Night Shift Work and Myocardial Infarction in the UK Biobank
Summary
This large UK Biobank study followed workers for about 12 years to examine night-shift schedules and myocardial infarction (heart attack). Compared with day workers, those doing occasional or some night shifts had a modestly higher chance of heart attack (about 9–13% higher). The elevation was greater for permanent night shifts (about 21% higher). Risk also tended to rise with time on nights (roughly 20% higher for under 10 years and about 50% higher for 10 years or more) and with frequency (more than 8 night shifts per month was about 45% higher). Among night-shift workers, having more rest days between shifts did not show a difference compared with one rest day. This was an observational study, so it identifies associations rather than proving cause.
Why It Matters For Night Shift Workers and Night Owls
These findings help contextualize how patterns of night work—not just whether someone works nights—relate to heart-attack risk. The increases were small with infrequent night work and larger with long-term or frequent night work, offering a clearer sense of where different schedules fall on the spectrum. This evidence can inform discussions about rota design and long-term planning, and it adds useful background when considering how work patterns fit into the broader picture of cardiovascular health.
Notes
UK Biobank analysis.