Occupational physical activity, mortality and CHD events in the Italian Longitudinal Study

Abstract

Purpose Several recent studies have suggested a ‘physical activity paradox’ whereby leisure-time physical activity benefits health, but occupational physical activity is harmful. However, other studies imply that occupational physical activity is beneficial. Using data from a nationally representative Italian sample, we investigate if the context, or domain, of physical activity matters for mortality and coronary heart disease (CHD) events. Methods Among 40,220 men and women aged 40–55 at baseline, we used Cox models to compare associations of occupational, domestic and leisure-time physical activity with risk of mortality and CHD events over a follow-up period of up to 14 years. We accounted for sociodemographic factors, smoking, body mass index (BMI), physical and mental health, and educational qualifications. Results Occupational physical activity was not significantly associated with risk of mortality or CHD events for women, or with CHD events for men. In crude models, risk of mortality was higher for men in the highest occupational activity group, compared to the lowest (HR 1.26, 95% CI 1.01, 1.57). This attenuated with adjustment for health-related behaviours, health, and education (HR 1.03, 95% CI 0.77, 1.38). In crude models, leisure-time physical activity was significantly associated with decreased mortality and CHD risk only for men. Domestic physical activity was not associated with either outcome for either gender. Conclusion In a large sample of middle-aged Italian workers, we found limited evidence of harmful or beneficial effects of occupational physical activity on mortality or CHD events. However, confidence intervals were wide, and results consistent with a range of effects in both directions.

Occupational physical activity, all-cause mortality and incidence of cardiovascular diseases: results from three Italian cohorts

“…Furthermore, the Ergo-index of the JEM, which was our measure of OPA, was constructed from many different ergonomic exposures, so that it reflects different dimensions of physical workload, including also awkward postures and repetitiveness, besides high physical effort. These other dimensions may be also relevant in increasing the risk of mortality or CVD, as suggested by the fact that in a previous study on the ILS cohort, in which OPA was assessed through self-reports at baseline based on one question on intensity of physical activity at work, no association was found between high OPA and mortality or coronary heart disease incidence in neither gender (Strippoli et al 2022 ). It is worth noting that in several other studies reporting no association, exposure assessment to OPA was also rather crude, as it was mainly based on one question on the type of job performed (e.g.…”

“…Furthermore, two recent large longitudinal studies with thorough adjustment for potential confounders found opposite results: while in a Norwegian study men exposed to high OPA showed significantly higher longevity (Dalene et al 2021 ), in a Danish study both CVD incidence and all-cause mortality were increased for exposure to high OPA (Holtermann et al 2021 ). Other recent studies reported an increased risk of mortality or CVD associated with high OPA in various countries (Martinez-Gomez et al 2022 ; Hermansen et al 2019 ; Wanner et al 2019 ; Quinn et al 2021 ), although several other studies did not find any association (Luo et al 2022 ; Pearce et al 2021 ; Strippoli et al 2022 ; Bonekamp et al 2022 ).…”

“…However, non-differential exposure misclassification may be increased, especially for those jobs with higher inter-individual variability in tasks performance and duration, because the JEM assigns the same exposure value to all workers holding the same job title, without accounting for individual differences, which may lead to an underestimation of the exposure‐outcome association. Given that we have conducted a previous study on overall mortality and coronary heart disease incidence on one of these cohorts (Strippoli et al 2022 ), in which exposure to OPA was self-reported at baseline, it is of particular interest the comparison of the results of that study with those of the present one, which may help clarifying if differences in methodology of exposure assessment employed may influence the association estimated between OPA and mortality. It appears worth noting that the only two previous studies on mortality which used a JEM for assigning exposure to OPA, both Scandinavian, found a significantly increased risk associated with high OPA (Ervasti et al 2019 ; Mikkola et al 2019 ).…”

Leisure time and occupational physical activity, overall and cardiovascular mortality: a 24-year follow-up in the OPERA study

“…However, recent studies have noted that high OPA does not necessarily increase the overall risk of mortality [ 35 ]. It has been noticed that after adjustments for socioeconomic status and other confounding factors, high and moderate OPA could even prolong life expectancy, while with no adjustments, the overall mortality and CVD mortality increased in higher OPA groups [ 17 , 36 ].…”

Child rearing or childbearing? Risk of cardiovascular diseases associated to parity and number of children

“…An overall LTPA classification was assigned based on the highest level of activity reported. Further details on the assessment of LTPA in the two cohorts can be found elsewhere [ 34 ].…”