A particular gene variant, which previously played a role in workers with low tolerance to shift work, could also be linked to an increased risk of Alzheimer's disease, according to a new Finnish study.
The results are published in the journal SLEEP .
Alzheimer's disease is a brain disorder that destroys memory and thinking skills over time. Risk factors include sleep disturbances and circadian rhythm, which is common among shiftworkers
Tolerance to the adverse effects of shiftwork varies from person to person and is in part related to intrinsic genetic factors.
The study conducted by Professor Tiina Paunio at the University of Helsinki and the National Institute of Health and Welfare in Finland showed that in addition to Alzheimer's diagnosis, the variation of melatonin receptor 1
In addition, when expression of the MTNR1A gene in cell culture was reduced, it began to accumulate the beta-amyloid protein characteristic of Alzheimer's disease.
In a previous study, researchers found the same gene variant that predisposes to a shift in work fatigue is associated with lower levels of MTNR1A gene expression in the brain. This means that the findings to date are consistent with the new findings in the epidemiological cohorts and cell cultures.
The circadian rhythm regulates the release of melatonin, which in turn supports the circadian rhythm through its receptors. The new findings support the notion that the circadian rhythm may play a role in the development of Alzheimer's disease.
"The finding of a common risk for both occupational fatigue in shift workers and for Alzheimer's does not directly mean that shift work would be predisposing to Alzheimer's disease," said Drs. Sonja Sulkava from the National Institute for Health and Welfare.
"However, the combination of genetic predisposition and a lifestyle that interrupts the circadian rhythm may increase the risk for Alzheimer's Disease.Another possible interpretation is that the brain-related disorders associated with Alzheimer's disease increased tolerance to shiftwork decades ago
Paunio said that although the results show a link between tolerance to shift work and the molecular level, Alzheimer's disease, the genetic variation still has a minimal effect on the individual level and may not be for the risk assessment or prediction can be used.
The study involved Alzheimer's patients and healthy controls living in Eastern Finland. The association could be seen in older cohorts, but not in younger patients and control cohorts.
Source: University of Helsinki