Easy exhaustion in shift work may indicate Alzheimer risk

A research directed by professor Tiina Paunio of the Finnish National Institute for Health and Welfare (THL) has found a genetic connection between being easily exhausted in shift work and the development of Alzheimers disease in older age.

The same research group established earlier that a risk variant of the melatonin receptor 1A gene (MTNR1A) causes lower ability to endure shift work as an adult. The researchers have now found that the same variant is associated with the risk of getting Alzheimers at an old age, the institute reported on Friday.

Paunio said though the findings cannot be used in predicting if a person is likely to develop Alzheimers.

"Even though our results prove a new molecular level connection between poor endurance of shift work and the development of Alzheimers later in life, the impact of the gene variant is small at the level of an individual."

Dr. Sonja Sulkava of the institute said genetic susceptibility combined with a life style that mixes up the 24 hour cycle can increase the risk of Alzheimers.

"A risk gene shared by easy exhaustion in shift work and Alzheimers does not mean directly that shift work would make a person prone to get Alzheimers", Sulkava said.

"The other way of interpreting the results is to say that the changes in the brains associated with Alzheimers affect the ability to endure shift work decades before the onslaught of the disease."

The research was based on Finnish population cohorts between 1991 and 2001. Part of the research has been published earlier in the magazine Sleep, THL noted.