The course of physical functional limitations and occupational conditions in a middle-aged working population in France

Exposure to environmental occupational constraints and all-cause mortality: Results for men and women from a 20-year follow-up prospective cohort, the VISAT study. Be aware of shift-night workers!

Objective

To determine the predictive value of the large panel of occupational constraints (OC) on all-cause mortality with a 20-year follow-up, in general population of workers.

Methods

In VISAT prospective cohort study, 3,138 workers (1,605 men; 1,533 women) were recruited during the periodic work health visits conducted by occupational physicians. OC (physical, organizational, psychological and employment categories) were collected through self-questionnaires. Exposure durations of each OC were divided by tertile distribution. Cox-regression models were performed to analyze the associations between all-cause mortality and each OC first separately and simultaneously in a single model.

Results

The mortality rates were higher among exposed participants to most of OC compared to those unexposed. Being exposed and longer exposure increased the risks of all-cause mortality for exposures to carrying heavy loads, loud noise, working more than 48 h/week, starting its first job before 18 years old although these risks became non-significant after adjustments for cardiovascular risk factors. Shift work and night work confirmed a high risk of mortality whatever the adjustments and notably when the other occupational exposures were taking into account, with, respectively: HR: 1.38 (1.01-1.91) and 1.44 (1.06-1.95). After adjustments being exposed more than 13 years to a work requiring getting-up before 5:00 a.m. and more than 16 years in rotating shift work significantly increased the risk of mortality by one and a half.

Conclusion

The links between each OC and all-cause mortality and the role of individual factors were stressed. For night-shift workers, it is urgent to implement preventive strategies at the workplace.

Blood pressure and cognitive performances in middle-aged adults: the Aging, Health and Work longitudinal study

BACKGROUND

Our objective was to investigate the impact of both prevalent and incident hypertension on cognition in middle-aged individuals followed up for 10 years and to explore the extent to which blood pressure control by antihypertensive drugs could modify this relationship.

METHOD

Three thousand, two hundred and one participants from the Vieillissement Santé Travail (Aging, Health and Work) (VISAT) cohort study, aged 32, 42, 52 and 62 years at baseline were followed up 5 and 10 years later. Blood pressure, antihypertensive medication use as well as memory and speed cognitive performances were assessed at baseline and follow-up. Linear mixed models were used for analyses.

RESULTS

At 10-year follow-up, compared with nonhypertensive participants, prevalent hypertensive individuals showed poorer global cognitive performances (β = -2.99 ± 0.96, P = 0.002 for participants aged 32 or 42 years at baseline and β = -5.94 ± 1.00, P < 0.001 for those aged 52 or 62). Patients with incident hypertension had poorer global cognitive performances over time compared with patients without hypertension. When considering prevalent hypertension and blood pressure control status by antihypertensive therapy, untreated and uncontrolled hypertension were associated with poorer cognitive performances than controlled and no hypertension (untreated hypertension compared with no hypertension: β = -5.51 ± 0.75, P < 0.001; uncontrolled hypertension compared with no hypertension: β = -6.13 ± 1.40, P < 0.001).

CONCLUSION

Our findings showed that both prevalent and incident hypertension are associated with poorer global cognitive function in middle-aged individuals and suggested a potential preventive effect of antihypertensive therapy on cognition. Thus, for brain functioning, heightened efforts to detect hypertension and adequately treat it are of critical importance.

Snap-fit assembly and upper limb functional limitations in automotive production workers: a nested case-control study

OBJECTIVES

The use of snap-fits in car-part assembling has developed into an industrial standard. Cross-sectional evidence indicates, however, that this assembling process might adversely affect workers' upper limb function. The objective of this study was to analyze incident cases of upper limb functional limitations (ULFL) in relation to exposure to snap-fit assembly.

METHODS

We performed a nested case-control study within a population of 5139 blue-collar automotive production workers. Cases with ULFL detected during follow-up were matched with controls based on employment duration and investigated on their exposure to snap-fit assembly. By conditional logistic regression, we modeled the risk for ULFL according to person-years of exposure to snap-fit assembly, adjusted for gender and baseline BMI.

RESULTS

Overall, 64 ULFL cases were detected during a follow-up of 20610.8 person-years (3.1 cases per 1000 person-years). Cases, matched with an average of 4 controls, had significantly longer exposure duration to snap-fit assembly compared with controls (M = 1.15 person-years, SD = 1.68 person-years vs. M = 0.41 person-years, SD = 1.25 person-years). One person-year of exposure to snap-fit assembly was associated with an approximate 20% risk increase of developing ULFLs (OR 1.23, 95% CI 1.08-1.39).

CONCLUSIONS

We confirm an association between accumulated exposure to snap-fits in car-part assembling and upper limb musculoskeletal disorders. Company physicians should thus be vigilant to symptoms of musculoskeletal disorders of the upper limbs in snap-fit assembly and support the development of threshold values for snap-fit insertion forces.

Impact of occupational environmental stressors on blood pressure changes and on incident cases of hypertension: a 5-year follow-up from the VISAT study

BACKGROUND

The role of occupational stressors (OS) on blood pressure (BP) is often suspected, but asserting its impact remains uncertain. Our goal was to evaluate their impact on BP increase and on incident cases of hypertension over a 5-year period.

METHODS

One thousand, one hundred and fifty-six men and women from the French prospective VISAT study were followed up over five-years (T1 to T2). Exposures to a large panel of OS (physical, organizational, psychosocial and employment categories) were collected. Linear and logistic regressions were used to assess associations between OS and T2-T1 SBP difference and incident cases of hypertension. They were performed to determine the role of OS first considered separately, then in combination, in crude and adjusted models for main cardiovascular risk factors (gender, age, education, BMI, lifestyle habits and medical history).

RESULTS

For initial SBP level < 130 mmHg, carrying loads, intense noise exposure, working more than 48 h/week, active and high strain tended to be associated with an SBP difference increase, while job recognition was associated with a decrease. After adjustment, only significant associations with job strain and job recognition persisted. For initial SBP level ≥ 130 mmHg, being exposed to an active job strain was positively associated with T2-T1 SBP difference only in unadjusted model. Considering all the OS, the recognition of completed tasks had a major protective role. No impact of OS on incident cases of hypertension was observed.

CONCLUSION

Associations between OS and SBP were observed mainly when initial SBP is within the normal range, and are mainly explained by cardiovascular factors, requiring physician's particular attention to people exposed to these OS. VISAT study is registered in "LE PORTAIL EPIDEMIOLOGIE - FRANCE- AVIESAN -ID 3666".

Contribution of occupational factors to the incidence and persistence of chronic low back pain among workers: results from the longitudinal VISAT study

OBJECTIVE

Among the aetiological factors of chronic low back pain (CLBP), occupational factors are often suspected, but their contribution remains to be ascertained. This study aimed to determine the impact of a wide range of occupational factors on the incidence and persistence of CLBP.

METHOD

From the VISAT (VIeillissement SAnté Travail) study, 1560 workers were examined at baseline and 5 years later. CLBP was defined as having low back pain or specific treatment for at least 6 months. Participants newly affected with CLBP and those with persistent CLBP at follow-up were distinguished. In addition to individual factors, a broad panel of occupational factors were analysed, covering employment, physical, organisational and psychosocial factors. Multivariate analyses were used to determine predictive factors of incidence and persistence of CLBP. Receiver operating characteristic (ROC) curves were performed to analyse the contribution of occupational factors.

RESULTS

22.6% of participants without any CLBP initially presented with CLBP 5 years later, while 53.7% of participants with CLBP at baseline had CLBP at the second collection. Carrying heavy loads, the lack of recognition of completed work and productivity-related income predicted a higher risk of incidence of CLBP. However, no significant association between occupational factors and the risk for persistence of CLBP was observed, while the risk was multiplied by two for history of depression and rheumatological events. ROC curves confirmed the significant contribution of occupational factors to incidence of CLBP.

CONCLUSIONS

Occupational factors played a pivotal role in the incidence of CLBP, while individual factors were the main determinants of persistence of CLBP.

Snap-fits and upper limb functional limitations in German automotive workers

BACKGROUND

The use of snap-fit fasteners in automotive assembly has increased in the last 10 years. Their impact on musculoskeletal function of the upper limbs in assembly workers is not well described.

AIMS

To investigate the association between snap-fit assembly and upper limb functional limitations (ULFLs) in workers after a large-scale expansion of snap-fit assembly by a German automotive company.

METHODS

Cross-sectional data on blue-collar production workers' exposure to snap-fit assembly and ULFLs were collected from medical check-ups and company registers. The association between duration of snap-fit assembly and ULFLs, and the dose-response relationship between the two were analysed using logistic regression, adjusted for body mass index, gender and employment duration before snap-fit exposure.

RESULTS

The study group included 10722 workers. Within the company, 8.4, 6.9 and 10.3% were exposed to snap-fit 1-12, 13-24 and ≥25 months, respectively. After adjusting for confounders, snap-fit exposure for 1-12 months [odds ratio (OR) = 1.59, 95% confidence interval (CI) 0.88-2.88] and 13-24 months (OR = 1.48, 95% CI 0.76-2.88) was not statistically significantly associated with ULFLs compared with an unexposed group. However, exposure to ≥25 months of snap-fit assembly was statistically significant associated with ULFLs showing >2-fold risk (OR = 2.44, 95% CI 1.52-3.92). No clear dose-response relationship was found.

CONCLUSIONS

Our study suggests a negative long-term impact from snap-fit assembly on workers' upper limb function. Company physicians should be vigilant for signs of upper limb musculoskeletal disorders among workers exposed to snap-fit assembly.

Elevated blood lead levels among unskilled construction workers in Jimma, Ethiopia

Background

No study has been carried out to assess the blood lead levels of workers or the contribution of common workplace practices to lead exposure in Ethiopia. This study was carried out to assess the blood lead levels of female and male laborers in the construction sector in Jimma town, Ethiopia.

Method

A cross-sectional study on the blood lead levels of 45 construction workers was carried out in the town of Jimma. The t-test, analysis of variance, the Kruskal-Wallis, Mann–Whitney and odds ratio tests were used to compare mean blood lead levels and to investigate the associations between specific job type, use of self-protection device, sex, service years and occurrence of non-specific symptoms with BLLs.

Results

The mean blood lead level of the exposed group (40.03 ± 10.41 μg/dL) was found to be significantly greater than that of the unexposed group (29.81 ± 10.21 μg/dL), p = 0.05. Among the exposed group female workers were found to have higher mean blood lead level (42.04 ± 4.11 μg/dL) than their male colleagues (33.99 ± 3.28 μg/dL). Laborers who were regularly using self-protection devices were found to have significantly lower blood lead levels than those who were not using.

Conclusion

The blood lead levels of construction workers in Jimma town are considerably high with a range of 20.46 – 70.46 μg/dL and the workers are in danger of imminent lead toxicity. More endangered are female construction workers who are bearers of the future children of the country and the issue requires urgent attention.