Retirement is a significant life event involving removal of work stress and changes in other psychological factors. These changes may induce physiological responses in the body, such as changes in levels of the stress hormone cortisol, but no previous studies exist on the topic. The aim of this study was to examine changes in hair cortisol concentration and the associated work-related factors during the retirement transition.

One hundred and ninety-nine workers from the Finnish Retirement and Aging study participated in annual hair sampling before and after the retirement transition. Hair cortisol concentration was measured using mass spectrometry. Work-related factors were examined through survey measures. Latent trajectory analysis was used to investigate the heterogeneity of the changes in hair cortisol concentration during the retirement transition.

The study population had a mean age of 63.1 (SD 1.1) years and 92 % were women. Three trajectory groups for hair cortisol changes were identified: ”stable low” (79 %), “fluctuating” (6 %) and “post-retirement increase” (15 %). ”Post-retirement increase” group consisted of older participants compared to the “stable low” and “fluctuating” groups. No significant differences in exposure to work-related stressors were found between the groups.

For the majority of the participants, the levels of hair cortisol remained relatively low and stable during the retirement transition, but for subgroups of individuals annual fluctuation and post-retirement increase in levels of hair cortisol were observed. Work-related stressors were not found to explain the variability, thus further research on changes in hair cortisol changes during retirement is warranted.