Dementia Incidence in the Elderly Population of Greece: Results From the HELIAD Study.

OBJECTIVES: Recently a declining trend in dementia incidence rates has been reported in high-income countries. We investigated dementia incidence in a representative sample of the Greek population in the age group of 65 years and above. METHODS: This research is part of the Hellenic Epidemiological Longitudinal Investigation of Aging and Diet (HELIAD). The incidence cohort consisted of 1072 participants who were reevaluated after a mean period of 3.09 years. RESULTS: The incidence rate of dementia was 19.0 cases per 1000 person-years (age-standardized and sex-standardized incidence: 25.4/1000 person-years), of which 16.3 per 1000 person-years were attributable to Alzheimer disease. Each additional year of age increased dementia risk by 19.3% and each additional year of education decreased dementia risk by 12.1%. Apolipoprotein E (APOE)-ε4 homozygous participants were 18 times more likely to be diagnosed with dementia. A baseline diagnosis of mild cognitive decline (MCI) resulted in a risk for dementia increased by 3.7 times compared with the cognitively normal; in participants with MCI at baseline, APOE-ε4 carriage increased dementia risk by 4.5 times. CONCLUSIONS: The incidence rate of dementia in people 65 years and above in Greece is generally consistent with recently published rates in Europe and North America. Advancing age, baseline MCI, and APOE-ε4 homozygosity are risk factors, while higher educational attainment seems protective.