An older age at retirement may be associated with a significantly decreased risk of dementia, according to research presented at the 2013 Alzheimer’s Association International Conference. In a study of 429,803 retired French workers, Carole Dufouil, PhD, and colleagues found that the hazard ratio of dementia was 0.968 for each extra year of age at retirement.
“Our results highlight the importance of maintaining high levels of cognitive and social stimulation throughout work and retiree life and emphasize the need for interventions and policies to help older individuals achieve such cognitive and social engagement,” stated Dr. Dufouil, Director of Research in Neuroepidemiology at INSERM in Paris.
The investigators based their findings on an analysis of health and pension databases including self-employed workers (average age, 74) who were living and retired as of December 31, 2010. All workers had been retired for an average of more than 12 years. Dementia cases were defined according to a diagnosis per the ICD-10 or whether the participant had filed a claim for donepezil, galantamine, or rivastigmine. Hazard ratios were computed after the researchers adjusted for gender, marital status, occupational category, type of retirement, pension amount, diagnosis of hypertension, and diabetes. The researchers also conducted sensitivity analyses to assess potential reverse causation and differential cohort or temporal diagnosis biases.
The overall prevalence of dementia in the cohort was 2.65%. Dr. Dufouil’s group found that a person who retired at 65 had about a 15% lower risk of dementia, compared with a person who retired at 60. The researchers’ results were unchanged and highly significant after they excluded workers who had had a diagnosis of dementia within five years following retirement. The findings were similar in further analyses that were stratified by age categories or year of dementia diagnosis.
“Our data show strong evidence of a significant decrease in the risk of developing dementia associated with older age at retirement, in line with the ‘use it or lose it’ hypothesis,” said Dr. Dufouil. “This health perspective should be taken into consideration when the age of cessation of professional activity is discussed.”