Sleep health as a mediator between depression and functional gastrointestinal disorders: A UK Biobank study

Depression and sleep are associated to irritable bowel syndrome (IBS), but their relationship with broader functional gastrointestinal disorders (FGIDs, which include IBS, dyspepsia, and functional intestinal disorders) remains unclear. We examined depression, sleep, and FGIDs risk, exploring sleep's mediating role.

Using UK Biobank data (n = 502,151), we assessed sleep via a new healthy sleep score. Depression and incident FGIDs were identified from health records. Associations were evaluated using Cox models; mediation analysis quantified sleep's role in depression-FGIDs pathways.

This study ultimately included 311,576 participants, of whom 24,487 were diagnosed with depression at baseline. During a mean follow-up of 14.84 years, 45,856 (14.72 %) participants developed FGIDs, while 6151 new cases of FGID were identified among those with depression. It has been found that depression increases the risk of FGIDs. Full adjustment showed that depression increased FGIDs risk by 74 % (HR: 1.74, 95 % CI: 1.69 to 1.78). There was a 6.02 % mediating effect of healthy sleep score on depression and FGIDs, and a similar result was found in a sex-stratified analysis.

Depression and the healthy sleep score were independently associated with an increased risk of FGIDs, with sleep being a partial mediator in the association between depression and FGIDs. The results revealed the relationship between depression, sleep, and FGIDs, and provided a basis for the prevention, early intervention and management of depression-FGIDs comorbidity.