To evaluate the association between exposure to occupational biomechanical factors and the incidence of surgically treated osteoarthritis (OA) treated with arthroplasty in the hip and knee among male construction workers.

Longitudinal register-based cohort study.

Male construction workers (n=291 062) who participated in a national Swedish occupational health examination programme between 1971 and 1993, delivered through multiple primary-level nationwide occupational health centres.

Hip and knee arthroplasties performed due to OA from 1987 to 2019 were identified through linkage with the Swedish National Patient Register. Data on age, smoking habits, body mass index, job title and self-reported biomechanical exposures were collected during the health examinations. Occupational biomechanical workload was assessed using eight factors from a job-exposure matrix. Poisson regression was applied to estimate adjusted incidence rate ratios (IRRs) associated with each type of occupational biomechanical exposure.

The study included 10 336 cases of hip arthroplasties and 8926 cases of knee arthroplasties. All studied biomechanical risk factors were associated with an increased risk of knee OA requiring arthroplasty, especially for individuals exposed to static work in non-neutral lumbar postures (IRR 1.38, 95% CI 1.16 to 1.65) and those with a high frequency of kneeling (IRR 1.27, 95% CI 1.12 to 1.45). In contrast, only a few biomechanical factors were associated with an increased risk of hip OA requiring arthroplasty. Similar results were observed when alternative exposure measures, such as occupational group and self-reported exposure assessments, were employed.

Occupational workload was associated with an increased risk of knee arthroplasty due to OA, whereas the association for hip arthroplasty remains unclear.

Climate change has led to extreme heat events, disproportionately affecting vulnerable populations. Heat stress during pregnancy is linked to adverse health outcomes, yet the biological mechanisms remain poorly understood. This research study aims to investigate the effect of environmental heat on maternal, fetal and infant health and examine the biological pathways linking heat stress to adverse pregnancy outcomes.

This prospective cohort study will recruit 6000 pregnant women from three districts in Sindh, Pakistan. Eligible participants ≥18 years old, will have a minimum of five scheduled visits from

The study has received ethical approval from the Aga Khan University (AKU) (Ref: 26249) and the Pakistan National Bioethics Committee (Ref: 1065/23/1736). Written informed consent will be obtained from all participants before enrolment. Referral pathways to healthcare facilities will be established to ensure timely management of pregnancy complications. Findings will be disseminated through peer-reviewed publications, scientific conferences, and engagement with policymakers and public health stakeholders to inform climate-resilient maternal health strategies. Results will also be shared with participants and communities through meetings and informal sessions to raise awareness and support evidence-based heat adaptation.

NCT01234567.