archives. Vital status of these subjects was ascertained using the information available in INAIL archives and in the national tax register. For those found to be deceased from INAIL or tax archives, or without any information on vital status, a mail follow-up was started. We considered as observation period the years from 1980 to 1993. A record linkage with the ISTAT (Italian Institute of Statistics) national mortality registry was performed and the cause of death was retrieved for 964 out of 1,259 subjects. The analysis was restricted to males, leaving altogether 863 observed deaths with ascertained cause (84.7% of 1,019 total male deaths). SMR for overall mortality and PMR for specific cause mortality were computed, using the general Italian male population as reference.

RESULTS

Overall mortality was significantly reduced (SMR = 79.0; 95% CI = 74.2-84.0). Proportional mortality analysis revealed significant excess risks for all malignant tumours (332 deaths, PMR = 1.08) and for digestive diseases (87 deaths, PMR = 1.34), while mortality for cardiovascular diseases was significantly decreased (288 deaths, PMR = 0.90). Among specific causes of death, significant excess mortality was found for cancer of testicles (2 deaths, PMR = 5.98), liver and biliary ducts (32 deaths, PMR = 1.40), and for silicosis (10 deaths, PMR = 3.07) and cirrhosis (64 deaths, PMR = 1.40).

CONCLUSIONS

The excess mortality observed for all cancers, digestive diseases and silicosis, and the decreased risk for cardiovascular diseases are in agreement with the results of other studies conducted on workers in road construction and maintenance. As expected, the low overall mortality and the reduced risk from cardiovascular diseases indicate that these workers present a strong "healthy worker effect".